pragma solidity =0.6.6;
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/math/SafeMath.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/utils/Pausable.sol";
import "./libraries/TransferHelper.sol";
import "./interfaces/IPancakeRouter02.sol";
import "./interfaces/IWETH.sol";
contract FeeReceiver is Pausable, Ownable {
    using SafeMath for uint256;
    event BuybackRateUpdated(uint256 newBuybackRate);
    event RevenueReceiverUpdated(address newRevenueReceiver);
    event RouterWhitelistUpdated(address router, bool status);
    event BuybackExecuted(uint256 amountBuyback, uint256 amountRevenue);
    address internal constant ZERO_ADDRESS = address(0);
    uint256 public constant FEE_DENOMINATOR = 10000;
    IPancakeRouter02 public pancakeRouter;
    address payable public revenueReceiver;
    uint256 public buybackRate;
    address public SYA;
    address public WETH;
    mapping(address => bool) public routerWhitelist;
    constructor(
        IPancakeRouter02 _pancakeRouterV2,
        address _SYA,
        address _WETH,
        address payable _revenueReceiver,
        uint256 _buybackRate
    ) public {
        pancakeRouter = _pancakeRouterV2;
        SYA = _SYA;
        WETH = _WETH;
        revenueReceiver = _revenueReceiver;
        buybackRate = _buybackRate;
        routerWhitelist[address(pancakeRouter)] = true;
    }
    /// @dev executes the buyback, buys SYA on pancake & sends revenue to the revenueReceiver by the defined rate.
    function executeBuyback() external whenNotPaused {
        require(address(this).balance > 0, "FeeReceiver: No balance for buyback");
        address[] memory path = new address[](2);
        path[0] = WETH;
        path[1] = SYA;
        uint256 balance = address(this).balance;
        uint256 amountBuyback = balance.mul(buybackRate).div(FEE_DENOMINATOR);
        uint256 amountRevenue = balance.sub(amountBuyback);
        pancakeRouter.swapExactETHForTokensSupportingFeeOnTransferTokens{value: amountBuyback}(
            0,
            path,
            ZERO_ADDRESS,
            block.timestamp
        );
        TransferHelper.safeTransferETH(revenueReceiver, amountRevenue);
        emit BuybackExecuted(amountBuyback, amountRevenue);
    }
    /// @dev converts collected tokens from fees to ETH for executing buybacks
    function convertToETH(
        address _router,
        IERC20 _token,
        bool _fee
    ) public whenNotPaused {
        require(routerWhitelist[_router], "FeeReceiver: Router not whitelisted");
        address[] memory path = new address[](2);
        path[0] = address(_token);
        path[1] = WETH;
        uint256 balance = _token.balanceOf(address(this));
        TransferHelper.safeApprove(address(_token), address(pancakeRouter), balance);
        if (_fee) {
            IPancakeRouter02(_router).swapExactTokensForETHSupportingFeeOnTransferTokens(
                balance,
                0,
                path,
                address(this),
                block.timestamp
            );
        } else {
            IPancakeRouter02(_router).swapExactTokensForETH(balance, 0, path, address(this), block.timestamp);
        }
    }
    /// @dev converts WETH to ETH
    function unwrapWETH() public whenNotPaused {
        uint256 balance = IWETH(WETH).balanceOf(address(this));
        require(balance > 0, "FeeReceiver: Nothing to unwrap");
        IWETH(WETH).withdraw(balance);
    }
    /// @dev lets the owner update update the router whitelist
    function updateRouterWhiteliste(address _router, bool _status) external onlyOwner {
        routerWhitelist[_router] = _status;
        emit RouterWhitelistUpdated(_router, _status);
    }
    /// @dev lets the owner update the buyback rate
    function updateBuybackRate(uint256 _newBuybackRate) external onlyOwner {
        buybackRate = _newBuybackRate;
        emit BuybackRateUpdated(_newBuybackRate);
    }
    /// @dev lets the owner update the revenue receiver address
    function updateRevenueReceiver(address payable _newRevenueReceiver) external onlyOwner {
        revenueReceiver = _newRevenueReceiver;
        emit RevenueReceiverUpdated(_newRevenueReceiver);
    }
    /// @dev lets the owner withdraw ETH from the contract
    function withdrawETH(address payable to, uint256 amount) external onlyOwner {
        to.transfer(amount);
    }
    /// @dev lets the owner withdraw any ERC20 Token from the contract
    function withdrawERC20Token(
        address token,
        address to,
        uint256 amount
    ) external onlyOwner {
        IERC20(token).transfer(to, amount);
    }
    /// @dev allows to receive ETH on this contract
    receive() external payable {}
    /// @dev lets the owner pause the contract
    function pause() external onlyOwner {
        _pause();
    }
    /// @dev lets the owner unpause the contract
    function unpause() external onlyOwner {
        _unpause();
    }
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0 <0.8.0;
/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);
    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);
    /**
     * @dev Moves `amount` tokens from the caller's account to `recipient`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address recipient, uint256 amount) external returns (bool);
    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);
    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);
    /**
     * @dev Moves `amount` tokens from `sender` to `recipient` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);
    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);
    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0 <0.8.0;
/**
 * @dev Wrappers over Solidity's arithmetic operations with added overflow
 * checks.
 *
 * Arithmetic operations in Solidity wrap on overflow. This can easily result
 * in bugs, because programmers usually assume that an overflow raises an
 * error, which is the standard behavior in high level programming languages.
 * `SafeMath` restores this intuition by reverting the transaction when an
 * operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 */
library SafeMath {
    /**
     * @dev Returns the addition of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        uint256 c = a + b;
        if (c < a) return (false, 0);
        return (true, c);
    }
    /**
     * @dev Returns the substraction of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        if (b > a) return (false, 0);
        return (true, a - b);
    }
    /**
     * @dev Returns the multiplication of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
        // benefit is lost if 'b' is also tested.
        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
        if (a == 0) return (true, 0);
        uint256 c = a * b;
        if (c / a != b) return (false, 0);
        return (true, c);
    }
    /**
     * @dev Returns the division of two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        if (b == 0) return (false, 0);
        return (true, a / b);
    }
    /**
     * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        if (b == 0) return (false, 0);
        return (true, a % b);
    }
    /**
     * @dev Returns the addition of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `+` operator.
     *
     * Requirements:
     *
     * - Addition cannot overflow.
     */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");
        return c;
    }
    /**
     * @dev Returns the subtraction of two unsigned integers, reverting on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b <= a, "SafeMath: subtraction overflow");
        return a - b;
    }
    /**
     * @dev Returns the multiplication of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `*` operator.
     *
     * Requirements:
     *
     * - Multiplication cannot overflow.
     */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        if (a == 0) return 0;
        uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");
        return c;
    }
    /**
     * @dev Returns the integer division of two unsigned integers, reverting on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b > 0, "SafeMath: division by zero");
        return a / b;
    }
    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b > 0, "SafeMath: modulo by zero");
        return a % b;
    }
    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {trySub}.
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b <= a, errorMessage);
        return a - b;
    }
    /**
     * @dev Returns the integer division of two unsigned integers, reverting with custom message on
     * division by zero. The result is rounded towards zero.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryDiv}.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b > 0, errorMessage);
        return a / b;
    }
    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting with custom message when dividing by zero.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryMod}.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b > 0, errorMessage);
        return a % b;
    }
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0 <0.8.0;
import "../utils/Context.sol";
/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. This
 * can later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
abstract contract Ownable is Context {
    address private _owner;
    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor () internal {
        address msgSender = _msgSender();
        _owner = msgSender;
        emit OwnershipTransferred(address(0), msgSender);
    }
    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view virtual returns (address) {
        return _owner;
    }
    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
        _;
    }
    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions anymore. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby removing any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        emit OwnershipTransferred(_owner, address(0));
        _owner = address(0);
    }
    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
    }
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0 <0.8.0;
import "./Context.sol";
/**
 * @dev Contract module which allows children to implement an emergency stop
 * mechanism that can be triggered by an authorized account.
 *
 * This module is used through inheritance. It will make available the
 * modifiers `whenNotPaused` and `whenPaused`, which can be applied to
 * the functions of your contract. Note that they will not be pausable by
 * simply including this module, only once the modifiers are put in place.
 */
abstract contract Pausable is Context {
    /**
     * @dev Emitted when the pause is triggered by `account`.
     */
    event Paused(address account);
    /**
     * @dev Emitted when the pause is lifted by `account`.
     */
    event Unpaused(address account);
    bool private _paused;
    /**
     * @dev Initializes the contract in unpaused state.
     */
    constructor () internal {
        _paused = false;
    }
    /**
     * @dev Returns true if the contract is paused, and false otherwise.
     */
    function paused() public view virtual returns (bool) {
        return _paused;
    }
    /**
     * @dev Modifier to make a function callable only when the contract is not paused.
     *
     * Requirements:
     *
     * - The contract must not be paused.
     */
    modifier whenNotPaused() {
        require(!paused(), "Pausable: paused");
        _;
    }
    /**
     * @dev Modifier to make a function callable only when the contract is paused.
     *
     * Requirements:
     *
     * - The contract must be paused.
     */
    modifier whenPaused() {
        require(paused(), "Pausable: not paused");
        _;
    }
    /**
     * @dev Triggers stopped state.
     *
     * Requirements:
     *
     * - The contract must not be paused.
     */
    function _pause() internal virtual whenNotPaused {
        _paused = true;
        emit Paused(_msgSender());
    }
    /**
     * @dev Returns to normal state.
     *
     * Requirements:
     *
     * - The contract must be paused.
     */
    function _unpause() internal virtual whenPaused {
        _paused = false;
        emit Unpaused(_msgSender());
    }
}
pragma solidity =0.6.6;
// helper methods for interacting with ERC20 tokens and sending ETH that do not consistently return true/false
library TransferHelper {
    function safeApprove(
        address token,
        address to,
        uint256 value
    ) internal {
        // bytes4(keccak256(bytes('approve(address,uint256)')));
        (bool success, bytes memory data) = token.call(abi.encodeWithSelector(0x095ea7b3, to, value));
        require(success && (data.length == 0 || abi.decode(data, (bool))), "TransferHelper: APPROVE_FAILED");
    }
    function safeTransfer(
        address token,
        address to,
        uint256 value
    ) internal {
        // bytes4(keccak256(bytes('transfer(address,uint256)')));
        (bool success, bytes memory data) = token.call(abi.encodeWithSelector(0xa9059cbb, to, value));
        require(success && (data.length == 0 || abi.decode(data, (bool))), "TransferHelper: TRANSFER_FAILED");
    }
    function safeTransferFrom(
        address token,
        address from,
        address to,
        uint256 value
    ) internal {
        // bytes4(keccak256(bytes('transferFrom(address,address,uint256)')));
        (bool success, bytes memory data) = token.call(abi.encodeWithSelector(0x23b872dd, from, to, value));
        require(success && (data.length == 0 || abi.decode(data, (bool))), "TransferHelper: TRANSFER_FROM_FAILED");
    }
    function safeTransferETH(address to, uint256 value) internal {
        (bool success, ) = to.call{value: value}(new bytes(0));
        require(success, "TransferHelper: ETH_TRANSFER_FAILED");
    }
}
pragma solidity >=0.6.2;
import "./IPancakeRouter01.sol";
interface IPancakeRouter02 is IPancakeRouter01 {
    function removeLiquidityETHSupportingFeeOnTransferTokens(
        address token,
        uint256 liquidity,
        uint256 amountTokenMin,
        uint256 amountETHMin,
        address to,
        uint256 deadline
    ) external returns (uint256 amountETH);
    function removeLiquidityETHWithPermitSupportingFeeOnTransferTokens(
        address token,
        uint256 liquidity,
        uint256 amountTokenMin,
        uint256 amountETHMin,
        address to,
        uint256 deadline,
        bool approveMax,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external returns (uint256 amountETH);
    function swapExactTokensForTokensSupportingFeeOnTransferTokens(
        uint256 amountIn,
        uint256 amountOutMin,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external;
    function swapExactETHForTokensSupportingFeeOnTransferTokens(
        uint256 amountOutMin,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external payable;
    function swapExactTokensForETHSupportingFeeOnTransferTokens(
        uint256 amountIn,
        uint256 amountOutMin,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external;
}
pragma solidity >=0.5.0;
interface IWETH {
    function deposit() external payable;
    function transfer(address to, uint256 value) external returns (bool);
    function withdraw(uint256) external;
    function approve(address _spender, uint256 _amount) external returns (bool);
    function balanceOf(address _account) external view returns (uint256);
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0 <0.8.0;
/*
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with GSN meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address payable) {
        return msg.sender;
    }
    function _msgData() internal view virtual returns (bytes memory) {
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        return msg.data;
    }
}
pragma solidity >=0.6.2;
interface IPancakeRouter01 {
    function factory() external pure returns (address);
    function WETH() external pure returns (address);
    function addLiquidity(
        address tokenA,
        address tokenB,
        uint256 amountADesired,
        uint256 amountBDesired,
        uint256 amountAMin,
        uint256 amountBMin,
        address to,
        uint256 deadline
    )
        external
        returns (
            uint256 amountA,
            uint256 amountB,
            uint256 liquidity
        );
    function addLiquidityETH(
        address token,
        uint256 amountTokenDesired,
        uint256 amountTokenMin,
        uint256 amountETHMin,
        address to,
        uint256 deadline
    )
        external
        payable
        returns (
            uint256 amountToken,
            uint256 amountETH,
            uint256 liquidity
        );
    function removeLiquidity(
        address tokenA,
        address tokenB,
        uint256 liquidity,
        uint256 amountAMin,
        uint256 amountBMin,
        address to,
        uint256 deadline
    ) external returns (uint256 amountA, uint256 amountB);
    function removeLiquidityETH(
        address token,
        uint256 liquidity,
        uint256 amountTokenMin,
        uint256 amountETHMin,
        address to,
        uint256 deadline
    ) external returns (uint256 amountToken, uint256 amountETH);
    function removeLiquidityWithPermit(
        address tokenA,
        address tokenB,
        uint256 liquidity,
        uint256 amountAMin,
        uint256 amountBMin,
        address to,
        uint256 deadline,
        bool approveMax,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external returns (uint256 amountA, uint256 amountB);
    function removeLiquidityETHWithPermit(
        address token,
        uint256 liquidity,
        uint256 amountTokenMin,
        uint256 amountETHMin,
        address to,
        uint256 deadline,
        bool approveMax,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external returns (uint256 amountToken, uint256 amountETH);
    function swapExactTokensForTokens(
        uint256 amountIn,
        uint256 amountOutMin,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external returns (uint256[] memory amounts);
    function swapTokensForExactTokens(
        uint256 amountOut,
        uint256 amountInMax,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external returns (uint256[] memory amounts);
    function swapExactETHForTokens(
        uint256 amountOutMin,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external payable returns (uint256[] memory amounts);
    function swapTokensForExactETH(
        uint256 amountOut,
        uint256 amountInMax,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external returns (uint256[] memory amounts);
    function swapExactTokensForETH(
        uint256 amountIn,
        uint256 amountOutMin,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external returns (uint256[] memory amounts);
    function swapETHForExactTokens(
        uint256 amountOut,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external payable returns (uint256[] memory amounts);
    function quote(
        uint256 amountA,
        uint256 reserveA,
        uint256 reserveB
    ) external pure returns (uint256 amountB);
    function getAmountOut(
        uint256 amountIn,
        uint256 reserveIn,
        uint256 reserveOut
    ) external pure returns (uint256 amountOut);
    function getAmountIn(
        uint256 amountOut,
        uint256 reserveIn,
        uint256 reserveOut
    ) external pure returns (uint256 amountIn);
    function getAmountsOut(uint256 amountIn, address[] calldata path) external view returns (uint256[] memory amounts);
    function getAmountsIn(uint256 amountOut, address[] calldata path) external view returns (uint256[] memory amounts);
}
pragma solidity =0.6.6;
import "@0x/contracts-utils/contracts/src/v06/LibBytesV06.sol";
import "@openzeppelin/contracts/utils/ReentrancyGuard.sol";
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/math/SafeMath.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/utils/Pausable.sol";
import "./libraries/TransferHelper.sol";
import "./libraries/PancakeLibrary.sol";
import "./interfaces/IReferralRegistry.sol";
import "./interfaces/IWETH.sol";
import "./interfaces/IZerox.sol";
contract FloozRouter is Ownable, Pausable, ReentrancyGuard {
    using SafeMath for uint256;
    using LibBytesV06 for bytes;
    event SwapFeeUpdated(uint16 swapFee);
    event ReferralRegistryUpdated(address referralRegistry);
    event ReferralRewardRateUpdated(uint16 referralRewardRate);
    event ReferralsActivatedUpdated(bool activated);
    event FeeReceiverUpdated(address payable feeReceiver);
    event BalanceThresholdUpdated(uint256 balanceThreshold);
    event CustomReferralRewardRateUpdated(address indexed account, uint16 referralRate);
    event ReferralRewardPaid(address from, address indexed to, address tokenOut, address tokenReward, uint256 amount);
    event ForkUpdated(address factory);
    // Denominator of fee
    uint256 public constant FEE_DENOMINATOR = 10000;
    // Numerator of fee
    uint16 public swapFee;
    // address of WETH
    address public immutable WETH;
    // address of zeroEx proxy contract to forward swaps
    address payable public immutable zeroEx;
    // address of 1inch contract to forward swaps
    address payable public immutable oneInch;
    // address of referral registry that stores referral anchors
    IReferralRegistry public referralRegistry;
    // address of SYA token
    IERC20 public saveYourAssetsToken;
    // balance threshold of SYA tokens which actives feeless swapping
    uint256 public balanceThreshold;
    // address that receives protocol fees
    address payable public feeReceiver;
    // percentage of fees that will be paid as rewards
    uint16 public referralRewardRate;
    // stores if the referral system is turned on or off
    bool public referralsActivated;
    // stores individual referral rates
    mapping(address => uint16) public customReferralRewardRate;
    // stores uniswap forks status, index is the factory address
    mapping(address => bool) public forkActivated;
    // stores uniswap forks initCodes, index is the factory address
    mapping(address => bytes) public forkInitCode;
    /// @dev construct this contract
    /// @param _WETH address of WETH.
    /// @param _swapFee nominator for swapFee. Denominator = 10000
    /// @param _referralRewardRate percentage of swapFee that are paid out as rewards
    /// @param _feeReceiver address that receives protocol fees
    /// @param _balanceThreshold balance threshold of SYA tokens which actives feeless swapping
    /// @param _saveYourAssetsToken address of SYA token
    /// @param _referralRegistry address of referral registry that stores referral anchors
    /// @param _zeroEx address of zeroX proxy contract to forward swaps
    /// @param _oneInch address of 1inch contract to forward swaps
    constructor(
        address _WETH,
        uint16 _swapFee,
        uint16 _referralRewardRate,
        address payable _feeReceiver,
        uint256 _balanceThreshold,
        IERC20 _saveYourAssetsToken,
        IReferralRegistry _referralRegistry,
        address payable _zeroEx,
        address payable _oneInch
    ) public {
        WETH = _WETH;
        swapFee = _swapFee;
        referralRewardRate = _referralRewardRate;
        feeReceiver = _feeReceiver;
        saveYourAssetsToken = _saveYourAssetsToken;
        balanceThreshold = _balanceThreshold;
        referralRegistry = _referralRegistry;
        zeroEx = _zeroEx;
        oneInch = _oneInch;
        referralsActivated = true;
    }
    /// @dev execute swap directly on Uniswap/Pancake & simular forks
    /// @param fork fork used to execute swap
    /// @param amountOutMin minimum tokens to receive
    /// @param path Sell path.
    /// @param referee address of referee for msg.sender, 0x adress if none
    /// @return amounts
    function swapExactETHForTokens(
        address fork,
        uint256 amountOutMin,
        address[] calldata path,
        address referee
    ) external payable whenNotPaused isValidFork(fork) isValidReferee(referee) returns (uint256[] memory amounts) {
        require(path[0] == WETH, "FloozRouter: INVALID_PATH");
        referee = _getReferee(referee);
        (uint256 swapAmount, uint256 feeAmount, uint256 referralReward) = _calculateFeesAndRewards(
            msg.value,
            referee,
            false
        );
        amounts = _getAmountsOut(fork, swapAmount, path);
        require(amounts[amounts.length - 1] >= amountOutMin, "FloozRouter: INSUFFICIENT_OUTPUT_AMOUNT");
        IWETH(WETH).deposit{value: amounts[0]}();
        assert(IWETH(WETH).transfer(_pairFor(fork, path[0], path[1]), amounts[0]));
        _swap(fork, amounts, path, msg.sender);
        if (feeAmount.add(referralReward) > 0)
            _withdrawFeesAndRewards(address(0), path[path.length - 1], referee, feeAmount, referralReward);
    }
    /// @dev execute swap directly on Uniswap/Pancake/...
    /// @param fork fork used to execute swap
    /// @param amountIn amount of tokensIn
    /// @param amountOutMin minimum tokens to receive
    /// @param path Sell path.
    /// @param referee address of referee for msg.sender, 0x adress if none
    function swapExactTokensForETHSupportingFeeOnTransferTokens(
        address fork,
        uint256 amountIn,
        uint256 amountOutMin,
        address[] calldata path,
        address referee
    ) external whenNotPaused isValidFork(fork) isValidReferee(referee) {
        require(path[path.length - 1] == WETH, "FloozRouter: INVALID_PATH");
        referee = _getReferee(referee);
        TransferHelper.safeTransferFrom(path[0], msg.sender, _pairFor(fork, path[0], path[1]), amountIn);
        _swapSupportingFeeOnTransferTokens(fork, path, address(this));
        uint256 amountOut = IERC20(WETH).balanceOf(address(this));
        IWETH(WETH).withdraw(amountOut);
        (uint256 amountWithdraw, uint256 feeAmount, uint256 referralReward) = _calculateFeesAndRewards(
            amountOut,
            referee,
            false
        );
        require(amountWithdraw >= amountOutMin, "FloozRouter: LOW_SLIPPAGE");
        TransferHelper.safeTransferETH(msg.sender, amountWithdraw);
        if (feeAmount.add(referralReward) > 0)
            _withdrawFeesAndRewards(address(0), path[path.length - 1], referee, feeAmount, referralReward);
    }
    /// @dev execute swap directly on Uniswap/Pancake/...
    /// @param fork fork used to execute swap
    /// @param amountIn amount if tokens In
    /// @param amountOutMin minimum tokens to receive
    /// @param path Sell path.
    /// @param referee address of referee for msg.sender, 0x adress if none
    /// @return amounts
    function swapExactTokensForTokens(
        address fork,
        uint256 amountIn,
        uint256 amountOutMin,
        address[] calldata path,
        address referee
    ) external whenNotPaused isValidFork(fork) isValidReferee(referee) returns (uint256[] memory amounts) {
        referee = _getReferee(referee);
        (uint256 swapAmount, uint256 feeAmount, uint256 referralReward) = _calculateFeesAndRewards(
            amountIn,
            referee,
            false
        );
        amounts = _getAmountsOut(fork, swapAmount, path);
        require(amounts[amounts.length - 1] >= amountOutMin, "FloozRouter: INSUFFICIENT_OUTPUT_AMOUNT");
        TransferHelper.safeTransferFrom(path[0], msg.sender, _pairFor(fork, path[0], path[1]), swapAmount);
        _swap(fork, amounts, path, msg.sender);
        if (feeAmount.add(referralReward) > 0)
            _withdrawFeesAndRewards(path[0], path[path.length - 1], referee, feeAmount, referralReward);
    }
    /// @dev execute swap directly on Uniswap/Pancake/...
    /// @param fork fork used to execute swap
    /// @param amountIn amount if tokens In
    /// @param amountOutMin minimum tokens to receive
    /// @param path Sell path.
    /// @param referee address of referee for msg.sender, 0x adress if none
    /// @return amounts
    function swapExactTokensForETH(
        address fork,
        uint256 amountIn,
        uint256 amountOutMin,
        address[] calldata path,
        address referee
    ) external whenNotPaused isValidFork(fork) isValidReferee(referee) returns (uint256[] memory amounts) {
        require(path[path.length - 1] == WETH, "FloozRouter: INVALID_PATH");
        referee = _getReferee(referee);
        amounts = _getAmountsOut(fork, amountIn, path);
        (uint256 amountWithdraw, uint256 feeAmount, uint256 referralReward) = _calculateFeesAndRewards(
            amounts[amounts.length - 1],
            referee,
            false
        );
        require(amountWithdraw >= amountOutMin, "FloozRouter: INSUFFICIENT_OUTPUT_AMOUNT");
        TransferHelper.safeTransferFrom(path[0], msg.sender, _pairFor(fork, path[0], path[1]), amounts[0]);
        _swap(fork, amounts, path, address(this));
        IWETH(WETH).withdraw(amounts[amounts.length - 1]);
        TransferHelper.safeTransferETH(msg.sender, amountWithdraw);
        if (feeAmount.add(referralReward) > 0)
            _withdrawFeesAndRewards(address(0), path[path.length - 1], referee, feeAmount, referralReward);
    }
    /// @dev execute swap directly on Uniswap/Pancake/...
    /// @param fork fork used to execute swap
    /// @param amountOut expected amount of tokens out
    /// @param path Sell path.
    /// @param referee address of referee for msg.sender, 0x adress if none
    /// @return amounts
    function swapETHForExactTokens(
        address fork,
        uint256 amountOut,
        address[] calldata path,
        address referee
    ) external payable whenNotPaused isValidFork(fork) isValidReferee(referee) returns (uint256[] memory amounts) {
        require(path[0] == WETH, "FloozRouter: INVALID_PATH");
        amounts = _getAmountsIn(fork, amountOut, path);
        (, uint256 feeAmount, uint256 referralReward) = _calculateFeesAndRewards(amounts[0], referee, true);
        require(amounts[0].add(feeAmount).add(referralReward) <= msg.value, "FloozRouter: EXCESSIVE_INPUT_AMOUNT");
        IWETH(WETH).deposit{value: amounts[0]}();
        assert(IWETH(WETH).transfer(_pairFor(fork, path[0], path[1]), amounts[0]));
        _swap(fork, amounts, path, msg.sender);
        // refund dust eth, if any
        if (msg.value > amounts[0].add(feeAmount).add(referralReward))
            TransferHelper.safeTransferETH(msg.sender, msg.value - amounts[0].add(feeAmount).add(referralReward));
        if (feeAmount.add(referralReward) > 0)
            _withdrawFeesAndRewards(address(0), path[path.length - 1], referee, feeAmount, referralReward);
    }
    /// @dev execute swap directly on Uniswap/Pancake/...
    /// @param fork fork used to execute swap
    /// @param amountIn amount if tokens In
    /// @param amountOutMin minimum tokens to receive
    /// @param path Sell path.
    /// @param referee address of referee for msg.sender, 0x adress if none
    function swapExactTokensForTokensSupportingFeeOnTransferTokens(
        address fork,
        uint256 amountIn,
        uint256 amountOutMin,
        address[] calldata path,
        address referee
    ) external whenNotPaused isValidFork(fork) isValidReferee(referee) {
        referee = _getReferee(referee);
        (uint256 swapAmount, uint256 feeAmount, uint256 referralReward) = _calculateFeesAndRewards(
            amountIn,
            referee,
            false
        );
        TransferHelper.safeTransferFrom(path[0], msg.sender, _pairFor(fork, path[0], path[1]), swapAmount);
        uint256 balanceBefore = IERC20(path[path.length - 1]).balanceOf(msg.sender);
        _swapSupportingFeeOnTransferTokens(fork, path, msg.sender);
        require(
            IERC20(path[path.length - 1]).balanceOf(msg.sender).sub(balanceBefore) >= amountOutMin,
            "FloozRouter: INSUFFICIENT_OUTPUT_AMOUNT"
        );
        if (feeAmount.add(referralReward) > 0)
            _withdrawFeesAndRewards(path[0], path[path.length - 1], referee, feeAmount, referralReward);
    }
    /// @dev execute swap directly on Uniswap/Pancake/...
    /// @param fork fork used to execute swap
    /// @param amountOut expected tokens to receive
    /// @param amountInMax maximum tokens to send
    /// @param path Sell path.
    /// @param referee address of referee for msg.sender, 0x adress if none
    /// @return amounts
    function swapTokensForExactTokens(
        address fork,
        uint256 amountOut,
        uint256 amountInMax,
        address[] calldata path,
        address referee
    ) external whenNotPaused isValidFork(fork) isValidReferee(referee) returns (uint256[] memory amounts) {
        referee = _getReferee(referee);
        amounts = _getAmountsIn(fork, amountOut, path);
        (, uint256 feeAmount, uint256 referralReward) = _calculateFeesAndRewards(amounts[0], referee, true);
        require(amounts[0].add(feeAmount).add(referralReward) <= amountInMax, "FloozRouter: EXCESSIVE_INPUT_AMOUNT");
        TransferHelper.safeTransferFrom(path[0], msg.sender, _pairFor(fork, path[0], path[1]), amounts[0]);
        _swap(fork, amounts, path, msg.sender);
        if (feeAmount.add(referralReward) > 0)
            _withdrawFeesAndRewards(path[0], path[path.length - 1], referee, feeAmount, referralReward);
    }
    /// @dev execute swap directly on Uniswap/Pancake/...
    /// @param fork fork used to execute swap
    /// @param amountOut expected tokens to receive
    /// @param amountInMax maximum tokens to send
    /// @param path Sell path.
    /// @param referee address of referee for msg.sender, 0x adress if none
    /// @return amounts
    function swapTokensForExactETH(
        address fork,
        uint256 amountOut,
        uint256 amountInMax,
        address[] calldata path,
        address referee
    ) external whenNotPaused isValidFork(fork) isValidReferee(referee) returns (uint256[] memory amounts) {
        require(path[path.length - 1] == WETH, "FloozRouter: INVALID_PATH");
        referee = _getReferee(referee);
        (, uint256 feeAmount, uint256 referralReward) = _calculateFeesAndRewards(amountOut, referee, true);
        amounts = _getAmountsIn(fork, amountOut.add(feeAmount).add(referralReward), path);
        require(amounts[0].add(feeAmount).add(referralReward) <= amountInMax, "FloozRouter: EXCESSIVE_INPUT_AMOUNT");
        TransferHelper.safeTransferFrom(path[0], msg.sender, _pairFor(fork, path[0], path[1]), amounts[0]);
        _swap(fork, amounts, path, address(this));
        IWETH(WETH).withdraw(amounts[amounts.length - 1]);
        TransferHelper.safeTransferETH(msg.sender, amountOut);
        if (feeAmount.add(referralReward) > 0)
            _withdrawFeesAndRewards(address(0), path[path.length - 1], referee, feeAmount, referralReward);
    }
    /// @dev execute swap directly on Uniswap/Pancake/...
    /// @param fork fork used to execute swap
    /// @param amountOutMin minimum expected tokens to receive
    /// @param path Sell path.
    /// @param referee address of referee for msg.sender, 0x adress if none
    function swapExactETHForTokensSupportingFeeOnTransferTokens(
        address fork,
        uint256 amountOutMin,
        address[] calldata path,
        address referee
    ) external payable whenNotPaused isValidFork(fork) isValidReferee(referee) {
        require(path[0] == WETH, "FloozRouter: INVALID_PATH");
        referee = _getReferee(referee);
        (uint256 swapAmount, uint256 feeAmount, uint256 referralReward) = _calculateFeesAndRewards(
            msg.value,
            referee,
            false
        );
        IWETH(WETH).deposit{value: swapAmount}();
        assert(IWETH(WETH).transfer(_pairFor(fork, path[0], path[1]), swapAmount));
        uint256 balanceBefore = IERC20(path[path.length - 1]).balanceOf(msg.sender);
        _swapSupportingFeeOnTransferTokens(fork, path, msg.sender);
        require(
            IERC20(path[path.length - 1]).balanceOf(msg.sender).sub(balanceBefore) >= amountOutMin,
            "FloozRouter: INSUFFICIENT_OUTPUT_AMOUNT"
        );
        if (feeAmount.add(referralReward) > 0)
            _withdrawFeesAndRewards(address(0), path[path.length - 1], referee, feeAmount, referralReward);
    }
    /// @dev returns the referee for a given address, if new, registers referee
    /// @param referee the address of the referee for msg.sender
    /// @return referee address from referral registry
    function _getReferee(address referee) internal returns (address) {
        address sender = msg.sender;
        if (!referralRegistry.hasUserReferee(sender) && referee != address(0)) {
            referralRegistry.createReferralAnchor(sender, referee);
        }
        return referralRegistry.getUserReferee(sender);
    }
    // **** SWAP ****
    // requires the initial amount to have already been sent to the first pair
    function _swap(
        address fork,
        uint256[] memory amounts,
        address[] memory path,
        address _to
    ) internal {
        for (uint256 i; i < path.length - 1; i++) {
            (address input, address output) = (path[i], path[i + 1]);
            (address token0, ) = PancakeLibrary.sortTokens(input, output);
            uint256 amountOut = amounts[i + 1];
            (uint256 amount0Out, uint256 amount1Out) = input == token0
                ? (uint256(0), amountOut)
                : (amountOut, uint256(0));
            address to = i < path.length - 2 ? _pairFor(fork, output, path[i + 2]) : _to;
            IPancakePair(_pairFor(fork, input, output)).swap(amount0Out, amount1Out, to, new bytes(0));
        }
    }
    // **** SWAP (supporting fee-on-transfer tokens) ****
    // requires the initial amount to have already been sent to the first pair
    function _swapSupportingFeeOnTransferTokens(
        address fork,
        address[] memory path,
        address _to
    ) internal {
        for (uint256 i; i < path.length - 1; i++) {
            (address input, address output) = (path[i], path[i + 1]);
            (address token0, ) = PancakeLibrary.sortTokens(input, output);
            IPancakePair pair = IPancakePair(_pairFor(fork, input, output));
            uint256 amountInput;
            uint256 amountOutput;
            {
                // scope to avoid stack too deep errors
                (uint256 reserve0, uint256 reserve1, ) = pair.getReserves();
                (uint256 reserveInput, uint256 reserveOutput) = input == token0
                    ? (reserve0, reserve1)
                    : (reserve1, reserve0);
                amountInput = IERC20(input).balanceOf(address(pair)).sub(reserveInput);
                amountOutput = _getAmountOut(amountInput, reserveInput, reserveOutput);
            }
            (uint256 amount0Out, uint256 amount1Out) = input == token0
                ? (uint256(0), amountOutput)
                : (amountOutput, uint256(0));
            address to = i < path.length - 2 ? _pairFor(fork, output, path[i + 2]) : _to;
            pair.swap(amount0Out, amount1Out, to, new bytes(0));
        }
    }
    /// @dev Executes a swap on 0x API
    /// @param data calldata expected by data field on 0x API (https://0x.org/docs/api#response-1)
    /// @param tokenOut the address of currency to sell – 0x address for ETH
    /// @param tokenIn the address of currency to buy – 0x address for ETH
    /// @param referee address of referee for msg.sender, 0x adress if none
    function executeZeroExSwap(
        bytes calldata data,
        address tokenOut,
        address tokenIn,
        address referee
    ) external payable nonReentrant whenNotPaused isValidReferee(referee) {
        referee = _getReferee(referee);
        bytes4 selector = data.readBytes4(0);
        address impl = IZerox(zeroEx).getFunctionImplementation(selector);
        require(impl != address(0), "FloozRouter: NO_IMPLEMENTATION");
        bool isAboveThreshold = userAboveBalanceThreshold(msg.sender);
        // skip fees & rewards for god mode users
        if (isAboveThreshold) {
            (bool success, ) = impl.delegatecall(data);
            require(success, "FloozRouter: REVERTED");
        } else {
            // if ETH in execute trade as router & distribute funds & fees
            if (msg.value > 0) {
                (uint256 swapAmount, uint256 feeAmount, uint256 referralReward) = _calculateFeesAndRewards(
                    msg.value,
                    referee,
                    false
                );
                (bool success, ) = impl.call{value: swapAmount}(data);
                require(success, "FloozRouter: REVERTED");
                TransferHelper.safeTransfer(tokenIn, msg.sender, IERC20(tokenIn).balanceOf(address(this)));
                _withdrawFeesAndRewards(address(0), tokenIn, referee, feeAmount, referralReward);
            } else {
                uint256 balanceBefore = IERC20(tokenOut).balanceOf(msg.sender);
                (bool success, ) = impl.delegatecall(data);
                require(success, "FloozRouter: REVERTED");
                uint256 balanceAfter = IERC20(tokenOut).balanceOf(msg.sender);
                require(balanceBefore > balanceAfter, "INVALID_TOKEN");
                (, uint256 feeAmount, uint256 referralReward) = _calculateFeesAndRewards(
                    balanceBefore.sub(balanceAfter),
                    referee,
                    true
                );
                _withdrawFeesAndRewards(tokenOut, tokenIn, referee, feeAmount, referralReward);
            }
        }
    }
    /// @dev calculates swap, fee & reward amounts
    /// @param amount total amount of tokens
    /// @param referee the address of the referee for msg.sender
    function _calculateFeesAndRewards(
        uint256 amount,
        address referee,
        bool additiveFee
    )
        internal
        view
        returns (
            uint256 swapAmount,
            uint256 feeAmount,
            uint256 referralReward
        )
    {
        // no fees for users above threshold
        if (userAboveBalanceThreshold(msg.sender)) {
            swapAmount = amount;
        } else {
            if (additiveFee) {
                swapAmount = amount;
                feeAmount = swapAmount.mul(FEE_DENOMINATOR).div(FEE_DENOMINATOR.sub(swapFee)).sub(amount);
            } else {
                feeAmount = amount.mul(swapFee).div(FEE_DENOMINATOR);
                swapAmount = amount.sub(feeAmount);
            }
            // calculate referral rates, if referee is not 0x
            if (referee != address(0) && referralsActivated) {
                uint16 referralRate = customReferralRewardRate[referee] > 0
                    ? customReferralRewardRate[referee]
                    : referralRewardRate;
                referralReward = feeAmount.mul(referralRate).div(FEE_DENOMINATOR);
                feeAmount = feeAmount.sub(referralReward);
            } else {
                referralReward = 0;
            }
        }
    }
    /// @dev lets the admin update an Uniswap style fork
    function updateFork(
        address _factory,
        bytes calldata _initCode,
        bool _activated
    ) external onlyOwner {
        forkActivated[_factory] = _activated;
        forkInitCode[_factory] = _initCode;
        emit ForkUpdated(_factory);
    }
    /// @dev returns if a users is above the SYA threshold and can swap without fees
    function userAboveBalanceThreshold(address _account) public view returns (bool) {
        return saveYourAssetsToken.balanceOf(_account) >= balanceThreshold;
    }
    /// @dev returns the fee nominator for a given user
    function getUserFee(address user) public view returns (uint256) {
        saveYourAssetsToken.balanceOf(user) >= balanceThreshold ? 0 : swapFee;
    }
    /// @dev lets the admin update the swapFee nominator
    function updateSwapFee(uint16 newSwapFee) external onlyOwner {
        swapFee = newSwapFee;
        emit SwapFeeUpdated(newSwapFee);
    }
    /// @dev lets the admin update the referral reward rate
    function updateReferralRewardRate(uint16 newReferralRewardRate) external onlyOwner {
        require(newReferralRewardRate <= FEE_DENOMINATOR, "FloozRouter: INVALID_RATE");
        referralRewardRate = newReferralRewardRate;
        emit ReferralRewardRateUpdated(newReferralRewardRate);
    }
    /// @dev lets the admin update which address receives the protocol fees
    function updateFeeReceiver(address payable newFeeReceiver) external onlyOwner {
        feeReceiver = newFeeReceiver;
        emit FeeReceiverUpdated(newFeeReceiver);
    }
    /// @dev lets the admin update the SYA balance threshold, which activates feeless trading for users
    function updateBalanceThreshold(uint256 newBalanceThreshold) external onlyOwner {
        balanceThreshold = newBalanceThreshold;
        emit BalanceThresholdUpdated(balanceThreshold);
    }
    /// @dev lets the admin update the status of the referral system
    function updateReferralsActivated(bool newReferralsActivated) external onlyOwner {
        referralsActivated = newReferralsActivated;
        emit ReferralsActivatedUpdated(newReferralsActivated);
    }
    /// @dev lets the admin set a new referral registry
    function updateReferralRegistry(address newReferralRegistry) external onlyOwner {
        referralRegistry = IReferralRegistry(newReferralRegistry);
        emit ReferralRegistryUpdated(newReferralRegistry);
    }
    /// @dev lets the admin set a custom referral rate
    function updateCustomReferralRewardRate(address account, uint16 referralRate) external onlyOwner returns (uint256) {
        require(referralRate <= FEE_DENOMINATOR, "FloozRouter: INVALID_RATE");
        customReferralRewardRate[account] = referralRate;
        emit CustomReferralRewardRateUpdated(account, referralRate);
    }
    /// @dev returns the referee for a given user – 0x address if none
    function getUserReferee(address user) external view returns (address) {
        return referralRegistry.getUserReferee(user);
    }
    /// @dev returns if the given user has been referred or not
    function hasUserReferee(address user) external view returns (bool) {
        return referralRegistry.hasUserReferee(user);
    }
    /// @dev lets the admin withdraw ETH from the contract.
    function withdrawETH(address payable to, uint256 amount) external onlyOwner {
        TransferHelper.safeTransferETH(to, amount);
    }
    /// @dev lets the admin withdraw ERC20s from the contract.
    function withdrawERC20Token(
        address token,
        address to,
        uint256 amount
    ) external onlyOwner {
        TransferHelper.safeTransfer(token, to, amount);
    }
    /// @dev distributes fees & referral rewards to users
    function _withdrawFeesAndRewards(
        address tokenReward,
        address tokenOut,
        address referee,
        uint256 feeAmount,
        uint256 referralReward
    ) internal {
        if (tokenReward == address(0)) {
            TransferHelper.safeTransferETH(feeReceiver, feeAmount);
            if (referralReward > 0) {
                TransferHelper.safeTransferETH(referee, referralReward);
                emit ReferralRewardPaid(msg.sender, referee, tokenOut, tokenReward, referralReward);
            }
        } else {
            TransferHelper.safeTransferFrom(tokenReward, msg.sender, feeReceiver, feeAmount);
            if (referralReward > 0) {
                TransferHelper.safeTransferFrom(tokenReward, msg.sender, referee, referralReward);
                emit ReferralRewardPaid(msg.sender, referee, tokenOut, tokenReward, referralReward);
            }
        }
    }
    /// @dev given an input amount of an asset and pair reserves, returns the maximum output amount of the other asset
    function _getAmountOut(
        uint256 amountIn,
        uint256 reserveIn,
        uint256 reserveOut
    ) internal pure returns (uint256 amountOut) {
        require(amountIn > 0, "FloozRouter: INSUFFICIENT_INPUT_AMOUNT");
        require(reserveIn > 0 && reserveOut > 0, "FloozRouter: INSUFFICIENT_LIQUIDITY");
        uint256 amountInWithFee = amountIn.mul((9980));
        uint256 numerator = amountInWithFee.mul(reserveOut);
        uint256 denominator = reserveIn.mul(10000).add(amountInWithFee);
        amountOut = numerator / denominator;
    }
    /// @dev given an output amount of an asset and pair reserves, returns a required input amount of the other asset
    function _getAmountIn(
        uint256 amountOut,
        uint256 reserveIn,
        uint256 reserveOut
    ) internal pure returns (uint256 amountIn) {
        require(amountOut > 0, "FloozRouter: INSUFFICIENT_OUTPUT_AMOUNT");
        require(reserveIn > 0 && reserveOut > 0, "FloozRouter: INSUFFICIENT_LIQUIDITY");
        uint256 numerator = reserveIn.mul(amountOut).mul(10000);
        uint256 denominator = reserveOut.sub(amountOut).mul(9980);
        amountIn = (numerator / denominator).add(1);
    }
    /// @dev performs chained getAmountOut calculations on any number of pairs
    function _getAmountsOut(
        address fork,
        uint256 amountIn,
        address[] memory path
    ) internal view returns (uint256[] memory amounts) {
        require(path.length >= 2, "FloozRouter: INVALID_PATH");
        amounts = new uint256[](path.length);
        amounts[0] = amountIn;
        for (uint256 i; i < path.length - 1; i++) {
            (uint256 reserveIn, uint256 reserveOut) = _getReserves(fork, path[i], path[i + 1]);
            amounts[i + 1] = _getAmountOut(amounts[i], reserveIn, reserveOut);
        }
    }
    /// @dev performs chained getAmountIn calculations on any number of pairs
    function _getAmountsIn(
        address factory,
        uint256 amountOut,
        address[] memory path
    ) internal view returns (uint256[] memory amounts) {
        require(path.length >= 2, "FloozRouter: INVALID_PATH");
        amounts = new uint256[](path.length);
        amounts[amounts.length - 1] = amountOut;
        for (uint256 i = path.length - 1; i > 0; i--) {
            (uint256 reserveIn, uint256 reserveOut) = _getReserves(factory, path[i - 1], path[i]);
            amounts[i - 1] = _getAmountIn(amounts[i], reserveIn, reserveOut);
        }
    }
    /// @dev fetches and sorts the reserves for a pair
    function _getReserves(
        address factory,
        address tokenA,
        address tokenB
    ) internal view returns (uint256 reserveA, uint256 reserveB) {
        (address token0, ) = PancakeLibrary.sortTokens(tokenA, tokenB);
        (uint256 reserve0, uint256 reserve1, ) = IPancakePair(_pairFor(factory, tokenA, tokenB)).getReserves();
        (reserveA, reserveB) = tokenA == token0 ? (reserve0, reserve1) : (reserve1, reserve0);
    }
    /// @dev calculates the CREATE2 address for a pair without making any external calls
    function _pairFor(
        address factory,
        address tokenA,
        address tokenB
    ) internal view returns (address pair) {
        (address token0, address token1) = PancakeLibrary.sortTokens(tokenA, tokenB);
        pair = address(
            uint256(
                keccak256(
                    abi.encodePacked(
                        hex"ff",
                        factory,
                        keccak256(abi.encodePacked(token0, token1)),
                        forkInitCode[factory] // init code hash
                    )
                )
            )
        );
    }
    /// @dev lets the admin pause this contract
    function pause() external onlyOwner {
        _pause();
    }
    /// @dev lets the admin unpause this contract
    function unpause() external onlyOwner {
        _unpause();
    }
    /// @dev allows to receive ETH on the contract
    receive() external payable {}
    modifier isValidFork(address factory) {
        require(forkActivated[factory], "FloozRouter: INVALID_FACTORY");
        _;
    }
    modifier isValidReferee(address referee) {
        require(msg.sender != referee, "FloozRouter: SELF_REFERRAL");
        _;
    }
}
// SPDX-License-Identifier: Apache-2.0
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
import "./errors/LibBytesRichErrorsV06.sol";
import "./errors/LibRichErrorsV06.sol";
library LibBytesV06 {
    using LibBytesV06 for bytes;
    /// @dev Gets the memory address for a byte array.
    /// @param input Byte array to lookup.
    /// @return memoryAddress Memory address of byte array. This
    ///         points to the header of the byte array which contains
    ///         the length.
    function rawAddress(bytes memory input)
        internal
        pure
        returns (uint256 memoryAddress)
    {
        assembly {
            memoryAddress := input
        }
        return memoryAddress;
    }
    /// @dev Gets the memory address for the contents of a byte array.
    /// @param input Byte array to lookup.
    /// @return memoryAddress Memory address of the contents of the byte array.
    function contentAddress(bytes memory input)
        internal
        pure
        returns (uint256 memoryAddress)
    {
        assembly {
            memoryAddress := add(input, 32)
        }
        return memoryAddress;
    }
    /// @dev Copies `length` bytes from memory location `source` to `dest`.
    /// @param dest memory address to copy bytes to.
    /// @param source memory address to copy bytes from.
    /// @param length number of bytes to copy.
    function memCopy(
        uint256 dest,
        uint256 source,
        uint256 length
    )
        internal
        pure
    {
        if (length < 32) {
            // Handle a partial word by reading destination and masking
            // off the bits we are interested in.
            // This correctly handles overlap, zero lengths and source == dest
            assembly {
                let mask := sub(exp(256, sub(32, length)), 1)
                let s := and(mload(source), not(mask))
                let d := and(mload(dest), mask)
                mstore(dest, or(s, d))
            }
        } else {
            // Skip the O(length) loop when source == dest.
            if (source == dest) {
                return;
            }
            // For large copies we copy whole words at a time. The final
            // word is aligned to the end of the range (instead of after the
            // previous) to handle partial words. So a copy will look like this:
            //
            //  ####
            //      ####
            //          ####
            //            ####
            //
            // We handle overlap in the source and destination range by
            // changing the copying direction. This prevents us from
            // overwriting parts of source that we still need to copy.
            //
            // This correctly handles source == dest
            //
            if (source > dest) {
                assembly {
                    // We subtract 32 from `sEnd` and `dEnd` because it
                    // is easier to compare with in the loop, and these
                    // are also the addresses we need for copying the
                    // last bytes.
                    length := sub(length, 32)
                    let sEnd := add(source, length)
                    let dEnd := add(dest, length)
                    // Remember the last 32 bytes of source
                    // This needs to be done here and not after the loop
                    // because we may have overwritten the last bytes in
                    // source already due to overlap.
                    let last := mload(sEnd)
                    // Copy whole words front to back
                    // Note: the first check is always true,
                    // this could have been a do-while loop.
                    // solhint-disable-next-line no-empty-blocks
                    for {} lt(source, sEnd) {} {
                        mstore(dest, mload(source))
                        source := add(source, 32)
                        dest := add(dest, 32)
                    }
                    // Write the last 32 bytes
                    mstore(dEnd, last)
                }
            } else {
                assembly {
                    // We subtract 32 from `sEnd` and `dEnd` because those
                    // are the starting points when copying a word at the end.
                    length := sub(length, 32)
                    let sEnd := add(source, length)
                    let dEnd := add(dest, length)
                    // Remember the first 32 bytes of source
                    // This needs to be done here and not after the loop
                    // because we may have overwritten the first bytes in
                    // source already due to overlap.
                    let first := mload(source)
                    // Copy whole words back to front
                    // We use a signed comparisson here to allow dEnd to become
                    // negative (happens when source and dest < 32). Valid
                    // addresses in local memory will never be larger than
                    // 2**255, so they can be safely re-interpreted as signed.
                    // Note: the first check is always true,
                    // this could have been a do-while loop.
                    // solhint-disable-next-line no-empty-blocks
                    for {} slt(dest, dEnd) {} {
                        mstore(dEnd, mload(sEnd))
                        sEnd := sub(sEnd, 32)
                        dEnd := sub(dEnd, 32)
                    }
                    // Write the first 32 bytes
                    mstore(dest, first)
                }
            }
        }
    }
    /// @dev Returns a slices from a byte array.
    /// @param b The byte array to take a slice from.
    /// @param from The starting index for the slice (inclusive).
    /// @param to The final index for the slice (exclusive).
    /// @return result The slice containing bytes at indices [from, to)
    function slice(
        bytes memory b,
        uint256 from,
        uint256 to
    )
        internal
        pure
        returns (bytes memory result)
    {
        // Ensure that the from and to positions are valid positions for a slice within
        // the byte array that is being used.
        if (from > to) {
            LibRichErrorsV06.rrevert(LibBytesRichErrorsV06.InvalidByteOperationError(
                LibBytesRichErrorsV06.InvalidByteOperationErrorCodes.FromLessThanOrEqualsToRequired,
                from,
                to
            ));
        }
        if (to > b.length) {
            LibRichErrorsV06.rrevert(LibBytesRichErrorsV06.InvalidByteOperationError(
                LibBytesRichErrorsV06.InvalidByteOperationErrorCodes.ToLessThanOrEqualsLengthRequired,
                to,
                b.length
            ));
        }
        // Create a new bytes structure and copy contents
        result = new bytes(to - from);
        memCopy(
            result.contentAddress(),
            b.contentAddress() + from,
            result.length
        );
        return result;
    }
    /// @dev Returns a slice from a byte array without preserving the input.
    ///      When `from == 0`, the original array will match the slice.
    ///      In other cases its state will be corrupted.
    /// @param b The byte array to take a slice from. Will be destroyed in the process.
    /// @param from The starting index for the slice (inclusive).
    /// @param to The final index for the slice (exclusive).
    /// @return result The slice containing bytes at indices [from, to)
    function sliceDestructive(
        bytes memory b,
        uint256 from,
        uint256 to
    )
        internal
        pure
        returns (bytes memory result)
    {
        // Ensure that the from and to positions are valid positions for a slice within
        // the byte array that is being used.
        if (from > to) {
            LibRichErrorsV06.rrevert(LibBytesRichErrorsV06.InvalidByteOperationError(
                LibBytesRichErrorsV06.InvalidByteOperationErrorCodes.FromLessThanOrEqualsToRequired,
                from,
                to
            ));
        }
        if (to > b.length) {
            LibRichErrorsV06.rrevert(LibBytesRichErrorsV06.InvalidByteOperationError(
                LibBytesRichErrorsV06.InvalidByteOperationErrorCodes.ToLessThanOrEqualsLengthRequired,
                to,
                b.length
            ));
        }
        // Create a new bytes structure around [from, to) in-place.
        assembly {
            result := add(b, from)
            mstore(result, sub(to, from))
        }
        return result;
    }
    /// @dev Pops the last byte off of a byte array by modifying its length.
    /// @param b Byte array that will be modified.
    /// @return result The byte that was popped off.
    function popLastByte(bytes memory b)
        internal
        pure
        returns (bytes1 result)
    {
        if (b.length == 0) {
            LibRichErrorsV06.rrevert(LibBytesRichErrorsV06.InvalidByteOperationError(
                LibBytesRichErrorsV06.InvalidByteOperationErrorCodes.LengthGreaterThanZeroRequired,
                b.length,
                0
            ));
        }
        // Store last byte.
        result = b[b.length - 1];
        assembly {
            // Decrement length of byte array.
            let newLen := sub(mload(b), 1)
            mstore(b, newLen)
        }
        return result;
    }
    /// @dev Tests equality of two byte arrays.
    /// @param lhs First byte array to compare.
    /// @param rhs Second byte array to compare.
    /// @return equal True if arrays are the same. False otherwise.
    function equals(
        bytes memory lhs,
        bytes memory rhs
    )
        internal
        pure
        returns (bool equal)
    {
        // Keccak gas cost is 30 + numWords * 6. This is a cheap way to compare.
        // We early exit on unequal lengths, but keccak would also correctly
        // handle this.
        return lhs.length == rhs.length && keccak256(lhs) == keccak256(rhs);
    }
    /// @dev Reads an address from a position in a byte array.
    /// @param b Byte array containing an address.
    /// @param index Index in byte array of address.
    /// @return result address from byte array.
    function readAddress(
        bytes memory b,
        uint256 index
    )
        internal
        pure
        returns (address result)
    {
        if (b.length < index + 20) {
            LibRichErrorsV06.rrevert(LibBytesRichErrorsV06.InvalidByteOperationError(
                LibBytesRichErrorsV06.InvalidByteOperationErrorCodes.LengthGreaterThanOrEqualsTwentyRequired,
                b.length,
                index + 20 // 20 is length of address
            ));
        }
        // Add offset to index:
        // 1. Arrays are prefixed by 32-byte length parameter (add 32 to index)
        // 2. Account for size difference between address length and 32-byte storage word (subtract 12 from index)
        index += 20;
        // Read address from array memory
        assembly {
            // 1. Add index to address of bytes array
            // 2. Load 32-byte word from memory
            // 3. Apply 20-byte mask to obtain address
            result := and(mload(add(b, index)), 0xffffffffffffffffffffffffffffffffffffffff)
        }
        return result;
    }
    /// @dev Writes an address into a specific position in a byte array.
    /// @param b Byte array to insert address into.
    /// @param index Index in byte array of address.
    /// @param input Address to put into byte array.
    function writeAddress(
        bytes memory b,
        uint256 index,
        address input
    )
        internal
        pure
    {
        if (b.length < index + 20) {
            LibRichErrorsV06.rrevert(LibBytesRichErrorsV06.InvalidByteOperationError(
                LibBytesRichErrorsV06.InvalidByteOperationErrorCodes.LengthGreaterThanOrEqualsTwentyRequired,
                b.length,
                index + 20 // 20 is length of address
            ));
        }
        // Add offset to index:
        // 1. Arrays are prefixed by 32-byte length parameter (add 32 to index)
        // 2. Account for size difference between address length and 32-byte storage word (subtract 12 from index)
        index += 20;
        // Store address into array memory
        assembly {
            // The address occupies 20 bytes and mstore stores 32 bytes.
            // First fetch the 32-byte word where we'll be storing the address, then
            // apply a mask so we have only the bytes in the word that the address will not occupy.
            // Then combine these bytes with the address and store the 32 bytes back to memory with mstore.
            // 1. Add index to address of bytes array
            // 2. Load 32-byte word from memory
            // 3. Apply 12-byte mask to obtain extra bytes occupying word of memory where we'll store the address
            let neighbors := and(
                mload(add(b, index)),
                0xffffffffffffffffffffffff0000000000000000000000000000000000000000
            )
            // Make sure input address is clean.
            // (Solidity does not guarantee this)
            input := and(input, 0xffffffffffffffffffffffffffffffffffffffff)
            // Store the neighbors and address into memory
            mstore(add(b, index), xor(input, neighbors))
        }
    }
    /// @dev Reads a bytes32 value from a position in a byte array.
    /// @param b Byte array containing a bytes32 value.
    /// @param index Index in byte array of bytes32 value.
    /// @return result bytes32 value from byte array.
    function readBytes32(
        bytes memory b,
        uint256 index
    )
        internal
        pure
        returns (bytes32 result)
    {
        if (b.length < index + 32) {
            LibRichErrorsV06.rrevert(LibBytesRichErrorsV06.InvalidByteOperationError(
                LibBytesRichErrorsV06.InvalidByteOperationErrorCodes.LengthGreaterThanOrEqualsThirtyTwoRequired,
                b.length,
                index + 32
            ));
        }
        // Arrays are prefixed by a 256 bit length parameter
        index += 32;
        // Read the bytes32 from array memory
        assembly {
            result := mload(add(b, index))
        }
        return result;
    }
    /// @dev Writes a bytes32 into a specific position in a byte array.
    /// @param b Byte array to insert <input> into.
    /// @param index Index in byte array of <input>.
    /// @param input bytes32 to put into byte array.
    function writeBytes32(
        bytes memory b,
        uint256 index,
        bytes32 input
    )
        internal
        pure
    {
        if (b.length < index + 32) {
            LibRichErrorsV06.rrevert(LibBytesRichErrorsV06.InvalidByteOperationError(
                LibBytesRichErrorsV06.InvalidByteOperationErrorCodes.LengthGreaterThanOrEqualsThirtyTwoRequired,
                b.length,
                index + 32
            ));
        }
        // Arrays are prefixed by a 256 bit length parameter
        index += 32;
        // Read the bytes32 from array memory
        assembly {
            mstore(add(b, index), input)
        }
    }
    /// @dev Reads a uint256 value from a position in a byte array.
    /// @param b Byte array containing a uint256 value.
    /// @param index Index in byte array of uint256 value.
    /// @return result uint256 value from byte array.
    function readUint256(
        bytes memory b,
        uint256 index
    )
        internal
        pure
        returns (uint256 result)
    {
        result = uint256(readBytes32(b, index));
        return result;
    }
    /// @dev Writes a uint256 into a specific position in a byte array.
    /// @param b Byte array to insert <input> into.
    /// @param index Index in byte array of <input>.
    /// @param input uint256 to put into byte array.
    function writeUint256(
        bytes memory b,
        uint256 index,
        uint256 input
    )
        internal
        pure
    {
        writeBytes32(b, index, bytes32(input));
    }
    /// @dev Reads an unpadded bytes4 value from a position in a byte array.
    /// @param b Byte array containing a bytes4 value.
    /// @param index Index in byte array of bytes4 value.
    /// @return result bytes4 value from byte array.
    function readBytes4(
        bytes memory b,
        uint256 index
    )
        internal
        pure
        returns (bytes4 result)
    {
        if (b.length < index + 4) {
            LibRichErrorsV06.rrevert(LibBytesRichErrorsV06.InvalidByteOperationError(
                LibBytesRichErrorsV06.InvalidByteOperationErrorCodes.LengthGreaterThanOrEqualsFourRequired,
                b.length,
                index + 4
            ));
        }
        // Arrays are prefixed by a 32 byte length field
        index += 32;
        // Read the bytes4 from array memory
        assembly {
            result := mload(add(b, index))
            // Solidity does not require us to clean the trailing bytes.
            // We do it anyway
            result := and(result, 0xFFFFFFFF00000000000000000000000000000000000000000000000000000000)
        }
        return result;
    }
    /// @dev Writes a new length to a byte array.
    ///      Decreasing length will lead to removing the corresponding lower order bytes from the byte array.
    ///      Increasing length may lead to appending adjacent in-memory bytes to the end of the byte array.
    /// @param b Bytes array to write new length to.
    /// @param length New length of byte array.
    function writeLength(bytes memory b, uint256 length)
        internal
        pure
    {
        assembly {
            mstore(b, length)
        }
    }
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0 <0.8.0;
/**
 * @dev Contract module that helps prevent reentrant calls to a function.
 *
 * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
 * available, which can be applied to functions to make sure there are no nested
 * (reentrant) calls to them.
 *
 * Note that because there is a single `nonReentrant` guard, functions marked as
 * `nonReentrant` may not call one another. This can be worked around by making
 * those functions `private`, and then adding `external` `nonReentrant` entry
 * points to them.
 *
 * TIP: If you would like to learn more about reentrancy and alternative ways
 * to protect against it, check out our blog post
 * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
 */
abstract contract ReentrancyGuard {
    // Booleans are more expensive than uint256 or any type that takes up a full
    // word because each write operation emits an extra SLOAD to first read the
    // slot's contents, replace the bits taken up by the boolean, and then write
    // back. This is the compiler's defense against contract upgrades and
    // pointer aliasing, and it cannot be disabled.
    // The values being non-zero value makes deployment a bit more expensive,
    // but in exchange the refund on every call to nonReentrant will be lower in
    // amount. Since refunds are capped to a percentage of the total
    // transaction's gas, it is best to keep them low in cases like this one, to
    // increase the likelihood of the full refund coming into effect.
    uint256 private constant _NOT_ENTERED = 1;
    uint256 private constant _ENTERED = 2;
    uint256 private _status;
    constructor () internal {
        _status = _NOT_ENTERED;
    }
    /**
     * @dev Prevents a contract from calling itself, directly or indirectly.
     * Calling a `nonReentrant` function from another `nonReentrant`
     * function is not supported. It is possible to prevent this from happening
     * by making the `nonReentrant` function external, and make it call a
     * `private` function that does the actual work.
     */
    modifier nonReentrant() {
        // On the first call to nonReentrant, _notEntered will be true
        require(_status != _ENTERED, "ReentrancyGuard: reentrant call");
        // Any calls to nonReentrant after this point will fail
        _status = _ENTERED;
        _;
        // By storing the original value once again, a refund is triggered (see
        // https://eips.ethereum.org/EIPS/eip-2200)
        _status = _NOT_ENTERED;
    }
}
pragma solidity =0.6.6;
import "@openzeppelin/contracts/math/SafeMath.sol";
interface IPancakePair {
    event Approval(address indexed owner, address indexed spender, uint256 value);
    event Transfer(address indexed from, address indexed to, uint256 value);
    function name() external pure returns (string memory);
    function symbol() external pure returns (string memory);
    function decimals() external pure returns (uint8);
    function totalSupply() external view returns (uint256);
    function balanceOf(address owner) external view returns (uint256);
    function allowance(address owner, address spender) external view returns (uint256);
    function approve(address spender, uint256 value) external returns (bool);
    function transfer(address to, uint256 value) external returns (bool);
    function transferFrom(
        address from,
        address to,
        uint256 value
    ) external returns (bool);
    function DOMAIN_SEPARATOR() external view returns (bytes32);
    function PERMIT_TYPEHASH() external pure returns (bytes32);
    function nonces(address owner) external view returns (uint256);
    function permit(
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external;
    event Mint(address indexed sender, uint256 amount0, uint256 amount1);
    event Burn(address indexed sender, uint256 amount0, uint256 amount1, address indexed to);
    event Swap(
        address indexed sender,
        uint256 amount0In,
        uint256 amount1In,
        uint256 amount0Out,
        uint256 amount1Out,
        address indexed to
    );
    event Sync(uint112 reserve0, uint112 reserve1);
    function MINIMUM_LIQUIDITY() external pure returns (uint256);
    function factory() external view returns (address);
    function token0() external view returns (address);
    function token1() external view returns (address);
    function getReserves()
        external
        view
        returns (
            uint112 reserve0,
            uint112 reserve1,
            uint32 blockTimestampLast
        );
    function price0CumulativeLast() external view returns (uint256);
    function price1CumulativeLast() external view returns (uint256);
    function kLast() external view returns (uint256);
    function mint(address to) external returns (uint256 liquidity);
    function burn(address to) external returns (uint256 amount0, uint256 amount1);
    function swap(
        uint256 amount0Out,
        uint256 amount1Out,
        address to,
        bytes calldata data
    ) external;
    function skim(address to) external;
    function sync() external;
    function initialize(address, address) external;
}
library PancakeLibrary {
    using SafeMath for uint256;
    // returns sorted token addresses, used to handle return values from pairs sorted in this order
    function sortTokens(address tokenA, address tokenB) internal pure returns (address token0, address token1) {
        require(tokenA != tokenB, "PancakeLibrary: IDENTICAL_ADDRESSES");
        (token0, token1) = tokenA < tokenB ? (tokenA, tokenB) : (tokenB, tokenA);
        require(token0 != address(0), "PancakeLibrary: ZERO_ADDRESS");
    }
    // given some amount of an asset and pair reserves, returns an equivalent amount of the other asset
    function quote(
        uint256 amountA,
        uint256 reserveA,
        uint256 reserveB
    ) internal pure returns (uint256 amountB) {
        require(amountA > 0, "PancakeLibrary: INSUFFICIENT_AMOUNT");
        require(reserveA > 0 && reserveB > 0, "PancakeLibrary: INSUFFICIENT_LIQUIDITY");
        amountB = amountA.mul(reserveB) / reserveA;
    }
}
pragma solidity >=0.5.0;
interface IReferralRegistry {
    function getUserReferee(address _user) external view returns (address);
    function hasUserReferee(address _user) external view returns (bool);
    function createReferralAnchor(address _user, address _referee) external;
}
pragma solidity ^0.6.5;
interface IZerox {
    function getFunctionImplementation(bytes4 selector) external returns (address payable);
}
// SPDX-License-Identifier: Apache-2.0
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
library LibBytesRichErrorsV06 {
    enum InvalidByteOperationErrorCodes {
        FromLessThanOrEqualsToRequired,
        ToLessThanOrEqualsLengthRequired,
        LengthGreaterThanZeroRequired,
        LengthGreaterThanOrEqualsFourRequired,
        LengthGreaterThanOrEqualsTwentyRequired,
        LengthGreaterThanOrEqualsThirtyTwoRequired,
        LengthGreaterThanOrEqualsNestedBytesLengthRequired,
        DestinationLengthGreaterThanOrEqualSourceLengthRequired
    }
    // bytes4(keccak256("InvalidByteOperationError(uint8,uint256,uint256)"))
    bytes4 internal constant INVALID_BYTE_OPERATION_ERROR_SELECTOR =
        0x28006595;
    // solhint-disable func-name-mixedcase
    function InvalidByteOperationError(
        InvalidByteOperationErrorCodes errorCode,
        uint256 offset,
        uint256 required
    )
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            INVALID_BYTE_OPERATION_ERROR_SELECTOR,
            errorCode,
            offset,
            required
        );
    }
}
// SPDX-License-Identifier: Apache-2.0
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
library LibRichErrorsV06 {
    // bytes4(keccak256("Error(string)"))
    bytes4 internal constant STANDARD_ERROR_SELECTOR = 0x08c379a0;
    // solhint-disable func-name-mixedcase
    /// @dev ABI encode a standard, string revert error payload.
    ///      This is the same payload that would be included by a `revert(string)`
    ///      solidity statement. It has the function signature `Error(string)`.
    /// @param message The error string.
    /// @return The ABI encoded error.
    function StandardError(string memory message)
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            STANDARD_ERROR_SELECTOR,
            bytes(message)
        );
    }
    // solhint-enable func-name-mixedcase
    /// @dev Reverts an encoded rich revert reason `errorData`.
    /// @param errorData ABI encoded error data.
    function rrevert(bytes memory errorData)
        internal
        pure
    {
        assembly {
            revert(add(errorData, 0x20), mload(errorData))
        }
    }
}
pragma solidity =0.6.6;
pragma experimental ABIEncoderV2;
import "@openzeppelin/contracts/utils/ReentrancyGuard.sol";
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/math/SafeMath.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/utils/Pausable.sol";
import "./libraries/TransferHelper.sol";
import "./libraries/PancakeLibrary.sol";
import "./interfaces/IReferralRegistry.sol";
import "./interfaces/IWETH.sol";
import "./interfaces/IZerox.sol";
contract FloozMultichainRouter is Ownable, Pausable, ReentrancyGuard {
    using SafeMath for uint256;
    event SwapFeeUpdated(uint16 swapFee);
    event ReferralRegistryUpdated(address referralRegistry);
    event ReferralRewardRateUpdated(uint16 referralRewardRate);
    event ReferralsActivatedUpdated(bool activated);
    event FeeReceiverUpdated(address payable feeReceiver);
    event CustomReferralRewardRateUpdated(address indexed account, uint16 referralRate);
    event ReferralRewardPaid(address from, address indexed to, address tokenOut, address tokenReward, uint256 amount);
    event ForkCreated(address factory);
    event ForkUpdated(address factory);
    struct SwapData {
        address fork;
        address referee;
        bool fee;
    }
    struct ExternalSwapData {
        bytes data;
        address fromToken;
        address toToken;
        uint256 amountFrom;
        address referee;
        uint256 minOut;
        bool fee;
    }
    // Denominator of fee
    uint256 public constant FEE_DENOMINATOR = 10000;
    // Numerator of fee
    uint16 public swapFee;
    // address of WETH
    address public immutable WETH;
    // address of zeroEx proxy contract to forward swaps
    address payable public immutable zeroEx;
    // address of 1inch contract to forward swaps
    address payable public immutable oneInch;
    // address of referral registry that stores referral anchors
    IReferralRegistry public referralRegistry;
    // address that receives protocol fees
    address payable public feeReceiver;
    // percentage of fees that will be paid as rewards
    uint16 public referralRewardRate;
    // stores if the referral system is turned on or off
    bool public referralsActivated;
    // stores individual referral rates
    mapping(address => uint16) public customReferralRewardRate;
    // stores uniswap forks status, index is the factory address
    mapping(address => bool) public forkActivated;
    // stores uniswap forks initCodes, index is the factory address
    mapping(address => bytes) public forkInitCode;
    /// @dev construct this contract
    /// @param _WETH address of WETH.
    /// @param _swapFee nominator for swapFee. Denominator = 10000
    /// @param _referralRewardRate percentage of swapFee that are paid out as rewards
    /// @param _feeReceiver address that receives protocol fees
    /// @param _referralRegistry address of referral registry that stores referral anchors
    /// @param _zeroEx address of zeroX proxy contract to forward swaps
    constructor(
        address _WETH,
        uint16 _swapFee,
        uint16 _referralRewardRate,
        address payable _feeReceiver,
        IReferralRegistry _referralRegistry,
        address payable _zeroEx,
        address payable _oneInch
    ) public {
        WETH = _WETH;
        swapFee = _swapFee;
        referralRewardRate = _referralRewardRate;
        feeReceiver = _feeReceiver;
        referralRegistry = _referralRegistry;
        zeroEx = _zeroEx;
        oneInch = _oneInch;
        referralsActivated = true;
    }
    /// @dev execute swap directly on Uniswap/Pancake & simular forks
    /// @param swapData stores the swapData information
    /// @param amountOutMin minimum tokens to receive
    /// @param path Sell path.
    /// @return amounts
    function swapExactETHForTokens(
        SwapData calldata swapData,
        uint256 amountOutMin,
        address[] calldata path
    )
        external
        payable
        whenNotPaused
        isValidFork(swapData.fork)
        isValidReferee(swapData.referee)
        returns (uint256[] memory amounts)
    {
        require(path[0] == WETH, "FloozRouter: INVALID_PATH");
        address referee = _getReferee(swapData.referee);
        (uint256 swapAmount, uint256 feeAmount, uint256 referralReward) = _calculateFeesAndRewards(
            swapData.fee,
            msg.value,
            referee,
            false
        );
        amounts = _getAmountsOut(swapData.fork, swapAmount, path);
        require(amounts[amounts.length - 1] >= amountOutMin, "FloozRouter: INSUFFICIENT_OUTPUT_AMOUNT");
        IWETH(WETH).deposit{value: amounts[0]}();
        assert(IWETH(WETH).transfer(_pairFor(swapData.fork, path[0], path[1]), amounts[0]));
        _swap(swapData.fork, amounts, path, msg.sender);
        if (feeAmount.add(referralReward) > 0)
            _withdrawFeesAndRewards(address(0), path[path.length - 1], referee, feeAmount, referralReward);
    }
    /// @dev execute swap directly on Uniswap/Pancake/...
    /// @param swapData stores the swapData information
    /// @param amountIn amount of tokensIn
    /// @param amountOutMin minimum tokens to receive
    /// @param path Sell path.
    function swapExactTokensForETHSupportingFeeOnTransferTokens(
        SwapData calldata swapData,
        uint256 amountIn,
        uint256 amountOutMin,
        address[] calldata path
    ) external whenNotPaused isValidFork(swapData.fork) isValidReferee(swapData.referee) {
        require(path[path.length - 1] == WETH, "FloozRouter: INVALID_PATH");
        address referee = _getReferee(swapData.referee);
        TransferHelper.safeTransferFrom(path[0], msg.sender, _pairFor(swapData.fork, path[0], path[1]), amountIn);
        _swapSupportingFeeOnTransferTokens(swapData.fork, path, address(this));
        uint256 amountOut = IERC20(WETH).balanceOf(address(this));
        IWETH(WETH).withdraw(amountOut);
        (uint256 amountWithdraw, uint256 feeAmount, uint256 referralReward) = _calculateFeesAndRewards(
            swapData.fee,
            amountOut,
            referee,
            false
        );
        require(amountWithdraw >= amountOutMin, "FloozRouter: LOW_SLIPPAGE");
        TransferHelper.safeTransferETH(msg.sender, amountWithdraw);
        if (feeAmount.add(referralReward) > 0)
            _withdrawFeesAndRewards(address(0), path[path.length - 1], referee, feeAmount, referralReward);
    }
    /// @dev execute swap directly on Uniswap/Pancake/...
    /// @param swapData stores the swapData information
    /// @param amountIn amount if tokens In
    /// @param amountOutMin minimum tokens to receive
    /// @param path Sell path.
    /// @return amounts
    function swapExactTokensForTokens(
        SwapData calldata swapData,
        uint256 amountIn,
        uint256 amountOutMin,
        address[] calldata path
    )
        external
        whenNotPaused
        isValidFork(swapData.fork)
        isValidReferee(swapData.referee)
        returns (uint256[] memory amounts)
    {
        address referee = _getReferee(swapData.referee);
        (uint256 swapAmount, uint256 feeAmount, uint256 referralReward) = _calculateFeesAndRewards(
            swapData.fee,
            amountIn,
            referee,
            false
        );
        amounts = _getAmountsOut(swapData.fork, swapAmount, path);
        require(amounts[amounts.length - 1] >= amountOutMin, "FloozRouter: INSUFFICIENT_OUTPUT_AMOUNT");
        TransferHelper.safeTransferFrom(path[0], msg.sender, _pairFor(swapData.fork, path[0], path[1]), swapAmount);
        _swap(swapData.fork, amounts, path, msg.sender);
        if (feeAmount.add(referralReward) > 0)
            _withdrawFeesAndRewards(path[0], path[path.length - 1], referee, feeAmount, referralReward);
    }
    /// @dev execute swap directly on Uniswap/Pancake/...
    /// @param swapData stores the swapData information
    /// @param amountIn amount if tokens In
    /// @param amountOutMin minimum tokens to receive
    /// @param path Sell path.
    /// @return amounts
    function swapExactTokensForETH(
        SwapData calldata swapData,
        uint256 amountIn,
        uint256 amountOutMin,
        address[] calldata path
    )
        external
        whenNotPaused
        isValidFork(swapData.fork)
        isValidReferee(swapData.referee)
        returns (uint256[] memory amounts)
    {
        require(path[path.length - 1] == WETH, "FloozRouter: INVALID_PATH");
        address referee = _getReferee(swapData.referee);
        amounts = _getAmountsOut(swapData.fork, amountIn, path);
        (uint256 amountWithdraw, uint256 feeAmount, uint256 referralReward) = _calculateFeesAndRewards(
            swapData.fee,
            amounts[amounts.length - 1],
            referee,
            false
        );
        require(amountWithdraw >= amountOutMin, "FloozRouter: INSUFFICIENT_OUTPUT_AMOUNT");
        TransferHelper.safeTransferFrom(path[0], msg.sender, _pairFor(swapData.fork, path[0], path[1]), amounts[0]);
        _swap(swapData.fork, amounts, path, address(this));
        IWETH(WETH).withdraw(amounts[amounts.length - 1]);
        TransferHelper.safeTransferETH(msg.sender, amountWithdraw);
        if (feeAmount.add(referralReward) > 0)
            _withdrawFeesAndRewards(address(0), path[path.length - 1], referee, feeAmount, referralReward);
    }
    /// @dev execute swap directly on Uniswap/Pancake/...
    /// @param swapData stores the swapData information
    /// @param amountOut expected amount of tokens out
    /// @param path Sell path.
    /// @return amounts
    function swapETHForExactTokens(
        SwapData calldata swapData,
        uint256 amountOut,
        address[] calldata path
    )
        external
        payable
        whenNotPaused
        isValidFork(swapData.fork)
        isValidReferee(swapData.referee)
        returns (uint256[] memory amounts)
    {
        require(path[0] == WETH, "FloozRouter: INVALID_PATH");
        address referee = _getReferee(swapData.referee);
        amounts = _getAmountsIn(swapData.fork, amountOut, path);
        (, uint256 feeAmount, uint256 referralReward) = _calculateFeesAndRewards(
            swapData.fee,
            amounts[0],
            referee,
            true
        );
        require(amounts[0].add(feeAmount).add(referralReward) <= msg.value, "FloozRouter: EXCESSIVE_INPUT_AMOUNT");
        IWETH(WETH).deposit{value: amounts[0]}();
        assert(IWETH(WETH).transfer(_pairFor(swapData.fork, path[0], path[1]), amounts[0]));
        _swap(swapData.fork, amounts, path, msg.sender);
        // refund dust eth, if any
        if (msg.value > amounts[0].add(feeAmount).add(referralReward))
            TransferHelper.safeTransferETH(msg.sender, msg.value - amounts[0].add(feeAmount).add(referralReward));
        if (feeAmount.add(referralReward) > 0)
            _withdrawFeesAndRewards(address(0), path[path.length - 1], referee, feeAmount, referralReward);
    }
    /// @dev execute swap directly on Uniswap/Pancake/...
    /// @param swapData stores the swapData information
    /// @param amountIn amount if tokens In
    /// @param amountOutMin minimum tokens to receive
    /// @param path Sell path.
    function swapExactTokensForTokensSupportingFeeOnTransferTokens(
        SwapData calldata swapData,
        uint256 amountIn,
        uint256 amountOutMin,
        address[] calldata path
    ) external whenNotPaused isValidFork(swapData.fork) isValidReferee(swapData.referee) {
        address referee = _getReferee(swapData.referee);
        (uint256 swapAmount, uint256 feeAmount, uint256 referralReward) = _calculateFeesAndRewards(
            swapData.fee,
            amountIn,
            referee,
            false
        );
        TransferHelper.safeTransferFrom(path[0], msg.sender, _pairFor(swapData.fork, path[0], path[1]), swapAmount);
        uint256 balanceBefore = IERC20(path[path.length - 1]).balanceOf(msg.sender);
        _swapSupportingFeeOnTransferTokens(swapData.fork, path, msg.sender);
        require(
            IERC20(path[path.length - 1]).balanceOf(msg.sender).sub(balanceBefore) >= amountOutMin,
            "FloozRouter: INSUFFICIENT_OUTPUT_AMOUNT"
        );
        if (feeAmount.add(referralReward) > 0)
            _withdrawFeesAndRewards(path[0], path[path.length - 1], referee, feeAmount, referralReward);
    }
    /// @dev execute swap directly on Uniswap/Pancake/...
    /// @param swapData stores the swapData information
    /// @param amountOut expected tokens to receive
    /// @param amountInMax maximum tokens to send
    /// @param path Sell path.
    /// @return amounts
    function swapTokensForExactTokens(
        SwapData calldata swapData,
        uint256 amountOut,
        uint256 amountInMax,
        address[] calldata path
    )
        external
        whenNotPaused
        isValidFork(swapData.fork)
        isValidReferee(swapData.referee)
        returns (uint256[] memory amounts)
    {
        address referee = _getReferee(swapData.referee);
        amounts = _getAmountsIn(swapData.fork, amountOut, path);
        (, uint256 feeAmount, uint256 referralReward) = _calculateFeesAndRewards(
            swapData.fee,
            amounts[0],
            referee,
            true
        );
        require(amounts[0].add(feeAmount).add(referralReward) <= amountInMax, "FloozRouter: EXCESSIVE_INPUT_AMOUNT");
        TransferHelper.safeTransferFrom(path[0], msg.sender, _pairFor(swapData.fork, path[0], path[1]), amounts[0]);
        _swap(swapData.fork, amounts, path, msg.sender);
        if (feeAmount.add(referralReward) > 0)
            _withdrawFeesAndRewards(path[0], path[path.length - 1], referee, feeAmount, referralReward);
    }
    /// @dev execute swap directly on Uniswap/Pancake/...
    /// @param swapData stores the swapData information
    /// @param amountOut expected tokens to receive
    /// @param amountInMax maximum tokens to send
    /// @param path Sell path.
    /// @return amounts
    function swapTokensForExactETH(
        SwapData calldata swapData,
        uint256 amountOut,
        uint256 amountInMax,
        address[] calldata path
    )
        external
        whenNotPaused
        isValidFork(swapData.fork)
        isValidReferee(swapData.referee)
        returns (uint256[] memory amounts)
    {
        require(path[path.length - 1] == WETH, "FloozRouter: INVALID_PATH");
        address referee = _getReferee(swapData.referee);
        (, uint256 feeAmount, uint256 referralReward) = _calculateFeesAndRewards(
            swapData.fee,
            amountOut,
            referee,
            true
        );
        amounts = _getAmountsIn(swapData.fork, amountOut.add(feeAmount).add(referralReward), path);
        require(amounts[0].add(feeAmount).add(referralReward) <= amountInMax, "FloozRouter: EXCESSIVE_INPUT_AMOUNT");
        TransferHelper.safeTransferFrom(path[0], msg.sender, _pairFor(swapData.fork, path[0], path[1]), amounts[0]);
        _swap(swapData.fork, amounts, path, address(this));
        IWETH(WETH).withdraw(amounts[amounts.length - 1]);
        TransferHelper.safeTransferETH(msg.sender, amountOut);
        if (feeAmount.add(referralReward) > 0)
            _withdrawFeesAndRewards(address(0), path[path.length - 1], referee, feeAmount, referralReward);
    }
    /// @dev execute swap directly on Uniswap/Pancake/...
    /// @param swapData stores the swapData information
    /// @param amountOutMin minimum expected tokens to receive
    /// @param path Sell path.
    function swapExactETHForTokensSupportingFeeOnTransferTokens(
        SwapData calldata swapData,
        uint256 amountOutMin,
        address[] calldata path
    ) external payable whenNotPaused isValidFork(swapData.fork) isValidReferee(swapData.referee) {
        require(path[0] == WETH, "FloozRouter: INVALID_PATH");
        address referee = _getReferee(swapData.referee);
        (uint256 swapAmount, uint256 feeAmount, uint256 referralReward) = _calculateFeesAndRewards(
            swapData.fee,
            msg.value,
            referee,
            false
        );
        IWETH(WETH).deposit{value: swapAmount}();
        assert(IWETH(WETH).transfer(_pairFor(swapData.fork, path[0], path[1]), swapAmount));
        uint256 balanceBefore = IERC20(path[path.length - 1]).balanceOf(msg.sender);
        _swapSupportingFeeOnTransferTokens(swapData.fork, path, msg.sender);
        require(
            IERC20(path[path.length - 1]).balanceOf(msg.sender).sub(balanceBefore) >= amountOutMin,
            "FloozRouter: INSUFFICIENT_OUTPUT_AMOUNT"
        );
        if (feeAmount.add(referralReward) > 0)
            _withdrawFeesAndRewards(address(0), path[path.length - 1], referee, feeAmount, referralReward);
    }
    /// @dev returns the referee for a given address, if new, registers referee
    /// @param referee the address of the referee for msg.sender
    /// @return referee address from referral registry
    function _getReferee(address referee) internal returns (address) {
        address sender = msg.sender;
        if (!referralRegistry.hasUserReferee(sender) && referee != address(0)) {
            referralRegistry.createReferralAnchor(sender, referee);
        }
        return referralRegistry.getUserReferee(sender);
    }
    // **** SWAP ****
    // requires the initial amount to have already been sent to the first pair
    function _swap(
        address fork,
        uint256[] memory amounts,
        address[] memory path,
        address _to
    ) internal {
        for (uint256 i; i < path.length - 1; i++) {
            (address input, address output) = (path[i], path[i + 1]);
            (address token0, ) = PancakeLibrary.sortTokens(input, output);
            uint256 amountOut = amounts[i + 1];
            (uint256 amount0Out, uint256 amount1Out) = input == token0
                ? (uint256(0), amountOut)
                : (amountOut, uint256(0));
            address to = i < path.length - 2 ? _pairFor(fork, output, path[i + 2]) : _to;
            IPancakePair(_pairFor(fork, input, output)).swap(amount0Out, amount1Out, to, new bytes(0));
        }
    }
    // **** SWAP (supporting fee-on-transfer tokens) ****
    // requires the initial amount to have already been sent to the first pair
    function _swapSupportingFeeOnTransferTokens(
        address fork,
        address[] memory path,
        address _to
    ) internal {
        for (uint256 i; i < path.length - 1; i++) {
            (address input, address output) = (path[i], path[i + 1]);
            (address token0, ) = PancakeLibrary.sortTokens(input, output);
            IPancakePair pair = IPancakePair(_pairFor(fork, input, output));
            uint256 amountInput;
            uint256 amountOutput;
            {
                // scope to avoid stack too deep errors
                (uint256 reserve0, uint256 reserve1, ) = pair.getReserves();
                (uint256 reserveInput, uint256 reserveOutput) = input == token0
                    ? (reserve0, reserve1)
                    : (reserve1, reserve0);
                amountInput = IERC20(input).balanceOf(address(pair)).sub(reserveInput);
                amountOutput = _getAmountOut(amountInput, reserveInput, reserveOutput);
            }
            (uint256 amount0Out, uint256 amount1Out) = input == token0
                ? (uint256(0), amountOutput)
                : (amountOutput, uint256(0));
            address to = i < path.length - 2 ? _pairFor(fork, output, path[i + 2]) : _to;
            pair.swap(amount0Out, amount1Out, to, new bytes(0));
        }
    }
    /// @dev Executes a swap on 1inch
    /// @param swapData encoded swap data
    function executeOneInchSwap(ExternalSwapData calldata swapData)
        external
        payable
        nonReentrant
        whenNotPaused
        isValidReferee(swapData.referee)
    {
        address referee = _getReferee(swapData.referee);
        uint256 balanceBefore;
        if (swapData.toToken == address(0)) {
            balanceBefore = msg.sender.balance;
        } else {
            balanceBefore = IERC20(swapData.toToken).balanceOf(msg.sender);
        }
        if (!swapData.fee) {
            // execute without fees
            if (swapData.fromToken != address(0)) {
                IERC20(swapData.fromToken).transferFrom(msg.sender, address(this), swapData.amountFrom);
                IERC20(swapData.fromToken).approve(oneInch, swapData.amountFrom);
            }
            // executes trade and sends toToken to defined recipient
            (bool success, ) = address(oneInch).call{value: msg.value}(swapData.data);
            require(success, "FloozRouter: REVERTED");
        } else {
            // Swap from ETH
            if (msg.value > 0 && swapData.fromToken == address(0)) {
                (uint256 swapAmount, uint256 feeAmount, uint256 referralReward) = _calculateFeesAndRewards(
                    swapData.fee,
                    msg.value,
                    referee,
                    false
                );
                (bool success, ) = address(oneInch).call{value: swapAmount}(swapData.data);
                require(success, "FloozRouter: REVERTED");
                _withdrawFeesAndRewards(address(0), swapData.toToken, referee, feeAmount, referralReward);
                // Swap from token
            } else {
                (uint256 swapAmount, uint256 feeAmount, uint256 referralReward) = _calculateFeesAndRewards(
                    swapData.fee,
                    swapData.amountFrom,
                    referee,
                    false
                );
                IERC20(swapData.fromToken).transferFrom(msg.sender, address(this), swapAmount);
                IERC20(swapData.fromToken).approve(oneInch, swapAmount);
                (bool success, ) = address(oneInch).call(swapData.data);
                require(success, "FloozRouter: REVERTED");
                _withdrawFeesAndRewards(swapData.fromToken, swapData.toToken, referee, feeAmount, referralReward);
            }
            uint256 balanceAfter;
            if (swapData.toToken == address(0)) {
                balanceAfter = msg.sender.balance;
            } else {
                balanceAfter = IERC20(swapData.toToken).balanceOf(msg.sender);
            }
            require(balanceAfter.sub(balanceBefore) >= swapData.minOut, "FloozRouter: INSUFFICIENT_OUTPUT");
        }
    }
    /// @dev Executes a swap on 0x
    /// @param swapData encoded swap data
    function executeZeroExSwap(ExternalSwapData calldata swapData)
        external
        payable
        nonReentrant
        whenNotPaused
        isValidReferee(swapData.referee)
    {
        address referee = _getReferee(swapData.referee);
        uint256 balanceBefore;
        if (swapData.toToken == address(0)) {
            balanceBefore = msg.sender.balance;
        } else {
            balanceBefore = IERC20(swapData.toToken).balanceOf(msg.sender);
        }
        if (!swapData.fee) {
            if (msg.value > 0 && swapData.fromToken == address(0)) {
                (bool success, ) = zeroEx.call{value: msg.value}(swapData.data);
                require(success, "FloozRouter: REVERTED");
                TransferHelper.safeTransfer(
                    swapData.toToken,
                    msg.sender,
                    IERC20(swapData.toToken).balanceOf(address(this))
                );
            } else {
                IERC20(swapData.fromToken).transferFrom(msg.sender, address(this), swapData.amountFrom);
                IERC20(swapData.fromToken).approve(zeroEx, swapData.amountFrom);
                (bool success, ) = zeroEx.call(swapData.data);
                require(success, "FloozRouter: REVERTED");
                if (swapData.toToken == address(0)) {
                    TransferHelper.safeTransferETH(msg.sender, address(this).balance);
                } else {
                    TransferHelper.safeTransfer(
                        swapData.toToken,
                        msg.sender,
                        IERC20(swapData.toToken).balanceOf(address(this))
                    );
                }
            }
        } else {
            // Swap from ETH
            if (msg.value > 0 && swapData.fromToken == address(0)) {
                (uint256 swapAmount, uint256 feeAmount, uint256 referralReward) = _calculateFeesAndRewards(
                    swapData.fee,
                    msg.value,
                    referee,
                    false
                );
                (bool success, ) = zeroEx.call{value: swapAmount}(swapData.data);
                require(success, "FloozRouter: REVERTED");
                TransferHelper.safeTransfer(
                    swapData.toToken,
                    msg.sender,
                    IERC20(swapData.toToken).balanceOf(address(this))
                );
                _withdrawFeesAndRewards(address(0), swapData.toToken, referee, feeAmount, referralReward);
                // Swap from Token
            } else {
                (uint256 swapAmount, uint256 feeAmount, uint256 referralReward) = _calculateFeesAndRewards(
                    swapData.fee,
                    swapData.amountFrom,
                    referee,
                    false
                );
                IERC20(swapData.fromToken).transferFrom(msg.sender, address(this), swapAmount);
                IERC20(swapData.fromToken).approve(zeroEx, swapAmount);
                (bool success, ) = zeroEx.call(swapData.data);
                require(success, "FloozRouter: REVERTED");
                if (swapData.toToken == address(0)) {
                    TransferHelper.safeTransferETH(msg.sender, address(this).balance);
                } else {
                    TransferHelper.safeTransfer(
                        swapData.toToken,
                        msg.sender,
                        IERC20(swapData.toToken).balanceOf(address(this))
                    );
                }
                _withdrawFeesAndRewards(swapData.fromToken, swapData.toToken, referee, feeAmount, referralReward);
            }
        }
        uint256 balanceAfter;
        if (swapData.toToken == address(0)) {
            balanceAfter = msg.sender.balance;
        } else {
            balanceAfter = IERC20(swapData.toToken).balanceOf(msg.sender);
        }
        require(balanceAfter.sub(balanceBefore) >= swapData.minOut, "FloozRouter: INSUFFICIENT_OUTPUT");
    }
    /// @dev calculates swap, fee & reward amounts
    /// @param fee boolean if fee will be applied or not
    /// @param amount total amount of tokens
    /// @param referee the address of the referee for msg.sender
    function _calculateFeesAndRewards(
        bool fee,
        uint256 amount,
        address referee,
        bool additiveFee
    )
        internal
        view
        returns (
            uint256 swapAmount,
            uint256 feeAmount,
            uint256 referralReward
        )
    {
        uint16 swapFee = swapFee;
        // no fees for users above threshold
        if (!fee) {
            swapAmount = amount;
        } else {
            if (additiveFee) {
                swapAmount = amount;
                feeAmount = swapAmount.mul(FEE_DENOMINATOR).div(FEE_DENOMINATOR.sub(swapFee)).sub(amount);
            } else {
                feeAmount = amount.mul(swapFee).div(FEE_DENOMINATOR);
                swapAmount = amount.sub(feeAmount);
            }
            // calculate referral rates, if referee is not 0x
            if (referee != address(0) && referralsActivated) {
                uint16 referralRate = customReferralRewardRate[referee] > 0
                    ? customReferralRewardRate[referee]
                    : referralRewardRate;
                referralReward = feeAmount.mul(referralRate).div(FEE_DENOMINATOR);
                feeAmount = feeAmount.sub(referralReward);
            } else {
                referralReward = 0;
            }
        }
    }
    /// @dev lets the admin register an Uniswap style fork
    function registerFork(address _factory, bytes calldata _initCode) external onlyOwner {
        require(!forkActivated[_factory], "FloozRouter: ACTIVE_FORK");
        forkActivated[_factory] = true;
        forkInitCode[_factory] = _initCode;
        emit ForkCreated(_factory);
    }
    /// @dev lets the admin update an Uniswap style fork
    function updateFork(
        address _factory,
        bytes calldata _initCode,
        bool _activated
    ) external onlyOwner {
        forkActivated[_factory] = _activated;
        forkInitCode[_factory] = _initCode;
        emit ForkUpdated(_factory);
    }
    /// @dev lets the admin update the swapFee nominator
    function updateSwapFee(uint16 newSwapFee) external onlyOwner {
        swapFee = newSwapFee;
        emit SwapFeeUpdated(newSwapFee);
    }
    /// @dev lets the admin update the referral reward rate
    function updateReferralRewardRate(uint16 newReferralRewardRate) external onlyOwner {
        require(newReferralRewardRate <= FEE_DENOMINATOR, "FloozRouter: INVALID_RATE");
        referralRewardRate = newReferralRewardRate;
        emit ReferralRewardRateUpdated(newReferralRewardRate);
    }
    /// @dev lets the admin update which address receives the protocol fees
    function updateFeeReceiver(address payable newFeeReceiver) external onlyOwner {
        feeReceiver = newFeeReceiver;
        emit FeeReceiverUpdated(newFeeReceiver);
    }
    /// @dev lets the admin update the status of the referral system
    function updateReferralsActivated(bool newReferralsActivated) external onlyOwner {
        referralsActivated = newReferralsActivated;
        emit ReferralsActivatedUpdated(newReferralsActivated);
    }
    /// @dev lets the admin set a new referral registry
    function updateReferralRegistry(address newReferralRegistry) external onlyOwner {
        referralRegistry = IReferralRegistry(newReferralRegistry);
        emit ReferralRegistryUpdated(newReferralRegistry);
    }
    /// @dev lets the admin set a custom referral rate
    function updateCustomReferralRewardRate(address account, uint16 referralRate) external onlyOwner returns (uint256) {
        require(referralRate <= FEE_DENOMINATOR, "FloozRouter: INVALID_RATE");
        customReferralRewardRate[account] = referralRate;
        emit CustomReferralRewardRateUpdated(account, referralRate);
    }
    /// @dev returns the referee for a given user - 0x address if none
    function getUserReferee(address user) external view returns (address) {
        return referralRegistry.getUserReferee(user);
    }
    /// @dev returns if the given user has been referred or not
    function hasUserReferee(address user) external view returns (bool) {
        return referralRegistry.hasUserReferee(user);
    }
    /// @dev lets the admin withdraw ETH from the contract.
    function withdrawETH(address payable to, uint256 amount) external onlyOwner {
        TransferHelper.safeTransferETH(to, amount);
    }
    /// @dev lets the admin withdraw ERC20s from the contract.
    function withdrawERC20Token(
        address token,
        address to,
        uint256 amount
    ) external onlyOwner {
        TransferHelper.safeTransfer(token, to, amount);
    }
    /// @dev distributes fees & referral rewards to users
    function _withdrawFeesAndRewards(
        address tokenReward,
        address tokenOut,
        address referee,
        uint256 feeAmount,
        uint256 referralReward
    ) internal {
        if (tokenReward == address(0)) {
            TransferHelper.safeTransferETH(feeReceiver, feeAmount);
            if (referralReward > 0) {
                TransferHelper.safeTransferETH(referee, referralReward);
                emit ReferralRewardPaid(msg.sender, referee, tokenOut, tokenReward, referralReward);
            }
        } else {
            TransferHelper.safeTransferFrom(tokenReward, msg.sender, feeReceiver, feeAmount);
            if (referralReward > 0) {
                TransferHelper.safeTransferFrom(tokenReward, msg.sender, referee, referralReward);
                emit ReferralRewardPaid(msg.sender, referee, tokenOut, tokenReward, referralReward);
            }
        }
    }
    /// @dev given an input amount of an asset and pair reserves, returns the maximum output amount of the other asset
    function _getAmountOut(
        uint256 amountIn,
        uint256 reserveIn,
        uint256 reserveOut
    ) internal pure returns (uint256 amountOut) {
        require(amountIn > 0, "FloozRouter: INSUFFICIENT_INPUT_AMOUNT");
        require(reserveIn > 0 && reserveOut > 0, "FloozRouter: INSUFFICIENT_LIQUIDITY");
        uint256 amountInWithFee = amountIn.mul((9970));
        uint256 numerator = amountInWithFee.mul(reserveOut);
        uint256 denominator = reserveIn.mul(10000).add(amountInWithFee);
        amountOut = numerator / denominator;
    }
    /// @dev given an output amount of an asset and pair reserves, returns a required input amount of the other asset
    function _getAmountIn(
        uint256 amountOut,
        uint256 reserveIn,
        uint256 reserveOut
    ) internal pure returns (uint256 amountIn) {
        require(amountOut > 0, "FloozRouter: INSUFFICIENT_OUTPUT_AMOUNT");
        require(reserveIn > 0 && reserveOut > 0, "FloozRouter: INSUFFICIENT_LIQUIDITY");
        uint256 numerator = reserveIn.mul(amountOut).mul(10000);
        uint256 denominator = reserveOut.sub(amountOut).mul(9970);
        amountIn = (numerator / denominator).add(1);
    }
    /// @dev performs chained getAmountOut calculations on any number of pairs
    function _getAmountsOut(
        address fork,
        uint256 amountIn,
        address[] memory path
    ) internal view returns (uint256[] memory amounts) {
        require(path.length >= 2, "FloozRouter: INVALID_PATH");
        amounts = new uint256[](path.length);
        amounts[0] = amountIn;
        for (uint256 i; i < path.length - 1; i++) {
            (uint256 reserveIn, uint256 reserveOut) = _getReserves(fork, path[i], path[i + 1]);
            amounts[i + 1] = _getAmountOut(amounts[i], reserveIn, reserveOut);
        }
    }
    /// @dev performs chained getAmountIn calculations on any number of pairs
    function _getAmountsIn(
        address factory,
        uint256 amountOut,
        address[] memory path
    ) internal view returns (uint256[] memory amounts) {
        require(path.length >= 2, "FloozRouter: INVALID_PATH");
        amounts = new uint256[](path.length);
        amounts[amounts.length - 1] = amountOut;
        for (uint256 i = path.length - 1; i > 0; i--) {
            (uint256 reserveIn, uint256 reserveOut) = _getReserves(factory, path[i - 1], path[i]);
            amounts[i - 1] = _getAmountIn(amounts[i], reserveIn, reserveOut);
        }
    }
    /// @dev fetches and sorts the reserves for a pair
    function _getReserves(
        address factory,
        address tokenA,
        address tokenB
    ) internal view returns (uint256 reserveA, uint256 reserveB) {
        (address token0, ) = PancakeLibrary.sortTokens(tokenA, tokenB);
        (uint256 reserve0, uint256 reserve1, ) = IPancakePair(_pairFor(factory, tokenA, tokenB)).getReserves();
        (reserveA, reserveB) = tokenA == token0 ? (reserve0, reserve1) : (reserve1, reserve0);
    }
    /// @dev calculates the CREATE2 address for a pair without making any external calls
    function _pairFor(
        address factory,
        address tokenA,
        address tokenB
    ) internal view returns (address pair) {
        (address token0, address token1) = PancakeLibrary.sortTokens(tokenA, tokenB);
        pair = address(
            uint256(
                keccak256(
                    abi.encodePacked(
                        hex"ff",
                        factory,
                        keccak256(abi.encodePacked(token0, token1)),
                        forkInitCode[factory] // init code hash
                    )
                )
            )
        );
    }
    /// @dev lets the admin pause this contract
    function pause() external onlyOwner {
        _pause();
    }
    /// @dev lets the admin unpause this contract
    function unpause() external onlyOwner {
        _unpause();
    }
    /// @dev allows to receive ETH on the contract
    receive() external payable {}
    modifier isValidFork(address factory) {
        require(forkActivated[factory], "FloozRouter: INVALID_FACTORY");
        _;
    }
    modifier isValidReferee(address referee) {
        require(msg.sender != referee, "FloozRouter: SELF_REFERRAL");
        _;
    }
}
pragma solidity =0.6.6;
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
import "./libraries/TransferHelper.sol";
import "./interfaces/IWETH.sol";
contract FeeReceiverMultichain is Ownable {
    address public WETH;
    constructor(address _WETH) public {
        WETH = _WETH;
    }
    /// @dev converts WETH to ETH
    function unwrapWETH() public {
        uint256 balance = IWETH(WETH).balanceOf(address(this));
        require(balance > 0, "FeeReceiver: Nothing to unwrap");
        IWETH(WETH).withdraw(balance);
    }
    /// @dev lets the owner withdraw ETH from the contract
    function withdrawETH(address payable to, uint256 amount) external onlyOwner {
        to.transfer(amount);
    }
    /// @dev lets the owner withdraw any ERC20 Token from the contract
    function withdrawERC20Token(
        address token,
        address to,
        uint256 amount
    ) external onlyOwner {
        IERC20(token).transfer(to, amount);
    }
    /// @dev allows to receive ETH on this contract
    receive() external payable {}
}
pragma solidity =0.6.6;
import "@openzeppelin/contracts/access/Ownable.sol";
contract ReferralRegistry is Ownable {
    event ReferralAnchorCreated(address indexed user, address indexed referee);
    event ReferralAnchorUpdated(address indexed user, address indexed referee);
    event AnchorManagerUpdated(address account, bool isManager);
    // stores addresses which are allowed to create new anchors
    mapping(address => bool) public isAnchorManager;
    // stores the address that referred a given user
    mapping(address => address) public referralAnchor;
    /// @dev create a new referral anchor on the registry
    /// @param _user address of the user
    /// @param _referee address wich referred the user
    function createReferralAnchor(address _user, address _referee) external onlyAnchorManager {
        require(referralAnchor[_user] == address(0), "ReferralRegistry: ANCHOR_EXISTS");
        referralAnchor[_user] = _referee;
        emit ReferralAnchorCreated(_user, _referee);
    }
    /// @dev allows admin to overwrite anchor
    /// @param _user address of the user
    /// @param _referee address wich referred the user
    function updateReferralAnchor(address _user, address _referee) external onlyOwner {
        referralAnchor[_user] = _referee;
        emit ReferralAnchorUpdated(_user, _referee);
    }
    /// @dev allows admin to grant/remove anchor priviliges
    /// @param _anchorManager address of the anchor manager
    /// @param _isManager add or remove privileges
    function updateAnchorManager(address _anchorManager, bool _isManager) external onlyOwner {
        isAnchorManager[_anchorManager] = _isManager;
        emit AnchorManagerUpdated(_anchorManager, _isManager);
    }
    function getUserReferee(address _user) external view returns (address) {
        return referralAnchor[_user];
    }
    function hasUserReferee(address _user) external view returns (bool) {
        return referralAnchor[_user] != address(0);
    }
    modifier onlyAnchorManager() {
        require(isAnchorManager[msg.sender], "ReferralRegistry: FORBIDDEN");
        _;
    }
}

// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0 <0.8.0;
import "../utils/Context.sol";
/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. This
 * can later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
abstract contract Ownable is Context {
    address private _owner;
    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor () internal {
        address msgSender = _msgSender();
        _owner = msgSender;
        emit OwnershipTransferred(address(0), msgSender);
    }
    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view virtual returns (address) {
        return _owner;
    }
    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
        _;
    }
    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions anymore. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby removing any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        emit OwnershipTransferred(_owner, address(0));
        _owner = address(0);
    }
    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
    }
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0 <0.8.0;
/*
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with GSN meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address payable) {
        return msg.sender;
    }
    function _msgData() internal view virtual returns (bytes memory) {
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        return msg.data;
    }
}
pragma solidity =0.6.6;
import "@openzeppelin/contracts/access/Ownable.sol";
contract ReferralRegistry is Ownable {
    event ReferralAnchorCreated(address indexed user, address indexed referee);
    event ReferralAnchorUpdated(address indexed user, address indexed referee);
    event AnchorManagerUpdated(address account, bool isManager);
    // stores addresses which are allowed to create new anchors
    mapping(address => bool) public isAnchorManager;
    // stores the address that referred a given user
    mapping(address => address) public referralAnchor;
    /// @dev create a new referral anchor on the registry
    /// @param _user address of the user
    /// @param _referee address wich referred the user
    function createReferralAnchor(address _user, address _referee) external onlyAnchorManager {
        require(referralAnchor[_user] == address(0), "ReferralRegistry: ANCHOR_EXISTS");
        referralAnchor[_user] = _referee;
        emit ReferralAnchorCreated(_user, _referee);
    }
    /// @dev allows admin to overwrite anchor
    /// @param _user address of the user
    /// @param _referee address wich referred the user
    function updateReferralAnchor(address _user, address _referee) external onlyOwner {
        referralAnchor[_user] = _referee;
        emit ReferralAnchorUpdated(_user, _referee);
    }
    /// @dev allows admin to grant/remove anchor priviliges
    /// @param _anchorManager address of the anchor manager
    /// @param _isManager add or remove privileges
    function updateAnchorManager(address _anchorManager, bool _isManager) external onlyOwner {
        isAnchorManager[_anchorManager] = _isManager;
        emit AnchorManagerUpdated(_anchorManager, _isManager);
    }
    function getUserReferee(address _user) external view returns (address) {
        return referralAnchor[_user];
    }
    function hasUserReferee(address _user) external view returns (bool) {
        return referralAnchor[_user] != address(0);
    }
    modifier onlyAnchorManager() {
        require(isAnchorManager[msg.sender], "ReferralRegistry: FORBIDDEN");
        _;
    }
}

pragma solidity 0.4.24;

// File: node_modules/zeppelin-solidity/contracts/ownership/Ownable.sol

/**
 * @title Ownable
 * @dev The Ownable contract has an owner address, and provides basic authorization control
 * functions, this simplifies the implementation of "user permissions".
 */
contract Ownable {
  address public owner;


  event OwnershipRenounced(address indexed previousOwner);
  event OwnershipTransferred(
    address indexed previousOwner,
    address indexed newOwner
  );


  /**
   * @dev The Ownable constructor sets the original `owner` of the contract to the sender
   * account.
   */
  constructor() public {
    owner = msg.sender;
  }

  /**
   * @dev Throws if called by any account other than the owner.
   */
  modifier onlyOwner() {
    require(msg.sender == owner);
    _;
  }

  /**
   * @dev Allows the current owner to relinquish control of the contract.
   * @notice Renouncing to ownership will leave the contract without an owner.
   * It will not be possible to call the functions with the `onlyOwner`
   * modifier anymore.
   */
  function renounceOwnership() public onlyOwner {
    emit OwnershipRenounced(owner);
    owner = address(0);
  }

  /**
   * @dev Allows the current owner to transfer control of the contract to a newOwner.
   * @param _newOwner The address to transfer ownership to.
   */
  function transferOwnership(address _newOwner) public onlyOwner {
    _transferOwnership(_newOwner);
  }

  /**
   * @dev Transfers control of the contract to a newOwner.
   * @param _newOwner The address to transfer ownership to.
   */
  function _transferOwnership(address _newOwner) internal {
    require(_newOwner != address(0));
    emit OwnershipTransferred(owner, _newOwner);
    owner = _newOwner;
  }
}

// File: node_modules/zeppelin-solidity/contracts/math/SafeMath.sol

/**
 * @title SafeMath
 * @dev Math operations with safety checks that throw on error
 */
library SafeMath {

  /**
  * @dev Multiplies two numbers, throws on overflow.
  */
  function mul(uint256 a, uint256 b) internal pure returns (uint256 c) {
    // Gas optimization: this is cheaper than asserting 'a' not being zero, but the
    // benefit is lost if 'b' is also tested.
    // See: https://github.com/OpenZeppelin/openzeppelin-solidity/pull/522
    if (a == 0) {
      return 0;
    }

    c = a * b;
    assert(c / a == b);
    return c;
  }

  /**
  * @dev Integer division of two numbers, truncating the quotient.
  */
  function div(uint256 a, uint256 b) internal pure returns (uint256) {
    // assert(b > 0); // Solidity automatically throws when dividing by 0
    // uint256 c = a / b;
    // assert(a == b * c + a % b); // There is no case in which this doesn't hold
    return a / b;
  }

  /**
  * @dev Subtracts two numbers, throws on overflow (i.e. if subtrahend is greater than minuend).
  */
  function sub(uint256 a, uint256 b) internal pure returns (uint256) {
    assert(b <= a);
    return a - b;
  }

  /**
  * @dev Adds two numbers, throws on overflow.
  */
  function add(uint256 a, uint256 b) internal pure returns (uint256 c) {
    c = a + b;
    assert(c >= a);
    return c;
  }
}

// File: node_modules/zeppelin-solidity/contracts/token/ERC20/ERC20Basic.sol

/**
 * @title ERC20Basic
 * @dev Simpler version of ERC20 interface
 * See https://github.com/ethereum/EIPs/issues/179
 */
contract ERC20Basic {
  function totalSupply() public view returns (uint256);
  function balanceOf(address who) public view returns (uint256);
  function transfer(address to, uint256 value) public returns (bool);
  event Transfer(address indexed from, address indexed to, uint256 value);
}

// File: node_modules/zeppelin-solidity/contracts/token/ERC20/BasicToken.sol

/**
 * @title Basic token
 * @dev Basic version of StandardToken, with no allowances.
 */
contract BasicToken is ERC20Basic {
  using SafeMath for uint256;

  mapping(address => uint256) balances;

  uint256 totalSupply_;

  /**
  * @dev Total number of tokens in existence
  */
  function totalSupply() public view returns (uint256) {
    return totalSupply_;
  }

  /**
  * @dev Transfer token for a specified address
  * @param _to The address to transfer to.
  * @param _value The amount to be transferred.
  */
  function transfer(address _to, uint256 _value) public returns (bool) {
    require(_to != address(0));
    require(_value <= balances[msg.sender]);

    balances[msg.sender] = balances[msg.sender].sub(_value);
    balances[_to] = balances[_to].add(_value);
    emit Transfer(msg.sender, _to, _value);
    return true;
  }

  /**
  * @dev Gets the balance of the specified address.
  * @param _owner The address to query the the balance of.
  * @return An uint256 representing the amount owned by the passed address.
  */
  function balanceOf(address _owner) public view returns (uint256) {
    return balances[_owner];
  }

}

// File: node_modules/zeppelin-solidity/contracts/token/ERC20/ERC20.sol

/**
 * @title ERC20 interface
 * @dev see https://github.com/ethereum/EIPs/issues/20
 */
contract ERC20 is ERC20Basic {
  function allowance(address owner, address spender)
    public view returns (uint256);

  function transferFrom(address from, address to, uint256 value)
    public returns (bool);

  function approve(address spender, uint256 value) public returns (bool);
  event Approval(
    address indexed owner,
    address indexed spender,
    uint256 value
  );
}

// File: node_modules/zeppelin-solidity/contracts/token/ERC20/StandardToken.sol

/**
 * @title Standard ERC20 token
 *
 * @dev Implementation of the basic standard token.
 * https://github.com/ethereum/EIPs/issues/20
 * Based on code by FirstBlood: https://github.com/Firstbloodio/token/blob/master/smart_contract/FirstBloodToken.sol
 */
contract StandardToken is ERC20, BasicToken {

  mapping (address => mapping (address => uint256)) internal allowed;


  /**
   * @dev Transfer tokens from one address to another
   * @param _from address The address which you want to send tokens from
   * @param _to address The address which you want to transfer to
   * @param _value uint256 the amount of tokens to be transferred
   */
  function transferFrom(
    address _from,
    address _to,
    uint256 _value
  )
    public
    returns (bool)
  {
    require(_to != address(0));
    require(_value <= balances[_from]);
    require(_value <= allowed[_from][msg.sender]);

    balances[_from] = balances[_from].sub(_value);
    balances[_to] = balances[_to].add(_value);
    allowed[_from][msg.sender] = allowed[_from][msg.sender].sub(_value);
    emit Transfer(_from, _to, _value);
    return true;
  }

  /**
   * @dev Approve the passed address to spend the specified amount of tokens on behalf of msg.sender.
   * Beware that changing an allowance with this method brings the risk that someone may use both the old
   * and the new allowance by unfortunate transaction ordering. One possible solution to mitigate this
   * race condition is to first reduce the spender's allowance to 0 and set the desired value afterwards:
   * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
   * @param _spender The address which will spend the funds.
   * @param _value The amount of tokens to be spent.
   */
  function approve(address _spender, uint256 _value) public returns (bool) {
    allowed[msg.sender][_spender] = _value;
    emit Approval(msg.sender, _spender, _value);
    return true;
  }

  /**
   * @dev Function to check the amount of tokens that an owner allowed to a spender.
   * @param _owner address The address which owns the funds.
   * @param _spender address The address which will spend the funds.
   * @return A uint256 specifying the amount of tokens still available for the spender.
   */
  function allowance(
    address _owner,
    address _spender
   )
    public
    view
    returns (uint256)
  {
    return allowed[_owner][_spender];
  }

  /**
   * @dev Increase the amount of tokens that an owner allowed to a spender.
   * approve should be called when allowed[_spender] == 0. To increment
   * allowed value is better to use this function to avoid 2 calls (and wait until
   * the first transaction is mined)
   * From MonolithDAO Token.sol
   * @param _spender The address which will spend the funds.
   * @param _addedValue The amount of tokens to increase the allowance by.
   */
  function increaseApproval(
    address _spender,
    uint256 _addedValue
  )
    public
    returns (bool)
  {
    allowed[msg.sender][_spender] = (
      allowed[msg.sender][_spender].add(_addedValue));
    emit Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
    return true;
  }

  /**
   * @dev Decrease the amount of tokens that an owner allowed to a spender.
   * approve should be called when allowed[_spender] == 0. To decrement
   * allowed value is better to use this function to avoid 2 calls (and wait until
   * the first transaction is mined)
   * From MonolithDAO Token.sol
   * @param _spender The address which will spend the funds.
   * @param _subtractedValue The amount of tokens to decrease the allowance by.
   */
  function decreaseApproval(
    address _spender,
    uint256 _subtractedValue
  )
    public
    returns (bool)
  {
    uint256 oldValue = allowed[msg.sender][_spender];
    if (_subtractedValue > oldValue) {
      allowed[msg.sender][_spender] = 0;
    } else {
      allowed[msg.sender][_spender] = oldValue.sub(_subtractedValue);
    }
    emit Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
    return true;
  }

}

// File: node_modules/zeppelin-solidity/contracts/token/ERC20/MintableToken.sol

/**
 * @title Mintable token
 * @dev Simple ERC20 Token example, with mintable token creation
 * Based on code by TokenMarketNet: https://github.com/TokenMarketNet/ico/blob/master/contracts/MintableToken.sol
 */
contract MintableToken is StandardToken, Ownable {
  event Mint(address indexed to, uint256 amount);
  event MintFinished();

  bool public mintingFinished = false;


  modifier canMint() {
    require(!mintingFinished);
    _;
  }

  modifier hasMintPermission() {
    require(msg.sender == owner);
    _;
  }

  /**
   * @dev Function to mint tokens
   * @param _to The address that will receive the minted tokens.
   * @param _amount The amount of tokens to mint.
   * @return A boolean that indicates if the operation was successful.
   */
  function mint(
    address _to,
    uint256 _amount
  )
    hasMintPermission
    canMint
    public
    returns (bool)
  {
    totalSupply_ = totalSupply_.add(_amount);
    balances[_to] = balances[_to].add(_amount);
    emit Mint(_to, _amount);
    emit Transfer(address(0), _to, _amount);
    return true;
  }

  /**
   * @dev Function to stop minting new tokens.
   * @return True if the operation was successful.
   */
  function finishMinting() onlyOwner canMint public returns (bool) {
    mintingFinished = true;
    emit MintFinished();
    return true;
  }
}

// File: node_modules/zeppelin-solidity/contracts/token/ERC20/CappedToken.sol

/**
 * @title Capped token
 * @dev Mintable token with a token cap.
 */
contract CappedToken is MintableToken {

  uint256 public cap;

  constructor(uint256 _cap) public {
    require(_cap > 0);
    cap = _cap;
  }

  /**
   * @dev Function to mint tokens
   * @param _to The address that will receive the minted tokens.
   * @param _amount The amount of tokens to mint.
   * @return A boolean that indicates if the operation was successful.
   */
  function mint(
    address _to,
    uint256 _amount
  )
    public
    returns (bool)
  {
    require(totalSupply_.add(_amount) <= cap);

    return super.mint(_to, _amount);
  }

}

// File: contracts/FlameToken.sol

contract FlameToken is CappedToken {

    string public constant name = "Flame";
    string public constant symbol = "XFL";
    uint8 public constant decimals = 18;

    constructor(uint _cap) public CappedToken(_cap) {
        
    }

    /// @notice Makes sure a spending racing approve attack will not occur.
    /// @notice Call this only after you decreased the approve to zero using decreaseApproval.
    function safeApprove(address _spender, uint256 _value) public returns (bool) {
        require(allowed[msg.sender][_spender] == 0 || _value == 0);
        require(approve(_spender, _value));
    }

}

/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-utils/contracts/src/v06/LibBytesV06.sol";
import "./migrations/LibBootstrap.sol";
import "./features/Bootstrap.sol";
import "./storage/LibProxyStorage.sol";
import "./errors/LibProxyRichErrors.sol";
/// @dev An extensible proxy contract that serves as a universal entry point for
///      interacting with the 0x protocol.
contract ZeroEx {
    // solhint-disable separate-by-one-line-in-contract,indent,var-name-mixedcase
    using LibBytesV06 for bytes;
    /// @dev Construct this contract and register the `Bootstrap` feature.
    ///      After constructing this contract, `bootstrap()` should be called
    ///      to seed the initial feature set.
    constructor() public {
        // Temporarily create and register the bootstrap feature.
        // It will deregister itself after `bootstrap()` has been called.
        Bootstrap bootstrap = new Bootstrap(msg.sender);
        LibProxyStorage.getStorage().impls[bootstrap.bootstrap.selector] =
            address(bootstrap);
    }
    // solhint-disable state-visibility
    /// @dev Forwards calls to the appropriate implementation contract.
    fallback() external payable {
        bytes4 selector = msg.data.readBytes4(0);
        address impl = getFunctionImplementation(selector);
        if (impl == address(0)) {
            _revertWithData(LibProxyRichErrors.NotImplementedError(selector));
        }
        (bool success, bytes memory resultData) = impl.delegatecall(msg.data);
        if (!success) {
            _revertWithData(resultData);
        }
        _returnWithData(resultData);
    }
    /// @dev Fallback for just receiving ether.
    receive() external payable {}
    // solhint-enable state-visibility
    /// @dev Get the implementation contract of a registered function.
    /// @param selector The function selector.
    /// @return impl The implementation contract address.
    function getFunctionImplementation(bytes4 selector)
        public
        view
        returns (address impl)
    {
        return LibProxyStorage.getStorage().impls[selector];
    }
    /// @dev Revert with arbitrary bytes.
    /// @param data Revert data.
    function _revertWithData(bytes memory data) private pure {
        assembly { revert(add(data, 32), mload(data)) }
    }
    /// @dev Return with arbitrary bytes.
    /// @param data Return data.
    function _returnWithData(bytes memory data) private pure {
        assembly { return(add(data, 32), mload(data)) }
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
import "./errors/LibBytesRichErrorsV06.sol";
import "./errors/LibRichErrorsV06.sol";
library LibBytesV06 {
    using LibBytesV06 for bytes;
    /// @dev Gets the memory address for a byte array.
    /// @param input Byte array to lookup.
    /// @return memoryAddress Memory address of byte array. This
    ///         points to the header of the byte array which contains
    ///         the length.
    function rawAddress(bytes memory input)
        internal
        pure
        returns (uint256 memoryAddress)
    {
        assembly {
            memoryAddress := input
        }
        return memoryAddress;
    }
    /// @dev Gets the memory address for the contents of a byte array.
    /// @param input Byte array to lookup.
    /// @return memoryAddress Memory address of the contents of the byte array.
    function contentAddress(bytes memory input)
        internal
        pure
        returns (uint256 memoryAddress)
    {
        assembly {
            memoryAddress := add(input, 32)
        }
        return memoryAddress;
    }
    /// @dev Copies `length` bytes from memory location `source` to `dest`.
    /// @param dest memory address to copy bytes to.
    /// @param source memory address to copy bytes from.
    /// @param length number of bytes to copy.
    function memCopy(
        uint256 dest,
        uint256 source,
        uint256 length
    )
        internal
        pure
    {
        if (length < 32) {
            // Handle a partial word by reading destination and masking
            // off the bits we are interested in.
            // This correctly handles overlap, zero lengths and source == dest
            assembly {
                let mask := sub(exp(256, sub(32, length)), 1)
                let s := and(mload(source), not(mask))
                let d := and(mload(dest), mask)
                mstore(dest, or(s, d))
            }
        } else {
            // Skip the O(length) loop when source == dest.
            if (source == dest) {
                return;
            }
            // For large copies we copy whole words at a time. The final
            // word is aligned to the end of the range (instead of after the
            // previous) to handle partial words. So a copy will look like this:
            //
            //  ####
            //      ####
            //          ####
            //            ####
            //
            // We handle overlap in the source and destination range by
            // changing the copying direction. This prevents us from
            // overwriting parts of source that we still need to copy.
            //
            // This correctly handles source == dest
            //
            if (source > dest) {
                assembly {
                    // We subtract 32 from `sEnd` and `dEnd` because it
                    // is easier to compare with in the loop, and these
                    // are also the addresses we need for copying the
                    // last bytes.
                    length := sub(length, 32)
                    let sEnd := add(source, length)
                    let dEnd := add(dest, length)
                    // Remember the last 32 bytes of source
                    // This needs to be done here and not after the loop
                    // because we may have overwritten the last bytes in
                    // source already due to overlap.
                    let last := mload(sEnd)
                    // Copy whole words front to back
                    // Note: the first check is always true,
                    // this could have been a do-while loop.
                    // solhint-disable-next-line no-empty-blocks
                    for {} lt(source, sEnd) {} {
                        mstore(dest, mload(source))
                        source := add(source, 32)
                        dest := add(dest, 32)
                    }
                    // Write the last 32 bytes
                    mstore(dEnd, last)
                }
            } else {
                assembly {
                    // We subtract 32 from `sEnd` and `dEnd` because those
                    // are the starting points when copying a word at the end.
                    length := sub(length, 32)
                    let sEnd := add(source, length)
                    let dEnd := add(dest, length)
                    // Remember the first 32 bytes of source
                    // This needs to be done here and not after the loop
                    // because we may have overwritten the first bytes in
                    // source already due to overlap.
                    let first := mload(source)
                    // Copy whole words back to front
                    // We use a signed comparisson here to allow dEnd to become
                    // negative (happens when source and dest < 32). Valid
                    // addresses in local memory will never be larger than
                    // 2**255, so they can be safely re-interpreted as signed.
                    // Note: the first check is always true,
                    // this could have been a do-while loop.
                    // solhint-disable-next-line no-empty-blocks
                    for {} slt(dest, dEnd) {} {
                        mstore(dEnd, mload(sEnd))
                        sEnd := sub(sEnd, 32)
                        dEnd := sub(dEnd, 32)
                    }
                    // Write the first 32 bytes
                    mstore(dest, first)
                }
            }
        }
    }
    /// @dev Returns a slices from a byte array.
    /// @param b The byte array to take a slice from.
    /// @param from The starting index for the slice (inclusive).
    /// @param to The final index for the slice (exclusive).
    /// @return result The slice containing bytes at indices [from, to)
    function slice(
        bytes memory b,
        uint256 from,
        uint256 to
    )
        internal
        pure
        returns (bytes memory result)
    {
        // Ensure that the from and to positions are valid positions for a slice within
        // the byte array that is being used.
        if (from > to) {
            LibRichErrorsV06.rrevert(LibBytesRichErrorsV06.InvalidByteOperationError(
                LibBytesRichErrorsV06.InvalidByteOperationErrorCodes.FromLessThanOrEqualsToRequired,
                from,
                to
            ));
        }
        if (to > b.length) {
            LibRichErrorsV06.rrevert(LibBytesRichErrorsV06.InvalidByteOperationError(
                LibBytesRichErrorsV06.InvalidByteOperationErrorCodes.ToLessThanOrEqualsLengthRequired,
                to,
                b.length
            ));
        }
        // Create a new bytes structure and copy contents
        result = new bytes(to - from);
        memCopy(
            result.contentAddress(),
            b.contentAddress() + from,
            result.length
        );
        return result;
    }
    /// @dev Returns a slice from a byte array without preserving the input.
    ///      When `from == 0`, the original array will match the slice.
    ///      In other cases its state will be corrupted.
    /// @param b The byte array to take a slice from. Will be destroyed in the process.
    /// @param from The starting index for the slice (inclusive).
    /// @param to The final index for the slice (exclusive).
    /// @return result The slice containing bytes at indices [from, to)
    function sliceDestructive(
        bytes memory b,
        uint256 from,
        uint256 to
    )
        internal
        pure
        returns (bytes memory result)
    {
        // Ensure that the from and to positions are valid positions for a slice within
        // the byte array that is being used.
        if (from > to) {
            LibRichErrorsV06.rrevert(LibBytesRichErrorsV06.InvalidByteOperationError(
                LibBytesRichErrorsV06.InvalidByteOperationErrorCodes.FromLessThanOrEqualsToRequired,
                from,
                to
            ));
        }
        if (to > b.length) {
            LibRichErrorsV06.rrevert(LibBytesRichErrorsV06.InvalidByteOperationError(
                LibBytesRichErrorsV06.InvalidByteOperationErrorCodes.ToLessThanOrEqualsLengthRequired,
                to,
                b.length
            ));
        }
        // Create a new bytes structure around [from, to) in-place.
        assembly {
            result := add(b, from)
            mstore(result, sub(to, from))
        }
        return result;
    }
    /// @dev Pops the last byte off of a byte array by modifying its length.
    /// @param b Byte array that will be modified.
    /// @return result The byte that was popped off.
    function popLastByte(bytes memory b)
        internal
        pure
        returns (bytes1 result)
    {
        if (b.length == 0) {
            LibRichErrorsV06.rrevert(LibBytesRichErrorsV06.InvalidByteOperationError(
                LibBytesRichErrorsV06.InvalidByteOperationErrorCodes.LengthGreaterThanZeroRequired,
                b.length,
                0
            ));
        }
        // Store last byte.
        result = b[b.length - 1];
        assembly {
            // Decrement length of byte array.
            let newLen := sub(mload(b), 1)
            mstore(b, newLen)
        }
        return result;
    }
    /// @dev Tests equality of two byte arrays.
    /// @param lhs First byte array to compare.
    /// @param rhs Second byte array to compare.
    /// @return equal True if arrays are the same. False otherwise.
    function equals(
        bytes memory lhs,
        bytes memory rhs
    )
        internal
        pure
        returns (bool equal)
    {
        // Keccak gas cost is 30 + numWords * 6. This is a cheap way to compare.
        // We early exit on unequal lengths, but keccak would also correctly
        // handle this.
        return lhs.length == rhs.length && keccak256(lhs) == keccak256(rhs);
    }
    /// @dev Reads an address from a position in a byte array.
    /// @param b Byte array containing an address.
    /// @param index Index in byte array of address.
    /// @return result address from byte array.
    function readAddress(
        bytes memory b,
        uint256 index
    )
        internal
        pure
        returns (address result)
    {
        if (b.length < index + 20) {
            LibRichErrorsV06.rrevert(LibBytesRichErrorsV06.InvalidByteOperationError(
                LibBytesRichErrorsV06.InvalidByteOperationErrorCodes.LengthGreaterThanOrEqualsTwentyRequired,
                b.length,
                index + 20 // 20 is length of address
            ));
        }
        // Add offset to index:
        // 1. Arrays are prefixed by 32-byte length parameter (add 32 to index)
        // 2. Account for size difference between address length and 32-byte storage word (subtract 12 from index)
        index += 20;
        // Read address from array memory
        assembly {
            // 1. Add index to address of bytes array
            // 2. Load 32-byte word from memory
            // 3. Apply 20-byte mask to obtain address
            result := and(mload(add(b, index)), 0xffffffffffffffffffffffffffffffffffffffff)
        }
        return result;
    }
    /// @dev Writes an address into a specific position in a byte array.
    /// @param b Byte array to insert address into.
    /// @param index Index in byte array of address.
    /// @param input Address to put into byte array.
    function writeAddress(
        bytes memory b,
        uint256 index,
        address input
    )
        internal
        pure
    {
        if (b.length < index + 20) {
            LibRichErrorsV06.rrevert(LibBytesRichErrorsV06.InvalidByteOperationError(
                LibBytesRichErrorsV06.InvalidByteOperationErrorCodes.LengthGreaterThanOrEqualsTwentyRequired,
                b.length,
                index + 20 // 20 is length of address
            ));
        }
        // Add offset to index:
        // 1. Arrays are prefixed by 32-byte length parameter (add 32 to index)
        // 2. Account for size difference between address length and 32-byte storage word (subtract 12 from index)
        index += 20;
        // Store address into array memory
        assembly {
            // The address occupies 20 bytes and mstore stores 32 bytes.
            // First fetch the 32-byte word where we'll be storing the address, then
            // apply a mask so we have only the bytes in the word that the address will not occupy.
            // Then combine these bytes with the address and store the 32 bytes back to memory with mstore.
            // 1. Add index to address of bytes array
            // 2. Load 32-byte word from memory
            // 3. Apply 12-byte mask to obtain extra bytes occupying word of memory where we'll store the address
            let neighbors := and(
                mload(add(b, index)),
                0xffffffffffffffffffffffff0000000000000000000000000000000000000000
            )
            // Make sure input address is clean.
            // (Solidity does not guarantee this)
            input := and(input, 0xffffffffffffffffffffffffffffffffffffffff)
            // Store the neighbors and address into memory
            mstore(add(b, index), xor(input, neighbors))
        }
    }
    /// @dev Reads a bytes32 value from a position in a byte array.
    /// @param b Byte array containing a bytes32 value.
    /// @param index Index in byte array of bytes32 value.
    /// @return result bytes32 value from byte array.
    function readBytes32(
        bytes memory b,
        uint256 index
    )
        internal
        pure
        returns (bytes32 result)
    {
        if (b.length < index + 32) {
            LibRichErrorsV06.rrevert(LibBytesRichErrorsV06.InvalidByteOperationError(
                LibBytesRichErrorsV06.InvalidByteOperationErrorCodes.LengthGreaterThanOrEqualsThirtyTwoRequired,
                b.length,
                index + 32
            ));
        }
        // Arrays are prefixed by a 256 bit length parameter
        index += 32;
        // Read the bytes32 from array memory
        assembly {
            result := mload(add(b, index))
        }
        return result;
    }
    /// @dev Writes a bytes32 into a specific position in a byte array.
    /// @param b Byte array to insert <input> into.
    /// @param index Index in byte array of <input>.
    /// @param input bytes32 to put into byte array.
    function writeBytes32(
        bytes memory b,
        uint256 index,
        bytes32 input
    )
        internal
        pure
    {
        if (b.length < index + 32) {
            LibRichErrorsV06.rrevert(LibBytesRichErrorsV06.InvalidByteOperationError(
                LibBytesRichErrorsV06.InvalidByteOperationErrorCodes.LengthGreaterThanOrEqualsThirtyTwoRequired,
                b.length,
                index + 32
            ));
        }
        // Arrays are prefixed by a 256 bit length parameter
        index += 32;
        // Read the bytes32 from array memory
        assembly {
            mstore(add(b, index), input)
        }
    }
    /// @dev Reads a uint256 value from a position in a byte array.
    /// @param b Byte array containing a uint256 value.
    /// @param index Index in byte array of uint256 value.
    /// @return result uint256 value from byte array.
    function readUint256(
        bytes memory b,
        uint256 index
    )
        internal
        pure
        returns (uint256 result)
    {
        result = uint256(readBytes32(b, index));
        return result;
    }
    /// @dev Writes a uint256 into a specific position in a byte array.
    /// @param b Byte array to insert <input> into.
    /// @param index Index in byte array of <input>.
    /// @param input uint256 to put into byte array.
    function writeUint256(
        bytes memory b,
        uint256 index,
        uint256 input
    )
        internal
        pure
    {
        writeBytes32(b, index, bytes32(input));
    }
    /// @dev Reads an unpadded bytes4 value from a position in a byte array.
    /// @param b Byte array containing a bytes4 value.
    /// @param index Index in byte array of bytes4 value.
    /// @return result bytes4 value from byte array.
    function readBytes4(
        bytes memory b,
        uint256 index
    )
        internal
        pure
        returns (bytes4 result)
    {
        if (b.length < index + 4) {
            LibRichErrorsV06.rrevert(LibBytesRichErrorsV06.InvalidByteOperationError(
                LibBytesRichErrorsV06.InvalidByteOperationErrorCodes.LengthGreaterThanOrEqualsFourRequired,
                b.length,
                index + 4
            ));
        }
        // Arrays are prefixed by a 32 byte length field
        index += 32;
        // Read the bytes4 from array memory
        assembly {
            result := mload(add(b, index))
            // Solidity does not require us to clean the trailing bytes.
            // We do it anyway
            result := and(result, 0xFFFFFFFF00000000000000000000000000000000000000000000000000000000)
        }
        return result;
    }
    /// @dev Writes a new length to a byte array.
    ///      Decreasing length will lead to removing the corresponding lower order bytes from the byte array.
    ///      Increasing length may lead to appending adjacent in-memory bytes to the end of the byte array.
    /// @param b Bytes array to write new length to.
    /// @param length New length of byte array.
    function writeLength(bytes memory b, uint256 length)
        internal
        pure
    {
        assembly {
            mstore(b, length)
        }
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
library LibBytesRichErrorsV06 {
    enum InvalidByteOperationErrorCodes {
        FromLessThanOrEqualsToRequired,
        ToLessThanOrEqualsLengthRequired,
        LengthGreaterThanZeroRequired,
        LengthGreaterThanOrEqualsFourRequired,
        LengthGreaterThanOrEqualsTwentyRequired,
        LengthGreaterThanOrEqualsThirtyTwoRequired,
        LengthGreaterThanOrEqualsNestedBytesLengthRequired,
        DestinationLengthGreaterThanOrEqualSourceLengthRequired
    }
    // bytes4(keccak256("InvalidByteOperationError(uint8,uint256,uint256)"))
    bytes4 internal constant INVALID_BYTE_OPERATION_ERROR_SELECTOR =
        0x28006595;
    // solhint-disable func-name-mixedcase
    function InvalidByteOperationError(
        InvalidByteOperationErrorCodes errorCode,
        uint256 offset,
        uint256 required
    )
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            INVALID_BYTE_OPERATION_ERROR_SELECTOR,
            errorCode,
            offset,
            required
        );
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
library LibRichErrorsV06 {
    // bytes4(keccak256("Error(string)"))
    bytes4 internal constant STANDARD_ERROR_SELECTOR = 0x08c379a0;
    // solhint-disable func-name-mixedcase
    /// @dev ABI encode a standard, string revert error payload.
    ///      This is the same payload that would be included by a `revert(string)`
    ///      solidity statement. It has the function signature `Error(string)`.
    /// @param message The error string.
    /// @return The ABI encoded error.
    function StandardError(string memory message)
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            STANDARD_ERROR_SELECTOR,
            bytes(message)
        );
    }
    // solhint-enable func-name-mixedcase
    /// @dev Reverts an encoded rich revert reason `errorData`.
    /// @param errorData ABI encoded error data.
    function rrevert(bytes memory errorData)
        internal
        pure
    {
        assembly {
            revert(add(errorData, 0x20), mload(errorData))
        }
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
import "../errors/LibProxyRichErrors.sol";
library LibBootstrap {
    /// @dev Magic bytes returned by the bootstrapper to indicate success.
    ///      This is `keccack('BOOTSTRAP_SUCCESS')`.
    bytes4 internal constant BOOTSTRAP_SUCCESS = 0xd150751b;
    using LibRichErrorsV06 for bytes;
    /// @dev Perform a delegatecall and ensure it returns the magic bytes.
    /// @param target The call target.
    /// @param data The call data.
    function delegatecallBootstrapFunction(
        address target,
        bytes memory data
    )
        internal
    {
        (bool success, bytes memory resultData) = target.delegatecall(data);
        if (!success ||
            resultData.length != 32 ||
            abi.decode(resultData, (bytes4)) != BOOTSTRAP_SUCCESS)
        {
            LibProxyRichErrors.BootstrapCallFailedError(target, resultData).rrevert();
        }
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
library LibProxyRichErrors {
    // solhint-disable func-name-mixedcase
    function NotImplementedError(bytes4 selector)
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("NotImplementedError(bytes4)")),
            selector
        );
    }
    function InvalidBootstrapCallerError(address actual, address expected)
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("InvalidBootstrapCallerError(address,address)")),
            actual,
            expected
        );
    }
    function InvalidDieCallerError(address actual, address expected)
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("InvalidDieCallerError(address,address)")),
            actual,
            expected
        );
    }
    function BootstrapCallFailedError(address target, bytes memory resultData)
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("BootstrapCallFailedError(address,bytes)")),
            target,
            resultData
        );
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
import "../migrations/LibBootstrap.sol";
import "../storage/LibProxyStorage.sol";
import "./IBootstrap.sol";
/// @dev Detachable `bootstrap()` feature.
contract Bootstrap is
    IBootstrap
{
    // solhint-disable state-visibility,indent
    /// @dev The ZeroEx contract.
    ///      This has to be immutable to persist across delegatecalls.
    address immutable private _deployer;
    /// @dev The implementation address of this contract.
    ///      This has to be immutable to persist across delegatecalls.
    address immutable private _implementation;
    /// @dev The deployer.
    ///      This has to be immutable to persist across delegatecalls.
    address immutable private _bootstrapCaller;
    // solhint-enable state-visibility,indent
    using LibRichErrorsV06 for bytes;
    /// @dev Construct this contract and set the bootstrap migration contract.
    ///      After constructing this contract, `bootstrap()` should be called
    ///      to seed the initial feature set.
    /// @param bootstrapCaller The allowed caller of `bootstrap()`.
    constructor(address bootstrapCaller) public {
        _deployer = msg.sender;
        _implementation = address(this);
        _bootstrapCaller = bootstrapCaller;
    }
    /// @dev Bootstrap the initial feature set of this contract by delegatecalling
    ///      into `target`. Before exiting the `bootstrap()` function will
    ///      deregister itself from the proxy to prevent being called again.
    /// @param target The bootstrapper contract address.
    /// @param callData The call data to execute on `target`.
    function bootstrap(address target, bytes calldata callData) external override {
        // Only the bootstrap caller can call this function.
        if (msg.sender != _bootstrapCaller) {
            LibProxyRichErrors.InvalidBootstrapCallerError(
                msg.sender,
                _bootstrapCaller
            ).rrevert();
        }
        // Deregister.
        LibProxyStorage.getStorage().impls[this.bootstrap.selector] = address(0);
        // Self-destruct.
        Bootstrap(_implementation).die();
        // Call the bootstrapper.
        LibBootstrap.delegatecallBootstrapFunction(target, callData);
    }
    /// @dev Self-destructs this contract.
    ///      Can only be called by the deployer.
    function die() external {
        if (msg.sender != _deployer) {
            LibProxyRichErrors.InvalidDieCallerError(msg.sender, _deployer).rrevert();
        }
        selfdestruct(msg.sender);
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "./LibStorage.sol";
/// @dev Storage helpers for the proxy contract.
library LibProxyStorage {
    /// @dev Storage bucket for proxy contract.
    struct Storage {
        // Mapping of function selector -> function implementation
        mapping(bytes4 => address) impls;
        // The owner of the proxy contract.
        address owner;
    }
    /// @dev Get the storage bucket for this contract.
    function getStorage() internal pure returns (Storage storage stor) {
        uint256 storageSlot = LibStorage.getStorageSlot(
            LibStorage.StorageId.Proxy
        );
        // Dip into assembly to change the slot pointed to by the local
        // variable `stor`.
        // See https://solidity.readthedocs.io/en/v0.6.8/assembly.html?highlight=slot#access-to-external-variables-functions-and-libraries
        assembly { stor_slot := storageSlot }
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
/// @dev Common storage helpers
library LibStorage {
    /// @dev What to bit-shift a storage ID by to get its slot.
    ///      This gives us a maximum of 2**128 inline fields in each bucket.
    uint256 private constant STORAGE_SLOT_EXP = 128;
    /// @dev Storage IDs for feature storage buckets.
    ///      WARNING: APPEND-ONLY.
    enum StorageId {
        Proxy,
        SimpleFunctionRegistry,
        Ownable,
        TokenSpender,
        TransformERC20
    }
    /// @dev Get the storage slot given a storage ID. We assign unique, well-spaced
    ///     slots to storage bucket variables to ensure they do not overlap.
    ///     See: https://solidity.readthedocs.io/en/v0.6.6/assembly.html#access-to-external-variables-functions-and-libraries
    /// @param storageId An entry in `StorageId`
    /// @return slot The storage slot.
    function getStorageSlot(StorageId storageId)
        internal
        pure
        returns (uint256 slot)
    {
        // This should never overflow with a reasonable `STORAGE_SLOT_EXP`
        // because Solidity will do a range check on `storageId` during the cast.
        return (uint256(storageId) + 1) << STORAGE_SLOT_EXP;
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
/// @dev Detachable `bootstrap()` feature.
interface IBootstrap {
    /// @dev Bootstrap the initial feature set of this contract by delegatecalling
    ///      into `target`. Before exiting the `bootstrap()` function will
    ///      deregister itself from the proxy to prevent being called again.
    /// @param target The bootstrapper contract address.
    /// @param callData The call data to execute on `target`.
    function bootstrap(address target, bytes calldata callData) external;
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
library LibCommonRichErrors {
    // solhint-disable func-name-mixedcase
    function OnlyCallableBySelfError(address sender)
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("OnlyCallableBySelfError(address)")),
            sender
        );
    }
    function IllegalReentrancyError()
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("IllegalReentrancyError()"))
        );
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
library LibOwnableRichErrors {
    // solhint-disable func-name-mixedcase
    function OnlyOwnerError(
        address sender,
        address owner
    )
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("OnlyOwnerError(address,address)")),
            sender,
            owner
        );
    }
    function TransferOwnerToZeroError()
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("TransferOwnerToZeroError()"))
        );
    }
    function MigrateCallFailedError(address target, bytes memory resultData)
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("MigrateCallFailedError(address,bytes)")),
            target,
            resultData
        );
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
library LibSimpleFunctionRegistryRichErrors {
    // solhint-disable func-name-mixedcase
    function NotInRollbackHistoryError(bytes4 selector, address targetImpl)
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("NotInRollbackHistoryError(bytes4,address)")),
            selector,
            targetImpl
        );
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
library LibSpenderRichErrors {
    // solhint-disable func-name-mixedcase
    function SpenderERC20TransferFromFailedError(
        address token,
        address owner,
        address to,
        uint256 amount,
        bytes memory errorData
    )
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("SpenderERC20TransferFromFailedError(address,address,address,uint256,bytes)")),
            token,
            owner,
            to,
            amount,
            errorData
        );
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
library LibTransformERC20RichErrors {
    // solhint-disable func-name-mixedcase,separate-by-one-line-in-contract
    function InsufficientEthAttachedError(
        uint256 ethAttached,
        uint256 ethNeeded
    )
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("InsufficientEthAttachedError(uint256,uint256)")),
            ethAttached,
            ethNeeded
        );
    }
    function IncompleteTransformERC20Error(
        address outputToken,
        uint256 outputTokenAmount,
        uint256 minOutputTokenAmount
    )
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("IncompleteTransformERC20Error(address,uint256,uint256)")),
            outputToken,
            outputTokenAmount,
            minOutputTokenAmount
        );
    }
    function NegativeTransformERC20OutputError(
        address outputToken,
        uint256 outputTokenLostAmount
    )
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("NegativeTransformERC20OutputError(address,uint256)")),
            outputToken,
            outputTokenLostAmount
        );
    }
    function TransformerFailedError(
        address transformer,
        bytes memory transformerData,
        bytes memory resultData
    )
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("TransformerFailedError(address,bytes,bytes)")),
            transformer,
            transformerData,
            resultData
        );
    }
    // Common Transformer errors ///////////////////////////////////////////////
    function OnlyCallableByDeployerError(
        address caller,
        address deployer
    )
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("OnlyCallableByDeployerError(address,address)")),
            caller,
            deployer
        );
    }
    function InvalidExecutionContextError(
        address actualContext,
        address expectedContext
    )
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("InvalidExecutionContextError(address,address)")),
            actualContext,
            expectedContext
        );
    }
    enum InvalidTransformDataErrorCode {
        INVALID_TOKENS,
        INVALID_ARRAY_LENGTH
    }
    function InvalidTransformDataError(
        InvalidTransformDataErrorCode errorCode,
        bytes memory transformData
    )
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("InvalidTransformDataError(uint8,bytes)")),
            errorCode,
            transformData
        );
    }
    // FillQuoteTransformer errors /////////////////////////////////////////////
    function IncompleteFillSellQuoteError(
        address sellToken,
        uint256 soldAmount,
        uint256 sellAmount
    )
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("IncompleteFillSellQuoteError(address,uint256,uint256)")),
            sellToken,
            soldAmount,
            sellAmount
        );
    }
    function IncompleteFillBuyQuoteError(
        address buyToken,
        uint256 boughtAmount,
        uint256 buyAmount
    )
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("IncompleteFillBuyQuoteError(address,uint256,uint256)")),
            buyToken,
            boughtAmount,
            buyAmount
        );
    }
    function InsufficientTakerTokenError(
        uint256 tokenBalance,
        uint256 tokensNeeded
    )
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("InsufficientTakerTokenError(uint256,uint256)")),
            tokenBalance,
            tokensNeeded
        );
    }
    function InsufficientProtocolFeeError(
        uint256 ethBalance,
        uint256 ethNeeded
    )
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("InsufficientProtocolFeeError(uint256,uint256)")),
            ethBalance,
            ethNeeded
        );
    }
    function InvalidERC20AssetDataError(
        bytes memory assetData
    )
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("InvalidERC20AssetDataError(bytes)")),
            assetData
        );
    }
    function InvalidTakerFeeTokenError(
        address token
    )
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("InvalidTakerFeeTokenError(address)")),
            token
        );
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
library LibWalletRichErrors {
    // solhint-disable func-name-mixedcase
    function WalletExecuteCallFailedError(
        address wallet,
        address callTarget,
        bytes memory callData,
        uint256 callValue,
        bytes memory errorData
    )
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("WalletExecuteCallFailedError(address,address,bytes,uint256,bytes)")),
            wallet,
            callTarget,
            callData,
            callValue,
            errorData
        );
    }
    function WalletExecuteDelegateCallFailedError(
        address wallet,
        address callTarget,
        bytes memory callData,
        bytes memory errorData
    )
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("WalletExecuteDelegateCallFailedError(address,address,bytes,bytes)")),
            wallet,
            callTarget,
            callData,
            errorData
        );
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
import "@0x/contracts-utils/contracts/src/v06/AuthorizableV06.sol";
import "../errors/LibSpenderRichErrors.sol";
import "./IAllowanceTarget.sol";
/// @dev The allowance target for the TokenSpender feature.
contract AllowanceTarget is
    IAllowanceTarget,
    AuthorizableV06
{
    // solhint-disable no-unused-vars,indent,no-empty-blocks
    using LibRichErrorsV06 for bytes;
    /// @dev Execute an arbitrary call. Only an authority can call this.
    /// @param target The call target.
    /// @param callData The call data.
    /// @return resultData The data returned by the call.
    function executeCall(
        address payable target,
        bytes calldata callData
    )
        external
        override
        onlyAuthorized
        returns (bytes memory resultData)
    {
        bool success;
        (success, resultData) = target.call(callData);
        if (!success) {
            resultData.rrevert();
        }
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
import "./interfaces/IAuthorizableV06.sol";
import "./errors/LibRichErrorsV06.sol";
import "./errors/LibAuthorizableRichErrorsV06.sol";
import "./OwnableV06.sol";
// solhint-disable no-empty-blocks
contract AuthorizableV06 is
    OwnableV06,
    IAuthorizableV06
{
    /// @dev Only authorized addresses can invoke functions with this modifier.
    modifier onlyAuthorized {
        _assertSenderIsAuthorized();
        _;
    }
    // @dev Whether an address is authorized to call privileged functions.
    // @param 0 Address to query.
    // @return 0 Whether the address is authorized.
    mapping (address => bool) public override authorized;
    // @dev Whether an address is authorized to call privileged functions.
    // @param 0 Index of authorized address.
    // @return 0 Authorized address.
    address[] public override authorities;
    /// @dev Initializes the `owner` address.
    constructor()
        public
        OwnableV06()
    {}
    /// @dev Authorizes an address.
    /// @param target Address to authorize.
    function addAuthorizedAddress(address target)
        external
        override
        onlyOwner
    {
        _addAuthorizedAddress(target);
    }
    /// @dev Removes authorizion of an address.
    /// @param target Address to remove authorization from.
    function removeAuthorizedAddress(address target)
        external
        override
        onlyOwner
    {
        if (!authorized[target]) {
            LibRichErrorsV06.rrevert(LibAuthorizableRichErrorsV06.TargetNotAuthorizedError(target));
        }
        for (uint256 i = 0; i < authorities.length; i++) {
            if (authorities[i] == target) {
                _removeAuthorizedAddressAtIndex(target, i);
                break;
            }
        }
    }
    /// @dev Removes authorizion of an address.
    /// @param target Address to remove authorization from.
    /// @param index Index of target in authorities array.
    function removeAuthorizedAddressAtIndex(
        address target,
        uint256 index
    )
        external
        override
        onlyOwner
    {
        _removeAuthorizedAddressAtIndex(target, index);
    }
    /// @dev Gets all authorized addresses.
    /// @return Array of authorized addresses.
    function getAuthorizedAddresses()
        external
        override
        view
        returns (address[] memory)
    {
        return authorities;
    }
    /// @dev Reverts if msg.sender is not authorized.
    function _assertSenderIsAuthorized()
        internal
        view
    {
        if (!authorized[msg.sender]) {
            LibRichErrorsV06.rrevert(LibAuthorizableRichErrorsV06.SenderNotAuthorizedError(msg.sender));
        }
    }
    /// @dev Authorizes an address.
    /// @param target Address to authorize.
    function _addAuthorizedAddress(address target)
        internal
    {
        // Ensure that the target is not the zero address.
        if (target == address(0)) {
            LibRichErrorsV06.rrevert(LibAuthorizableRichErrorsV06.ZeroCantBeAuthorizedError());
        }
        // Ensure that the target is not already authorized.
        if (authorized[target]) {
            LibRichErrorsV06.rrevert(LibAuthorizableRichErrorsV06.TargetAlreadyAuthorizedError(target));
        }
        authorized[target] = true;
        authorities.push(target);
        emit AuthorizedAddressAdded(target, msg.sender);
    }
    /// @dev Removes authorizion of an address.
    /// @param target Address to remove authorization from.
    /// @param index Index of target in authorities array.
    function _removeAuthorizedAddressAtIndex(
        address target,
        uint256 index
    )
        internal
    {
        if (!authorized[target]) {
            LibRichErrorsV06.rrevert(LibAuthorizableRichErrorsV06.TargetNotAuthorizedError(target));
        }
        if (index >= authorities.length) {
            LibRichErrorsV06.rrevert(LibAuthorizableRichErrorsV06.IndexOutOfBoundsError(
                index,
                authorities.length
            ));
        }
        if (authorities[index] != target) {
            LibRichErrorsV06.rrevert(LibAuthorizableRichErrorsV06.AuthorizedAddressMismatchError(
                authorities[index],
                target
            ));
        }
        delete authorized[target];
        authorities[index] = authorities[authorities.length - 1];
        authorities.pop();
        emit AuthorizedAddressRemoved(target, msg.sender);
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
import "./IOwnableV06.sol";
interface IAuthorizableV06 is
    IOwnableV06
{
    // Event logged when a new address is authorized.
    event AuthorizedAddressAdded(
        address indexed target,
        address indexed caller
    );
    // Event logged when a currently authorized address is unauthorized.
    event AuthorizedAddressRemoved(
        address indexed target,
        address indexed caller
    );
    /// @dev Authorizes an address.
    /// @param target Address to authorize.
    function addAuthorizedAddress(address target)
        external;
    /// @dev Removes authorizion of an address.
    /// @param target Address to remove authorization from.
    function removeAuthorizedAddress(address target)
        external;
    /// @dev Removes authorizion of an address.
    /// @param target Address to remove authorization from.
    /// @param index Index of target in authorities array.
    function removeAuthorizedAddressAtIndex(
        address target,
        uint256 index
    )
        external;
    /// @dev Gets all authorized addresses.
    /// @return authorizedAddresses Array of authorized addresses.
    function getAuthorizedAddresses()
        external
        view
        returns (address[] memory authorizedAddresses);
    /// @dev Whether an adderss is authorized to call privileged functions.
    /// @param addr Address to query.
    /// @return isAuthorized Whether the address is authorized.
    function authorized(address addr) external view returns (bool isAuthorized);
    /// @dev All addresseses authorized to call privileged functions.
    /// @param idx Index of authorized address.
    /// @return addr Authorized address.
    function authorities(uint256 idx) external view returns (address addr);
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
interface IOwnableV06 {
    /// @dev Emitted by Ownable when ownership is transferred.
    /// @param previousOwner The previous owner of the contract.
    /// @param newOwner The new owner of the contract.
    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
    /// @dev Transfers ownership of the contract to a new address.
    /// @param newOwner The address that will become the owner.
    function transferOwnership(address newOwner) external;
    /// @dev The owner of this contract.
    /// @return ownerAddress The owner address.
    function owner() external view returns (address ownerAddress);
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
library LibAuthorizableRichErrorsV06 {
    // bytes4(keccak256("AuthorizedAddressMismatchError(address,address)"))
    bytes4 internal constant AUTHORIZED_ADDRESS_MISMATCH_ERROR_SELECTOR =
        0x140a84db;
    // bytes4(keccak256("IndexOutOfBoundsError(uint256,uint256)"))
    bytes4 internal constant INDEX_OUT_OF_BOUNDS_ERROR_SELECTOR =
        0xe9f83771;
    // bytes4(keccak256("SenderNotAuthorizedError(address)"))
    bytes4 internal constant SENDER_NOT_AUTHORIZED_ERROR_SELECTOR =
        0xb65a25b9;
    // bytes4(keccak256("TargetAlreadyAuthorizedError(address)"))
    bytes4 internal constant TARGET_ALREADY_AUTHORIZED_ERROR_SELECTOR =
        0xde16f1a0;
    // bytes4(keccak256("TargetNotAuthorizedError(address)"))
    bytes4 internal constant TARGET_NOT_AUTHORIZED_ERROR_SELECTOR =
        0xeb5108a2;
    // bytes4(keccak256("ZeroCantBeAuthorizedError()"))
    bytes internal constant ZERO_CANT_BE_AUTHORIZED_ERROR_BYTES =
        hex"57654fe4";
    // solhint-disable func-name-mixedcase
    function AuthorizedAddressMismatchError(
        address authorized,
        address target
    )
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            AUTHORIZED_ADDRESS_MISMATCH_ERROR_SELECTOR,
            authorized,
            target
        );
    }
    function IndexOutOfBoundsError(
        uint256 index,
        uint256 length
    )
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            INDEX_OUT_OF_BOUNDS_ERROR_SELECTOR,
            index,
            length
        );
    }
    function SenderNotAuthorizedError(address sender)
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            SENDER_NOT_AUTHORIZED_ERROR_SELECTOR,
            sender
        );
    }
    function TargetAlreadyAuthorizedError(address target)
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            TARGET_ALREADY_AUTHORIZED_ERROR_SELECTOR,
            target
        );
    }
    function TargetNotAuthorizedError(address target)
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            TARGET_NOT_AUTHORIZED_ERROR_SELECTOR,
            target
        );
    }
    function ZeroCantBeAuthorizedError()
        internal
        pure
        returns (bytes memory)
    {
        return ZERO_CANT_BE_AUTHORIZED_ERROR_BYTES;
    }
}
/*
  Copyright 2019 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
import "./interfaces/IOwnableV06.sol";
import "./errors/LibRichErrorsV06.sol";
import "./errors/LibOwnableRichErrorsV06.sol";
contract OwnableV06 is
    IOwnableV06
{
    /// @dev The owner of this contract.
    /// @return 0 The owner address.
    address public override owner;
    constructor() public {
        owner = msg.sender;
    }
    modifier onlyOwner() {
        _assertSenderIsOwner();
        _;
    }
    /// @dev Change the owner of this contract.
    /// @param newOwner New owner address.
    function transferOwnership(address newOwner)
        public
        override
        onlyOwner
    {
        if (newOwner == address(0)) {
            LibRichErrorsV06.rrevert(LibOwnableRichErrorsV06.TransferOwnerToZeroError());
        } else {
            owner = newOwner;
            emit OwnershipTransferred(msg.sender, newOwner);
        }
    }
    function _assertSenderIsOwner()
        internal
        view
    {
        if (msg.sender != owner) {
            LibRichErrorsV06.rrevert(LibOwnableRichErrorsV06.OnlyOwnerError(
                msg.sender,
                owner
            ));
        }
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
library LibOwnableRichErrorsV06 {
    // bytes4(keccak256("OnlyOwnerError(address,address)"))
    bytes4 internal constant ONLY_OWNER_ERROR_SELECTOR =
        0x1de45ad1;
    // bytes4(keccak256("TransferOwnerToZeroError()"))
    bytes internal constant TRANSFER_OWNER_TO_ZERO_ERROR_BYTES =
        hex"e69edc3e";
    // solhint-disable func-name-mixedcase
    function OnlyOwnerError(
        address sender,
        address owner
    )
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            ONLY_OWNER_ERROR_SELECTOR,
            sender,
            owner
        );
    }
    function TransferOwnerToZeroError()
        internal
        pure
        returns (bytes memory)
    {
        return TRANSFER_OWNER_TO_ZERO_ERROR_BYTES;
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-utils/contracts/src/v06/interfaces/IAuthorizableV06.sol";
/// @dev The allowance target for the TokenSpender feature.
interface IAllowanceTarget is
    IAuthorizableV06
{
    /// @dev Execute an arbitrary call. Only an authority can call this.
    /// @param target The call target.
    /// @param callData The call data.
    /// @return resultData The data returned by the call.
    function executeCall(
        address payable target,
        bytes calldata callData
    )
        external
        returns (bytes memory resultData);
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
import "@0x/contracts-utils/contracts/src/v06/errors/LibOwnableRichErrorsV06.sol";
import "../errors/LibWalletRichErrors.sol";
import "./IFlashWallet.sol";
/// @dev A contract that can execute arbitrary calls from its owner.
contract FlashWallet is
    IFlashWallet
{
    // solhint-disable no-unused-vars,indent,no-empty-blocks
    using LibRichErrorsV06 for bytes;
    // solhint-disable
    /// @dev Store the owner/deployer as an immutable to make this contract stateless.
    address public override immutable owner;
    // solhint-enable
    constructor() public {
        // The deployer is the owner.
        owner = msg.sender;
    }
    /// @dev Allows only the (immutable) owner to call a function.
    modifier onlyOwner() virtual {
        if (msg.sender != owner) {
            LibOwnableRichErrorsV06.OnlyOwnerError(
                msg.sender,
                owner
            ).rrevert();
        }
        _;
    }
    /// @dev Execute an arbitrary call. Only an authority can call this.
    /// @param target The call target.
    /// @param callData The call data.
    /// @param value Ether to attach to the call.
    /// @return resultData The data returned by the call.
    function executeCall(
        address payable target,
        bytes calldata callData,
        uint256 value
    )
        external
        payable
        override
        onlyOwner
        returns (bytes memory resultData)
    {
        bool success;
        (success, resultData) = target.call{value: value}(callData);
        if (!success) {
            LibWalletRichErrors
                .WalletExecuteCallFailedError(
                    address(this),
                    target,
                    callData,
                    value,
                    resultData
                )
                .rrevert();
        }
    }
    /// @dev Execute an arbitrary delegatecall, in the context of this puppet.
    ///      Only an authority can call this.
    /// @param target The call target.
    /// @param callData The call data.
    /// @return resultData The data returned by the call.
    function executeDelegateCall(
        address payable target,
        bytes calldata callData
    )
        external
        payable
        override
        onlyOwner
        returns (bytes memory resultData)
    {
        bool success;
        (success, resultData) = target.delegatecall(callData);
        if (!success) {
            LibWalletRichErrors
                .WalletExecuteDelegateCallFailedError(
                    address(this),
                    target,
                    callData,
                    resultData
                )
                .rrevert();
        }
    }
    // solhint-disable
    /// @dev Allows this contract to receive ether.
    receive() external override payable {}
    // solhint-enable
    /// @dev Signal support for receiving ERC1155 tokens.
    /// @param interfaceID The interface ID, as per ERC-165 rules.
    /// @return hasSupport `true` if this contract supports an ERC-165 interface.
    function supportsInterface(bytes4 interfaceID)
        external
        pure
        returns (bool hasSupport)
    {
        return  interfaceID == this.supportsInterface.selector ||
                interfaceID == this.onERC1155Received.selector ^ this.onERC1155BatchReceived.selector ||
                interfaceID == this.tokenFallback.selector;
    }
    ///  @dev Allow this contract to receive ERC1155 tokens.
    ///  @return success  `bytes4(keccak256("onERC1155Received(address,address,uint256,uint256,bytes)"))`
    function onERC1155Received(
        address, // operator,
        address, // from,
        uint256, // id,
        uint256, // value,
        bytes calldata //data
    )
        external
        pure
        returns (bytes4 success)
    {
        return this.onERC1155Received.selector;
    }
    ///  @dev Allow this contract to receive ERC1155 tokens.
    ///  @return success  `bytes4(keccak256("onERC1155BatchReceived(address,address,uint256[],uint256[],bytes)"))`
    function onERC1155BatchReceived(
        address, // operator,
        address, // from,
        uint256[] calldata, // ids,
        uint256[] calldata, // values,
        bytes calldata // data
    )
        external
        pure
        returns (bytes4 success)
    {
        return this.onERC1155BatchReceived.selector;
    }
    /// @dev Allows this contract to receive ERC223 tokens.
    function tokenFallback(
        address, // from,
        uint256, // value,
        bytes calldata // value
    )
        external
        pure
    {}
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-utils/contracts/src/v06/interfaces/IOwnableV06.sol";
/// @dev A contract that can execute arbitrary calls from its owner.
interface IFlashWallet {
    /// @dev Execute an arbitrary call. Only an authority can call this.
    /// @param target The call target.
    /// @param callData The call data.
    /// @param value Ether to attach to the call.
    /// @return resultData The data returned by the call.
    function executeCall(
        address payable target,
        bytes calldata callData,
        uint256 value
    )
        external
        payable
        returns (bytes memory resultData);
    /// @dev Execute an arbitrary delegatecall, in the context of this puppet.
    ///      Only an authority can call this.
    /// @param target The call target.
    /// @param callData The call data.
    /// @return resultData The data returned by the call.
    function executeDelegateCall(
        address payable target,
        bytes calldata callData
    )
        external
        payable
        returns (bytes memory resultData);
    /// @dev Allows the puppet to receive ETH.
    receive() external payable;
    /// @dev Fetch the immutable owner/deployer of this contract.
    /// @return owner_ The immutable owner/deployer/
    function owner() external view returns (address owner_);
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-utils/contracts/src/v06/AuthorizableV06.sol";
/// @dev A contract with a `die()` function.
interface IKillable {
    function die() external;
}
/// @dev Deployer contract for ERC20 transformers.
///      Only authorities may call `deploy()` and `kill()`.
contract TransformerDeployer is
    AuthorizableV06
{
    /// @dev Emitted when a contract is deployed via `deploy()`.
    /// @param deployedAddress The address of the deployed contract.
    /// @param nonce The deployment nonce.
    /// @param sender The caller of `deploy()`.
    event Deployed(address deployedAddress, uint256 nonce, address sender);
    /// @dev Emitted when a contract is killed via `kill()`.
    /// @param target The address of the contract being killed..
    /// @param sender The caller of `kill()`.
    event Killed(address target, address sender);
    // @dev The current nonce of this contract.
    uint256 public nonce = 1;
    // @dev Mapping of deployed contract address to deployment nonce.
    mapping (address => uint256) public toDeploymentNonce;
    /// @dev Create this contract and register authorities.
    constructor(address[] memory authorities) public {
        for (uint256 i = 0; i < authorities.length; ++i) {
            _addAuthorizedAddress(authorities[i]);
        }
    }
    /// @dev Deploy a new contract. Only callable by an authority.
    ///      Any attached ETH will also be forwarded.
    function deploy(bytes memory bytecode)
        public
        payable
        onlyAuthorized
        returns (address deployedAddress)
    {
        uint256 deploymentNonce = nonce;
        nonce += 1;
        assembly {
            deployedAddress := create(callvalue(), add(bytecode, 32), mload(bytecode))
        }
        toDeploymentNonce[deployedAddress] = deploymentNonce;
        emit Deployed(deployedAddress, deploymentNonce, msg.sender);
    }
    /// @dev Call `die()` on a contract. Only callable by an authority.
    function kill(IKillable target)
        public
        onlyAuthorized
    {
        target.die();
        emit Killed(address(target), msg.sender);
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
/// @dev Basic interface for a feature contract.
interface IFeature {
    // solhint-disable func-name-mixedcase
    /// @dev The name of this feature set.
    function FEATURE_NAME() external view returns (string memory name);
    /// @dev The version of this feature set.
    function FEATURE_VERSION() external view returns (uint256 version);
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-utils/contracts/src/v06/interfaces/IOwnableV06.sol";
// solhint-disable no-empty-blocks
/// @dev Owner management and migration features.
interface IOwnable is
    IOwnableV06
{
    /// @dev Emitted when `migrate()` is called.
    /// @param caller The caller of `migrate()`.
    /// @param migrator The migration contract.
    /// @param newOwner The address of the new owner.
    event Migrated(address caller, address migrator, address newOwner);
    /// @dev Execute a migration function in the context of the ZeroEx contract.
    ///      The result of the function being called should be the magic bytes
    ///      0x2c64c5ef (`keccack('MIGRATE_SUCCESS')`). Only callable by the owner.
    ///      The owner will be temporarily set to `address(this)` inside the call.
    ///      Before returning, the owner will be set to `newOwner`.
    /// @param target The migrator contract address.
    /// @param newOwner The address of the new owner.
    /// @param data The call data.
    function migrate(address target, bytes calldata data, address newOwner) external;
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
/// @dev Basic registry management features.
interface ISimpleFunctionRegistry {
    /// @dev A function implementation was updated via `extend()` or `rollback()`.
    /// @param selector The function selector.
    /// @param oldImpl The implementation contract address being replaced.
    /// @param newImpl The replacement implementation contract address.
    event ProxyFunctionUpdated(bytes4 indexed selector, address oldImpl, address newImpl);
    /// @dev Roll back to a prior implementation of a function.
    /// @param selector The function selector.
    /// @param targetImpl The address of an older implementation of the function.
    function rollback(bytes4 selector, address targetImpl) external;
    /// @dev Register or replace a function.
    /// @param selector The function selector.
    /// @param impl The implementation contract for the function.
    function extend(bytes4 selector, address impl) external;
    /// @dev Retrieve the length of the rollback history for a function.
    /// @param selector The function selector.
    /// @return rollbackLength The number of items in the rollback history for
    ///         the function.
    function getRollbackLength(bytes4 selector)
        external
        view
        returns (uint256 rollbackLength);
    /// @dev Retrieve an entry in the rollback history for a function.
    /// @param selector The function selector.
    /// @param idx The index in the rollback history.
    /// @return impl An implementation address for the function at
    ///         index `idx`.
    function getRollbackEntryAtIndex(bytes4 selector, uint256 idx)
        external
        view
        returns (address impl);
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-erc20/contracts/src/v06/IERC20TokenV06.sol";
/// @dev Feature that allows spending token allowances.
interface ITokenSpender {
    /// @dev Transfers ERC20 tokens from `owner` to `to`.
    ///      Only callable from within.
    /// @param token The token to spend.
    /// @param owner The owner of the tokens.
    /// @param to The recipient of the tokens.
    /// @param amount The amount of `token` to transfer.
    function _spendERC20Tokens(
        IERC20TokenV06 token,
        address owner,
        address to,
        uint256 amount
    )
        external;
    /// @dev Gets the maximum amount of an ERC20 token `token` that can be
    ///      pulled from `owner`.
    /// @param token The token to spend.
    /// @param owner The owner of the tokens.
    /// @return amount The amount of tokens that can be pulled.
    function getSpendableERC20BalanceOf(IERC20TokenV06 token, address owner)
        external
        view
        returns (uint256 amount);
    /// @dev Get the address of the allowance target.
    /// @return target The target of token allowances.
    function getAllowanceTarget() external view returns (address target);
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
interface IERC20TokenV06 {
    // solhint-disable no-simple-event-func-name
    event Transfer(
        address indexed from,
        address indexed to,
        uint256 value
    );
    event Approval(
        address indexed owner,
        address indexed spender,
        uint256 value
    );
    /// @dev send `value` token to `to` from `msg.sender`
    /// @param to The address of the recipient
    /// @param value The amount of token to be transferred
    /// @return True if transfer was successful
    function transfer(address to, uint256 value)
        external
        returns (bool);
    /// @dev send `value` token to `to` from `from` on the condition it is approved by `from`
    /// @param from The address of the sender
    /// @param to The address of the recipient
    /// @param value The amount of token to be transferred
    /// @return True if transfer was successful
    function transferFrom(
        address from,
        address to,
        uint256 value
    )
        external
        returns (bool);
    /// @dev `msg.sender` approves `spender` to spend `value` tokens
    /// @param spender The address of the account able to transfer the tokens
    /// @param value The amount of wei to be approved for transfer
    /// @return Always true if the call has enough gas to complete execution
    function approve(address spender, uint256 value)
        external
        returns (bool);
    /// @dev Query total supply of token
    /// @return Total supply of token
    function totalSupply()
        external
        view
        returns (uint256);
    /// @dev Get the balance of `owner`.
    /// @param owner The address from which the balance will be retrieved
    /// @return Balance of owner
    function balanceOf(address owner)
        external
        view
        returns (uint256);
    /// @dev Get the allowance for `spender` to spend from `owner`.
    /// @param owner The address of the account owning tokens
    /// @param spender The address of the account able to transfer the tokens
    /// @return Amount of remaining tokens allowed to spent
    function allowance(address owner, address spender)
        external
        view
        returns (uint256);
    /// @dev Get the number of decimals this token has.
    function decimals()
        external
        view
        returns (uint8);
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-erc20/contracts/src/v06/IERC20TokenV06.sol";
import "../transformers/IERC20Transformer.sol";
import "../external/IFlashWallet.sol";
/// @dev Feature to composably transform between ERC20 tokens.
interface ITransformERC20 {
    /// @dev Defines a transformation to run in `transformERC20()`.
    struct Transformation {
        // The deployment nonce for the transformer.
        // The address of the transformer contract will be derived from this
        // value.
        uint32 deploymentNonce;
        // Arbitrary data to pass to the transformer.
        bytes data;
    }
    /// @dev Raised upon a successful `transformERC20`.
    /// @param taker The taker (caller) address.
    /// @param inputToken The token being provided by the taker.
    ///        If `0xeee...`, ETH is implied and should be provided with the call.`
    /// @param outputToken The token to be acquired by the taker.
    ///        `0xeee...` implies ETH.
    /// @param inputTokenAmount The amount of `inputToken` to take from the taker.
    /// @param outputTokenAmount The amount of `outputToken` received by the taker.
    event TransformedERC20(
        address indexed taker,
        address inputToken,
        address outputToken,
        uint256 inputTokenAmount,
        uint256 outputTokenAmount
    );
    /// @dev Raised when `setTransformerDeployer()` is called.
    /// @param transformerDeployer The new deployer address.
    event TransformerDeployerUpdated(address transformerDeployer);
    /// @dev Replace the allowed deployer for transformers.
    ///      Only callable by the owner.
    /// @param transformerDeployer The address of the trusted deployer for transformers.
    function setTransformerDeployer(address transformerDeployer)
        external;
    /// @dev Deploy a new flash wallet instance and replace the current one with it.
    ///      Useful if we somehow break the current wallet instance.
    ///      Anyone can call this.
    /// @return wallet The new wallet instance.
    function createTransformWallet()
        external
        returns (IFlashWallet wallet);
    /// @dev Executes a series of transformations to convert an ERC20 `inputToken`
    ///      to an ERC20 `outputToken`.
    /// @param inputToken The token being provided by the sender.
    ///        If `0xeee...`, ETH is implied and should be provided with the call.`
    /// @param outputToken The token to be acquired by the sender.
    ///        `0xeee...` implies ETH.
    /// @param inputTokenAmount The amount of `inputToken` to take from the sender.
    /// @param minOutputTokenAmount The minimum amount of `outputToken` the sender
    ///        must receive for the entire transformation to succeed.
    /// @param transformations The transformations to execute on the token balance(s)
    ///        in sequence.
    /// @return outputTokenAmount The amount of `outputToken` received by the sender.
    function transformERC20(
        IERC20TokenV06 inputToken,
        IERC20TokenV06 outputToken,
        uint256 inputTokenAmount,
        uint256 minOutputTokenAmount,
        Transformation[] calldata transformations
    )
        external
        payable
        returns (uint256 outputTokenAmount);
    /// @dev Internal version of `transformERC20()`. Only callable from within.
    /// @param callDataHash Hash of the ingress calldata.
    /// @param taker The taker address.
    /// @param inputToken The token being provided by the taker.
    ///        If `0xeee...`, ETH is implied and should be provided with the call.`
    /// @param outputToken The token to be acquired by the taker.
    ///        `0xeee...` implies ETH.
    /// @param inputTokenAmount The amount of `inputToken` to take from the taker.
    /// @param minOutputTokenAmount The minimum amount of `outputToken` the taker
    ///        must receive for the entire transformation to succeed.
    /// @param transformations The transformations to execute on the token balance(s)
    ///        in sequence.
    /// @return outputTokenAmount The amount of `outputToken` received by the taker.
    function _transformERC20(
        bytes32 callDataHash,
        address payable taker,
        IERC20TokenV06 inputToken,
        IERC20TokenV06 outputToken,
        uint256 inputTokenAmount,
        uint256 minOutputTokenAmount,
        Transformation[] calldata transformations
    )
        external
        payable
        returns (uint256 outputTokenAmount);
    /// @dev Return the current wallet instance that will serve as the execution
    ///      context for transformations.
    /// @return wallet The wallet instance.
    function getTransformWallet()
        external
        view
        returns (IFlashWallet wallet);
    /// @dev Return the allowed deployer for transformers.
    /// @return deployer The transform deployer address.
    function getTransformerDeployer()
        external
        view
        returns (address deployer);
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-erc20/contracts/src/v06/IERC20TokenV06.sol";
/// @dev A transformation callback used in `TransformERC20.transformERC20()`.
interface IERC20Transformer {
    /// @dev Called from `TransformERC20.transformERC20()`. This will be
    ///      delegatecalled in the context of the FlashWallet instance being used.
    /// @param callDataHash The hash of the `TransformERC20.transformERC20()` calldata.
    /// @param taker The taker address (caller of `TransformERC20.transformERC20()`).
    /// @param data Arbitrary data to pass to the transformer.
    /// @return success The success bytes (`LibERC20Transformer.TRANSFORMER_SUCCESS`).
    function transform(
        bytes32 callDataHash,
        address payable taker,
        bytes calldata data
    )
        external
        returns (bytes4 success);
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
import "../fixins/FixinCommon.sol";
import "../errors/LibOwnableRichErrors.sol";
import "../storage/LibOwnableStorage.sol";
import "../migrations/LibBootstrap.sol";
import "../migrations/LibMigrate.sol";
import "./IFeature.sol";
import "./IOwnable.sol";
import "./SimpleFunctionRegistry.sol";
/// @dev Owner management features.
contract Ownable is
    IFeature,
    IOwnable,
    FixinCommon
{
    // solhint-disable
    /// @dev Name of this feature.
    string public constant override FEATURE_NAME = "Ownable";
    /// @dev Version of this feature.
    uint256 public immutable override FEATURE_VERSION = _encodeVersion(1, 0, 0);
    /// @dev The deployed address of this contract.
    address immutable private _implementation;
    // solhint-enable
    using LibRichErrorsV06 for bytes;
    constructor() public {
        _implementation = address(this);
    }
    /// @dev Initializes this feature. The intial owner will be set to this (ZeroEx)
    ///      to allow the bootstrappers to call `extend()`. Ownership should be
    ///      transferred to the real owner by the bootstrapper after
    ///      bootstrapping is complete.
    /// @return success Magic bytes if successful.
    function bootstrap() external returns (bytes4 success) {
        // Set the owner to ourselves to allow bootstrappers to call `extend()`.
        LibOwnableStorage.getStorage().owner = address(this);
        // Register feature functions.
        SimpleFunctionRegistry(address(this))._extendSelf(this.transferOwnership.selector, _implementation);
        SimpleFunctionRegistry(address(this))._extendSelf(this.owner.selector, _implementation);
        SimpleFunctionRegistry(address(this))._extendSelf(this.migrate.selector, _implementation);
        return LibBootstrap.BOOTSTRAP_SUCCESS;
    }
    /// @dev Change the owner of this contract.
    ///      Only directly callable by the owner.
    /// @param newOwner New owner address.
    function transferOwnership(address newOwner)
        external
        override
        onlyOwner
    {
        LibOwnableStorage.Storage storage proxyStor = LibOwnableStorage.getStorage();
        if (newOwner == address(0)) {
            LibOwnableRichErrors.TransferOwnerToZeroError().rrevert();
        } else {
            proxyStor.owner = newOwner;
            emit OwnershipTransferred(msg.sender, newOwner);
        }
    }
    /// @dev Execute a migration function in the context of the ZeroEx contract.
    ///      The result of the function being called should be the magic bytes
    ///      0x2c64c5ef (`keccack('MIGRATE_SUCCESS')`). Only callable by the owner.
    ///      Temporarily sets the owner to ourselves so we can perform admin functions.
    ///      Before returning, the owner will be set to `newOwner`.
    /// @param target The migrator contract address.
    /// @param data The call data.
    /// @param newOwner The address of the new owner.
    function migrate(address target, bytes calldata data, address newOwner)
        external
        override
        onlyOwner
    {
        if (newOwner == address(0)) {
            LibOwnableRichErrors.TransferOwnerToZeroError().rrevert();
        }
        LibOwnableStorage.Storage storage stor = LibOwnableStorage.getStorage();
        // The owner will be temporarily set to `address(this)` inside the call.
        stor.owner = address(this);
        // Perform the migration.
        LibMigrate.delegatecallMigrateFunction(target, data);
        // Update the owner.
        stor.owner = newOwner;
        emit Migrated(msg.sender, target, newOwner);
    }
    /// @dev Get the owner of this contract.
    /// @return owner_ The owner of this contract.
    function owner() external override view returns (address owner_) {
        return LibOwnableStorage.getStorage().owner;
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
import "../errors/LibCommonRichErrors.sol";
import "../errors/LibOwnableRichErrors.sol";
import "../features/IOwnable.sol";
/// @dev Common feature utilities.
contract FixinCommon {
    using LibRichErrorsV06 for bytes;
    /// @dev The caller must be this contract.
    modifier onlySelf() virtual {
        if (msg.sender != address(this)) {
            LibCommonRichErrors.OnlyCallableBySelfError(msg.sender).rrevert();
        }
        _;
    }
    /// @dev The caller of this function must be the owner.
    modifier onlyOwner() virtual {
        {
            address owner = IOwnable(address(this)).owner();
            if (msg.sender != owner) {
                LibOwnableRichErrors.OnlyOwnerError(
                    msg.sender,
                    owner
                ).rrevert();
            }
        }
        _;
    }
    /// @dev Encode a feature version as a `uint256`.
    /// @param major The major version number of the feature.
    /// @param minor The minor version number of the feature.
    /// @param revision The revision number of the feature.
    /// @return encodedVersion The encoded version number.
    function _encodeVersion(uint32 major, uint32 minor, uint32 revision)
        internal
        pure
        returns (uint256 encodedVersion)
    {
        return (major << 64) | (minor << 32) | revision;
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "./LibStorage.sol";
/// @dev Storage helpers for the `Ownable` feature.
library LibOwnableStorage {
    /// @dev Storage bucket for this feature.
    struct Storage {
        // The owner of this contract.
        address owner;
    }
    /// @dev Get the storage bucket for this contract.
    function getStorage() internal pure returns (Storage storage stor) {
        uint256 storageSlot = LibStorage.getStorageSlot(
            LibStorage.StorageId.Ownable
        );
        // Dip into assembly to change the slot pointed to by the local
        // variable `stor`.
        // See https://solidity.readthedocs.io/en/v0.6.8/assembly.html?highlight=slot#access-to-external-variables-functions-and-libraries
        assembly { stor_slot := storageSlot }
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
import "../errors/LibOwnableRichErrors.sol";
library LibMigrate {
    /// @dev Magic bytes returned by a migrator to indicate success.
    ///      This is `keccack('MIGRATE_SUCCESS')`.
    bytes4 internal constant MIGRATE_SUCCESS = 0x2c64c5ef;
    using LibRichErrorsV06 for bytes;
    /// @dev Perform a delegatecall and ensure it returns the magic bytes.
    /// @param target The call target.
    /// @param data The call data.
    function delegatecallMigrateFunction(
        address target,
        bytes memory data
    )
        internal
    {
        (bool success, bytes memory resultData) = target.delegatecall(data);
        if (!success ||
            resultData.length != 32 ||
            abi.decode(resultData, (bytes4)) != MIGRATE_SUCCESS)
        {
            LibOwnableRichErrors.MigrateCallFailedError(target, resultData).rrevert();
        }
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
import "../fixins/FixinCommon.sol";
import "../storage/LibProxyStorage.sol";
import "../storage/LibSimpleFunctionRegistryStorage.sol";
import "../errors/LibSimpleFunctionRegistryRichErrors.sol";
import "../migrations/LibBootstrap.sol";
import "./IFeature.sol";
import "./ISimpleFunctionRegistry.sol";
/// @dev Basic registry management features.
contract SimpleFunctionRegistry is
    IFeature,
    ISimpleFunctionRegistry,
    FixinCommon
{
    // solhint-disable
    /// @dev Name of this feature.
    string public constant override FEATURE_NAME = "SimpleFunctionRegistry";
    /// @dev Version of this feature.
    uint256 public immutable override FEATURE_VERSION = _encodeVersion(1, 0, 0);
    /// @dev The deployed address of this contract.
    address private immutable _implementation;
    // solhint-enable
    using LibRichErrorsV06 for bytes;
    constructor() public {
        _implementation = address(this);
    }
    /// @dev Initializes this feature, registering its own functions.
    /// @return success Magic bytes if successful.
    function bootstrap()
        external
        returns (bytes4 success)
    {
        // Register the registration functions (inception vibes).
        _extend(this.extend.selector, _implementation);
        _extend(this._extendSelf.selector, _implementation);
        // Register the rollback function.
        _extend(this.rollback.selector, _implementation);
        // Register getters.
        _extend(this.getRollbackLength.selector, _implementation);
        _extend(this.getRollbackEntryAtIndex.selector, _implementation);
        return LibBootstrap.BOOTSTRAP_SUCCESS;
    }
    /// @dev Roll back to a prior implementation of a function.
    ///      Only directly callable by an authority.
    /// @param selector The function selector.
    /// @param targetImpl The address of an older implementation of the function.
    function rollback(bytes4 selector, address targetImpl)
        external
        override
        onlyOwner
    {
        (
            LibSimpleFunctionRegistryStorage.Storage storage stor,
            LibProxyStorage.Storage storage proxyStor
        ) = _getStorages();
        address currentImpl = proxyStor.impls[selector];
        if (currentImpl == targetImpl) {
            // Do nothing if already at targetImpl.
            return;
        }
        // Walk history backwards until we find the target implementation.
        address[] storage history = stor.implHistory[selector];
        uint256 i = history.length;
        for (; i > 0; --i) {
            address impl = history[i - 1];
            history.pop();
            if (impl == targetImpl) {
                break;
            }
        }
        if (i == 0) {
            LibSimpleFunctionRegistryRichErrors.NotInRollbackHistoryError(
                selector,
                targetImpl
            ).rrevert();
        }
        proxyStor.impls[selector] = targetImpl;
        emit ProxyFunctionUpdated(selector, currentImpl, targetImpl);
    }
    /// @dev Register or replace a function.
    ///      Only directly callable by an authority.
    /// @param selector The function selector.
    /// @param impl The implementation contract for the function.
    function extend(bytes4 selector, address impl)
        external
        override
        onlyOwner
    {
        _extend(selector, impl);
    }
    /// @dev Register or replace a function.
    ///      Only callable from within.
    ///      This function is only used during the bootstrap process and
    ///      should be deregistered by the deployer after bootstrapping is
    ///      complete.
    /// @param selector The function selector.
    /// @param impl The implementation contract for the function.
    function _extendSelf(bytes4 selector, address impl)
        external
        onlySelf
    {
        _extend(selector, impl);
    }
    /// @dev Retrieve the length of the rollback history for a function.
    /// @param selector The function selector.
    /// @return rollbackLength The number of items in the rollback history for
    ///         the function.
    function getRollbackLength(bytes4 selector)
        external
        override
        view
        returns (uint256 rollbackLength)
    {
        return LibSimpleFunctionRegistryStorage.getStorage().implHistory[selector].length;
    }
    /// @dev Retrieve an entry in the rollback history for a function.
    /// @param selector The function selector.
    /// @param idx The index in the rollback history.
    /// @return impl An implementation address for the function at
    ///         index `idx`.
    function getRollbackEntryAtIndex(bytes4 selector, uint256 idx)
        external
        override
        view
        returns (address impl)
    {
        return LibSimpleFunctionRegistryStorage.getStorage().implHistory[selector][idx];
    }
    /// @dev Register or replace a function.
    /// @param selector The function selector.
    /// @param impl The implementation contract for the function.
    function _extend(bytes4 selector, address impl)
        private
    {
        (
            LibSimpleFunctionRegistryStorage.Storage storage stor,
            LibProxyStorage.Storage storage proxyStor
        ) = _getStorages();
        address oldImpl = proxyStor.impls[selector];
        address[] storage history = stor.implHistory[selector];
        history.push(oldImpl);
        proxyStor.impls[selector] = impl;
        emit ProxyFunctionUpdated(selector, oldImpl, impl);
    }
    /// @dev Get the storage buckets for this feature and the proxy.
    /// @return stor Storage bucket for this feature.
    /// @return proxyStor age bucket for the proxy.
    function _getStorages()
        private
        pure
        returns (
            LibSimpleFunctionRegistryStorage.Storage storage stor,
            LibProxyStorage.Storage storage proxyStor
        )
    {
        return (
            LibSimpleFunctionRegistryStorage.getStorage(),
            LibProxyStorage.getStorage()
        );
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "./LibStorage.sol";
/// @dev Storage helpers for the `SimpleFunctionRegistry` feature.
library LibSimpleFunctionRegistryStorage {
    /// @dev Storage bucket for this feature.
    struct Storage {
        // Mapping of function selector -> implementation history.
        mapping(bytes4 => address[]) implHistory;
    }
    /// @dev Get the storage bucket for this contract.
    function getStorage() internal pure returns (Storage storage stor) {
        uint256 storageSlot = LibStorage.getStorageSlot(
            LibStorage.StorageId.SimpleFunctionRegistry
        );
        // Dip into assembly to change the slot pointed to by the local
        // variable `stor`.
        // See https://solidity.readthedocs.io/en/v0.6.8/assembly.html?highlight=slot#access-to-external-variables-functions-and-libraries
        assembly { stor_slot := storageSlot }
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
import "@0x/contracts-utils/contracts/src/v06/LibSafeMathV06.sol";
import "@0x/contracts-erc20/contracts/src/v06/IERC20TokenV06.sol";
import "@0x/contracts-erc20/contracts/src/v06/LibERC20TokenV06.sol";
import "../errors/LibSpenderRichErrors.sol";
import "../fixins/FixinCommon.sol";
import "../migrations/LibMigrate.sol";
import "../external/IAllowanceTarget.sol";
import "../storage/LibTokenSpenderStorage.sol";
import "./ITokenSpender.sol";
import "./IFeature.sol";
import "./ISimpleFunctionRegistry.sol";
/// @dev Feature that allows spending token allowances.
contract TokenSpender is
    IFeature,
    ITokenSpender,
    FixinCommon
{
    // solhint-disable
    /// @dev Name of this feature.
    string public constant override FEATURE_NAME = "TokenSpender";
    /// @dev Version of this feature.
    uint256 public immutable override FEATURE_VERSION = _encodeVersion(1, 0, 0);
    /// @dev The implementation address of this feature.
    address private immutable _implementation;
    // solhint-enable
    using LibRichErrorsV06 for bytes;
    constructor() public {
        _implementation = address(this);
    }
    /// @dev Initialize and register this feature. Should be delegatecalled
    ///      into during a `Migrate.migrate()`.
    /// @param allowanceTarget An `allowanceTarget` instance, configured to have
    ///        the ZeroeEx contract as an authority.
    /// @return success `MIGRATE_SUCCESS` on success.
    function migrate(IAllowanceTarget allowanceTarget) external returns (bytes4 success) {
        LibTokenSpenderStorage.getStorage().allowanceTarget = allowanceTarget;
        ISimpleFunctionRegistry(address(this))
            .extend(this.getAllowanceTarget.selector, _implementation);
        ISimpleFunctionRegistry(address(this))
            .extend(this._spendERC20Tokens.selector, _implementation);
        ISimpleFunctionRegistry(address(this))
            .extend(this.getSpendableERC20BalanceOf.selector, _implementation);
        return LibMigrate.MIGRATE_SUCCESS;
    }
    /// @dev Transfers ERC20 tokens from `owner` to `to`. Only callable from within.
    /// @param token The token to spend.
    /// @param owner The owner of the tokens.
    /// @param to The recipient of the tokens.
    /// @param amount The amount of `token` to transfer.
    function _spendERC20Tokens(
        IERC20TokenV06 token,
        address owner,
        address to,
        uint256 amount
    )
        external
        override
        onlySelf
    {
        IAllowanceTarget spender = LibTokenSpenderStorage.getStorage().allowanceTarget;
        // Have the allowance target execute an ERC20 `transferFrom()`.
        (bool didSucceed, bytes memory resultData) = address(spender).call(
            abi.encodeWithSelector(
                IAllowanceTarget.executeCall.selector,
                address(token),
                abi.encodeWithSelector(
                    IERC20TokenV06.transferFrom.selector,
                    owner,
                    to,
                    amount
                )
            )
        );
        if (didSucceed) {
            resultData = abi.decode(resultData, (bytes));
        }
        if (!didSucceed || !LibERC20TokenV06.isSuccessfulResult(resultData)) {
            LibSpenderRichErrors.SpenderERC20TransferFromFailedError(
                address(token),
                owner,
                to,
                amount,
                resultData
            ).rrevert();
        }
    }
    /// @dev Gets the maximum amount of an ERC20 token `token` that can be
    ///      pulled from `owner` by the token spender.
    /// @param token The token to spend.
    /// @param owner The owner of the tokens.
    /// @return amount The amount of tokens that can be pulled.
    function getSpendableERC20BalanceOf(IERC20TokenV06 token, address owner)
        external
        override
        view
        returns (uint256 amount)
    {
        return LibSafeMathV06.min256(
            token.allowance(owner, address(LibTokenSpenderStorage.getStorage().allowanceTarget)),
            token.balanceOf(owner)
        );
    }
    /// @dev Get the address of the allowance target.
    /// @return target The target of token allowances.
    function getAllowanceTarget()
        external
        override
        view
        returns (address target)
    {
        return address(LibTokenSpenderStorage.getStorage().allowanceTarget);
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
import "./errors/LibRichErrorsV06.sol";
import "./errors/LibSafeMathRichErrorsV06.sol";
library LibSafeMathV06 {
    function safeMul(uint256 a, uint256 b)
        internal
        pure
        returns (uint256)
    {
        if (a == 0) {
            return 0;
        }
        uint256 c = a * b;
        if (c / a != b) {
            LibRichErrorsV06.rrevert(LibSafeMathRichErrorsV06.Uint256BinOpError(
                LibSafeMathRichErrorsV06.BinOpErrorCodes.MULTIPLICATION_OVERFLOW,
                a,
                b
            ));
        }
        return c;
    }
    function safeDiv(uint256 a, uint256 b)
        internal
        pure
        returns (uint256)
    {
        if (b == 0) {
            LibRichErrorsV06.rrevert(LibSafeMathRichErrorsV06.Uint256BinOpError(
                LibSafeMathRichErrorsV06.BinOpErrorCodes.DIVISION_BY_ZERO,
                a,
                b
            ));
        }
        uint256 c = a / b;
        return c;
    }
    function safeSub(uint256 a, uint256 b)
        internal
        pure
        returns (uint256)
    {
        if (b > a) {
            LibRichErrorsV06.rrevert(LibSafeMathRichErrorsV06.Uint256BinOpError(
                LibSafeMathRichErrorsV06.BinOpErrorCodes.SUBTRACTION_UNDERFLOW,
                a,
                b
            ));
        }
        return a - b;
    }
    function safeAdd(uint256 a, uint256 b)
        internal
        pure
        returns (uint256)
    {
        uint256 c = a + b;
        if (c < a) {
            LibRichErrorsV06.rrevert(LibSafeMathRichErrorsV06.Uint256BinOpError(
                LibSafeMathRichErrorsV06.BinOpErrorCodes.ADDITION_OVERFLOW,
                a,
                b
            ));
        }
        return c;
    }
    function max256(uint256 a, uint256 b)
        internal
        pure
        returns (uint256)
    {
        return a >= b ? a : b;
    }
    function min256(uint256 a, uint256 b)
        internal
        pure
        returns (uint256)
    {
        return a < b ? a : b;
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
library LibSafeMathRichErrorsV06 {
    // bytes4(keccak256("Uint256BinOpError(uint8,uint256,uint256)"))
    bytes4 internal constant UINT256_BINOP_ERROR_SELECTOR =
        0xe946c1bb;
    // bytes4(keccak256("Uint256DowncastError(uint8,uint256)"))
    bytes4 internal constant UINT256_DOWNCAST_ERROR_SELECTOR =
        0xc996af7b;
    enum BinOpErrorCodes {
        ADDITION_OVERFLOW,
        MULTIPLICATION_OVERFLOW,
        SUBTRACTION_UNDERFLOW,
        DIVISION_BY_ZERO
    }
    enum DowncastErrorCodes {
        VALUE_TOO_LARGE_TO_DOWNCAST_TO_UINT32,
        VALUE_TOO_LARGE_TO_DOWNCAST_TO_UINT64,
        VALUE_TOO_LARGE_TO_DOWNCAST_TO_UINT96
    }
    // solhint-disable func-name-mixedcase
    function Uint256BinOpError(
        BinOpErrorCodes errorCode,
        uint256 a,
        uint256 b
    )
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            UINT256_BINOP_ERROR_SELECTOR,
            errorCode,
            a,
            b
        );
    }
    function Uint256DowncastError(
        DowncastErrorCodes errorCode,
        uint256 a
    )
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            UINT256_DOWNCAST_ERROR_SELECTOR,
            errorCode,
            a
        );
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
import "@0x/contracts-utils/contracts/src/v06/LibBytesV06.sol";
import "./IERC20TokenV06.sol";
library LibERC20TokenV06 {
    bytes constant private DECIMALS_CALL_DATA = hex"313ce567";
    /// @dev Calls `IERC20TokenV06(token).approve()`.
    ///      Reverts if the result fails `isSuccessfulResult()` or the call reverts.
    /// @param token The address of the token contract.
    /// @param spender The address that receives an allowance.
    /// @param allowance The allowance to set.
    function compatApprove(
        IERC20TokenV06 token,
        address spender,
        uint256 allowance
    )
        internal
    {
        bytes memory callData = abi.encodeWithSelector(
            token.approve.selector,
            spender,
            allowance
        );
        _callWithOptionalBooleanResult(address(token), callData);
    }
    /// @dev Calls `IERC20TokenV06(token).approve()` and sets the allowance to the
    ///      maximum if the current approval is not already >= an amount.
    ///      Reverts if the result fails `isSuccessfulResult()` or the call reverts.
    /// @param token The address of the token contract.
    /// @param spender The address that receives an allowance.
    /// @param amount The minimum allowance needed.
    function approveIfBelow(
        IERC20TokenV06 token,
        address spender,
        uint256 amount
    )
        internal
    {
        if (token.allowance(address(this), spender) < amount) {
            compatApprove(token, spender, uint256(-1));
        }
    }
    /// @dev Calls `IERC20TokenV06(token).transfer()`.
    ///      Reverts if the result fails `isSuccessfulResult()` or the call reverts.
    /// @param token The address of the token contract.
    /// @param to The address that receives the tokens
    /// @param amount Number of tokens to transfer.
    function compatTransfer(
        IERC20TokenV06 token,
        address to,
        uint256 amount
    )
        internal
    {
        bytes memory callData = abi.encodeWithSelector(
            token.transfer.selector,
            to,
            amount
        );
        _callWithOptionalBooleanResult(address(token), callData);
    }
    /// @dev Calls `IERC20TokenV06(token).transferFrom()`.
    ///      Reverts if the result fails `isSuccessfulResult()` or the call reverts.
    /// @param token The address of the token contract.
    /// @param from The owner of the tokens.
    /// @param to The address that receives the tokens
    /// @param amount Number of tokens to transfer.
    function compatTransferFrom(
        IERC20TokenV06 token,
        address from,
        address to,
        uint256 amount
    )
        internal
    {
        bytes memory callData = abi.encodeWithSelector(
            token.transferFrom.selector,
            from,
            to,
            amount
        );
        _callWithOptionalBooleanResult(address(token), callData);
    }
    /// @dev Retrieves the number of decimals for a token.
    ///      Returns `18` if the call reverts.
    /// @param token The address of the token contract.
    /// @return tokenDecimals The number of decimals places for the token.
    function compatDecimals(IERC20TokenV06 token)
        internal
        view
        returns (uint8 tokenDecimals)
    {
        tokenDecimals = 18;
        (bool didSucceed, bytes memory resultData) = address(token).staticcall(DECIMALS_CALL_DATA);
        if (didSucceed && resultData.length == 32) {
            tokenDecimals = uint8(LibBytesV06.readUint256(resultData, 0));
        }
    }
    /// @dev Retrieves the allowance for a token, owner, and spender.
    ///      Returns `0` if the call reverts.
    /// @param token The address of the token contract.
    /// @param owner The owner of the tokens.
    /// @param spender The address the spender.
    /// @return allowance_ The allowance for a token, owner, and spender.
    function compatAllowance(IERC20TokenV06 token, address owner, address spender)
        internal
        view
        returns (uint256 allowance_)
    {
        (bool didSucceed, bytes memory resultData) = address(token).staticcall(
            abi.encodeWithSelector(
                token.allowance.selector,
                owner,
                spender
            )
        );
        if (didSucceed && resultData.length == 32) {
            allowance_ = LibBytesV06.readUint256(resultData, 0);
        }
    }
    /// @dev Retrieves the balance for a token owner.
    ///      Returns `0` if the call reverts.
    /// @param token The address of the token contract.
    /// @param owner The owner of the tokens.
    /// @return balance The token balance of an owner.
    function compatBalanceOf(IERC20TokenV06 token, address owner)
        internal
        view
        returns (uint256 balance)
    {
        (bool didSucceed, bytes memory resultData) = address(token).staticcall(
            abi.encodeWithSelector(
                token.balanceOf.selector,
                owner
            )
        );
        if (didSucceed && resultData.length == 32) {
            balance = LibBytesV06.readUint256(resultData, 0);
        }
    }
    /// @dev Check if the data returned by a non-static call to an ERC20 token
    ///      is a successful result. Supported functions are `transfer()`,
    ///      `transferFrom()`, and `approve()`.
    /// @param resultData The raw data returned by a non-static call to the ERC20 token.
    /// @return isSuccessful Whether the result data indicates success.
    function isSuccessfulResult(bytes memory resultData)
        internal
        pure
        returns (bool isSuccessful)
    {
        if (resultData.length == 0) {
            return true;
        }
        if (resultData.length == 32) {
            uint256 result = LibBytesV06.readUint256(resultData, 0);
            if (result == 1) {
                return true;
            }
        }
    }
    /// @dev Executes a call on address `target` with calldata `callData`
    ///      and asserts that either nothing was returned or a single boolean
    ///      was returned equal to `true`.
    /// @param target The call target.
    /// @param callData The abi-encoded call data.
    function _callWithOptionalBooleanResult(
        address target,
        bytes memory callData
    )
        private
    {
        (bool didSucceed, bytes memory resultData) = target.call(callData);
        if (didSucceed && isSuccessfulResult(resultData)) {
            return;
        }
        LibRichErrorsV06.rrevert(resultData);
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "./LibStorage.sol";
import "../external/IAllowanceTarget.sol";
/// @dev Storage helpers for the `TokenSpender` feature.
library LibTokenSpenderStorage {
    /// @dev Storage bucket for this feature.
    struct Storage {
        // Allowance target contract.
        IAllowanceTarget allowanceTarget;
    }
    /// @dev Get the storage bucket for this contract.
    function getStorage() internal pure returns (Storage storage stor) {
        uint256 storageSlot = LibStorage.getStorageSlot(
            LibStorage.StorageId.TokenSpender
        );
        // Dip into assembly to change the slot pointed to by the local
        // variable `stor`.
        // See https://solidity.readthedocs.io/en/v0.6.8/assembly.html?highlight=slot#access-to-external-variables-functions-and-libraries
        assembly { stor_slot := storageSlot }
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-erc20/contracts/src/v06/IERC20TokenV06.sol";
import "@0x/contracts-erc20/contracts/src/v06/LibERC20TokenV06.sol";
import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
import "@0x/contracts-utils/contracts/src/v06/LibSafeMathV06.sol";
import "../errors/LibTransformERC20RichErrors.sol";
import "../fixins/FixinCommon.sol";
import "../migrations/LibMigrate.sol";
import "../external/IFlashWallet.sol";
import "../external/FlashWallet.sol";
import "../storage/LibTransformERC20Storage.sol";
import "../transformers/IERC20Transformer.sol";
import "../transformers/LibERC20Transformer.sol";
import "./ITransformERC20.sol";
import "./ITokenSpender.sol";
import "./IFeature.sol";
import "./ISimpleFunctionRegistry.sol";
/// @dev Feature to composably transform between ERC20 tokens.
contract TransformERC20 is
    IFeature,
    ITransformERC20,
    FixinCommon
{
    /// @dev Stack vars for `_transformERC20Private()`.
    struct TransformERC20PrivateState {
        IFlashWallet wallet;
        address transformerDeployer;
        uint256 takerOutputTokenBalanceBefore;
        uint256 takerOutputTokenBalanceAfter;
    }
    // solhint-disable
    /// @dev Name of this feature.
    string public constant override FEATURE_NAME = "TransformERC20";
    /// @dev Version of this feature.
    uint256 public immutable override FEATURE_VERSION = _encodeVersion(1, 0, 0);
    /// @dev The implementation address of this feature.
    address private immutable _implementation;
    // solhint-enable
    using LibSafeMathV06 for uint256;
    using LibRichErrorsV06 for bytes;
    constructor() public {
        _implementation = address(this);
    }
    /// @dev Initialize and register this feature.
    ///      Should be delegatecalled by `Migrate.migrate()`.
    /// @param transformerDeployer The trusted deployer for transformers.
    /// @return success `LibMigrate.SUCCESS` on success.
    function migrate(address transformerDeployer) external returns (bytes4 success) {
        ISimpleFunctionRegistry(address(this))
            .extend(this.getTransformerDeployer.selector, _implementation);
        ISimpleFunctionRegistry(address(this))
            .extend(this.createTransformWallet.selector, _implementation);
        ISimpleFunctionRegistry(address(this))
            .extend(this.getTransformWallet.selector, _implementation);
        ISimpleFunctionRegistry(address(this))
            .extend(this.setTransformerDeployer.selector, _implementation);
        ISimpleFunctionRegistry(address(this))
            .extend(this.transformERC20.selector, _implementation);
        ISimpleFunctionRegistry(address(this))
            .extend(this._transformERC20.selector, _implementation);
        createTransformWallet();
        LibTransformERC20Storage.getStorage().transformerDeployer = transformerDeployer;
        return LibMigrate.MIGRATE_SUCCESS;
    }
    /// @dev Replace the allowed deployer for transformers.
    ///      Only callable by the owner.
    /// @param transformerDeployer The address of the trusted deployer for transformers.
    function setTransformerDeployer(address transformerDeployer)
        external
        override
        onlyOwner
    {
        LibTransformERC20Storage.getStorage().transformerDeployer = transformerDeployer;
        emit TransformerDeployerUpdated(transformerDeployer);
    }
    /// @dev Return the allowed deployer for transformers.
    /// @return deployer The transform deployer address.
    function getTransformerDeployer()
        public
        override
        view
        returns (address deployer)
    {
        return LibTransformERC20Storage.getStorage().transformerDeployer;
    }
    /// @dev Deploy a new wallet instance and replace the current one with it.
    ///      Useful if we somehow break the current wallet instance.
    ///      Anyone can call this.
    /// @return wallet The new wallet instance.
    function createTransformWallet()
        public
        override
        returns (IFlashWallet wallet)
    {
        wallet = new FlashWallet();
        LibTransformERC20Storage.getStorage().wallet = wallet;
    }
    /// @dev Executes a series of transformations to convert an ERC20 `inputToken`
    ///      to an ERC20 `outputToken`.
    /// @param inputToken The token being provided by the sender.
    ///        If `0xeee...`, ETH is implied and should be provided with the call.`
    /// @param outputToken The token to be acquired by the sender.
    ///        `0xeee...` implies ETH.
    /// @param inputTokenAmount The amount of `inputToken` to take from the sender.
    ///        If set to `uint256(-1)`, the entire spendable balance of the taker
    ///        will be solt.
    /// @param minOutputTokenAmount The minimum amount of `outputToken` the sender
    ///        must receive for the entire transformation to succeed. If set to zero,
    ///        the minimum output token transfer will not be asserted.
    /// @param transformations The transformations to execute on the token balance(s)
    ///        in sequence.
    /// @return outputTokenAmount The amount of `outputToken` received by the sender.
    function transformERC20(
        IERC20TokenV06 inputToken,
        IERC20TokenV06 outputToken,
        uint256 inputTokenAmount,
        uint256 minOutputTokenAmount,
        Transformation[] memory transformations
    )
        public
        override
        payable
        returns (uint256 outputTokenAmount)
    {
        return _transformERC20Private(
            keccak256(msg.data),
            msg.sender,
            inputToken,
            outputToken,
            inputTokenAmount,
            minOutputTokenAmount,
            transformations
        );
    }
    /// @dev Internal version of `transformERC20()`. Only callable from within.
    /// @param callDataHash Hash of the ingress calldata.
    /// @param taker The taker address.
    /// @param inputToken The token being provided by the taker.
    ///        If `0xeee...`, ETH is implied and should be provided with the call.`
    /// @param outputToken The token to be acquired by the taker.
    ///        `0xeee...` implies ETH.
    /// @param inputTokenAmount The amount of `inputToken` to take from the taker.
    ///        If set to `uint256(-1)`, the entire spendable balance of the taker
    ///        will be solt.
    /// @param minOutputTokenAmount The minimum amount of `outputToken` the taker
    ///        must receive for the entire transformation to succeed. If set to zero,
    ///        the minimum output token transfer will not be asserted.
    /// @param transformations The transformations to execute on the token balance(s)
    ///        in sequence.
    /// @return outputTokenAmount The amount of `outputToken` received by the taker.
    function _transformERC20(
        bytes32 callDataHash,
        address payable taker,
        IERC20TokenV06 inputToken,
        IERC20TokenV06 outputToken,
        uint256 inputTokenAmount,
        uint256 minOutputTokenAmount,
        Transformation[] memory transformations
    )
        public
        override
        payable
        onlySelf
        returns (uint256 outputTokenAmount)
    {
        return _transformERC20Private(
            callDataHash,
            taker,
            inputToken,
            outputToken,
            inputTokenAmount,
            minOutputTokenAmount,
            transformations
        );
    }
    /// @dev Private version of `transformERC20()`.
    /// @param callDataHash Hash of the ingress calldata.
    /// @param taker The taker address.
    /// @param inputToken The token being provided by the taker.
    ///        If `0xeee...`, ETH is implied and should be provided with the call.`
    /// @param outputToken The token to be acquired by the taker.
    ///        `0xeee...` implies ETH.
    /// @param inputTokenAmount The amount of `inputToken` to take from the taker.
    ///        If set to `uint256(-1)`, the entire spendable balance of the taker
    ///        will be solt.
    /// @param minOutputTokenAmount The minimum amount of `outputToken` the taker
    ///        must receive for the entire transformation to succeed. If set to zero,
    ///        the minimum output token transfer will not be asserted.
    /// @param transformations The transformations to execute on the token balance(s)
    ///        in sequence.
    /// @return outputTokenAmount The amount of `outputToken` received by the taker.
    function _transformERC20Private(
        bytes32 callDataHash,
        address payable taker,
        IERC20TokenV06 inputToken,
        IERC20TokenV06 outputToken,
        uint256 inputTokenAmount,
        uint256 minOutputTokenAmount,
        Transformation[] memory transformations
    )
        private
        returns (uint256 outputTokenAmount)
    {
        // If the input token amount is -1, transform the taker's entire
        // spendable balance.
        if (inputTokenAmount == uint256(-1)) {
            inputTokenAmount = ITokenSpender(address(this))
                .getSpendableERC20BalanceOf(inputToken, taker);
        }
        TransformERC20PrivateState memory state;
        state.wallet = getTransformWallet();
        state.transformerDeployer = getTransformerDeployer();
        // Remember the initial output token balance of the taker.
        state.takerOutputTokenBalanceBefore =
            LibERC20Transformer.getTokenBalanceOf(outputToken, taker);
        // Pull input tokens from the taker to the wallet and transfer attached ETH.
        _transferInputTokensAndAttachedEth(
            inputToken,
            taker,
            address(state.wallet),
            inputTokenAmount
        );
        // Perform transformations.
        for (uint256 i = 0; i < transformations.length; ++i) {
            _executeTransformation(
                state.wallet,
                transformations[i],
                state.transformerDeployer,
                taker,
                callDataHash
            );
        }
        // Compute how much output token has been transferred to the taker.
        state.takerOutputTokenBalanceAfter =
            LibERC20Transformer.getTokenBalanceOf(outputToken, taker);
        if (state.takerOutputTokenBalanceAfter > state.takerOutputTokenBalanceBefore) {
            outputTokenAmount = state.takerOutputTokenBalanceAfter.safeSub(
                state.takerOutputTokenBalanceBefore
            );
        } else if (state.takerOutputTokenBalanceAfter < state.takerOutputTokenBalanceBefore) {
            LibTransformERC20RichErrors.NegativeTransformERC20OutputError(
                address(outputToken),
                state.takerOutputTokenBalanceBefore - state.takerOutputTokenBalanceAfter
            ).rrevert();
        }
        // Ensure enough output token has been sent to the taker.
        if (outputTokenAmount < minOutputTokenAmount) {
            LibTransformERC20RichErrors.IncompleteTransformERC20Error(
                address(outputToken),
                outputTokenAmount,
                minOutputTokenAmount
            ).rrevert();
        }
        // Emit an event.
        emit TransformedERC20(
            taker,
            address(inputToken),
            address(outputToken),
            inputTokenAmount,
            outputTokenAmount
        );
    }
    /// @dev Return the current wallet instance that will serve as the execution
    ///      context for transformations.
    /// @return wallet The wallet instance.
    function getTransformWallet()
        public
        override
        view
        returns (IFlashWallet wallet)
    {
        return LibTransformERC20Storage.getStorage().wallet;
    }
    /// @dev Transfer input tokens from the taker and any attached ETH to `to`
    /// @param inputToken The token to pull from the taker.
    /// @param from The from (taker) address.
    /// @param to The recipient of tokens and ETH.
    /// @param amount Amount of `inputToken` tokens to transfer.
    function _transferInputTokensAndAttachedEth(
        IERC20TokenV06 inputToken,
        address from,
        address payable to,
        uint256 amount
    )
        private
    {
        // Transfer any attached ETH.
        if (msg.value != 0) {
            to.transfer(msg.value);
        }
        // Transfer input tokens.
        if (!LibERC20Transformer.isTokenETH(inputToken)) {
            // Token is not ETH, so pull ERC20 tokens.
            ITokenSpender(address(this))._spendERC20Tokens(
                inputToken,
                from,
                to,
                amount
            );
        } else if (msg.value < amount) {
             // Token is ETH, so the caller must attach enough ETH to the call.
            LibTransformERC20RichErrors.InsufficientEthAttachedError(
                msg.value,
                amount
            ).rrevert();
        }
    }
    /// @dev Executs a transformer in the context of `wallet`.
    /// @param wallet The wallet instance.
    /// @param transformation The transformation.
    /// @param transformerDeployer The address of the transformer deployer.
    /// @param taker The taker address.
    /// @param callDataHash Hash of the calldata.
    function _executeTransformation(
        IFlashWallet wallet,
        Transformation memory transformation,
        address transformerDeployer,
        address payable taker,
        bytes32 callDataHash
    )
        private
    {
        // Derive the transformer address from the deployment nonce.
        address payable transformer = LibERC20Transformer.getDeployedAddress(
            transformerDeployer,
            transformation.deploymentNonce
        );
        // Call `transformer.transform()` as the wallet.
        bytes memory resultData = wallet.executeDelegateCall(
            // The call target.
            transformer,
            // Call data.
            abi.encodeWithSelector(
                IERC20Transformer.transform.selector,
                callDataHash,
                taker,
                transformation.data
            )
        );
        // Ensure the transformer returned the magic bytes.
        if (resultData.length != 32 ||
            abi.decode(resultData, (bytes4)) != LibERC20Transformer.TRANSFORMER_SUCCESS
        ) {
            LibTransformERC20RichErrors.TransformerFailedError(
                transformer,
                transformation.data,
                resultData
            ).rrevert();
        }
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "./LibStorage.sol";
import "../external/IFlashWallet.sol";
/// @dev Storage helpers for the `TokenSpender` feature.
library LibTransformERC20Storage {
    /// @dev Storage bucket for this feature.
    struct Storage {
        // The current wallet instance.
        IFlashWallet wallet;
        // The transformer deployer address.
        address transformerDeployer;
    }
    /// @dev Get the storage bucket for this contract.
    function getStorage() internal pure returns (Storage storage stor) {
        uint256 storageSlot = LibStorage.getStorageSlot(
            LibStorage.StorageId.TransformERC20
        );
        // Dip into assembly to change the slot pointed to by the local
        // variable `stor`.
        // See https://solidity.readthedocs.io/en/v0.6.8/assembly.html?highlight=slot#access-to-external-variables-functions-and-libraries
        assembly { stor_slot := storageSlot }
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-erc20/contracts/src/v06/IERC20TokenV06.sol";
import "@0x/contracts-erc20/contracts/src/v06/LibERC20TokenV06.sol";
library LibERC20Transformer {
    using LibERC20TokenV06 for IERC20TokenV06;
    /// @dev ETH pseudo-token address.
    address constant internal ETH_TOKEN_ADDRESS = 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE;
    /// @dev Return value indicating success in `IERC20Transformer.transform()`.
    ///      This is just `keccak256('TRANSFORMER_SUCCESS')`.
    bytes4 constant internal TRANSFORMER_SUCCESS = 0x13c9929e;
    /// @dev Transfer ERC20 tokens and ETH.
    /// @param token An ERC20 or the ETH pseudo-token address (`ETH_TOKEN_ADDRESS`).
    /// @param to The recipient.
    /// @param amount The transfer amount.
    function transformerTransfer(
        IERC20TokenV06 token,
        address payable to,
        uint256 amount
    )
        internal
    {
        if (isTokenETH(token)) {
            to.transfer(amount);
        } else {
            token.compatTransfer(to, amount);
        }
    }
    /// @dev Check if a token is the ETH pseudo-token.
    /// @param token The token to check.
    /// @return isETH `true` if the token is the ETH pseudo-token.
    function isTokenETH(IERC20TokenV06 token)
        internal
        pure
        returns (bool isETH)
    {
        return address(token) == ETH_TOKEN_ADDRESS;
    }
    /// @dev Check the balance of an ERC20 token or ETH.
    /// @param token An ERC20 or the ETH pseudo-token address (`ETH_TOKEN_ADDRESS`).
    /// @param owner Holder of the tokens.
    /// @return tokenBalance The balance of `owner`.
    function getTokenBalanceOf(IERC20TokenV06 token, address owner)
        internal
        view
        returns (uint256 tokenBalance)
    {
        if (isTokenETH(token)) {
            return owner.balance;
        }
        return token.balanceOf(owner);
    }
    /// @dev RLP-encode a 32-bit or less account nonce.
    /// @param nonce A positive integer in the range 0 <= nonce < 2^32.
    /// @return rlpNonce The RLP encoding.
    function rlpEncodeNonce(uint32 nonce)
        internal
        pure
        returns (bytes memory rlpNonce)
    {
        // See https://github.com/ethereum/wiki/wiki/RLP for RLP encoding rules.
        if (nonce == 0) {
            rlpNonce = new bytes(1);
            rlpNonce[0] = 0x80;
        } else if (nonce < 0x80) {
            rlpNonce = new bytes(1);
            rlpNonce[0] = byte(uint8(nonce));
        } else if (nonce <= 0xFF) {
            rlpNonce = new bytes(2);
            rlpNonce[0] = 0x81;
            rlpNonce[1] = byte(uint8(nonce));
        } else if (nonce <= 0xFFFF) {
            rlpNonce = new bytes(3);
            rlpNonce[0] = 0x82;
            rlpNonce[1] = byte(uint8((nonce & 0xFF00) >> 8));
            rlpNonce[2] = byte(uint8(nonce));
        } else if (nonce <= 0xFFFFFF) {
            rlpNonce = new bytes(4);
            rlpNonce[0] = 0x83;
            rlpNonce[1] = byte(uint8((nonce & 0xFF0000) >> 16));
            rlpNonce[2] = byte(uint8((nonce & 0xFF00) >> 8));
            rlpNonce[3] = byte(uint8(nonce));
        } else {
            rlpNonce = new bytes(5);
            rlpNonce[0] = 0x84;
            rlpNonce[1] = byte(uint8((nonce & 0xFF000000) >> 24));
            rlpNonce[2] = byte(uint8((nonce & 0xFF0000) >> 16));
            rlpNonce[3] = byte(uint8((nonce & 0xFF00) >> 8));
            rlpNonce[4] = byte(uint8(nonce));
        }
    }
    /// @dev Compute the expected deployment address by `deployer` at
    ///      the nonce given by `deploymentNonce`.
    /// @param deployer The address of the deployer.
    /// @param deploymentNonce The nonce that the deployer had when deploying
    ///        a contract.
    /// @return deploymentAddress The deployment address.
    function getDeployedAddress(address deployer, uint32 deploymentNonce)
        internal
        pure
        returns (address payable deploymentAddress)
    {
        // The address of if a deployed contract is the lower 20 bytes of the
        // hash of the RLP-encoded deployer's account address + account nonce.
        // See: https://ethereum.stackexchange.com/questions/760/how-is-the-address-of-an-ethereum-contract-computed
        bytes memory rlpNonce = rlpEncodeNonce(deploymentNonce);
        return address(uint160(uint256(keccak256(abi.encodePacked(
            byte(uint8(0xC0 + 21 + rlpNonce.length)),
            byte(uint8(0x80 + 20)),
            deployer,
            rlpNonce
        )))));
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "../ZeroEx.sol";
import "../features/IOwnable.sol";
import "../features/TokenSpender.sol";
import "../features/TransformERC20.sol";
import "../external/AllowanceTarget.sol";
import "./InitialMigration.sol";
/// @dev A contract for deploying and configuring the full ZeroEx contract.
contract FullMigration {
    // solhint-disable no-empty-blocks,indent
    /// @dev Features to add the the proxy contract.
    struct Features {
        SimpleFunctionRegistry registry;
        Ownable ownable;
        TokenSpender tokenSpender;
        TransformERC20 transformERC20;
    }
    /// @dev Parameters needed to initialize features.
    struct MigrateOpts {
        address transformerDeployer;
    }
    /// @dev The allowed caller of `deploy()`.
    address public immutable deployer;
    /// @dev The initial migration contract.
    InitialMigration private _initialMigration;
    /// @dev Instantiate this contract and set the allowed caller of `deploy()`
    ///      to `deployer`.
    /// @param deployer_ The allowed caller of `deploy()`.
    constructor(address payable deployer_)
        public
    {
        deployer = deployer_;
        // Create an initial migration contract with this contract set to the
        // allowed deployer.
        _initialMigration = new InitialMigration(address(this));
    }
    /// @dev Deploy the `ZeroEx` contract with the full feature set,
    ///      transfer ownership to `owner`, then self-destruct.
    /// @param owner The owner of the contract.
    /// @param features Features to add to the proxy.
    /// @return zeroEx The deployed and configured `ZeroEx` contract.
    /// @param migrateOpts Parameters needed to initialize features.
    function deploy(
        address payable owner,
        Features memory features,
        MigrateOpts memory migrateOpts
    )
        public
        returns (ZeroEx zeroEx)
    {
        require(msg.sender == deployer, "FullMigration/INVALID_SENDER");
        // Perform the initial migration with the owner set to this contract.
        zeroEx = _initialMigration.deploy(
            address(uint160(address(this))),
            InitialMigration.BootstrapFeatures({
                registry: features.registry,
                ownable: features.ownable
            })
        );
        // Add features.
        _addFeatures(zeroEx, owner, features, migrateOpts);
        // Transfer ownership to the real owner.
        IOwnable(address(zeroEx)).transferOwnership(owner);
        // Self-destruct.
        this.die(owner);
    }
    /// @dev Destroy this contract. Only callable from ourselves (from `deploy()`).
    /// @param ethRecipient Receiver of any ETH in this contract.
    function die(address payable ethRecipient)
        external
        virtual
    {
        require(msg.sender == address(this), "FullMigration/INVALID_SENDER");
        // This contract should not hold any funds but we send
        // them to the ethRecipient just in case.
        selfdestruct(ethRecipient);
    }
    /// @dev Deploy and register features to the ZeroEx contract.
    /// @param zeroEx The bootstrapped ZeroEx contract.
    /// @param owner The ultimate owner of the ZeroEx contract.
    /// @param features Features to add to the proxy.
    /// @param migrateOpts Parameters needed to initialize features.
    function _addFeatures(
        ZeroEx zeroEx,
        address owner,
        Features memory features,
        MigrateOpts memory migrateOpts
    )
        private
    {
        IOwnable ownable = IOwnable(address(zeroEx));
        // TokenSpender
        {
            // Create the allowance target.
            AllowanceTarget allowanceTarget = new AllowanceTarget();
            // Let the ZeroEx contract use the allowance target.
            allowanceTarget.addAuthorizedAddress(address(zeroEx));
            // Transfer ownership of the allowance target to the (real) owner.
            allowanceTarget.transferOwnership(owner);
            // Register the feature.
            ownable.migrate(
                address(features.tokenSpender),
                abi.encodeWithSelector(
                    TokenSpender.migrate.selector,
                    allowanceTarget
                ),
                address(this)
            );
        }
        // TransformERC20
        {
            // Register the feature.
            ownable.migrate(
                address(features.transformERC20),
                abi.encodeWithSelector(
                    TransformERC20.migrate.selector,
                    migrateOpts.transformerDeployer
                ),
                address(this)
            );
        }
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "../ZeroEx.sol";
import "../features/IBootstrap.sol";
import "../features/SimpleFunctionRegistry.sol";
import "../features/Ownable.sol";
import "./LibBootstrap.sol";
/// @dev A contract for deploying and configuring a minimal ZeroEx contract.
contract InitialMigration {
    /// @dev Features to bootstrap into the the proxy contract.
    struct BootstrapFeatures {
        SimpleFunctionRegistry registry;
        Ownable ownable;
    }
    /// @dev The allowed caller of `deploy()`. In production, this would be
    ///      the governor.
    address public immutable deployer;
    /// @dev The real address of this contract.
    address private immutable _implementation;
    /// @dev Instantiate this contract and set the allowed caller of `deploy()`
    ///      to `deployer_`.
    /// @param deployer_ The allowed caller of `deploy()`.
    constructor(address deployer_) public {
        deployer = deployer_;
        _implementation = address(this);
    }
    /// @dev Deploy the `ZeroEx` contract with the minimum feature set,
    ///      transfers ownership to `owner`, then self-destructs.
    ///      Only callable by `deployer` set in the contstructor.
    /// @param owner The owner of the contract.
    /// @param features Features to bootstrap into the proxy.
    /// @return zeroEx The deployed and configured `ZeroEx` contract.
    function deploy(address payable owner, BootstrapFeatures memory features)
        public
        virtual
        returns (ZeroEx zeroEx)
    {
        // Must be called by the allowed deployer.
        require(msg.sender == deployer, "InitialMigration/INVALID_SENDER");
        // Deploy the ZeroEx contract, setting ourselves as the bootstrapper.
        zeroEx = new ZeroEx();
        // Bootstrap the initial feature set.
        IBootstrap(address(zeroEx)).bootstrap(
            address(this),
            abi.encodeWithSelector(this.bootstrap.selector, owner, features)
        );
        // Self-destruct. This contract should not hold any funds but we send
        // them to the owner just in case.
        this.die(owner);
    }
    /// @dev Sets up the initial state of the `ZeroEx` contract.
    ///      The `ZeroEx` contract will delegatecall into this function.
    /// @param owner The new owner of the ZeroEx contract.
    /// @param features Features to bootstrap into the proxy.
    /// @return success Magic bytes if successful.
    function bootstrap(address owner, BootstrapFeatures memory features)
        public
        virtual
        returns (bytes4 success)
    {
        // Deploy and migrate the initial features.
        // Order matters here.
        // Initialize Registry.
        LibBootstrap.delegatecallBootstrapFunction(
            address(features.registry),
            abi.encodeWithSelector(
                SimpleFunctionRegistry.bootstrap.selector
            )
        );
        // Initialize Ownable.
        LibBootstrap.delegatecallBootstrapFunction(
            address(features.ownable),
            abi.encodeWithSelector(
                Ownable.bootstrap.selector
            )
        );
        // De-register `SimpleFunctionRegistry._extendSelf`.
        SimpleFunctionRegistry(address(this)).rollback(
            SimpleFunctionRegistry._extendSelf.selector,
            address(0)
        );
        // Transfer ownership to the real owner.
        Ownable(address(this)).transferOwnership(owner);
        success = LibBootstrap.BOOTSTRAP_SUCCESS;
    }
    /// @dev Self-destructs this contract. Only callable by this contract.
    /// @param ethRecipient Who to transfer outstanding ETH to.
    function die(address payable ethRecipient) public virtual {
        require(msg.sender == _implementation, "InitialMigration/INVALID_SENDER");
        selfdestruct(ethRecipient);
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
import "@0x/contracts-utils/contracts/src/v06/LibSafeMathV06.sol";
import "@0x/contracts-erc20/contracts/src/v06/IERC20TokenV06.sol";
import "@0x/contracts-erc20/contracts/src/v06/LibERC20TokenV06.sol";
import "../errors/LibTransformERC20RichErrors.sol";
import "./Transformer.sol";
import "./LibERC20Transformer.sol";
/// @dev A transformer that transfers tokens to arbitrary addresses.
contract AffiliateFeeTransformer is
    Transformer
{
    // solhint-disable no-empty-blocks
    using LibRichErrorsV06 for bytes;
    using LibSafeMathV06 for uint256;
    using LibERC20Transformer for IERC20TokenV06;
    /// @dev Information for a single fee.
    struct TokenFee {
        // The token to transfer to `recipient`.
        IERC20TokenV06 token;
        // Amount of each `token` to transfer to `recipient`.
        // If `amount == uint256(-1)`, the entire balance of `token` will be
        // transferred.
        uint256 amount;
        // Recipient of `token`.
        address payable recipient;
    }
    uint256 private constant MAX_UINT256 = uint256(-1);
    /// @dev Create this contract.
    constructor()
        public
        Transformer()
    {}
    /// @dev Transfers tokens to recipients.
    /// @param data ABI-encoded `TokenFee[]`, indicating which tokens to transfer.
    /// @return success The success bytes (`LibERC20Transformer.TRANSFORMER_SUCCESS`).
    function transform(
        bytes32, // callDataHash,
        address payable, // taker,
        bytes calldata data
    )
        external
        override
        returns (bytes4 success)
    {
        TokenFee[] memory fees = abi.decode(data, (TokenFee[]));
        // Transfer tokens to recipients.
        for (uint256 i = 0; i < fees.length; ++i) {
            uint256 amount = fees[i].amount;
            if (amount == MAX_UINT256) {
                amount = LibERC20Transformer.getTokenBalanceOf(fees[i].token, address(this));
            }
            if (amount != 0) {
                fees[i].token.transformerTransfer(fees[i].recipient, amount);
            }
        }
        return LibERC20Transformer.TRANSFORMER_SUCCESS;
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
import "../errors/LibTransformERC20RichErrors.sol";
import "./IERC20Transformer.sol";
/// @dev Abstract base class for transformers.
abstract contract Transformer is
    IERC20Transformer
{
    using LibRichErrorsV06 for bytes;
    /// @dev The address of the deployer.
    address public immutable deployer;
    /// @dev The original address of this contract.
    address private immutable _implementation;
    /// @dev Create this contract.
    constructor() public {
        deployer = msg.sender;
        _implementation = address(this);
    }
    /// @dev Destruct this contract. Only callable by the deployer and will not
    ///      succeed in the context of a delegatecall (from another contract).
    /// @param ethRecipient The recipient of ETH held in this contract.
    function die(address payable ethRecipient)
        external
        virtual
    {
        // Only the deployer can call this.
        if (msg.sender != deployer) {
            LibTransformERC20RichErrors
                .OnlyCallableByDeployerError(msg.sender, deployer)
                .rrevert();
        }
        // Must be executing our own context.
        if (address(this) != _implementation) {
            LibTransformERC20RichErrors
                .InvalidExecutionContextError(address(this), _implementation)
                .rrevert();
        }
        selfdestruct(ethRecipient);
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
import "@0x/contracts-erc20/contracts/src/v06/IERC20TokenV06.sol";
import "@0x/contracts-utils/contracts/src/v06/LibBytesV06.sol";
import "@0x/contracts-erc20/contracts/src/v06/LibERC20TokenV06.sol";
import "@0x/contracts-utils/contracts/src/v06/LibSafeMathV06.sol";
import "@0x/contracts-utils/contracts/src/v06/LibMathV06.sol";
import "../errors/LibTransformERC20RichErrors.sol";
import "../vendor/v3/IExchange.sol";
import "./Transformer.sol";
import "./LibERC20Transformer.sol";
/// @dev A transformer that fills an ERC20 market sell/buy quote.
contract FillQuoteTransformer is
    Transformer
{
    using LibERC20TokenV06 for IERC20TokenV06;
    using LibERC20Transformer for IERC20TokenV06;
    using LibSafeMathV06 for uint256;
    using LibRichErrorsV06 for bytes;
    /// @dev Whether we are performing a market sell or buy.
    enum Side {
        Sell,
        Buy
    }
    /// @dev Transform data to ABI-encode and pass into `transform()`.
    struct TransformData {
        // Whether we aer performing a market sell or buy.
        Side side;
        // The token being sold.
        // This should be an actual token, not the ETH pseudo-token.
        IERC20TokenV06 sellToken;
        // The token being bought.
        // This should be an actual token, not the ETH pseudo-token.
        IERC20TokenV06 buyToken;
        // The orders to fill.
        IExchange.Order[] orders;
        // Signatures for each respective order in `orders`.
        bytes[] signatures;
        // Maximum fill amount for each order. This may be shorter than the
        // number of orders, where missing entries will be treated as `uint256(-1)`.
        // For sells, this will be the maximum sell amount (taker asset).
        // For buys, this will be the maximum buy amount (maker asset).
        uint256[] maxOrderFillAmounts;
        // Amount of `sellToken` to sell or `buyToken` to buy.
        // For sells, this may be `uint256(-1)` to sell the entire balance of
        // `sellToken`.
        uint256 fillAmount;
    }
    /// @dev Results of a call to `_fillOrder()`.
    struct FillOrderResults {
        // The amount of taker tokens sold, according to balance checks.
        uint256 takerTokenSoldAmount;
        // The amount of maker tokens sold, according to balance checks.
        uint256 makerTokenBoughtAmount;
        // The amount of protocol fee paid.
        uint256 protocolFeePaid;
    }
    /// @dev The Exchange ERC20Proxy ID.
    bytes4 private constant ERC20_ASSET_PROXY_ID = 0xf47261b0;
    /// @dev Maximum uint256 value.
    uint256 private constant MAX_UINT256 = uint256(-1);
    /// @dev The Exchange contract.
    IExchange public immutable exchange;
    /// @dev The ERC20Proxy address.
    address public immutable erc20Proxy;
    /// @dev Create this contract.
    /// @param exchange_ The Exchange V3 instance.
    constructor(IExchange exchange_)
        public
        Transformer()
    {
        exchange = exchange_;
        erc20Proxy = exchange_.getAssetProxy(ERC20_ASSET_PROXY_ID);
    }
    /// @dev Sell this contract's entire balance of of `sellToken` in exchange
    ///      for `buyToken` by filling `orders`. Protocol fees should be attached
    ///      to this call. `buyToken` and excess ETH will be transferred back to the caller.
    /// @param data_ ABI-encoded `TransformData`.
    /// @return success The success bytes (`LibERC20Transformer.TRANSFORMER_SUCCESS`).
    function transform(
        bytes32, // callDataHash,
        address payable, // taker,
        bytes calldata data_
    )
        external
        override
        returns (bytes4 success)
    {
        TransformData memory data = abi.decode(data_, (TransformData));
        // Validate data fields.
        if (data.sellToken.isTokenETH() || data.buyToken.isTokenETH()) {
            LibTransformERC20RichErrors.InvalidTransformDataError(
                LibTransformERC20RichErrors.InvalidTransformDataErrorCode.INVALID_TOKENS,
                data_
            ).rrevert();
        }
        if (data.orders.length != data.signatures.length) {
            LibTransformERC20RichErrors.InvalidTransformDataError(
                LibTransformERC20RichErrors.InvalidTransformDataErrorCode.INVALID_ARRAY_LENGTH,
                data_
            ).rrevert();
        }
        if (data.side == Side.Sell && data.fillAmount == MAX_UINT256) {
            // If `sellAmount == -1 then we are selling
            // the entire balance of `sellToken`. This is useful in cases where
            // the exact sell amount is not exactly known in advance, like when
            // unwrapping Chai/cUSDC/cDAI.
            data.fillAmount = data.sellToken.getTokenBalanceOf(address(this));
        }
        // Approve the ERC20 proxy to spend `sellToken`.
        data.sellToken.approveIfBelow(erc20Proxy, data.fillAmount);
        // Fill the orders.
        uint256 singleProtocolFee = exchange.protocolFeeMultiplier().safeMul(tx.gasprice);
        uint256 ethRemaining = address(this).balance;
        uint256 boughtAmount = 0;
        uint256 soldAmount = 0;
        for (uint256 i = 0; i < data.orders.length; ++i) {
            // Check if we've hit our targets.
            if (data.side == Side.Sell) {
                // Market sell check.
                if (soldAmount >= data.fillAmount) {
                    break;
                }
            } else {
                // Market buy check.
                if (boughtAmount >= data.fillAmount) {
                    break;
                }
            }
            // Ensure we have enough ETH to cover the protocol fee.
            if (ethRemaining < singleProtocolFee) {
                LibTransformERC20RichErrors
                    .InsufficientProtocolFeeError(ethRemaining, singleProtocolFee)
                    .rrevert();
            }
            // Fill the order.
            FillOrderResults memory results;
            if (data.side == Side.Sell) {
                // Market sell.
                results = _sellToOrder(
                    data.buyToken,
                    data.sellToken,
                    data.orders[i],
                    data.signatures[i],
                    data.fillAmount.safeSub(soldAmount).min256(
                        data.maxOrderFillAmounts.length > i
                        ? data.maxOrderFillAmounts[i]
                        : MAX_UINT256
                    ),
                    singleProtocolFee
                );
            } else {
                // Market buy.
                results = _buyFromOrder(
                    data.buyToken,
                    data.sellToken,
                    data.orders[i],
                    data.signatures[i],
                    data.fillAmount.safeSub(boughtAmount).min256(
                        data.maxOrderFillAmounts.length > i
                        ? data.maxOrderFillAmounts[i]
                        : MAX_UINT256
                    ),
                    singleProtocolFee
                );
            }
            // Accumulate totals.
            soldAmount = soldAmount.safeAdd(results.takerTokenSoldAmount);
            boughtAmount = boughtAmount.safeAdd(results.makerTokenBoughtAmount);
            ethRemaining = ethRemaining.safeSub(results.protocolFeePaid);
        }
        // Ensure we hit our targets.
        if (data.side == Side.Sell) {
            // Market sell check.
            if (soldAmount < data.fillAmount) {
                LibTransformERC20RichErrors
                    .IncompleteFillSellQuoteError(
                        address(data.sellToken),
                        soldAmount,
                        data.fillAmount
                    ).rrevert();
            }
        } else {
            // Market buy check.
            if (boughtAmount < data.fillAmount) {
                LibTransformERC20RichErrors
                    .IncompleteFillBuyQuoteError(
                        address(data.buyToken),
                        boughtAmount,
                        data.fillAmount
                    ).rrevert();
            }
        }
        return LibERC20Transformer.TRANSFORMER_SUCCESS;
    }
    /// @dev Try to sell up to `sellAmount` from an order.
    /// @param makerToken The maker/buy token.
    /// @param takerToken The taker/sell token.
    /// @param order The order to fill.
    /// @param signature The signature for `order`.
    /// @param sellAmount Amount of taker token to sell.
    /// @param protocolFee The protocol fee needed to fill `order`.
    function _sellToOrder(
        IERC20TokenV06 makerToken,
        IERC20TokenV06 takerToken,
        IExchange.Order memory order,
        bytes memory signature,
        uint256 sellAmount,
        uint256 protocolFee
    )
        private
        returns (FillOrderResults memory results)
    {
        IERC20TokenV06 takerFeeToken =
            _getTokenFromERC20AssetData(order.takerFeeAssetData);
        uint256 takerTokenFillAmount = sellAmount;
        if (order.takerFee != 0) {
            if (takerFeeToken == makerToken) {
                // Taker fee is payable in the maker token, so we need to
                // approve the proxy to spend the maker token.
                // It isn't worth computing the actual taker fee
                // since `approveIfBelow()` will set the allowance to infinite. We
                // just need a reasonable upper bound to avoid unnecessarily re-approving.
                takerFeeToken.approveIfBelow(erc20Proxy, order.takerFee);
            } else if (takerFeeToken == takerToken){
                // Taker fee is payable in the taker token, so we need to
                // reduce the fill amount to cover the fee.
                // takerTokenFillAmount' =
                //   (takerTokenFillAmount * order.takerAssetAmount) /
                //   (order.takerAssetAmount + order.takerFee)
                takerTokenFillAmount = LibMathV06.getPartialAmountCeil(
                    order.takerAssetAmount,
                    order.takerAssetAmount.safeAdd(order.takerFee),
                    sellAmount
                );
            } else {
                //  Only support taker or maker asset denominated taker fees.
                LibTransformERC20RichErrors.InvalidTakerFeeTokenError(
                    address(takerFeeToken)
                ).rrevert();
            }
        }
        // Clamp fill amount to order size.
        takerTokenFillAmount = LibSafeMathV06.min256(
            takerTokenFillAmount,
            order.takerAssetAmount
        );
        // Perform the fill.
        return _fillOrder(
            order,
            signature,
            takerTokenFillAmount,
            protocolFee,
            makerToken,
            takerFeeToken == takerToken
        );
    }
    /// @dev Try to buy up to `buyAmount` from an order.
    /// @param makerToken The maker/buy token.
    /// @param takerToken The taker/sell token.
    /// @param order The order to fill.
    /// @param signature The signature for `order`.
    /// @param buyAmount Amount of maker token to buy.
    /// @param protocolFee The protocol fee needed to fill `order`.
    function _buyFromOrder(
        IERC20TokenV06 makerToken,
        IERC20TokenV06 takerToken,
        IExchange.Order memory order,
        bytes memory signature,
        uint256 buyAmount,
        uint256 protocolFee
    )
        private
        returns (FillOrderResults memory results)
    {
        IERC20TokenV06 takerFeeToken =
            _getTokenFromERC20AssetData(order.takerFeeAssetData);
        // Compute the default taker token fill amount.
        uint256 takerTokenFillAmount = LibMathV06.getPartialAmountCeil(
            buyAmount,
            order.makerAssetAmount,
            order.takerAssetAmount
        );
        if (order.takerFee != 0) {
            if (takerFeeToken == makerToken) {
                // Taker fee is payable in the maker token.
                // Adjust the taker token fill amount to account for maker
                // tokens being lost to the taker fee.
                // takerTokenFillAmount' =
                //  (order.takerAssetAmount * buyAmount) /
                //  (order.makerAssetAmount - order.takerFee)
                takerTokenFillAmount = LibMathV06.getPartialAmountCeil(
                    buyAmount,
                    order.makerAssetAmount.safeSub(order.takerFee),
                    order.takerAssetAmount
                );
                // Approve the proxy to spend the maker token.
                // It isn't worth computing the actual taker fee
                // since `approveIfBelow()` will set the allowance to infinite. We
                // just need a reasonable upper bound to avoid unnecessarily re-approving.
                takerFeeToken.approveIfBelow(erc20Proxy, order.takerFee);
            } else if (takerFeeToken != takerToken) {
                //  Only support taker or maker asset denominated taker fees.
                LibTransformERC20RichErrors.InvalidTakerFeeTokenError(
                    address(takerFeeToken)
                ).rrevert();
            }
        }
        // Clamp to order size.
        takerTokenFillAmount = LibSafeMathV06.min256(
            order.takerAssetAmount,
            takerTokenFillAmount
        );
        // Perform the fill.
        return _fillOrder(
            order,
            signature,
            takerTokenFillAmount,
            protocolFee,
            makerToken,
            takerFeeToken == takerToken
        );
    }
    /// @dev Attempt to fill an order. If the fill reverts, the revert will be
    ///      swallowed and `results` will be zeroed out.
    /// @param order The order to fill.
    /// @param signature The order signature.
    /// @param takerAssetFillAmount How much taker asset to fill.
    /// @param protocolFee The protocol fee needed to fill this order.
    /// @param makerToken The maker token.
    /// @param isTakerFeeInTakerToken Whether the taker fee token is the same as the
    ///        taker token.
    function _fillOrder(
        IExchange.Order memory order,
        bytes memory signature,
        uint256 takerAssetFillAmount,
        uint256 protocolFee,
        IERC20TokenV06 makerToken,
        bool isTakerFeeInTakerToken
    )
        private
        returns (FillOrderResults memory results)
    {
        // Track changes in the maker token balance.
        uint256 initialMakerTokenBalance = makerToken.balanceOf(address(this));
        try
            exchange.fillOrder
                {value: protocolFee}
                (order, takerAssetFillAmount, signature)
            returns (IExchange.FillResults memory fillResults)
        {
            // Update maker quantity based on changes in token balances.
            results.makerTokenBoughtAmount = makerToken.balanceOf(address(this))
                .safeSub(initialMakerTokenBalance);
            // We can trust the other fill result quantities.
            results.protocolFeePaid = fillResults.protocolFeePaid;
            results.takerTokenSoldAmount = fillResults.takerAssetFilledAmount;
            // If the taker fee is payable in the taker asset, include the
            // taker fee in the total amount sold.
            if (isTakerFeeInTakerToken) {
                results.takerTokenSoldAmount =
                    results.takerTokenSoldAmount.safeAdd(fillResults.takerFeePaid);
            }
        } catch (bytes memory) {
            // Swallow failures, leaving all results as zero.
        }
    }
    /// @dev Extract the token from plain ERC20 asset data.
    ///      If the asset-data is empty, a zero token address will be returned.
    /// @param assetData The order asset data.
    function _getTokenFromERC20AssetData(bytes memory assetData)
        private
        pure
        returns (IERC20TokenV06 token)
    {
        if (assetData.length == 0) {
            return IERC20TokenV06(address(0));
        }
        if (assetData.length != 36 ||
            LibBytesV06.readBytes4(assetData, 0) != ERC20_ASSET_PROXY_ID)
        {
            LibTransformERC20RichErrors
                .InvalidERC20AssetDataError(assetData)
                .rrevert();
        }
        return IERC20TokenV06(LibBytesV06.readAddress(assetData, 16));
    }
}
/*
  Copyright 2019 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
import "./LibSafeMathV06.sol";
import "./errors/LibRichErrorsV06.sol";
import "./errors/LibMathRichErrorsV06.sol";
library LibMathV06 {
    using LibSafeMathV06 for uint256;
    /// @dev Calculates partial value given a numerator and denominator rounded down.
    ///      Reverts if rounding error is >= 0.1%
    /// @param numerator Numerator.
    /// @param denominator Denominator.
    /// @param target Value to calculate partial of.
    /// @return partialAmount Partial value of target rounded down.
    function safeGetPartialAmountFloor(
        uint256 numerator,
        uint256 denominator,
        uint256 target
    )
        internal
        pure
        returns (uint256 partialAmount)
    {
        if (isRoundingErrorFloor(
                numerator,
                denominator,
                target
        )) {
            LibRichErrorsV06.rrevert(LibMathRichErrorsV06.RoundingError(
                numerator,
                denominator,
                target
            ));
        }
        partialAmount = numerator.safeMul(target).safeDiv(denominator);
        return partialAmount;
    }
    /// @dev Calculates partial value given a numerator and denominator rounded down.
    ///      Reverts if rounding error is >= 0.1%
    /// @param numerator Numerator.
    /// @param denominator Denominator.
    /// @param target Value to calculate partial of.
    /// @return partialAmount Partial value of target rounded up.
    function safeGetPartialAmountCeil(
        uint256 numerator,
        uint256 denominator,
        uint256 target
    )
        internal
        pure
        returns (uint256 partialAmount)
    {
        if (isRoundingErrorCeil(
                numerator,
                denominator,
                target
        )) {
            LibRichErrorsV06.rrevert(LibMathRichErrorsV06.RoundingError(
                numerator,
                denominator,
                target
            ));
        }
        // safeDiv computes `floor(a / b)`. We use the identity (a, b integer):
        //       ceil(a / b) = floor((a + b - 1) / b)
        // To implement `ceil(a / b)` using safeDiv.
        partialAmount = numerator.safeMul(target)
            .safeAdd(denominator.safeSub(1))
            .safeDiv(denominator);
        return partialAmount;
    }
    /// @dev Calculates partial value given a numerator and denominator rounded down.
    /// @param numerator Numerator.
    /// @param denominator Denominator.
    /// @param target Value to calculate partial of.
    /// @return partialAmount Partial value of target rounded down.
    function getPartialAmountFloor(
        uint256 numerator,
        uint256 denominator,
        uint256 target
    )
        internal
        pure
        returns (uint256 partialAmount)
    {
        partialAmount = numerator.safeMul(target).safeDiv(denominator);
        return partialAmount;
    }
    /// @dev Calculates partial value given a numerator and denominator rounded down.
    /// @param numerator Numerator.
    /// @param denominator Denominator.
    /// @param target Value to calculate partial of.
    /// @return partialAmount Partial value of target rounded up.
    function getPartialAmountCeil(
        uint256 numerator,
        uint256 denominator,
        uint256 target
    )
        internal
        pure
        returns (uint256 partialAmount)
    {
        // safeDiv computes `floor(a / b)`. We use the identity (a, b integer):
        //       ceil(a / b) = floor((a + b - 1) / b)
        // To implement `ceil(a / b)` using safeDiv.
        partialAmount = numerator.safeMul(target)
            .safeAdd(denominator.safeSub(1))
            .safeDiv(denominator);
        return partialAmount;
    }
    /// @dev Checks if rounding error >= 0.1% when rounding down.
    /// @param numerator Numerator.
    /// @param denominator Denominator.
    /// @param target Value to multiply with numerator/denominator.
    /// @return isError Rounding error is present.
    function isRoundingErrorFloor(
        uint256 numerator,
        uint256 denominator,
        uint256 target
    )
        internal
        pure
        returns (bool isError)
    {
        if (denominator == 0) {
            LibRichErrorsV06.rrevert(LibMathRichErrorsV06.DivisionByZeroError());
        }
        // The absolute rounding error is the difference between the rounded
        // value and the ideal value. The relative rounding error is the
        // absolute rounding error divided by the absolute value of the
        // ideal value. This is undefined when the ideal value is zero.
        //
        // The ideal value is `numerator * target / denominator`.
        // Let's call `numerator * target % denominator` the remainder.
        // The absolute error is `remainder / denominator`.
        //
        // When the ideal value is zero, we require the absolute error to
        // be zero. Fortunately, this is always the case. The ideal value is
        // zero iff `numerator == 0` and/or `target == 0`. In this case the
        // remainder and absolute error are also zero.
        if (target == 0 || numerator == 0) {
            return false;
        }
        // Otherwise, we want the relative rounding error to be strictly
        // less than 0.1%.
        // The relative error is `remainder / (numerator * target)`.
        // We want the relative error less than 1 / 1000:
        //        remainder / (numerator * denominator)  <  1 / 1000
        // or equivalently:
        //        1000 * remainder  <  numerator * target
        // so we have a rounding error iff:
        //        1000 * remainder  >=  numerator * target
        uint256 remainder = mulmod(
            target,
            numerator,
            denominator
        );
        isError = remainder.safeMul(1000) >= numerator.safeMul(target);
        return isError;
    }
    /// @dev Checks if rounding error >= 0.1% when rounding up.
    /// @param numerator Numerator.
    /// @param denominator Denominator.
    /// @param target Value to multiply with numerator/denominator.
    /// @return isError Rounding error is present.
    function isRoundingErrorCeil(
        uint256 numerator,
        uint256 denominator,
        uint256 target
    )
        internal
        pure
        returns (bool isError)
    {
        if (denominator == 0) {
            LibRichErrorsV06.rrevert(LibMathRichErrorsV06.DivisionByZeroError());
        }
        // See the comments in `isRoundingError`.
        if (target == 0 || numerator == 0) {
            // When either is zero, the ideal value and rounded value are zero
            // and there is no rounding error. (Although the relative error
            // is undefined.)
            return false;
        }
        // Compute remainder as before
        uint256 remainder = mulmod(
            target,
            numerator,
            denominator
        );
        remainder = denominator.safeSub(remainder) % denominator;
        isError = remainder.safeMul(1000) >= numerator.safeMul(target);
        return isError;
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
library LibMathRichErrorsV06 {
    // bytes4(keccak256("DivisionByZeroError()"))
    bytes internal constant DIVISION_BY_ZERO_ERROR =
        hex"a791837c";
    // bytes4(keccak256("RoundingError(uint256,uint256,uint256)"))
    bytes4 internal constant ROUNDING_ERROR_SELECTOR =
        0x339f3de2;
    // solhint-disable func-name-mixedcase
    function DivisionByZeroError()
        internal
        pure
        returns (bytes memory)
    {
        return DIVISION_BY_ZERO_ERROR;
    }
    function RoundingError(
        uint256 numerator,
        uint256 denominator,
        uint256 target
    )
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            ROUNDING_ERROR_SELECTOR,
            numerator,
            denominator,
            target
        );
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
/// @dev Interface to the V3 Exchange.
interface IExchange {
    /// @dev V3 Order structure.
    struct Order {
        // Address that created the order.
        address makerAddress;
        // Address that is allowed to fill the order.
        // If set to 0, any address is allowed to fill the order.
        address takerAddress;
        // Address that will recieve fees when order is filled.
        address feeRecipientAddress;
        // Address that is allowed to call Exchange contract methods that affect this order.
        // If set to 0, any address is allowed to call these methods.
        address senderAddress;
        // Amount of makerAsset being offered by maker. Must be greater than 0.
        uint256 makerAssetAmount;
        // Amount of takerAsset being bid on by maker. Must be greater than 0.
        uint256 takerAssetAmount;
        // Fee paid to feeRecipient by maker when order is filled.
        uint256 makerFee;
        // Fee paid to feeRecipient by taker when order is filled.
        uint256 takerFee;
        // Timestamp in seconds at which order expires.
        uint256 expirationTimeSeconds;
        // Arbitrary number to facilitate uniqueness of the order's hash.
        uint256 salt;
        // Encoded data that can be decoded by a specified proxy contract when transferring makerAsset.
        // The leading bytes4 references the id of the asset proxy.
        bytes makerAssetData;
        // Encoded data that can be decoded by a specified proxy contract when transferring takerAsset.
        // The leading bytes4 references the id of the asset proxy.
        bytes takerAssetData;
        // Encoded data that can be decoded by a specified proxy contract when transferring makerFeeAsset.
        // The leading bytes4 references the id of the asset proxy.
        bytes makerFeeAssetData;
        // Encoded data that can be decoded by a specified proxy contract when transferring takerFeeAsset.
        // The leading bytes4 references the id of the asset proxy.
        bytes takerFeeAssetData;
    }
    /// @dev V3 `fillOrder()` results.`
    struct FillResults {
        // Total amount of makerAsset(s) filled.
        uint256 makerAssetFilledAmount;
        // Total amount of takerAsset(s) filled.
        uint256 takerAssetFilledAmount;
        // Total amount of fees paid by maker(s) to feeRecipient(s).
        uint256 makerFeePaid;
        // Total amount of fees paid by taker to feeRecipients(s).
        uint256 takerFeePaid;
        // Total amount of fees paid by taker to the staking contract.
        uint256 protocolFeePaid;
    }
    /// @dev Fills the input order.
    /// @param order Order struct containing order specifications.
    /// @param takerAssetFillAmount Desired amount of takerAsset to sell.
    /// @param signature Proof that order has been created by maker.
    /// @return fillResults Amounts filled and fees paid by maker and taker.
    function fillOrder(
        Order calldata order,
        uint256 takerAssetFillAmount,
        bytes calldata signature
    )
        external
        payable
        returns (FillResults memory fillResults);
    /// @dev Returns the protocolFeeMultiplier
    /// @return multiplier The multiplier for protocol fees.
    function protocolFeeMultiplier()
        external
        view
        returns (uint256 multiplier);
    /// @dev Gets an asset proxy.
    /// @param assetProxyId Id of the asset proxy.
    /// @return proxyAddress The asset proxy registered to assetProxyId.
    ///         Returns 0x0 if no proxy is registered.
    function getAssetProxy(bytes4 assetProxyId)
        external
        view
        returns (address proxyAddress);
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
import "@0x/contracts-utils/contracts/src/v06/LibSafeMathV06.sol";
import "@0x/contracts-erc20/contracts/src/v06/IERC20TokenV06.sol";
import "@0x/contracts-erc20/contracts/src/v06/LibERC20TokenV06.sol";
import "../errors/LibTransformERC20RichErrors.sol";
import "./Transformer.sol";
import "./LibERC20Transformer.sol";
/// @dev A transformer that transfers tokens to the taker.
contract PayTakerTransformer is
    Transformer
{
    // solhint-disable no-empty-blocks
    using LibRichErrorsV06 for bytes;
    using LibSafeMathV06 for uint256;
    using LibERC20Transformer for IERC20TokenV06;
    /// @dev Transform data to ABI-encode and pass into `transform()`.
    struct TransformData {
        // The tokens to transfer to the taker.
        IERC20TokenV06[] tokens;
        // Amount of each token in `tokens` to transfer to the taker.
        // `uint(-1)` will transfer the entire balance.
        uint256[] amounts;
    }
    /// @dev Maximum uint256 value.
    uint256 private constant MAX_UINT256 = uint256(-1);
    /// @dev Create this contract.
    constructor()
        public
        Transformer()
    {}
    /// @dev Forwards tokens to the taker.
    /// @param taker The taker address (caller of `TransformERC20.transformERC20()`).
    /// @param data_ ABI-encoded `TransformData`, indicating which tokens to transfer.
    /// @return success The success bytes (`LibERC20Transformer.TRANSFORMER_SUCCESS`).
    function transform(
        bytes32, // callDataHash,
        address payable taker,
        bytes calldata data_
    )
        external
        override
        returns (bytes4 success)
    {
        TransformData memory data = abi.decode(data_, (TransformData));
        // Transfer tokens directly to the taker.
        for (uint256 i = 0; i < data.tokens.length; ++i) {
            // The `amounts` array can be shorter than the `tokens` array.
            // Missing elements are treated as `uint256(-1)`.
            uint256 amount = data.amounts.length > i ? data.amounts[i] : uint256(-1);
            if (amount == MAX_UINT256) {
                amount = data.tokens[i].getTokenBalanceOf(address(this));
            }
            if (amount != 0) {
                data.tokens[i].transformerTransfer(taker, amount);
            }
        }
        return LibERC20Transformer.TRANSFORMER_SUCCESS;
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
import "@0x/contracts-utils/contracts/src/v06/LibSafeMathV06.sol";
import "@0x/contracts-erc20/contracts/src/v06/IEtherTokenV06.sol";
import "../errors/LibTransformERC20RichErrors.sol";
import "./Transformer.sol";
import "./LibERC20Transformer.sol";
/// @dev A transformer that wraps or unwraps WETH.
contract WethTransformer is
    Transformer
{
    using LibRichErrorsV06 for bytes;
    using LibSafeMathV06 for uint256;
    using LibERC20Transformer for IERC20TokenV06;
    /// @dev Transform data to ABI-encode and pass into `transform()`.
    struct TransformData {
        // The token to wrap/unwrap. Must be either ETH or WETH.
        IERC20TokenV06 token;
        // Amount of `token` to wrap or unwrap.
        // `uint(-1)` will unwrap the entire balance.
        uint256 amount;
    }
    /// @dev The WETH contract address.
    IEtherTokenV06 public immutable weth;
    /// @dev Maximum uint256 value.
    uint256 private constant MAX_UINT256 = uint256(-1);
    /// @dev Construct the transformer and store the WETH address in an immutable.
    /// @param weth_ The weth token.
    constructor(IEtherTokenV06 weth_)
        public
        Transformer()
    {
        weth = weth_;
    }
    /// @dev Wraps and unwraps WETH.
    /// @param data_ ABI-encoded `TransformData`, indicating which token to wrap/umwrap.
    /// @return success The success bytes (`LibERC20Transformer.TRANSFORMER_SUCCESS`).
    function transform(
        bytes32, // callDataHash,
        address payable, // taker,
        bytes calldata data_
    )
        external
        override
        returns (bytes4 success)
    {
        TransformData memory data = abi.decode(data_, (TransformData));
        if (!data.token.isTokenETH() && data.token != weth) {
            LibTransformERC20RichErrors.InvalidTransformDataError(
                LibTransformERC20RichErrors.InvalidTransformDataErrorCode.INVALID_TOKENS,
                data_
            ).rrevert();
        }
        uint256 amount = data.amount;
        if (amount == MAX_UINT256) {
            amount = data.token.getTokenBalanceOf(address(this));
        }
        if (amount != 0) {
            if (data.token.isTokenETH()) {
                // Wrap ETH.
                weth.deposit{value: amount}();
            } else {
                // Unwrap WETH.
                weth.withdraw(amount);
            }
        }
        return LibERC20Transformer.TRANSFORMER_SUCCESS;
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
import "./IERC20TokenV06.sol";
interface IEtherTokenV06 is
    IERC20TokenV06
{
    /// @dev Wrap ether.
    function deposit() external payable;
    /// @dev Unwrap ether.
    function withdraw(uint256 amount) external;
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
interface ITestSimpleFunctionRegistryFeature {
    function testFn() external view returns (uint256 id);
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
contract TestCallTarget {
    event CallTargetCalled(
        address context,
        address sender,
        bytes data,
        uint256 value
    );
    bytes4 private constant MAGIC_BYTES = 0x12345678;
    bytes private constant REVERTING_DATA = hex"1337";
    fallback() external payable {
        if (keccak256(msg.data) == keccak256(REVERTING_DATA)) {
            revert("TestCallTarget/REVERT");
        }
        emit CallTargetCalled(
            address(this),
            msg.sender,
            msg.data,
            msg.value
        );
        bytes4 rval = MAGIC_BYTES;
        assembly {
            mstore(0, rval)
            return(0, 32)
        }
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
contract TestDelegateCaller {
    function executeDelegateCall(
        address target,
        bytes calldata callData
    )
        external
    {
        (bool success, bytes memory resultData) = target.delegatecall(callData);
        if (!success) {
            assembly { revert(add(resultData, 32), mload(resultData)) }
        }
        assembly { return(add(resultData, 32), mload(resultData)) }
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-utils/contracts/src/v06/LibBytesV06.sol";
import "@0x/contracts-utils/contracts/src/v06/LibMathV06.sol";
import "@0x/contracts-utils/contracts/src/v06/LibSafeMathV06.sol";
import "../src/vendor/v3/IExchange.sol";
import "./TestMintableERC20Token.sol";
contract TestFillQuoteTransformerExchange {
    struct FillBehavior {
        // How much of the order is filled, in taker asset amount.
        uint256 filledTakerAssetAmount;
        // Scaling for maker assets minted, in 1e18.
        uint256 makerAssetMintRatio;
    }
    uint256 private constant PROTOCOL_FEE_MULTIPLIER = 1337;
    using LibSafeMathV06 for uint256;
    function fillOrder(
        IExchange.Order calldata order,
        uint256 takerAssetFillAmount,
        bytes calldata signature
    )
        external
        payable
        returns (IExchange.FillResults memory fillResults)
    {
        require(
            signature.length != 0,
            "TestFillQuoteTransformerExchange/INVALID_SIGNATURE"
        );
        // The signature is the ABI-encoded FillBehavior data.
        FillBehavior memory behavior = abi.decode(signature, (FillBehavior));
        uint256 protocolFee = PROTOCOL_FEE_MULTIPLIER * tx.gasprice;
        require(
            msg.value == protocolFee,
            "TestFillQuoteTransformerExchange/INSUFFICIENT_PROTOCOL_FEE"
        );
        // Return excess protocol fee.
        msg.sender.transfer(msg.value - protocolFee);
        // Take taker tokens.
        TestMintableERC20Token takerToken = _getTokenFromAssetData(order.takerAssetData);
        takerAssetFillAmount = LibSafeMathV06.min256(
            order.takerAssetAmount.safeSub(behavior.filledTakerAssetAmount),
            takerAssetFillAmount
        );
        require(
            takerToken.getSpendableAmount(msg.sender, address(this)) >= takerAssetFillAmount,
            "TestFillQuoteTransformerExchange/INSUFFICIENT_TAKER_FUNDS"
        );
        takerToken.transferFrom(msg.sender, order.makerAddress, takerAssetFillAmount);
        // Mint maker tokens.
        uint256 makerAssetFilledAmount = LibMathV06.getPartialAmountFloor(
            takerAssetFillAmount,
            order.takerAssetAmount,
            order.makerAssetAmount
        );
        TestMintableERC20Token makerToken = _getTokenFromAssetData(order.makerAssetData);
        makerToken.mint(
            msg.sender,
            LibMathV06.getPartialAmountFloor(
                behavior.makerAssetMintRatio,
                1e18,
                makerAssetFilledAmount
            )
        );
        // Take taker fee.
        TestMintableERC20Token takerFeeToken = _getTokenFromAssetData(order.takerFeeAssetData);
        uint256 takerFee = LibMathV06.getPartialAmountFloor(
            takerAssetFillAmount,
            order.takerAssetAmount,
            order.takerFee
        );
        require(
            takerFeeToken.getSpendableAmount(msg.sender, address(this)) >= takerFee,
            "TestFillQuoteTransformerExchange/INSUFFICIENT_TAKER_FEE_FUNDS"
        );
        takerFeeToken.transferFrom(msg.sender, order.feeRecipientAddress, takerFee);
        fillResults.makerAssetFilledAmount = makerAssetFilledAmount;
        fillResults.takerAssetFilledAmount = takerAssetFillAmount;
        fillResults.makerFeePaid = uint256(-1);
        fillResults.takerFeePaid = takerFee;
        fillResults.protocolFeePaid = protocolFee;
    }
    function encodeBehaviorData(FillBehavior calldata behavior)
        external
        pure
        returns (bytes memory encoded)
    {
        return abi.encode(behavior);
    }
    function protocolFeeMultiplier()
        external
        pure
        returns (uint256)
    {
        return PROTOCOL_FEE_MULTIPLIER;
    }
    function getAssetProxy(bytes4)
        external
        view
        returns (address)
    {
        return address(this);
    }
    function _getTokenFromAssetData(bytes memory assetData)
        private
        pure
        returns (TestMintableERC20Token token)
    {
        return TestMintableERC20Token(LibBytesV06.readAddress(assetData, 16));
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
contract TestMintableERC20Token {
    mapping(address => uint256) public balanceOf;
    mapping(address => mapping(address => uint256)) public allowance;
    function transfer(address to, uint256 amount)
        external
        virtual
        returns (bool)
    {
        return transferFrom(msg.sender, to, amount);
    }
    function approve(address spender, uint256 amount)
        external
        virtual
        returns (bool)
    {
        allowance[msg.sender][spender] = amount;
        return true;
    }
    function mint(address owner, uint256 amount)
        external
        virtual
    {
        balanceOf[owner] += amount;
    }
    function burn(address owner, uint256 amount)
        external
        virtual
    {
        require(balanceOf[owner] >= amount, "TestMintableERC20Token/INSUFFICIENT_FUNDS");
        balanceOf[owner] -= amount;
    }
    function transferFrom(address from, address to, uint256 amount)
        public
        virtual
        returns (bool)
    {
        if (from != msg.sender) {
            require(
                allowance[from][msg.sender] >= amount,
                "TestMintableERC20Token/INSUFFICIENT_ALLOWANCE"
            );
            allowance[from][msg.sender] -= amount;
        }
        require(balanceOf[from] >= amount, "TestMintableERC20Token/INSUFFICIENT_FUNDS");
        balanceOf[from] -= amount;
        balanceOf[to] += amount;
        return true;
    }
    function getSpendableAmount(address owner, address spender)
        external
        view
        returns (uint256)
    {
        return balanceOf[owner] < allowance[owner][spender]
            ? balanceOf[owner]
            : allowance[owner][spender];
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "../src/transformers/IERC20Transformer.sol";
import "./TestMintableERC20Token.sol";
import "./TestTransformerHost.sol";
contract TestFillQuoteTransformerHost is
    TestTransformerHost
{
    function executeTransform(
        IERC20Transformer transformer,
        TestMintableERC20Token inputToken,
        uint256 inputTokenAmount,
        bytes calldata data
    )
        external
        payable
    {
        if (inputTokenAmount != 0) {
            inputToken.mint(address(this), inputTokenAmount);
        }
        // Have to make this call externally because transformers aren't payable.
        this.rawExecuteTransform(transformer, bytes32(0), msg.sender, data);
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
import "@0x/contracts-erc20/contracts/src/v06/IERC20TokenV06.sol";
import "../src/transformers/IERC20Transformer.sol";
import "../src/transformers/LibERC20Transformer.sol";
contract TestTransformerHost {
    using LibERC20Transformer for IERC20TokenV06;
    using LibRichErrorsV06 for bytes;
    function rawExecuteTransform(
        IERC20Transformer transformer,
        bytes32 callDataHash,
        address taker,
        bytes calldata data
    )
        external
    {
        (bool _success, bytes memory resultData) =
            address(transformer).delegatecall(abi.encodeWithSelector(
                transformer.transform.selector,
                callDataHash,
                taker,
                data
            ));
        if (!_success) {
            resultData.rrevert();
        }
        require(
            abi.decode(resultData, (bytes4)) == LibERC20Transformer.TRANSFORMER_SUCCESS,
            "TestTransformerHost/INVALID_TRANSFORMER_RESULT"
        );
    }
    // solhint-disable
    receive() external payable {}
    // solhint-enable
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "../src/ZeroEx.sol";
import "../src/features/IBootstrap.sol";
import "../src/migrations/FullMigration.sol";
contract TestFullMigration is
    FullMigration
{
    address public dieRecipient;
    // solhint-disable-next-line no-empty-blocks
    constructor(address payable deployer) public FullMigration(deployer) {}
    function die(address payable ethRecipient) external override {
        dieRecipient = ethRecipient;
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "../src/ZeroEx.sol";
import "../src/features/IBootstrap.sol";
import "../src/migrations/InitialMigration.sol";
contract TestInitialMigration is
    InitialMigration
{
    address public bootstrapFeature;
    address public dieRecipient;
    // solhint-disable-next-line no-empty-blocks
    constructor(address deployer) public InitialMigration(deployer) {}
    function callBootstrap(ZeroEx zeroEx) external {
        IBootstrap(address(zeroEx)).bootstrap(address(this), new bytes(0));
    }
    function bootstrap(address owner, BootstrapFeatures memory features)
        public
        override
        returns (bytes4 success)
    {
        success = InitialMigration.bootstrap(owner, features);
        // Snoop the bootstrap feature contract.
        bootstrapFeature = ZeroEx(address(uint160(address(this))))
            .getFunctionImplementation(IBootstrap.bootstrap.selector);
    }
    function die(address payable ethRecipient) public override {
        dieRecipient = ethRecipient;
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "../src/migrations/LibMigrate.sol";
import "../src/features/IOwnable.sol";
contract TestMigrator {
    event TestMigrateCalled(
        bytes callData,
        address owner
    );
    function succeedingMigrate() external returns (bytes4 success) {
        emit TestMigrateCalled(
            msg.data,
            IOwnable(address(this)).owner()
        );
        return LibMigrate.MIGRATE_SUCCESS;
    }
    function failingMigrate() external returns (bytes4 success) {
        emit TestMigrateCalled(
            msg.data,
            IOwnable(address(this)).owner()
        );
        return 0xdeadbeef;
    }
    function revertingMigrate() external pure {
        revert("OOPSIE");
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-erc20/contracts/src/v06/IERC20TokenV06.sol";
import "../src/transformers/IERC20Transformer.sol";
import "../src/transformers/LibERC20Transformer.sol";
import "./TestMintableERC20Token.sol";
contract TestMintTokenERC20Transformer is
    IERC20Transformer
{
    struct TransformData {
        IERC20TokenV06 inputToken;
        TestMintableERC20Token outputToken;
        uint256 burnAmount;
        uint256 mintAmount;
        uint256 feeAmount;
    }
    event MintTransform(
        address context,
        address caller,
        bytes32 callDataHash,
        address taker,
        bytes data,
        uint256 inputTokenBalance,
        uint256 ethBalance
    );
    function transform(
        bytes32 callDataHash,
        address payable taker,
        bytes calldata data_
    )
        external
        override
        returns (bytes4 success)
    {
        TransformData memory data = abi.decode(data_, (TransformData));
        emit MintTransform(
            address(this),
            msg.sender,
            callDataHash,
            taker,
            data_,
            data.inputToken.balanceOf(address(this)),
            address(this).balance
        );
        // "Burn" input tokens.
        data.inputToken.transfer(address(0), data.burnAmount);
        // Mint output tokens.
        if (LibERC20Transformer.isTokenETH(IERC20TokenV06(address(data.outputToken)))) {
            taker.transfer(data.mintAmount);
        } else {
            data.outputToken.mint(
                taker,
                data.mintAmount
            );
            // Burn fees from output.
            data.outputToken.burn(taker, data.feeAmount);
        }
        return LibERC20Transformer.TRANSFORMER_SUCCESS;
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "../src/fixins/FixinCommon.sol";
contract TestSimpleFunctionRegistryFeatureImpl1 is
    FixinCommon
{
    function testFn()
        external
        pure
        returns (uint256 id)
    {
        return 1337;
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "../src/fixins/FixinCommon.sol";
contract TestSimpleFunctionRegistryFeatureImpl2 is
    FixinCommon
{
    function testFn()
        external
        pure
        returns (uint256 id)
    {
        return 1338;
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "../src/features/TokenSpender.sol";
contract TestTokenSpender is
    TokenSpender
{
    modifier onlySelf() override {
        _;
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "./TestMintableERC20Token.sol";
contract TestTokenSpenderERC20Token is
    TestMintableERC20Token
{
    event TransferFromCalled(
        address sender,
        address from,
        address to,
        uint256 amount
    );
    // `transferFrom()` behavior depends on the value of `amount`.
    uint256 constant private EMPTY_RETURN_AMOUNT = 1337;
    uint256 constant private FALSE_RETURN_AMOUNT = 1338;
    uint256 constant private REVERT_RETURN_AMOUNT = 1339;
    function transferFrom(address from, address to, uint256 amount)
        public
        override
        returns (bool)
    {
        emit TransferFromCalled(msg.sender, from, to, amount);
        if (amount == EMPTY_RETURN_AMOUNT) {
            assembly { return(0, 0) }
        }
        if (amount == FALSE_RETURN_AMOUNT) {
            return false;
        }
        if (amount == REVERT_RETURN_AMOUNT) {
            revert("TestTokenSpenderERC20Token/Revert");
        }
        return true;
    }
    function setBalanceAndAllowanceOf(
        address owner,
        uint256 balance,
        address spender,
        uint256 allowance_
    )
        external
    {
        balanceOf[owner] = balance;
        allowance[owner][spender] = allowance_;
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "../src/features/TransformERC20.sol";
contract TestTransformERC20 is
    TransformERC20
{
    // solhint-disable no-empty-blocks
    constructor()
        TransformERC20()
        public
    {}
    modifier onlySelf() override {
        _;
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "../src/transformers/Transformer.sol";
import "../src/transformers/LibERC20Transformer.sol";
contract TestTransformerBase is
    Transformer
{
    function transform(
        bytes32,
        address payable,
        bytes calldata
    )
        external
        override
        returns (bytes4 success)
    {
        return LibERC20Transformer.TRANSFORMER_SUCCESS;
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "../src/transformers/LibERC20Transformer.sol";
contract TestTransformerDeployerTransformer {
    address payable public immutable deployer;
    constructor() public payable {
        deployer = msg.sender;
    }
    modifier onlyDeployer() {
        require(msg.sender == deployer, "TestTransformerDeployerTransformer/ONLY_DEPLOYER");
        _;
    }
    function die()
        external
        onlyDeployer
    {
        selfdestruct(deployer);
    }
    function isDeployedByDeployer(uint32 nonce)
        external
        view
        returns (bool)
    {
        return LibERC20Transformer.getDeployedAddress(deployer, nonce) == address(this);
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "./TestMintableERC20Token.sol";
contract TestWeth is
    TestMintableERC20Token
{
    function deposit()
        external
        payable
    {
        this.mint(msg.sender, msg.value);
    }
    function withdraw(uint256 amount)
        external
    {
        require(balanceOf[msg.sender] >= amount, "TestWeth/INSUFFICIENT_FUNDS");
        balanceOf[msg.sender] -= amount;
        msg.sender.transfer(amount);
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "../src/transformers/IERC20Transformer.sol";
import "./TestMintableERC20Token.sol";
import "./TestTransformerHost.sol";
import "./TestWeth.sol";
contract TestWethTransformerHost is
    TestTransformerHost
{
    // solhint-disable
    TestWeth private immutable _weth;
    // solhint-enable
    constructor(TestWeth weth) public {
        _weth = weth;
    }
    function executeTransform(
        uint256 wethAmount,
        IERC20Transformer transformer,
        bytes calldata data
    )
        external
        payable
    {
        if (wethAmount != 0) {
            _weth.deposit{value: wethAmount}();
        }
        // Have to make this call externally because transformers aren't payable.
        this.rawExecuteTransform(transformer, bytes32(0), msg.sender, data);
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "../src/fixins/FixinCommon.sol";
import "../src/ZeroEx.sol";
contract TestZeroExFeature is
    FixinCommon
{
    event PayableFnCalled(uint256 value);
    event NotPayableFnCalled();
    function payableFn()
        external
        payable
    {
        emit PayableFnCalled(msg.value);
    }
    function notPayableFn()
        external
    {
        emit NotPayableFnCalled();
    }
    // solhint-disable no-empty-blocks
    function unimplmentedFn()
        external
    {}
    function internalFn()
        external
        onlySelf
    {}
}

// SPDX-License-Identifier: Apache-2.0
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-erc20/contracts/src/v06/IERC20TokenV06.sol";
import "@0x/contracts-erc20/contracts/src/v06/IEtherTokenV06.sol";
import "../migrations/LibMigrate.sol";
import "../external/IAllowanceTarget.sol";
import "../fixins/FixinCommon.sol";
import "./IFeature.sol";
import "./IUniswapFeature.sol";
/// @dev VIP uniswap fill functions.
contract UniswapFeature is
    IFeature,
    IUniswapFeature,
    FixinCommon
{
    /// @dev Name of this feature.
    string public constant override FEATURE_NAME = "UniswapFeature";
    /// @dev Version of this feature.
    uint256 public immutable override FEATURE_VERSION = _encodeVersion(1, 1, 1);
    /// @dev A bloom filter for tokens that consume all gas when `transferFrom()` fails.
    bytes32 public immutable GREEDY_TOKENS_BLOOM_FILTER;
    /// @dev WETH contract.
    IEtherTokenV06 private immutable WETH;
    /// @dev AllowanceTarget instance.
    IAllowanceTarget private immutable ALLOWANCE_TARGET;
    // 0xFF + address of the UniswapV2Factory contract.
    uint256 constant private FF_UNISWAP_FACTORY = 0xFF5C69bEe701ef814a2B6a3EDD4B1652CB9cc5aA6f0000000000000000000000;
    // 0xFF + address of the (Sushiswap) UniswapV2Factory contract.
    uint256 constant private FF_SUSHISWAP_FACTORY = 0xFFC0AEe478e3658e2610c5F7A4A2E1777cE9e4f2Ac0000000000000000000000;
    // Init code hash of the UniswapV2Pair contract.
    uint256 constant private UNISWAP_PAIR_INIT_CODE_HASH = 0x96e8ac4277198ff8b6f785478aa9a39f403cb768dd02cbee326c3e7da348845f;
    // Init code hash of the (Sushiswap) UniswapV2Pair contract.
    uint256 constant private SUSHISWAP_PAIR_INIT_CODE_HASH = 0xe18a34eb0e04b04f7a0ac29a6e80748dca96319b42c54d679cb821dca90c6303;
    // Mask of the lower 20 bytes of a bytes32.
    uint256 constant private ADDRESS_MASK = 0x000000000000000000000000ffffffffffffffffffffffffffffffffffffffff;
    // ETH pseudo-token address.
    uint256 constant private ETH_TOKEN_ADDRESS_32 = 0x000000000000000000000000eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee;
    // Maximum token quantity that can be swapped against the UniswapV2Pair contract.
    uint256 constant private MAX_SWAP_AMOUNT = 2**112;
    // bytes4(keccak256("executeCall(address,bytes)"))
    uint256 constant private ALLOWANCE_TARGET_EXECUTE_CALL_SELECTOR_32 = 0xbca8c7b500000000000000000000000000000000000000000000000000000000;
    // bytes4(keccak256("getReserves()"))
    uint256 constant private UNISWAP_PAIR_RESERVES_CALL_SELECTOR_32 = 0x0902f1ac00000000000000000000000000000000000000000000000000000000;
    // bytes4(keccak256("swap(uint256,uint256,address,bytes)"))
    uint256 constant private UNISWAP_PAIR_SWAP_CALL_SELECTOR_32 = 0x022c0d9f00000000000000000000000000000000000000000000000000000000;
    // bytes4(keccak256("transferFrom(address,address,uint256)"))
    uint256 constant private TRANSFER_FROM_CALL_SELECTOR_32 = 0x23b872dd00000000000000000000000000000000000000000000000000000000;
    // bytes4(keccak256("allowance(address,address)"))
    uint256 constant private ALLOWANCE_CALL_SELECTOR_32 = 0xdd62ed3e00000000000000000000000000000000000000000000000000000000;
    // bytes4(keccak256("withdraw(uint256)"))
    uint256 constant private WETH_WITHDRAW_CALL_SELECTOR_32 = 0x2e1a7d4d00000000000000000000000000000000000000000000000000000000;
    // bytes4(keccak256("deposit()"))
    uint256 constant private WETH_DEPOSIT_CALL_SELECTOR_32 = 0xd0e30db000000000000000000000000000000000000000000000000000000000;
    // bytes4(keccak256("transfer(address,uint256)"))
    uint256 constant private ERC20_TRANSFER_CALL_SELECTOR_32 = 0xa9059cbb00000000000000000000000000000000000000000000000000000000;
    /// @dev Construct this contract.
    /// @param weth The WETH contract.
    /// @param allowanceTarget The AllowanceTarget contract.
    /// @param greedyTokensBloomFilter The bloom filter for greedy tokens.
    constructor(
        IEtherTokenV06 weth,
        IAllowanceTarget allowanceTarget,
        bytes32 greedyTokensBloomFilter
    ) public {
        WETH = weth;
        ALLOWANCE_TARGET = allowanceTarget;
        GREEDY_TOKENS_BLOOM_FILTER = greedyTokensBloomFilter;
    }
    /// @dev Initialize and register this feature.
    ///      Should be delegatecalled by `Migrate.migrate()`.
    /// @return success `LibMigrate.SUCCESS` on success.
    function migrate()
        external
        returns (bytes4 success)
    {
        _registerFeatureFunction(this.sellToUniswap.selector);
        return LibMigrate.MIGRATE_SUCCESS;
    }
    /// @dev Efficiently sell directly to uniswap/sushiswap.
    /// @param tokens Sell path.
    /// @param sellAmount of `tokens[0]` Amount to sell.
    /// @param minBuyAmount Minimum amount of `tokens[-1]` to buy.
    /// @param isSushi Use sushiswap if true.
    /// @return buyAmount Amount of `tokens[-1]` bought.
    function sellToUniswap(
        IERC20TokenV06[] calldata tokens,
        uint256 sellAmount,
        uint256 minBuyAmount,
        bool isSushi
    )
        external
        payable
        override
        returns (uint256 buyAmount)
    {
        require(tokens.length > 1, "UniswapFeature/InvalidTokensLength");
        {
            // Load immutables onto the stack.
            IEtherTokenV06 weth = WETH;
            IAllowanceTarget allowanceTarget = ALLOWANCE_TARGET;
            bytes32 greedyTokensBloomFilter = GREEDY_TOKENS_BLOOM_FILTER;
            // Store some vars in memory to get around stack limits.
            assembly {
                // calldataload(mload(0xA00)) == first element of `tokens` array
                mstore(0xA00, add(calldataload(0x04), 0x24))
                // mload(0xA20) == isSushi
                mstore(0xA20, isSushi)
                // mload(0xA40) == WETH
                mstore(0xA40, weth)
                // mload(0xA60) == ALLOWANCE_TARGET
                mstore(0xA60, allowanceTarget)
                // mload(0xA80) == GREEDY_TOKENS_BLOOM_FILTER
                mstore(0xA80, greedyTokensBloomFilter)
            }
        }
        assembly {
            // numPairs == tokens.length - 1
            let numPairs := sub(calldataload(add(calldataload(0x04), 0x4)), 1)
            // We use the previous buy amount as the sell amount for the next
            // pair in a path. So for the first swap we want to set it to `sellAmount`.
            buyAmount := sellAmount
            let buyToken
            let nextPair := 0
            for {let i := 0} lt(i, numPairs) {i := add(i, 1)} {
                // sellToken = tokens[i]
                let sellToken := loadTokenAddress(i)
                // buyToken = tokens[i+1]
                buyToken := loadTokenAddress(add(i, 1))
                // The canonical ordering of this token pair.
                let pairOrder := lt(normalizeToken(sellToken), normalizeToken(buyToken))
                // Compute the pair address if it hasn't already been computed
                // from the last iteration.
                let pair := nextPair
                if iszero(pair) {
                    pair := computePairAddress(sellToken, buyToken)
                    nextPair := 0
                }
                if iszero(i) {
                    // This is the first token in the path.
                    switch eq(sellToken, ETH_TOKEN_ADDRESS_32)
                        case 0 { // Not selling ETH. Selling an ERC20 instead.
                            // Make sure ETH was not attached to the call.
                            if gt(callvalue(), 0) {
                                revert(0, 0)
                            }
                            // For the first pair we need to transfer sellTokens into the
                            // pair contract.
                            moveTakerTokensTo(sellToken, pair, sellAmount)
                        }
                        default {
                            // If selling ETH, we need to wrap it to WETH and transfer to the
                            // pair contract.
                            if iszero(eq(callvalue(), sellAmount)) {
                                revert(0, 0)
                            }
                            sellToken := mload(0xA40)// Re-assign to WETH
                            // Call `WETH.deposit{value: sellAmount}()`
                            mstore(0xB00, WETH_DEPOSIT_CALL_SELECTOR_32)
                            if iszero(call(gas(), sellToken, sellAmount, 0xB00, 0x4, 0x00, 0x0)) {
                                bubbleRevert()
                            }
                            // Call `WETH.transfer(pair, sellAmount)`
                            mstore(0xB00, ERC20_TRANSFER_CALL_SELECTOR_32)
                            mstore(0xB04, pair)
                            mstore(0xB24, sellAmount)
                            if iszero(call(gas(), sellToken, 0, 0xB00, 0x44, 0x00, 0x0)) {
                                bubbleRevert()
                            }
                        }
                    // No need to check results, if deposit/transfers failed the UniswapV2Pair will
                    // reject our trade (or it may succeed if somehow the reserve was out of sync)
                    // this is fine for the taker.
                }
                // Call pair.getReserves(), store the results at `0xC00`
                mstore(0xB00, UNISWAP_PAIR_RESERVES_CALL_SELECTOR_32)
                if iszero(staticcall(gas(), pair, 0xB00, 0x4, 0xC00, 0x40)) {
                    bubbleRevert()
                }
                // Revert if the pair contract does not return at least two words.
                if lt(returndatasize(), 0x40) {
                    revert(0,0)
                }
                // Sell amount for this hop is the previous buy amount.
                let pairSellAmount := buyAmount
                // Compute the buy amount based on the pair reserves.
                {
                    let sellReserve
                    let buyReserve
                    switch iszero(pairOrder)
                        case 0 {
                            // Transpose if pair order is different.
                            sellReserve := mload(0xC00)
                            buyReserve := mload(0xC20)
                        }
                        default {
                            sellReserve := mload(0xC20)
                            buyReserve := mload(0xC00)
                        }
                    // Ensure that the sellAmount is < 2B9B9B2.
                    if gt(pairSellAmount, MAX_SWAP_AMOUNT) {
                        revert(0, 0)
                    }
                    // Pairs are in the range (0, 2B9B9B2) so this shouldn't overflow.
                    // buyAmount = (pairSellAmount * 997 * buyReserve) /
                    //     (pairSellAmount * 997 + sellReserve * 1000);
                    let sellAmountWithFee := mul(pairSellAmount, 997)
                    buyAmount := div(
                        mul(sellAmountWithFee, buyReserve),
                        add(sellAmountWithFee, mul(sellReserve, 1000))
                    )
                }
                let receiver
                // Is this the last pair contract?
                switch eq(add(i, 1), numPairs)
                    case 0 {
                        // Not the last pair contract, so forward bought tokens to
                        // the next pair contract.
                        nextPair := computePairAddress(
                            buyToken,
                            loadTokenAddress(add(i, 2))
                        )
                        receiver := nextPair
                    }
                    default {
                        // The last pair contract.
                        // Forward directly to taker UNLESS they want ETH back.
                        switch eq(buyToken, ETH_TOKEN_ADDRESS_32)
                            case 0 {
                                receiver := caller()
                            }
                            default {
                                receiver := address()
                            }
                    }
                // Call pair.swap()
                mstore(0xB00, UNISWAP_PAIR_SWAP_CALL_SELECTOR_32)
                switch pairOrder
                    case 0 {
                        mstore(0xB04, buyAmount)
                        mstore(0xB24, 0)
                    }
                    default {
                        mstore(0xB04, 0)
                        mstore(0xB24, buyAmount)
                    }
                mstore(0xB44, receiver)
                mstore(0xB64, 0x80)
                mstore(0xB84, 0)
                if iszero(call(gas(), pair, 0, 0xB00, 0xA4, 0, 0)) {
                    bubbleRevert()
                }
            } // End for-loop.
            // If buying ETH, unwrap the WETH first
            if eq(buyToken, ETH_TOKEN_ADDRESS_32) {
                // Call `WETH.withdraw(buyAmount)`
                mstore(0xB00, WETH_WITHDRAW_CALL_SELECTOR_32)
                mstore(0xB04, buyAmount)
                if iszero(call(gas(), mload(0xA40), 0, 0xB00, 0x24, 0x00, 0x0)) {
                    bubbleRevert()
                }
                // Transfer ETH to the caller.
                if iszero(call(gas(), caller(), buyAmount, 0xB00, 0x0, 0x00, 0x0)) {
                    bubbleRevert()
                }
            }
            // Functions ///////////////////////////////////////////////////////
            // Load a token address from the `tokens` calldata argument.
            function loadTokenAddress(idx) -> addr {
                addr := and(ADDRESS_MASK, calldataload(add(mload(0xA00), mul(idx, 0x20))))
            }
            // Convert ETH pseudo-token addresses to WETH.
            function normalizeToken(token) -> normalized {
                normalized := token
                // Translate ETH pseudo-tokens to WETH.
                if eq(token, ETH_TOKEN_ADDRESS_32) {
                    normalized := mload(0xA40)
                }
            }
            // Compute the address of the UniswapV2Pair contract given two
            // tokens.
            function computePairAddress(tokenA, tokenB) -> pair {
                // Convert ETH pseudo-token addresses to WETH.
                tokenA := normalizeToken(tokenA)
                tokenB := normalizeToken(tokenB)
                // There is one contract for every combination of tokens,
                // which is deployed using CREATE2.
                // The derivation of this address is given by:
                //   address(keccak256(abi.encodePacked(
                //       bytes(0xFF),
                //       address(UNISWAP_FACTORY_ADDRESS),
                //       keccak256(abi.encodePacked(
                //           tokenA < tokenB ? tokenA : tokenB,
                //           tokenA < tokenB ? tokenB : tokenA,
                //       )),
                //       bytes32(UNISWAP_PAIR_INIT_CODE_HASH),
                //   )));
                // Compute the salt (the hash of the sorted tokens).
                // Tokens are written in reverse memory order to packed encode
                // them as two 20-byte values in a 40-byte chunk of memory
                // starting at 0xB0C.
                switch lt(tokenA, tokenB)
                    case 0 {
                        mstore(0xB14, tokenA)
                        mstore(0xB00, tokenB)
                    }
                    default {
                        mstore(0xB14, tokenB)
                        mstore(0xB00, tokenA)
                    }
                let salt := keccak256(0xB0C, 0x28)
                // Compute the pair address by hashing all the components together.
                switch mload(0xA20) // isSushi
                    case 0 {
                        mstore(0xB00, FF_UNISWAP_FACTORY)
                        mstore(0xB15, salt)
                        mstore(0xB35, UNISWAP_PAIR_INIT_CODE_HASH)
                    }
                    default {
                        mstore(0xB00, FF_SUSHISWAP_FACTORY)
                        mstore(0xB15, salt)
                        mstore(0xB35, SUSHISWAP_PAIR_INIT_CODE_HASH)
                    }
                pair := and(ADDRESS_MASK, keccak256(0xB00, 0x55))
            }
            // Revert with the return data from the most recent call.
            function bubbleRevert() {
                returndatacopy(0, 0, returndatasize())
                revert(0, returndatasize())
            }
            // Move `amount` tokens from the taker/caller to `to`.
            function moveTakerTokensTo(token, to, amount) {
                // If the token is possibly greedy, we check the allowance rather
                // than relying on letting the transferFrom() call fail and
                // falling through to legacy allowance target because the token
                // will eat all our gas.
                if isTokenPossiblyGreedy(token) {
                    // Check if we have enough direct allowance by calling
                    // `token.allowance()``
                    mstore(0xB00, ALLOWANCE_CALL_SELECTOR_32)
                    mstore(0xB04, caller())
                    mstore(0xB24, address())
                    let success := staticcall(gas(), token, 0xB00, 0x44, 0xC00, 0x20)
                    if iszero(success) {
                        // Call to allowance() failed.
                        bubbleRevert()
                    }
                    // Make sure the allowance call returned at least a word.
                    if lt(returndatasize(), 0x20) {
                        revert(0, 0)
                    }
                    // Call succeeded.
                    // Result is stored in 0xC00-0xC20.
                    if lt(mload(0xC00), amount) {
                        // We don't have enough direct allowance, so try
                        // going through the legacy allowance taregt.
                        moveTakerTokensToWithLegacyAllowanceTarget(token, to, amount)
                        leave
                    }
                }
                // Otherwise we will optimistically try to perform a `transferFrom()`
                // directly then if it fails we will go through the legacy allowance target.
                mstore(0xB00, TRANSFER_FROM_CALL_SELECTOR_32)
                mstore(0xB04, caller())
                mstore(0xB24, to)
                mstore(0xB44, amount)
                let success := call(
                    gas(),
                    token,
                    0,
                    0xB00,
                    0x64,
                    0xC00,
                    // Copy only the first 32 bytes of return data. We
                    // only care about reading a boolean in the success
                    // case, and we discard the return data in the
                    // failure case.
                    0x20
                )
                let rdsize := returndatasize()
                // Check for ERC20 success. ERC20 tokens should
                // return a boolean, but some return nothing or
                // extra data. We accept 0-length return data as
                // success, or at least 32 bytes that starts with
                // a 32-byte boolean true.
                success := and(
                    success,                         // call itself succeeded
                    or(
                        iszero(rdsize),              // no return data, or
                        and(
                            iszero(lt(rdsize, 32)),  // at least 32 bytes
                            eq(mload(0xC00), 1)      // starts with uint256(1)
                        )
                    )
                )
                if iszero(success) {
                    // Try to fall back to the allowance target.
                    moveTakerTokensToWithLegacyAllowanceTarget(token, to, amount)
                }
            }
            // Move tokens by going through the legacy allowance target contract.
            function moveTakerTokensToWithLegacyAllowanceTarget(token, to, amount) {
                mstore(0xB00, ALLOWANCE_TARGET_EXECUTE_CALL_SELECTOR_32)
                mstore(0xB04, token)
                mstore(0xB24, 0x40)
                mstore(0xB44, 0x64)
                mstore(0xB64, TRANSFER_FROM_CALL_SELECTOR_32)
                mstore(0xB68, caller())
                mstore(0xB88, to)
                mstore(0xBA8, amount)
                if iszero(call(gas(), mload(0xA60), 0, 0xB00, 0xC8, 0x00, 0x0)) {
                    bubbleRevert()
                }
                // If this fall back failed, the swap will most likely fail
                // so there's no need to validate the result.
            }
            // Checks if a token possibly belongs to the GREEDY_TOKENS_BLOOM_FILTER
            // bloom filter.
            function isTokenPossiblyGreedy(token) -> isPossiblyGreedy {
                // The hash is given by:
                // (1 << (keccak256(token) % 256)) | (1 << (token % 256))
                mstore(0, token)
                let h := or(shl(mod(keccak256(0, 32), 256), 1), shl(mod(token, 256), 1))
                isPossiblyGreedy := eq(and(h, mload(0xA80)), h)
            }
        }
        // Revert if we bought too little.
        // TODO: replace with rich revert?
        require(buyAmount >= minBuyAmount, "UniswapFeature/UnderBought");
    }
}
// SPDX-License-Identifier: Apache-2.0
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
interface IERC20TokenV06 {
    // solhint-disable no-simple-event-func-name
    event Transfer(
        address indexed from,
        address indexed to,
        uint256 value
    );
    event Approval(
        address indexed owner,
        address indexed spender,
        uint256 value
    );
    /// @dev send `value` token to `to` from `msg.sender`
    /// @param to The address of the recipient
    /// @param value The amount of token to be transferred
    /// @return True if transfer was successful
    function transfer(address to, uint256 value)
        external
        returns (bool);
    /// @dev send `value` token to `to` from `from` on the condition it is approved by `from`
    /// @param from The address of the sender
    /// @param to The address of the recipient
    /// @param value The amount of token to be transferred
    /// @return True if transfer was successful
    function transferFrom(
        address from,
        address to,
        uint256 value
    )
        external
        returns (bool);
    /// @dev `msg.sender` approves `spender` to spend `value` tokens
    /// @param spender The address of the account able to transfer the tokens
    /// @param value The amount of wei to be approved for transfer
    /// @return Always true if the call has enough gas to complete execution
    function approve(address spender, uint256 value)
        external
        returns (bool);
    /// @dev Query total supply of token
    /// @return Total supply of token
    function totalSupply()
        external
        view
        returns (uint256);
    /// @dev Get the balance of `owner`.
    /// @param owner The address from which the balance will be retrieved
    /// @return Balance of owner
    function balanceOf(address owner)
        external
        view
        returns (uint256);
    /// @dev Get the allowance for `spender` to spend from `owner`.
    /// @param owner The address of the account owning tokens
    /// @param spender The address of the account able to transfer the tokens
    /// @return Amount of remaining tokens allowed to spent
    function allowance(address owner, address spender)
        external
        view
        returns (uint256);
    /// @dev Get the number of decimals this token has.
    function decimals()
        external
        view
        returns (uint8);
}
// SPDX-License-Identifier: Apache-2.0
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
import "./IERC20TokenV06.sol";
interface IEtherTokenV06 is
    IERC20TokenV06
{
    /// @dev Wrap ether.
    function deposit() external payable;
    /// @dev Unwrap ether.
    function withdraw(uint256 amount) external;
}
// SPDX-License-Identifier: Apache-2.0
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
import "../errors/LibOwnableRichErrors.sol";
library LibMigrate {
    /// @dev Magic bytes returned by a migrator to indicate success.
    ///      This is `keccack('MIGRATE_SUCCESS')`.
    bytes4 internal constant MIGRATE_SUCCESS = 0x2c64c5ef;
    using LibRichErrorsV06 for bytes;
    /// @dev Perform a delegatecall and ensure it returns the magic bytes.
    /// @param target The call target.
    /// @param data The call data.
    function delegatecallMigrateFunction(
        address target,
        bytes memory data
    )
        internal
    {
        (bool success, bytes memory resultData) = target.delegatecall(data);
        if (!success ||
            resultData.length != 32 ||
            abi.decode(resultData, (bytes4)) != MIGRATE_SUCCESS)
        {
            LibOwnableRichErrors.MigrateCallFailedError(target, resultData).rrevert();
        }
    }
}
// SPDX-License-Identifier: Apache-2.0
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
library LibRichErrorsV06 {
    // bytes4(keccak256("Error(string)"))
    bytes4 internal constant STANDARD_ERROR_SELECTOR = 0x08c379a0;
    // solhint-disable func-name-mixedcase
    /// @dev ABI encode a standard, string revert error payload.
    ///      This is the same payload that would be included by a `revert(string)`
    ///      solidity statement. It has the function signature `Error(string)`.
    /// @param message The error string.
    /// @return The ABI encoded error.
    function StandardError(string memory message)
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            STANDARD_ERROR_SELECTOR,
            bytes(message)
        );
    }
    // solhint-enable func-name-mixedcase
    /// @dev Reverts an encoded rich revert reason `errorData`.
    /// @param errorData ABI encoded error data.
    function rrevert(bytes memory errorData)
        internal
        pure
    {
        assembly {
            revert(add(errorData, 0x20), mload(errorData))
        }
    }
}
// SPDX-License-Identifier: Apache-2.0
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
library LibOwnableRichErrors {
    // solhint-disable func-name-mixedcase
    function OnlyOwnerError(
        address sender,
        address owner
    )
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("OnlyOwnerError(address,address)")),
            sender,
            owner
        );
    }
    function TransferOwnerToZeroError()
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("TransferOwnerToZeroError()"))
        );
    }
    function MigrateCallFailedError(address target, bytes memory resultData)
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("MigrateCallFailedError(address,bytes)")),
            target,
            resultData
        );
    }
}
// SPDX-License-Identifier: Apache-2.0
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-utils/contracts/src/v06/interfaces/IAuthorizableV06.sol";
/// @dev The allowance target for the TokenSpender feature.
interface IAllowanceTarget is
    IAuthorizableV06
{
    /// @dev Execute an arbitrary call. Only an authority can call this.
    /// @param target The call target.
    /// @param callData The call data.
    /// @return resultData The data returned by the call.
    function executeCall(
        address payable target,
        bytes calldata callData
    )
        external
        returns (bytes memory resultData);
}
// SPDX-License-Identifier: Apache-2.0
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
import "./IOwnableV06.sol";
interface IAuthorizableV06 is
    IOwnableV06
{
    // Event logged when a new address is authorized.
    event AuthorizedAddressAdded(
        address indexed target,
        address indexed caller
    );
    // Event logged when a currently authorized address is unauthorized.
    event AuthorizedAddressRemoved(
        address indexed target,
        address indexed caller
    );
    /// @dev Authorizes an address.
    /// @param target Address to authorize.
    function addAuthorizedAddress(address target)
        external;
    /// @dev Removes authorizion of an address.
    /// @param target Address to remove authorization from.
    function removeAuthorizedAddress(address target)
        external;
    /// @dev Removes authorizion of an address.
    /// @param target Address to remove authorization from.
    /// @param index Index of target in authorities array.
    function removeAuthorizedAddressAtIndex(
        address target,
        uint256 index
    )
        external;
    /// @dev Gets all authorized addresses.
    /// @return authorizedAddresses Array of authorized addresses.
    function getAuthorizedAddresses()
        external
        view
        returns (address[] memory authorizedAddresses);
    /// @dev Whether an adderss is authorized to call privileged functions.
    /// @param addr Address to query.
    /// @return isAuthorized Whether the address is authorized.
    function authorized(address addr) external view returns (bool isAuthorized);
    /// @dev All addresseses authorized to call privileged functions.
    /// @param idx Index of authorized address.
    /// @return addr Authorized address.
    function authorities(uint256 idx) external view returns (address addr);
}
// SPDX-License-Identifier: Apache-2.0
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
interface IOwnableV06 {
    /// @dev Emitted by Ownable when ownership is transferred.
    /// @param previousOwner The previous owner of the contract.
    /// @param newOwner The new owner of the contract.
    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
    /// @dev Transfers ownership of the contract to a new address.
    /// @param newOwner The address that will become the owner.
    function transferOwnership(address newOwner) external;
    /// @dev The owner of this contract.
    /// @return ownerAddress The owner address.
    function owner() external view returns (address ownerAddress);
}
// SPDX-License-Identifier: Apache-2.0
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
import "../errors/LibCommonRichErrors.sol";
import "../errors/LibOwnableRichErrors.sol";
import "../features/IOwnableFeature.sol";
import "../features/ISimpleFunctionRegistryFeature.sol";
/// @dev Common feature utilities.
abstract contract FixinCommon {
    using LibRichErrorsV06 for bytes;
    /// @dev The implementation address of this feature.
    address internal immutable _implementation;
    /// @dev The caller must be this contract.
    modifier onlySelf() virtual {
        if (msg.sender != address(this)) {
            LibCommonRichErrors.OnlyCallableBySelfError(msg.sender).rrevert();
        }
        _;
    }
    /// @dev The caller of this function must be the owner.
    modifier onlyOwner() virtual {
        {
            address owner = IOwnableFeature(address(this)).owner();
            if (msg.sender != owner) {
                LibOwnableRichErrors.OnlyOwnerError(
                    msg.sender,
                    owner
                ).rrevert();
            }
        }
        _;
    }
    constructor() internal {
        // Remember this feature's original address.
        _implementation = address(this);
    }
    /// @dev Registers a function implemented by this feature at `_implementation`.
    ///      Can and should only be called within a `migrate()`.
    /// @param selector The selector of the function whose implementation
    ///        is at `_implementation`.
    function _registerFeatureFunction(bytes4 selector)
        internal
    {
        ISimpleFunctionRegistryFeature(address(this)).extend(selector, _implementation);
    }
    /// @dev Encode a feature version as a `uint256`.
    /// @param major The major version number of the feature.
    /// @param minor The minor version number of the feature.
    /// @param revision The revision number of the feature.
    /// @return encodedVersion The encoded version number.
    function _encodeVersion(uint32 major, uint32 minor, uint32 revision)
        internal
        pure
        returns (uint256 encodedVersion)
    {
        return (uint256(major) << 64) | (uint256(minor) << 32) | uint256(revision);
    }
}
// SPDX-License-Identifier: Apache-2.0
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
library LibCommonRichErrors {
    // solhint-disable func-name-mixedcase
    function OnlyCallableBySelfError(address sender)
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("OnlyCallableBySelfError(address)")),
            sender
        );
    }
    function IllegalReentrancyError(bytes4 selector, uint256 reentrancyFlags)
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("IllegalReentrancyError(bytes4,uint256)")),
            selector,
            reentrancyFlags
        );
    }
}
// SPDX-License-Identifier: Apache-2.0
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-utils/contracts/src/v06/interfaces/IOwnableV06.sol";
// solhint-disable no-empty-blocks
/// @dev Owner management and migration features.
interface IOwnableFeature is
    IOwnableV06
{
    /// @dev Emitted when `migrate()` is called.
    /// @param caller The caller of `migrate()`.
    /// @param migrator The migration contract.
    /// @param newOwner The address of the new owner.
    event Migrated(address caller, address migrator, address newOwner);
    /// @dev Execute a migration function in the context of the ZeroEx contract.
    ///      The result of the function being called should be the magic bytes
    ///      0x2c64c5ef (`keccack('MIGRATE_SUCCESS')`). Only callable by the owner.
    ///      The owner will be temporarily set to `address(this)` inside the call.
    ///      Before returning, the owner will be set to `newOwner`.
    /// @param target The migrator contract address.
    /// @param newOwner The address of the new owner.
    /// @param data The call data.
    function migrate(address target, bytes calldata data, address newOwner) external;
}
// SPDX-License-Identifier: Apache-2.0
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
/// @dev Basic registry management features.
interface ISimpleFunctionRegistryFeature {
    /// @dev A function implementation was updated via `extend()` or `rollback()`.
    /// @param selector The function selector.
    /// @param oldImpl The implementation contract address being replaced.
    /// @param newImpl The replacement implementation contract address.
    event ProxyFunctionUpdated(bytes4 indexed selector, address oldImpl, address newImpl);
    /// @dev Roll back to a prior implementation of a function.
    /// @param selector The function selector.
    /// @param targetImpl The address of an older implementation of the function.
    function rollback(bytes4 selector, address targetImpl) external;
    /// @dev Register or replace a function.
    /// @param selector The function selector.
    /// @param impl The implementation contract for the function.
    function extend(bytes4 selector, address impl) external;
    /// @dev Retrieve the length of the rollback history for a function.
    /// @param selector The function selector.
    /// @return rollbackLength The number of items in the rollback history for
    ///         the function.
    function getRollbackLength(bytes4 selector)
        external
        view
        returns (uint256 rollbackLength);
    /// @dev Retrieve an entry in the rollback history for a function.
    /// @param selector The function selector.
    /// @param idx The index in the rollback history.
    /// @return impl An implementation address for the function at
    ///         index `idx`.
    function getRollbackEntryAtIndex(bytes4 selector, uint256 idx)
        external
        view
        returns (address impl);
}
// SPDX-License-Identifier: Apache-2.0
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
/// @dev Basic interface for a feature contract.
interface IFeature {
    // solhint-disable func-name-mixedcase
    /// @dev The name of this feature set.
    function FEATURE_NAME() external view returns (string memory name);
    /// @dev The version of this feature set.
    function FEATURE_VERSION() external view returns (uint256 version);
}
// SPDX-License-Identifier: Apache-2.0
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-erc20/contracts/src/v06/IERC20TokenV06.sol";
/// @dev VIP uniswap fill functions.
interface IUniswapFeature {
    /// @dev Efficiently sell directly to uniswap/sushiswap.
    /// @param tokens Sell path.
    /// @param sellAmount of `tokens[0]` Amount to sell.
    /// @param minBuyAmount Minimum amount of `tokens[-1]` to buy.
    /// @param isSushi Use sushiswap if true.
    /// @return buyAmount Amount of `tokens[-1]` bought.
    function sellToUniswap(
        IERC20TokenV06[] calldata tokens,
        uint256 sellAmount,
        uint256 minBuyAmount,
        bool isSushi
    )
        external
        payable
        returns (uint256 buyAmount);
}

// Copyright (C) 2015, 2016, 2017 Dapphub

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

pragma solidity ^0.4.18;

contract WETH9 {
    string public name     = "Wrapped Ether";
    string public symbol   = "WETH";
    uint8  public decimals = 18;

    event  Approval(address indexed src, address indexed guy, uint wad);
    event  Transfer(address indexed src, address indexed dst, uint wad);
    event  Deposit(address indexed dst, uint wad);
    event  Withdrawal(address indexed src, uint wad);

    mapping (address => uint)                       public  balanceOf;
    mapping (address => mapping (address => uint))  public  allowance;

    function() public payable {
        deposit();
    }
    function deposit() public payable {
        balanceOf[msg.sender] += msg.value;
        Deposit(msg.sender, msg.value);
    }
    function withdraw(uint wad) public {
        require(balanceOf[msg.sender] >= wad);
        balanceOf[msg.sender] -= wad;
        msg.sender.transfer(wad);
        Withdrawal(msg.sender, wad);
    }

    function totalSupply() public view returns (uint) {
        return this.balance;
    }

    function approve(address guy, uint wad) public returns (bool) {
        allowance[msg.sender][guy] = wad;
        Approval(msg.sender, guy, wad);
        return true;
    }

    function transfer(address dst, uint wad) public returns (bool) {
        return transferFrom(msg.sender, dst, wad);
    }

    function transferFrom(address src, address dst, uint wad)
        public
        returns (bool)
    {
        require(balanceOf[src] >= wad);

        if (src != msg.sender && allowance[src][msg.sender] != uint(-1)) {
            require(allowance[src][msg.sender] >= wad);
            allowance[src][msg.sender] -= wad;
        }

        balanceOf[src] -= wad;
        balanceOf[dst] += wad;

        Transfer(src, dst, wad);

        return true;
    }
}


/*
                    GNU GENERAL PUBLIC LICENSE
                       Version 3, 29 June 2007

 Copyright (C) 2007 Free Software Foundation, Inc. <http://fsf.org/>
 Everyone is permitted to copy and distribute verbatim copies
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GNU General Public License for most of our software; it applies also to
any other work released this way by its authors.  You can apply it to
your programs, too.

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option of following the terms and conditions either of that numbered
version or of any later version published by the Free Software
Foundation.  If the Program does not specify a version number of the
GNU General Public License, you may choose any version ever published
by the Free Software Foundation.

  If the Program specifies that a proxy can decide which future
versions of the GNU General Public License can be used, that proxy's
public statement of acceptance of a version permanently authorizes you
to choose that version for the Program.

  Later license versions may give you additional or different
permissions.  However, no additional obligations are imposed on any
author or copyright holder as a result of your choosing to follow a
later version.

  15. Disclaimer of Warranty.

  THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY
APPLICABLE LAW.  EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT
HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY
OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO,
THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
PURPOSE.  THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM
IS WITH YOU.  SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF
ALL NECESSARY SERVICING, REPAIR OR CORRECTION.

  16. Limitation of Liability.

  IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS
THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY
GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE
USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF
DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD
PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS),
EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
SUCH DAMAGES.

  17. Interpretation of Sections 15 and 16.

  If the disclaimer of warranty and limitation of liability provided
above cannot be given local legal effect according to their terms,
reviewing courts shall apply local law that most closely approximates
an absolute waiver of all civil liability in connection with the
Program, unless a warranty or assumption of liability accompanies a
copy of the Program in return for a fee.

                     END OF TERMS AND CONDITIONS

            How to Apply These Terms to Your New Programs

  If you develop a new program, and you want it to be of the greatest
possible use to the public, the best way to achieve this is to make it
free software which everyone can redistribute and change under these terms.

  To do so, attach the following notices to the program.  It is safest
to attach them to the start of each source file to most effectively
state the exclusion of warranty; and each file should have at least
the "copyright" line and a pointer to where the full notice is found.

    <one line to give the program's name and a brief idea of what it does.>
    Copyright (C) <year>  <name of author>

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.

Also add information on how to contact you by electronic and paper mail.

  If the program does terminal interaction, make it output a short
notice like this when it starts in an interactive mode:

    <program>  Copyright (C) <year>  <name of author>
    This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
    This is free software, and you are welcome to redistribute it
    under certain conditions; type `show c' for details.

The hypothetical commands `show w' and `show c' should show the appropriate
parts of the General Public License.  Of course, your program's commands
might be different; for a GUI interface, you would use an "about box".

  You should also get your employer (if you work as a programmer) or school,
if any, to sign a "copyright disclaimer" for the program, if necessary.
For more information on this, and how to apply and follow the GNU GPL, see
<http://www.gnu.org/licenses/>.

  The GNU General Public License does not permit incorporating your program
into proprietary programs.  If your program is a subroutine library, you
may consider it more useful to permit linking proprietary applications with
the library.  If this is what you want to do, use the GNU Lesser General
Public License instead of this License.  But first, please read
<http://www.gnu.org/philosophy/why-not-lgpl.html>.

*/

// File: contracts/uniswapv2/interfaces/IUniswapV2Factory.sol

pragma solidity >=0.5.0;

interface IUniswapV2Factory {
    event PairCreated(address indexed token0, address indexed token1, address pair, uint);

    function feeTo() external view returns (address);
    function feeToSetter() external view returns (address);
    function migrator() external view returns (address);

    function getPair(address tokenA, address tokenB) external view returns (address pair);
    function allPairs(uint) external view returns (address pair);
    function allPairsLength() external view returns (uint);

    function createPair(address tokenA, address tokenB) external returns (address pair);

    function setFeeTo(address) external;
    function setFeeToSetter(address) external;
    function setMigrator(address) external;
}

// File: contracts/uniswapv2/libraries/SafeMath.sol

pragma solidity =0.6.12;

// a library for performing overflow-safe math, courtesy of DappHub (https://github.com/dapphub/ds-math)

library SafeMathUniswap {
    function add(uint x, uint y) internal pure returns (uint z) {
        require((z = x + y) >= x, 'ds-math-add-overflow');
    }

    function sub(uint x, uint y) internal pure returns (uint z) {
        require((z = x - y) <= x, 'ds-math-sub-underflow');
    }

    function mul(uint x, uint y) internal pure returns (uint z) {
        require(y == 0 || (z = x * y) / y == x, 'ds-math-mul-overflow');
    }
}

// File: contracts/uniswapv2/UniswapV2ERC20.sol

pragma solidity =0.6.12;


contract UniswapV2ERC20 {
    using SafeMathUniswap for uint;

    string public constant name = 'SushiSwap LP Token';
    string public constant symbol = 'SLP';
    uint8 public constant decimals = 18;
    uint  public totalSupply;
    mapping(address => uint) public balanceOf;
    mapping(address => mapping(address => uint)) public allowance;

    bytes32 public DOMAIN_SEPARATOR;
    // keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)");
    bytes32 public constant PERMIT_TYPEHASH = 0x6e71edae12b1b97f4d1f60370fef10105fa2faae0126114a169c64845d6126c9;
    mapping(address => uint) public nonces;

    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    constructor() public {
        uint chainId;
        assembly {
            chainId := chainid()
        }
        DOMAIN_SEPARATOR = keccak256(
            abi.encode(
                keccak256('EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)'),
                keccak256(bytes(name)),
                keccak256(bytes('1')),
                chainId,
                address(this)
            )
        );
    }

    function _mint(address to, uint value) internal {
        totalSupply = totalSupply.add(value);
        balanceOf[to] = balanceOf[to].add(value);
        emit Transfer(address(0), to, value);
    }

    function _burn(address from, uint value) internal {
        balanceOf[from] = balanceOf[from].sub(value);
        totalSupply = totalSupply.sub(value);
        emit Transfer(from, address(0), value);
    }

    function _approve(address owner, address spender, uint value) private {
        allowance[owner][spender] = value;
        emit Approval(owner, spender, value);
    }

    function _transfer(address from, address to, uint value) private {
        balanceOf[from] = balanceOf[from].sub(value);
        balanceOf[to] = balanceOf[to].add(value);
        emit Transfer(from, to, value);
    }

    function approve(address spender, uint value) external returns (bool) {
        _approve(msg.sender, spender, value);
        return true;
    }

    function transfer(address to, uint value) external returns (bool) {
        _transfer(msg.sender, to, value);
        return true;
    }

    function transferFrom(address from, address to, uint value) external returns (bool) {
        if (allowance[from][msg.sender] != uint(-1)) {
            allowance[from][msg.sender] = allowance[from][msg.sender].sub(value);
        }
        _transfer(from, to, value);
        return true;
    }

    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external {
        require(deadline >= block.timestamp, 'UniswapV2: EXPIRED');
        bytes32 digest = keccak256(
            abi.encodePacked(
                '\x19\x01',
                DOMAIN_SEPARATOR,
                keccak256(abi.encode(PERMIT_TYPEHASH, owner, spender, value, nonces[owner]++, deadline))
            )
        );
        address recoveredAddress = ecrecover(digest, v, r, s);
        require(recoveredAddress != address(0) && recoveredAddress == owner, 'UniswapV2: INVALID_SIGNATURE');
        _approve(owner, spender, value);
    }
}

// File: contracts/uniswapv2/libraries/Math.sol

pragma solidity =0.6.12;

// a library for performing various math operations

library Math {
    function min(uint x, uint y) internal pure returns (uint z) {
        z = x < y ? x : y;
    }

    // babylonian method (https://en.wikipedia.org/wiki/Methods_of_computing_square_roots#Babylonian_method)
    function sqrt(uint y) internal pure returns (uint z) {
        if (y > 3) {
            z = y;
            uint x = y / 2 + 1;
            while (x < z) {
                z = x;
                x = (y / x + x) / 2;
            }
        } else if (y != 0) {
            z = 1;
        }
    }
}

// File: contracts/uniswapv2/libraries/UQ112x112.sol

pragma solidity =0.6.12;

// a library for handling binary fixed point numbers (https://en.wikipedia.org/wiki/Q_(number_format))

// range: [0, 2**112 - 1]
// resolution: 1 / 2**112

library UQ112x112 {
    uint224 constant Q112 = 2**112;

    // encode a uint112 as a UQ112x112
    function encode(uint112 y) internal pure returns (uint224 z) {
        z = uint224(y) * Q112; // never overflows
    }

    // divide a UQ112x112 by a uint112, returning a UQ112x112
    function uqdiv(uint224 x, uint112 y) internal pure returns (uint224 z) {
        z = x / uint224(y);
    }
}

// File: contracts/uniswapv2/interfaces/IERC20.sol

pragma solidity >=0.5.0;

interface IERC20Uniswap {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external view returns (string memory);
    function symbol() external view returns (string memory);
    function decimals() external view returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);
}

// File: contracts/uniswapv2/interfaces/IUniswapV2Callee.sol

pragma solidity >=0.5.0;

interface IUniswapV2Callee {
    function uniswapV2Call(address sender, uint amount0, uint amount1, bytes calldata data) external;
}

// File: contracts/uniswapv2/UniswapV2Pair.sol

pragma solidity =0.6.12;








interface IMigrator {
    // Return the desired amount of liquidity token that the migrator wants.
    function desiredLiquidity() external view returns (uint256);
}

contract UniswapV2Pair is UniswapV2ERC20 {
    using SafeMathUniswap  for uint;
    using UQ112x112 for uint224;

    uint public constant MINIMUM_LIQUIDITY = 10**3;
    bytes4 private constant SELECTOR = bytes4(keccak256(bytes('transfer(address,uint256)')));

    address public factory;
    address public token0;
    address public token1;

    uint112 private reserve0;           // uses single storage slot, accessible via getReserves
    uint112 private reserve1;           // uses single storage slot, accessible via getReserves
    uint32  private blockTimestampLast; // uses single storage slot, accessible via getReserves

    uint public price0CumulativeLast;
    uint public price1CumulativeLast;
    uint public kLast; // reserve0 * reserve1, as of immediately after the most recent liquidity event

    uint private unlocked = 1;
    modifier lock() {
        require(unlocked == 1, 'UniswapV2: LOCKED');
        unlocked = 0;
        _;
        unlocked = 1;
    }

    function getReserves() public view returns (uint112 _reserve0, uint112 _reserve1, uint32 _blockTimestampLast) {
        _reserve0 = reserve0;
        _reserve1 = reserve1;
        _blockTimestampLast = blockTimestampLast;
    }

    function _safeTransfer(address token, address to, uint value) private {
        (bool success, bytes memory data) = token.call(abi.encodeWithSelector(SELECTOR, to, value));
        require(success && (data.length == 0 || abi.decode(data, (bool))), 'UniswapV2: TRANSFER_FAILED');
    }

    event Mint(address indexed sender, uint amount0, uint amount1);
    event Burn(address indexed sender, uint amount0, uint amount1, address indexed to);
    event Swap(
        address indexed sender,
        uint amount0In,
        uint amount1In,
        uint amount0Out,
        uint amount1Out,
        address indexed to
    );
    event Sync(uint112 reserve0, uint112 reserve1);

    constructor() public {
        factory = msg.sender;
    }

    // called once by the factory at time of deployment
    function initialize(address _token0, address _token1) external {
        require(msg.sender == factory, 'UniswapV2: FORBIDDEN'); // sufficient check
        token0 = _token0;
        token1 = _token1;
    }

    // update reserves and, on the first call per block, price accumulators
    function _update(uint balance0, uint balance1, uint112 _reserve0, uint112 _reserve1) private {
        require(balance0 <= uint112(-1) && balance1 <= uint112(-1), 'UniswapV2: OVERFLOW');
        uint32 blockTimestamp = uint32(block.timestamp % 2**32);
        uint32 timeElapsed = blockTimestamp - blockTimestampLast; // overflow is desired
        if (timeElapsed > 0 && _reserve0 != 0 && _reserve1 != 0) {
            // * never overflows, and + overflow is desired
            price0CumulativeLast += uint(UQ112x112.encode(_reserve1).uqdiv(_reserve0)) * timeElapsed;
            price1CumulativeLast += uint(UQ112x112.encode(_reserve0).uqdiv(_reserve1)) * timeElapsed;
        }
        reserve0 = uint112(balance0);
        reserve1 = uint112(balance1);
        blockTimestampLast = blockTimestamp;
        emit Sync(reserve0, reserve1);
    }

    // if fee is on, mint liquidity equivalent to 1/6th of the growth in sqrt(k)
    function _mintFee(uint112 _reserve0, uint112 _reserve1) private returns (bool feeOn) {
        address feeTo = IUniswapV2Factory(factory).feeTo();
        feeOn = feeTo != address(0);
        uint _kLast = kLast; // gas savings
        if (feeOn) {
            if (_kLast != 0) {
                uint rootK = Math.sqrt(uint(_reserve0).mul(_reserve1));
                uint rootKLast = Math.sqrt(_kLast);
                if (rootK > rootKLast) {
                    uint numerator = totalSupply.mul(rootK.sub(rootKLast));
                    uint denominator = rootK.mul(5).add(rootKLast);
                    uint liquidity = numerator / denominator;
                    if (liquidity > 0) _mint(feeTo, liquidity);
                }
            }
        } else if (_kLast != 0) {
            kLast = 0;
        }
    }

    // this low-level function should be called from a contract which performs important safety checks
    function mint(address to) external lock returns (uint liquidity) {
        (uint112 _reserve0, uint112 _reserve1,) = getReserves(); // gas savings
        uint balance0 = IERC20Uniswap(token0).balanceOf(address(this));
        uint balance1 = IERC20Uniswap(token1).balanceOf(address(this));
        uint amount0 = balance0.sub(_reserve0);
        uint amount1 = balance1.sub(_reserve1);

        bool feeOn = _mintFee(_reserve0, _reserve1);
        uint _totalSupply = totalSupply; // gas savings, must be defined here since totalSupply can update in _mintFee
        if (_totalSupply == 0) {
            address migrator = IUniswapV2Factory(factory).migrator();
            if (msg.sender == migrator) {
                liquidity = IMigrator(migrator).desiredLiquidity();
                require(liquidity > 0 && liquidity != uint256(-1), "Bad desired liquidity");
            } else {
                require(migrator == address(0), "Must not have migrator");
                liquidity = Math.sqrt(amount0.mul(amount1)).sub(MINIMUM_LIQUIDITY);
                _mint(address(0), MINIMUM_LIQUIDITY); // permanently lock the first MINIMUM_LIQUIDITY tokens
            }
        } else {
            liquidity = Math.min(amount0.mul(_totalSupply) / _reserve0, amount1.mul(_totalSupply) / _reserve1);
        }
        require(liquidity > 0, 'UniswapV2: INSUFFICIENT_LIQUIDITY_MINTED');
        _mint(to, liquidity);

        _update(balance0, balance1, _reserve0, _reserve1);
        if (feeOn) kLast = uint(reserve0).mul(reserve1); // reserve0 and reserve1 are up-to-date
        emit Mint(msg.sender, amount0, amount1);
    }

    // this low-level function should be called from a contract which performs important safety checks
    function burn(address to) external lock returns (uint amount0, uint amount1) {
        (uint112 _reserve0, uint112 _reserve1,) = getReserves(); // gas savings
        address _token0 = token0;                                // gas savings
        address _token1 = token1;                                // gas savings
        uint balance0 = IERC20Uniswap(_token0).balanceOf(address(this));
        uint balance1 = IERC20Uniswap(_token1).balanceOf(address(this));
        uint liquidity = balanceOf[address(this)];

        bool feeOn = _mintFee(_reserve0, _reserve1);
        uint _totalSupply = totalSupply; // gas savings, must be defined here since totalSupply can update in _mintFee
        amount0 = liquidity.mul(balance0) / _totalSupply; // using balances ensures pro-rata distribution
        amount1 = liquidity.mul(balance1) / _totalSupply; // using balances ensures pro-rata distribution
        require(amount0 > 0 && amount1 > 0, 'UniswapV2: INSUFFICIENT_LIQUIDITY_BURNED');
        _burn(address(this), liquidity);
        _safeTransfer(_token0, to, amount0);
        _safeTransfer(_token1, to, amount1);
        balance0 = IERC20Uniswap(_token0).balanceOf(address(this));
        balance1 = IERC20Uniswap(_token1).balanceOf(address(this));

        _update(balance0, balance1, _reserve0, _reserve1);
        if (feeOn) kLast = uint(reserve0).mul(reserve1); // reserve0 and reserve1 are up-to-date
        emit Burn(msg.sender, amount0, amount1, to);
    }

    // this low-level function should be called from a contract which performs important safety checks
    function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external lock {
        require(amount0Out > 0 || amount1Out > 0, 'UniswapV2: INSUFFICIENT_OUTPUT_AMOUNT');
        (uint112 _reserve0, uint112 _reserve1,) = getReserves(); // gas savings
        require(amount0Out < _reserve0 && amount1Out < _reserve1, 'UniswapV2: INSUFFICIENT_LIQUIDITY');

        uint balance0;
        uint balance1;
        { // scope for _token{0,1}, avoids stack too deep errors
        address _token0 = token0;
        address _token1 = token1;
        require(to != _token0 && to != _token1, 'UniswapV2: INVALID_TO');
        if (amount0Out > 0) _safeTransfer(_token0, to, amount0Out); // optimistically transfer tokens
        if (amount1Out > 0) _safeTransfer(_token1, to, amount1Out); // optimistically transfer tokens
        if (data.length > 0) IUniswapV2Callee(to).uniswapV2Call(msg.sender, amount0Out, amount1Out, data);
        balance0 = IERC20Uniswap(_token0).balanceOf(address(this));
        balance1 = IERC20Uniswap(_token1).balanceOf(address(this));
        }
        uint amount0In = balance0 > _reserve0 - amount0Out ? balance0 - (_reserve0 - amount0Out) : 0;
        uint amount1In = balance1 > _reserve1 - amount1Out ? balance1 - (_reserve1 - amount1Out) : 0;
        require(amount0In > 0 || amount1In > 0, 'UniswapV2: INSUFFICIENT_INPUT_AMOUNT');
        { // scope for reserve{0,1}Adjusted, avoids stack too deep errors
        uint balance0Adjusted = balance0.mul(1000).sub(amount0In.mul(3));
        uint balance1Adjusted = balance1.mul(1000).sub(amount1In.mul(3));
        require(balance0Adjusted.mul(balance1Adjusted) >= uint(_reserve0).mul(_reserve1).mul(1000**2), 'UniswapV2: K');
        }

        _update(balance0, balance1, _reserve0, _reserve1);
        emit Swap(msg.sender, amount0In, amount1In, amount0Out, amount1Out, to);
    }

    // force balances to match reserves
    function skim(address to) external lock {
        address _token0 = token0; // gas savings
        address _token1 = token1; // gas savings
        _safeTransfer(_token0, to, IERC20Uniswap(_token0).balanceOf(address(this)).sub(reserve0));
        _safeTransfer(_token1, to, IERC20Uniswap(_token1).balanceOf(address(this)).sub(reserve1));
    }

    // force reserves to match balances
    function sync() external lock {
        _update(IERC20Uniswap(token0).balanceOf(address(this)), IERC20Uniswap(token1).balanceOf(address(this)), reserve0, reserve1);
    }
}

pragma solidity ^0.4.24;

// File: zos-lib/contracts/upgradeability/Proxy.sol

/**
 * @title Proxy
 * @dev Implements delegation of calls to other contracts, with proper
 * forwarding of return values and bubbling of failures.
 * It defines a fallback function that delegates all calls to the address
 * returned by the abstract _implementation() internal function.
 */
contract Proxy {
  /**
   * @dev Fallback function.
   * Implemented entirely in `_fallback`.
   */
  function () payable external {
    _fallback();
  }

  /**
   * @return The Address of the implementation.
   */
  function _implementation() internal view returns (address);

  /**
   * @dev Delegates execution to an implementation contract.
   * This is a low level function that doesn't return to its internal call site.
   * It will return to the external caller whatever the implementation returns.
   * @param implementation Address to delegate.
   */
  function _delegate(address implementation) internal {
    assembly {
      // Copy msg.data. We take full control of memory in this inline assembly
      // block because it will not return to Solidity code. We overwrite the
      // Solidity scratch pad at memory position 0.
      calldatacopy(0, 0, calldatasize)

      // Call the implementation.
      // out and outsize are 0 because we don't know the size yet.
      let result := delegatecall(gas, implementation, 0, calldatasize, 0, 0)

      // Copy the returned data.
      returndatacopy(0, 0, returndatasize)

      switch result
      // delegatecall returns 0 on error.
      case 0 { revert(0, returndatasize) }
      default { return(0, returndatasize) }
    }
  }

  /**
   * @dev Function that is run as the first thing in the fallback function.
   * Can be redefined in derived contracts to add functionality.
   * Redefinitions must call super._willFallback().
   */
  function _willFallback() internal {
  }

  /**
   * @dev fallback implementation.
   * Extracted to enable manual triggering.
   */
  function _fallback() internal {
    _willFallback();
    _delegate(_implementation());
  }
}

// File: openzeppelin-solidity/contracts/AddressUtils.sol

/**
 * Utility library of inline functions on addresses
 */
library AddressUtils {

  /**
   * Returns whether the target address is a contract
   * @dev This function will return false if invoked during the constructor of a contract,
   * as the code is not actually created until after the constructor finishes.
   * @param addr address to check
   * @return whether the target address is a contract
   */
  function isContract(address addr) internal view returns (bool) {
    uint256 size;
    // XXX Currently there is no better way to check if there is a contract in an address
    // than to check the size of the code at that address.
    // See https://ethereum.stackexchange.com/a/14016/36603
    // for more details about how this works.
    // TODO Check this again before the Serenity release, because all addresses will be
    // contracts then.
    // solium-disable-next-line security/no-inline-assembly
    assembly { size := extcodesize(addr) }
    return size > 0;
  }

}

// File: zos-lib/contracts/upgradeability/UpgradeabilityProxy.sol

/**
 * @title UpgradeabilityProxy
 * @dev This contract implements a proxy that allows to change the
 * implementation address to which it will delegate.
 * Such a change is called an implementation upgrade.
 */
contract UpgradeabilityProxy is Proxy {
  /**
   * @dev Emitted when the implementation is upgraded.
   * @param implementation Address of the new implementation.
   */
  event Upgraded(address implementation);

  /**
   * @dev Storage slot with the address of the current implementation.
   * This is the keccak-256 hash of "org.zeppelinos.proxy.implementation", and is
   * validated in the constructor.
   */
  bytes32 private constant IMPLEMENTATION_SLOT = 0x7050c9e0f4ca769c69bd3a8ef740bc37934f8e2c036e5a723fd8ee048ed3f8c3;

  /**
   * @dev Contract constructor.
   * @param _implementation Address of the initial implementation.
   */
  constructor(address _implementation) public {
    assert(IMPLEMENTATION_SLOT == keccak256("org.zeppelinos.proxy.implementation"));

    _setImplementation(_implementation);
  }

  /**
   * @dev Returns the current implementation.
   * @return Address of the current implementation
   */
  function _implementation() internal view returns (address impl) {
    bytes32 slot = IMPLEMENTATION_SLOT;
    assembly {
      impl := sload(slot)
    }
  }

  /**
   * @dev Upgrades the proxy to a new implementation.
   * @param newImplementation Address of the new implementation.
   */
  function _upgradeTo(address newImplementation) internal {
    _setImplementation(newImplementation);
    emit Upgraded(newImplementation);
  }

  /**
   * @dev Sets the implementation address of the proxy.
   * @param newImplementation Address of the new implementation.
   */
  function _setImplementation(address newImplementation) private {
    require(AddressUtils.isContract(newImplementation), "Cannot set a proxy implementation to a non-contract address");

    bytes32 slot = IMPLEMENTATION_SLOT;

    assembly {
      sstore(slot, newImplementation)
    }
  }
}

// File: zos-lib/contracts/upgradeability/AdminUpgradeabilityProxy.sol

/**
 * @title AdminUpgradeabilityProxy
 * @dev This contract combines an upgradeability proxy with an authorization
 * mechanism for administrative tasks.
 * All external functions in this contract must be guarded by the
 * `ifAdmin` modifier. See ethereum/solidity#3864 for a Solidity
 * feature proposal that would enable this to be done automatically.
 */
contract AdminUpgradeabilityProxy is UpgradeabilityProxy {
  /**
   * @dev Emitted when the administration has been transferred.
   * @param previousAdmin Address of the previous admin.
   * @param newAdmin Address of the new admin.
   */
  event AdminChanged(address previousAdmin, address newAdmin);

  /**
   * @dev Storage slot with the admin of the contract.
   * This is the keccak-256 hash of "org.zeppelinos.proxy.admin", and is
   * validated in the constructor.
   */
  bytes32 private constant ADMIN_SLOT = 0x10d6a54a4754c8869d6886b5f5d7fbfa5b4522237ea5c60d11bc4e7a1ff9390b;

  /**
   * @dev Modifier to check whether the `msg.sender` is the admin.
   * If it is, it will run the function. Otherwise, it will delegate the call
   * to the implementation.
   */
  modifier ifAdmin() {
    if (msg.sender == _admin()) {
      _;
    } else {
      _fallback();
    }
  }

  /**
   * Contract constructor.
   * It sets the `msg.sender` as the proxy administrator.
   * @param _implementation address of the initial implementation.
   */
  constructor(address _implementation) UpgradeabilityProxy(_implementation) public {
    assert(ADMIN_SLOT == keccak256("org.zeppelinos.proxy.admin"));

    _setAdmin(msg.sender);
  }

  /**
   * @return The address of the proxy admin.
   */
  function admin() external view ifAdmin returns (address) {
    return _admin();
  }

  /**
   * @return The address of the implementation.
   */
  function implementation() external view ifAdmin returns (address) {
    return _implementation();
  }

  /**
   * @dev Changes the admin of the proxy.
   * Only the current admin can call this function.
   * @param newAdmin Address to transfer proxy administration to.
   */
  function changeAdmin(address newAdmin) external ifAdmin {
    require(newAdmin != address(0), "Cannot change the admin of a proxy to the zero address");
    emit AdminChanged(_admin(), newAdmin);
    _setAdmin(newAdmin);
  }

  /**
   * @dev Upgrade the backing implementation of the proxy.
   * Only the admin can call this function.
   * @param newImplementation Address of the new implementation.
   */
  function upgradeTo(address newImplementation) external ifAdmin {
    _upgradeTo(newImplementation);
  }

  /**
   * @dev Upgrade the backing implementation of the proxy and call a function
   * on the new implementation.
   * This is useful to initialize the proxied contract.
   * @param newImplementation Address of the new implementation.
   * @param data Data to send as msg.data in the low level call.
   * It should include the signature and the parameters of the function to be
   * called, as described in
   * https://solidity.readthedocs.io/en/develop/abi-spec.html#function-selector-and-argument-encoding.
   */
  function upgradeToAndCall(address newImplementation, bytes data) payable external ifAdmin {
    _upgradeTo(newImplementation);
    require(address(this).call.value(msg.value)(data));
  }

  /**
   * @return The admin slot.
   */
  function _admin() internal view returns (address adm) {
    bytes32 slot = ADMIN_SLOT;
    assembly {
      adm := sload(slot)
    }
  }

  /**
   * @dev Sets the address of the proxy admin.
   * @param newAdmin Address of the new proxy admin.
   */
  function _setAdmin(address newAdmin) internal {
    bytes32 slot = ADMIN_SLOT;

    assembly {
      sstore(slot, newAdmin)
    }
  }

  /**
   * @dev Only fall back when the sender is not the admin.
   */
  function _willFallback() internal {
    require(msg.sender != _admin(), "Cannot call fallback function from the proxy admin");
    super._willFallback();
  }
}

// File: contracts/FiatTokenProxy.sol

/**
* Copyright CENTRE SECZ 2018
*
* Permission is hereby granted, free of charge, to any person obtaining a copy 
* of this software and associated documentation files (the "Software"), to deal 
* in the Software without restriction, including without limitation the rights 
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 
* copies of the Software, and to permit persons to whom the Software is furnished to 
* do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all 
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN 
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/

pragma solidity ^0.4.24;


/**
 * @title FiatTokenProxy
 * @dev This contract proxies FiatToken calls and enables FiatToken upgrades
*/ 
contract FiatTokenProxy is AdminUpgradeabilityProxy {
    constructor(address _implementation) public AdminUpgradeabilityProxy(_implementation) {
    }
}

// File: @openzeppelin/contracts/math/SafeMath.sol

// SPDX-License-Identifier: MIT

pragma solidity ^0.6.0;

/**
 * @dev Wrappers over Solidity's arithmetic operations with added overflow
 * checks.
 *
 * Arithmetic operations in Solidity wrap on overflow. This can easily result
 * in bugs, because programmers usually assume that an overflow raises an
 * error, which is the standard behavior in high level programming languages.
 * `SafeMath` restores this intuition by reverting the transaction when an
 * operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 */
library SafeMath {
    /**
     * @dev Returns the addition of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `+` operator.
     *
     * Requirements:
     *
     * - Addition cannot overflow.
     */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");

        return c;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        return sub(a, b, "SafeMath: subtraction overflow");
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        require(b <= a, errorMessage);
        uint256 c = a - b;

        return c;
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `*` operator.
     *
     * Requirements:
     *
     * - Multiplication cannot overflow.
     */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
        // benefit is lost if 'b' is also tested.
        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
        if (a == 0) {
            return 0;
        }

        uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");

        return c;
    }

    /**
     * @dev Returns the integer division of two unsigned integers. Reverts on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        return div(a, b, "SafeMath: division by zero");
    }

    /**
     * @dev Returns the integer division of two unsigned integers. Reverts with custom message on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        require(b > 0, errorMessage);
        uint256 c = a / b;
        // assert(a == b * c + a % b); // There is no case in which this doesn't hold

        return c;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * Reverts when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        return mod(a, b, "SafeMath: modulo by zero");
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * Reverts with custom message when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        require(b != 0, errorMessage);
        return a % b;
    }
}

// File: @openzeppelin/contracts/token/ERC20/IERC20.sol

pragma solidity ^0.6.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves `amount` tokens from the caller's account to `recipient`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address recipient, uint256 amount)
        external
        returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender)
        external
        view
        returns (uint256);

    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `sender` to `recipient` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(
        address sender,
        address recipient,
        uint256 amount
    ) external returns (bool);

    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(
        address indexed owner,
        address indexed spender,
        uint256 value
    );
}

// File: contracts/v1/AbstractFiatTokenV1.sol

/**
 * Copyright (c) 2018-2020 CENTRE SECZ
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

pragma solidity 0.6.12;

abstract contract AbstractFiatTokenV1 is IERC20 {
    function _approve(
        address owner,
        address spender,
        uint256 value
    ) internal virtual;

    function _transfer(
        address from,
        address to,
        uint256 value
    ) internal virtual;
}

// File: contracts/v1/Ownable.sol

/**
 * Copyright (c) 2018 zOS Global Limited.
 * Copyright (c) 2018-2020 CENTRE SECZ
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */
pragma solidity 0.6.12;

/**
 * @notice The Ownable contract has an owner address, and provides basic
 * authorization control functions
 * @dev Forked from https://github.com/OpenZeppelin/openzeppelin-labs/blob/3887ab77b8adafba4a26ace002f3a684c1a3388b/upgradeability_ownership/contracts/ownership/Ownable.sol
 * Modifications:
 * 1. Consolidate OwnableStorage into this contract (7/13/18)
 * 2. Reformat, conform to Solidity 0.6 syntax, and add error messages (5/13/20)
 * 3. Make public functions external (5/27/20)
 */
contract Ownable {
    // Owner of the contract
    address private _owner;

    /**
     * @dev Event to show ownership has been transferred
     * @param previousOwner representing the address of the previous owner
     * @param newOwner representing the address of the new owner
     */
    event OwnershipTransferred(address previousOwner, address newOwner);

    /**
     * @dev The constructor sets the original owner of the contract to the sender account.
     */
    constructor() public {
        setOwner(msg.sender);
    }

    /**
     * @dev Tells the address of the owner
     * @return the address of the owner
     */
    function owner() external view returns (address) {
        return _owner;
    }

    /**
     * @dev Sets a new owner address
     */
    function setOwner(address newOwner) internal {
        _owner = newOwner;
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        require(msg.sender == _owner, "Ownable: caller is not the owner");
        _;
    }

    /**
     * @dev Allows the current owner to transfer control of the contract to a newOwner.
     * @param newOwner The address to transfer ownership to.
     */
    function transferOwnership(address newOwner) external onlyOwner {
        require(
            newOwner != address(0),
            "Ownable: new owner is the zero address"
        );
        emit OwnershipTransferred(_owner, newOwner);
        setOwner(newOwner);
    }
}

// File: contracts/v1/Pausable.sol

/**
 * Copyright (c) 2016 Smart Contract Solutions, Inc.
 * Copyright (c) 2018-2020 CENTRE SECZ0
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

pragma solidity 0.6.12;

/**
 * @notice Base contract which allows children to implement an emergency stop
 * mechanism
 * @dev Forked from https://github.com/OpenZeppelin/openzeppelin-contracts/blob/feb665136c0dae9912e08397c1a21c4af3651ef3/contracts/lifecycle/Pausable.sol
 * Modifications:
 * 1. Added pauser role, switched pause/unpause to be onlyPauser (6/14/2018)
 * 2. Removed whenNotPause/whenPaused from pause/unpause (6/14/2018)
 * 3. Removed whenPaused (6/14/2018)
 * 4. Switches ownable library to use ZeppelinOS (7/12/18)
 * 5. Remove constructor (7/13/18)
 * 6. Reformat, conform to Solidity 0.6 syntax and add error messages (5/13/20)
 * 7. Make public functions external (5/27/20)
 */
contract Pausable is Ownable {
    event Pause();
    event Unpause();
    event PauserChanged(address indexed newAddress);

    address public pauser;
    bool public paused = false;

    /**
     * @dev Modifier to make a function callable only when the contract is not paused.
     */
    modifier whenNotPaused() {
        require(!paused, "Pausable: paused");
        _;
    }

    /**
     * @dev throws if called by any account other than the pauser
     */
    modifier onlyPauser() {
        require(msg.sender == pauser, "Pausable: caller is not the pauser");
        _;
    }

    /**
     * @dev called by the owner to pause, triggers stopped state
     */
    function pause() external onlyPauser {
        paused = true;
        emit Pause();
    }

    /**
     * @dev called by the owner to unpause, returns to normal state
     */
    function unpause() external onlyPauser {
        paused = false;
        emit Unpause();
    }

    /**
     * @dev update the pauser role
     */
    function updatePauser(address _newPauser) external onlyOwner {
        require(
            _newPauser != address(0),
            "Pausable: new pauser is the zero address"
        );
        pauser = _newPauser;
        emit PauserChanged(pauser);
    }
}

// File: contracts/v1/Blacklistable.sol

/**
 * Copyright (c) 2018-2020 CENTRE SECZ
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

pragma solidity 0.6.12;

/**
 * @title Blacklistable Token
 * @dev Allows accounts to be blacklisted by a "blacklister" role
 */
contract Blacklistable is Ownable {
    address public blacklister;
    mapping(address => bool) internal blacklisted;

    event Blacklisted(address indexed _account);
    event UnBlacklisted(address indexed _account);
    event BlacklisterChanged(address indexed newBlacklister);

    /**
     * @dev Throws if called by any account other than the blacklister
     */
    modifier onlyBlacklister() {
        require(
            msg.sender == blacklister,
            "Blacklistable: caller is not the blacklister"
        );
        _;
    }

    /**
     * @dev Throws if argument account is blacklisted
     * @param _account The address to check
     */
    modifier notBlacklisted(address _account) {
        require(
            !blacklisted[_account],
            "Blacklistable: account is blacklisted"
        );
        _;
    }

    /**
     * @dev Checks if account is blacklisted
     * @param _account The address to check
     */
    function isBlacklisted(address _account) external view returns (bool) {
        return blacklisted[_account];
    }

    /**
     * @dev Adds account to blacklist
     * @param _account The address to blacklist
     */
    function blacklist(address _account) external onlyBlacklister {
        blacklisted[_account] = true;
        emit Blacklisted(_account);
    }

    /**
     * @dev Removes account from blacklist
     * @param _account The address to remove from the blacklist
     */
    function unBlacklist(address _account) external onlyBlacklister {
        blacklisted[_account] = false;
        emit UnBlacklisted(_account);
    }

    function updateBlacklister(address _newBlacklister) external onlyOwner {
        require(
            _newBlacklister != address(0),
            "Blacklistable: new blacklister is the zero address"
        );
        blacklister = _newBlacklister;
        emit BlacklisterChanged(blacklister);
    }
}

// File: contracts/v1/FiatTokenV1.sol

/**
 *
 * Copyright (c) 2018-2020 CENTRE SECZ
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

pragma solidity 0.6.12;

/**
 * @title FiatToken
 * @dev ERC20 Token backed by fiat reserves
 */
contract FiatTokenV1 is AbstractFiatTokenV1, Ownable, Pausable, Blacklistable {
    using SafeMath for uint256;

    string public name;
    string public symbol;
    uint8 public decimals;
    string public currency;
    address public masterMinter;
    bool internal initialized;

    mapping(address => uint256) internal balances;
    mapping(address => mapping(address => uint256)) internal allowed;
    uint256 internal totalSupply_ = 0;
    mapping(address => bool) internal minters;
    mapping(address => uint256) internal minterAllowed;

    event Mint(address indexed minter, address indexed to, uint256 amount);
    event Burn(address indexed burner, uint256 amount);
    event MinterConfigured(address indexed minter, uint256 minterAllowedAmount);
    event MinterRemoved(address indexed oldMinter);
    event MasterMinterChanged(address indexed newMasterMinter);

    function initialize(
        string memory tokenName,
        string memory tokenSymbol,
        string memory tokenCurrency,
        uint8 tokenDecimals,
        address newMasterMinter,
        address newPauser,
        address newBlacklister,
        address newOwner
    ) public {
        require(!initialized, "FiatToken: contract is already initialized");
        require(
            newMasterMinter != address(0),
            "FiatToken: new masterMinter is the zero address"
        );
        require(
            newPauser != address(0),
            "FiatToken: new pauser is the zero address"
        );
        require(
            newBlacklister != address(0),
            "FiatToken: new blacklister is the zero address"
        );
        require(
            newOwner != address(0),
            "FiatToken: new owner is the zero address"
        );

        name = tokenName;
        symbol = tokenSymbol;
        currency = tokenCurrency;
        decimals = tokenDecimals;
        masterMinter = newMasterMinter;
        pauser = newPauser;
        blacklister = newBlacklister;
        setOwner(newOwner);
        initialized = true;
    }

    /**
     * @dev Throws if called by any account other than a minter
     */
    modifier onlyMinters() {
        require(minters[msg.sender], "FiatToken: caller is not a minter");
        _;
    }

    /**
     * @dev Function to mint tokens
     * @param _to The address that will receive the minted tokens.
     * @param _amount The amount of tokens to mint. Must be less than or equal
     * to the minterAllowance of the caller.
     * @return A boolean that indicates if the operation was successful.
     */
    function mint(address _to, uint256 _amount)
        external
        whenNotPaused
        onlyMinters
        notBlacklisted(msg.sender)
        notBlacklisted(_to)
        returns (bool)
    {
        require(_to != address(0), "FiatToken: mint to the zero address");
        require(_amount > 0, "FiatToken: mint amount not greater than 0");

        uint256 mintingAllowedAmount = minterAllowed[msg.sender];
        require(
            _amount <= mintingAllowedAmount,
            "FiatToken: mint amount exceeds minterAllowance"
        );

        totalSupply_ = totalSupply_.add(_amount);
        balances[_to] = balances[_to].add(_amount);
        minterAllowed[msg.sender] = mintingAllowedAmount.sub(_amount);
        emit Mint(msg.sender, _to, _amount);
        emit Transfer(address(0), _to, _amount);
        return true;
    }

    /**
     * @dev Throws if called by any account other than the masterMinter
     */
    modifier onlyMasterMinter() {
        require(
            msg.sender == masterMinter,
            "FiatToken: caller is not the masterMinter"
        );
        _;
    }

    /**
     * @dev Get minter allowance for an account
     * @param minter The address of the minter
     */
    function minterAllowance(address minter) external view returns (uint256) {
        return minterAllowed[minter];
    }

    /**
     * @dev Checks if account is a minter
     * @param account The address to check
     */
    function isMinter(address account) external view returns (bool) {
        return minters[account];
    }

    /**
     * @notice Amount of remaining tokens spender is allowed to transfer on
     * behalf of the token owner
     * @param owner     Token owner's address
     * @param spender   Spender's address
     * @return Allowance amount
     */
    function allowance(address owner, address spender)
        external
        override
        view
        returns (uint256)
    {
        return allowed[owner][spender];
    }

    /**
     * @dev Get totalSupply of token
     */
    function totalSupply() external override view returns (uint256) {
        return totalSupply_;
    }

    /**
     * @dev Get token balance of an account
     * @param account address The account
     */
    function balanceOf(address account)
        external
        override
        view
        returns (uint256)
    {
        return balances[account];
    }

    /**
     * @notice Set spender's allowance over the caller's tokens to be a given
     * value.
     * @param spender   Spender's address
     * @param value     Allowance amount
     * @return True if successful
     */
    function approve(address spender, uint256 value)
        external
        override
        whenNotPaused
        notBlacklisted(msg.sender)
        notBlacklisted(spender)
        returns (bool)
    {
        _approve(msg.sender, spender, value);
        return true;
    }

    /**
     * @dev Internal function to set allowance
     * @param owner     Token owner's address
     * @param spender   Spender's address
     * @param value     Allowance amount
     */
    function _approve(
        address owner,
        address spender,
        uint256 value
    ) internal override {
        require(owner != address(0), "ERC20: approve from the zero address");
        require(spender != address(0), "ERC20: approve to the zero address");
        allowed[owner][spender] = value;
        emit Approval(owner, spender, value);
    }

    /**
     * @notice Transfer tokens by spending allowance
     * @param from  Payer's address
     * @param to    Payee's address
     * @param value Transfer amount
     * @return True if successful
     */
    function transferFrom(
        address from,
        address to,
        uint256 value
    )
        external
        override
        whenNotPaused
        notBlacklisted(msg.sender)
        notBlacklisted(from)
        notBlacklisted(to)
        returns (bool)
    {
        require(
            value <= allowed[from][msg.sender],
            "ERC20: transfer amount exceeds allowance"
        );
        _transfer(from, to, value);
        allowed[from][msg.sender] = allowed[from][msg.sender].sub(value);
        return true;
    }

    /**
     * @notice Transfer tokens from the caller
     * @param to    Payee's address
     * @param value Transfer amount
     * @return True if successful
     */
    function transfer(address to, uint256 value)
        external
        override
        whenNotPaused
        notBlacklisted(msg.sender)
        notBlacklisted(to)
        returns (bool)
    {
        _transfer(msg.sender, to, value);
        return true;
    }

    /**
     * @notice Internal function to process transfers
     * @param from  Payer's address
     * @param to    Payee's address
     * @param value Transfer amount
     */
    function _transfer(
        address from,
        address to,
        uint256 value
    ) internal override {
        require(from != address(0), "ERC20: transfer from the zero address");
        require(to != address(0), "ERC20: transfer to the zero address");
        require(
            value <= balances[from],
            "ERC20: transfer amount exceeds balance"
        );

        balances[from] = balances[from].sub(value);
        balances[to] = balances[to].add(value);
        emit Transfer(from, to, value);
    }

    /**
     * @dev Function to add/update a new minter
     * @param minter The address of the minter
     * @param minterAllowedAmount The minting amount allowed for the minter
     * @return True if the operation was successful.
     */
    function configureMinter(address minter, uint256 minterAllowedAmount)
        external
        whenNotPaused
        onlyMasterMinter
        returns (bool)
    {
        minters[minter] = true;
        minterAllowed[minter] = minterAllowedAmount;
        emit MinterConfigured(minter, minterAllowedAmount);
        return true;
    }

    /**
     * @dev Function to remove a minter
     * @param minter The address of the minter to remove
     * @return True if the operation was successful.
     */
    function removeMinter(address minter)
        external
        onlyMasterMinter
        returns (bool)
    {
        minters[minter] = false;
        minterAllowed[minter] = 0;
        emit MinterRemoved(minter);
        return true;
    }

    /**
     * @dev allows a minter to burn some of its own tokens
     * Validates that caller is a minter and that sender is not blacklisted
     * amount is less than or equal to the minter's account balance
     * @param _amount uint256 the amount of tokens to be burned
     */
    function burn(uint256 _amount)
        external
        whenNotPaused
        onlyMinters
        notBlacklisted(msg.sender)
    {
        uint256 balance = balances[msg.sender];
        require(_amount > 0, "FiatToken: burn amount not greater than 0");
        require(balance >= _amount, "FiatToken: burn amount exceeds balance");

        totalSupply_ = totalSupply_.sub(_amount);
        balances[msg.sender] = balance.sub(_amount);
        emit Burn(msg.sender, _amount);
        emit Transfer(msg.sender, address(0), _amount);
    }

    function updateMasterMinter(address _newMasterMinter) external onlyOwner {
        require(
            _newMasterMinter != address(0),
            "FiatToken: new masterMinter is the zero address"
        );
        masterMinter = _newMasterMinter;
        emit MasterMinterChanged(masterMinter);
    }
}

// File: @openzeppelin/contracts/utils/Address.sol

pragma solidity ^0.6.2;

/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // According to EIP-1052, 0x0 is the value returned for not-yet created accounts
        // and 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470 is returned
        // for accounts without code, i.e. `keccak256('')`
        bytes32 codehash;

            bytes32 accountHash
         = 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470;
        // solhint-disable-next-line no-inline-assembly
        assembly {
            codehash := extcodehash(account)
        }
        return (codehash != accountHash && codehash != 0x0);
    }

    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(
            address(this).balance >= amount,
            "Address: insufficient balance"
        );

        // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
        (bool success, ) = recipient.call{ value: amount }("");
        require(
            success,
            "Address: unable to send value, recipient may have reverted"
        );
    }

    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain`call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data)
        internal
        returns (bytes memory)
    {
        return functionCall(target, data, "Address: low-level call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        return _functionCallWithValue(target, data, 0, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value
    ) internal returns (bytes memory) {
        return
            functionCallWithValue(
                target,
                data,
                value,
                "Address: low-level call with value failed"
            );
    }

    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(
            address(this).balance >= value,
            "Address: insufficient balance for call"
        );
        return _functionCallWithValue(target, data, value, errorMessage);
    }

    function _functionCallWithValue(
        address target,
        bytes memory data,
        uint256 weiValue,
        string memory errorMessage
    ) private returns (bytes memory) {
        require(isContract(target), "Address: call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.call{
            value: weiValue
        }(data);
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly

                // solhint-disable-next-line no-inline-assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}

// File: @openzeppelin/contracts/token/ERC20/SafeERC20.sol

pragma solidity ^0.6.0;

/**
 * @title SafeERC20
 * @dev Wrappers around ERC20 operations that throw on failure (when the token
 * contract returns false). Tokens that return no value (and instead revert or
 * throw on failure) are also supported, non-reverting calls are assumed to be
 * successful.
 * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
 */
library SafeERC20 {
    using SafeMath for uint256;
    using Address for address;

    function safeTransfer(
        IERC20 token,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(
            token,
            abi.encodeWithSelector(token.transfer.selector, to, value)
        );
    }

    function safeTransferFrom(
        IERC20 token,
        address from,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(
            token,
            abi.encodeWithSelector(token.transferFrom.selector, from, to, value)
        );
    }

    /**
     * @dev Deprecated. This function has issues similar to the ones found in
     * {IERC20-approve}, and its usage is discouraged.
     *
     * Whenever possible, use {safeIncreaseAllowance} and
     * {safeDecreaseAllowance} instead.
     */
    function safeApprove(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        // safeApprove should only be called when setting an initial allowance,
        // or when resetting it to zero. To increase and decrease it, use
        // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
        // solhint-disable-next-line max-line-length
        require(
            (value == 0) || (token.allowance(address(this), spender) == 0),
            "SafeERC20: approve from non-zero to non-zero allowance"
        );
        _callOptionalReturn(
            token,
            abi.encodeWithSelector(token.approve.selector, spender, value)
        );
    }

    function safeIncreaseAllowance(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        uint256 newAllowance = token.allowance(address(this), spender).add(
            value
        );
        _callOptionalReturn(
            token,
            abi.encodeWithSelector(
                token.approve.selector,
                spender,
                newAllowance
            )
        );
    }

    function safeDecreaseAllowance(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        uint256 newAllowance = token.allowance(address(this), spender).sub(
            value,
            "SafeERC20: decreased allowance below zero"
        );
        _callOptionalReturn(
            token,
            abi.encodeWithSelector(
                token.approve.selector,
                spender,
                newAllowance
            )
        );
    }

    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     */
    function _callOptionalReturn(IERC20 token, bytes memory data) private {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that
        // the target address contains contract code and also asserts for success in the low-level call.

        bytes memory returndata = address(token).functionCall(
            data,
            "SafeERC20: low-level call failed"
        );
        if (returndata.length > 0) {
            // Return data is optional
            // solhint-disable-next-line max-line-length
            require(
                abi.decode(returndata, (bool)),
                "SafeERC20: ERC20 operation did not succeed"
            );
        }
    }
}

// File: contracts/v1.1/Rescuable.sol

/**
 * Copyright (c) 2018-2020 CENTRE SECZ
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

pragma solidity 0.6.12;

contract Rescuable is Ownable {
    using SafeERC20 for IERC20;

    address private _rescuer;

    event RescuerChanged(address indexed newRescuer);

    /**
     * @notice Returns current rescuer
     * @return Rescuer's address
     */
    function rescuer() external view returns (address) {
        return _rescuer;
    }

    /**
     * @notice Revert if called by any account other than the rescuer.
     */
    modifier onlyRescuer() {
        require(msg.sender == _rescuer, "Rescuable: caller is not the rescuer");
        _;
    }

    /**
     * @notice Rescue ERC20 tokens locked up in this contract.
     * @param tokenContract ERC20 token contract address
     * @param to        Recipient address
     * @param amount    Amount to withdraw
     */
    function rescueERC20(
        IERC20 tokenContract,
        address to,
        uint256 amount
    ) external onlyRescuer {
        tokenContract.safeTransfer(to, amount);
    }

    /**
     * @notice Assign the rescuer role to a given address.
     * @param newRescuer New rescuer's address
     */
    function updateRescuer(address newRescuer) external onlyOwner {
        require(
            newRescuer != address(0),
            "Rescuable: new rescuer is the zero address"
        );
        _rescuer = newRescuer;
        emit RescuerChanged(newRescuer);
    }
}

// File: contracts/v1.1/FiatTokenV1_1.sol

/**
 * Copyright (c) 2018-2020 CENTRE SECZ
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

pragma solidity 0.6.12;

/**
 * @title FiatTokenV1_1
 * @dev ERC20 Token backed by fiat reserves
 */
contract FiatTokenV1_1 is FiatTokenV1, Rescuable {

}

// File: contracts/v2/AbstractFiatTokenV2.sol

/**
 * Copyright (c) 2018-2020 CENTRE SECZ
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

pragma solidity 0.6.12;

abstract contract AbstractFiatTokenV2 is AbstractFiatTokenV1 {
    function _increaseAllowance(
        address owner,
        address spender,
        uint256 increment
    ) internal virtual;

    function _decreaseAllowance(
        address owner,
        address spender,
        uint256 decrement
    ) internal virtual;
}

// File: contracts/util/ECRecover.sol

/**
 * Copyright (c) 2016-2019 zOS Global Limited
 * Copyright (c) 2018-2020 CENTRE SECZ
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

pragma solidity 0.6.12;

/**
 * @title ECRecover
 * @notice A library that provides a safe ECDSA recovery function
 */
library ECRecover {
    /**
     * @notice Recover signer's address from a signed message
     * @dev Adapted from: https://github.com/OpenZeppelin/openzeppelin-contracts/blob/65e4ffde586ec89af3b7e9140bdc9235d1254853/contracts/cryptography/ECDSA.sol
     * Modifications: Accept v, r, and s as separate arguments
     * @param digest    Keccak-256 hash digest of the signed message
     * @param v         v of the signature
     * @param r         r of the signature
     * @param s         s of the signature
     * @return Signer address
     */
    function recover(
        bytes32 digest,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) internal pure returns (address) {
        // EIP-2 still allows signature malleability for ecrecover(). Remove this possibility and make the signature
        // unique. Appendix F in the Ethereum Yellow paper (https://ethereum.github.io/yellowpaper/paper.pdf), defines
        // the valid range for s in (281): 0 < s < secp256k1n ÷ 2 + 1, and for v in (282): v ∈ {27, 28}. Most
        // signatures from current libraries generate a unique signature with an s-value in the lower half order.
        //
        // If your library generates malleable signatures, such as s-values in the upper range, calculate a new s-value
        // with 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141 - s1 and flip v from 27 to 28 or
        // vice versa. If your library also generates signatures with 0/1 for v instead 27/28, add 27 to v to accept
        // these malleable signatures as well.
        if (
            uint256(s) >
            0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0
        ) {
            revert("ECRecover: invalid signature 's' value");
        }

        if (v != 27 && v != 28) {
            revert("ECRecover: invalid signature 'v' value");
        }

        // If the signature is valid (and not malleable), return the signer address
        address signer = ecrecover(digest, v, r, s);
        require(signer != address(0), "ECRecover: invalid signature");

        return signer;
    }
}

// File: contracts/util/EIP712.sol

/**
 * Copyright (c) 2018-2020 CENTRE SECZ
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

pragma solidity 0.6.12;

/**
 * @title EIP712
 * @notice A library that provides EIP712 helper functions
 */
library EIP712 {
    /**
     * @notice Make EIP712 domain separator
     * @param name      Contract name
     * @param version   Contract version
     * @return Domain separator
     */
    function makeDomainSeparator(string memory name, string memory version)
        internal
        view
        returns (bytes32)
    {
        uint256 chainId;
        assembly {
            chainId := chainid()
        }
        return
            keccak256(
                abi.encode(
                    // keccak256("EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)")
                    0x8b73c3c69bb8fe3d512ecc4cf759cc79239f7b179b0ffacaa9a75d522b39400f,
                    keccak256(bytes(name)),
                    keccak256(bytes(version)),
                    chainId,
                    address(this)
                )
            );
    }

    /**
     * @notice Recover signer's address from a EIP712 signature
     * @param domainSeparator   Domain separator
     * @param v                 v of the signature
     * @param r                 r of the signature
     * @param s                 s of the signature
     * @param typeHashAndData   Type hash concatenated with data
     * @return Signer's address
     */
    function recover(
        bytes32 domainSeparator,
        uint8 v,
        bytes32 r,
        bytes32 s,
        bytes memory typeHashAndData
    ) internal pure returns (address) {
        bytes32 digest = keccak256(
            abi.encodePacked(
                "\x19\x01",
                domainSeparator,
                keccak256(typeHashAndData)
            )
        );
        return ECRecover.recover(digest, v, r, s);
    }
}

// File: contracts/v2/EIP712Domain.sol

/**
 * Copyright (c) 2018-2020 CENTRE SECZ
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

pragma solidity 0.6.12;

/**
 * @title EIP712 Domain
 */
contract EIP712Domain {
    /**
     * @dev EIP712 Domain Separator
     */
    bytes32 public DOMAIN_SEPARATOR;
}

// File: contracts/v2/EIP3009.sol

/**
 * Copyright (c) 2018-2020 CENTRE SECZ
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

pragma solidity 0.6.12;

/**
 * @title EIP-3009
 * @notice Provide internal implementation for gas-abstracted transfers
 * @dev Contracts that inherit from this must wrap these with publicly
 * accessible functions, optionally adding modifiers where necessary
 */
abstract contract EIP3009 is AbstractFiatTokenV2, EIP712Domain {
    // keccak256("TransferWithAuthorization(address from,address to,uint256 value,uint256 validAfter,uint256 validBefore,bytes32 nonce)")
    bytes32
        public constant TRANSFER_WITH_AUTHORIZATION_TYPEHASH = 0x7c7c6cdb67a18743f49ec6fa9b35f50d52ed05cbed4cc592e13b44501c1a2267;

    // keccak256("ReceiveWithAuthorization(address from,address to,uint256 value,uint256 validAfter,uint256 validBefore,bytes32 nonce)")
    bytes32
        public constant RECEIVE_WITH_AUTHORIZATION_TYPEHASH = 0xd099cc98ef71107a616c4f0f941f04c322d8e254fe26b3c6668db87aae413de8;

    // keccak256("CancelAuthorization(address authorizer,bytes32 nonce)")
    bytes32
        public constant CANCEL_AUTHORIZATION_TYPEHASH = 0x158b0a9edf7a828aad02f63cd515c68ef2f50ba807396f6d12842833a1597429;

    /**
     * @dev authorizer address => nonce => bool (true if nonce is used)
     */
    mapping(address => mapping(bytes32 => bool)) private _authorizationStates;

    event AuthorizationUsed(address indexed authorizer, bytes32 indexed nonce);
    event AuthorizationCanceled(
        address indexed authorizer,
        bytes32 indexed nonce
    );

    /**
     * @notice Returns the state of an authorization
     * @dev Nonces are randomly generated 32-byte data unique to the
     * authorizer's address
     * @param authorizer    Authorizer's address
     * @param nonce         Nonce of the authorization
     * @return True if the nonce is used
     */
    function authorizationState(address authorizer, bytes32 nonce)
        external
        view
        returns (bool)
    {
        return _authorizationStates[authorizer][nonce];
    }

    /**
     * @notice Execute a transfer with a signed authorization
     * @param from          Payer's address (Authorizer)
     * @param to            Payee's address
     * @param value         Amount to be transferred
     * @param validAfter    The time after which this is valid (unix time)
     * @param validBefore   The time before which this is valid (unix time)
     * @param nonce         Unique nonce
     * @param v             v of the signature
     * @param r             r of the signature
     * @param s             s of the signature
     */
    function _transferWithAuthorization(
        address from,
        address to,
        uint256 value,
        uint256 validAfter,
        uint256 validBefore,
        bytes32 nonce,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) internal {
        _requireValidAuthorization(from, nonce, validAfter, validBefore);

        bytes memory data = abi.encode(
            TRANSFER_WITH_AUTHORIZATION_TYPEHASH,
            from,
            to,
            value,
            validAfter,
            validBefore,
            nonce
        );
        require(
            EIP712.recover(DOMAIN_SEPARATOR, v, r, s, data) == from,
            "FiatTokenV2: invalid signature"
        );

        _markAuthorizationAsUsed(from, nonce);
        _transfer(from, to, value);
    }

    /**
     * @notice Receive a transfer with a signed authorization from the payer
     * @dev This has an additional check to ensure that the payee's address
     * matches the caller of this function to prevent front-running attacks.
     * @param from          Payer's address (Authorizer)
     * @param to            Payee's address
     * @param value         Amount to be transferred
     * @param validAfter    The time after which this is valid (unix time)
     * @param validBefore   The time before which this is valid (unix time)
     * @param nonce         Unique nonce
     * @param v             v of the signature
     * @param r             r of the signature
     * @param s             s of the signature
     */
    function _receiveWithAuthorization(
        address from,
        address to,
        uint256 value,
        uint256 validAfter,
        uint256 validBefore,
        bytes32 nonce,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) internal {
        require(to == msg.sender, "FiatTokenV2: caller must be the payee");
        _requireValidAuthorization(from, nonce, validAfter, validBefore);

        bytes memory data = abi.encode(
            RECEIVE_WITH_AUTHORIZATION_TYPEHASH,
            from,
            to,
            value,
            validAfter,
            validBefore,
            nonce
        );
        require(
            EIP712.recover(DOMAIN_SEPARATOR, v, r, s, data) == from,
            "FiatTokenV2: invalid signature"
        );

        _markAuthorizationAsUsed(from, nonce);
        _transfer(from, to, value);
    }

    /**
     * @notice Attempt to cancel an authorization
     * @param authorizer    Authorizer's address
     * @param nonce         Nonce of the authorization
     * @param v             v of the signature
     * @param r             r of the signature
     * @param s             s of the signature
     */
    function _cancelAuthorization(
        address authorizer,
        bytes32 nonce,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) internal {
        _requireUnusedAuthorization(authorizer, nonce);

        bytes memory data = abi.encode(
            CANCEL_AUTHORIZATION_TYPEHASH,
            authorizer,
            nonce
        );
        require(
            EIP712.recover(DOMAIN_SEPARATOR, v, r, s, data) == authorizer,
            "FiatTokenV2: invalid signature"
        );

        _authorizationStates[authorizer][nonce] = true;
        emit AuthorizationCanceled(authorizer, nonce);
    }

    /**
     * @notice Check that an authorization is unused
     * @param authorizer    Authorizer's address
     * @param nonce         Nonce of the authorization
     */
    function _requireUnusedAuthorization(address authorizer, bytes32 nonce)
        private
        view
    {
        require(
            !_authorizationStates[authorizer][nonce],
            "FiatTokenV2: authorization is used or canceled"
        );
    }

    /**
     * @notice Check that authorization is valid
     * @param authorizer    Authorizer's address
     * @param nonce         Nonce of the authorization
     * @param validAfter    The time after which this is valid (unix time)
     * @param validBefore   The time before which this is valid (unix time)
     */
    function _requireValidAuthorization(
        address authorizer,
        bytes32 nonce,
        uint256 validAfter,
        uint256 validBefore
    ) private view {
        require(
            now > validAfter,
            "FiatTokenV2: authorization is not yet valid"
        );
        require(now < validBefore, "FiatTokenV2: authorization is expired");
        _requireUnusedAuthorization(authorizer, nonce);
    }

    /**
     * @notice Mark an authorization as used
     * @param authorizer    Authorizer's address
     * @param nonce         Nonce of the authorization
     */
    function _markAuthorizationAsUsed(address authorizer, bytes32 nonce)
        private
    {
        _authorizationStates[authorizer][nonce] = true;
        emit AuthorizationUsed(authorizer, nonce);
    }
}

// File: contracts/v2/EIP2612.sol

/**
 * Copyright (c) 2018-2020 CENTRE SECZ
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

pragma solidity 0.6.12;

/**
 * @title EIP-2612
 * @notice Provide internal implementation for gas-abstracted approvals
 */
abstract contract EIP2612 is AbstractFiatTokenV2, EIP712Domain {
    // keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)")
    bytes32
        public constant PERMIT_TYPEHASH = 0x6e71edae12b1b97f4d1f60370fef10105fa2faae0126114a169c64845d6126c9;

    mapping(address => uint256) private _permitNonces;

    /**
     * @notice Nonces for permit
     * @param owner Token owner's address (Authorizer)
     * @return Next nonce
     */
    function nonces(address owner) external view returns (uint256) {
        return _permitNonces[owner];
    }

    /**
     * @notice Verify a signed approval permit and execute if valid
     * @param owner     Token owner's address (Authorizer)
     * @param spender   Spender's address
     * @param value     Amount of allowance
     * @param deadline  The time at which this expires (unix time)
     * @param v         v of the signature
     * @param r         r of the signature
     * @param s         s of the signature
     */
    function _permit(
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) internal {
        require(deadline >= now, "FiatTokenV2: permit is expired");

        bytes memory data = abi.encode(
            PERMIT_TYPEHASH,
            owner,
            spender,
            value,
            _permitNonces[owner]++,
            deadline
        );
        require(
            EIP712.recover(DOMAIN_SEPARATOR, v, r, s, data) == owner,
            "EIP2612: invalid signature"
        );

        _approve(owner, spender, value);
    }
}

// File: contracts/v2/FiatTokenV2.sol

/**
 * Copyright (c) 2018-2020 CENTRE SECZ
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

pragma solidity 0.6.12;

/**
 * @title FiatToken V2
 * @notice ERC20 Token backed by fiat reserves, version 2
 */
contract FiatTokenV2 is FiatTokenV1_1, EIP3009, EIP2612 {
    uint8 internal _initializedVersion;

    /**
     * @notice Initialize v2
     * @param newName   New token name
     */
    function initializeV2(string calldata newName) external {
        // solhint-disable-next-line reason-string
        require(initialized && _initializedVersion == 0);
        name = newName;
        DOMAIN_SEPARATOR = EIP712.makeDomainSeparator(newName, "2");
        _initializedVersion = 1;
    }

    /**
     * @notice Increase the allowance by a given increment
     * @param spender   Spender's address
     * @param increment Amount of increase in allowance
     * @return True if successful
     */
    function increaseAllowance(address spender, uint256 increment)
        external
        whenNotPaused
        notBlacklisted(msg.sender)
        notBlacklisted(spender)
        returns (bool)
    {
        _increaseAllowance(msg.sender, spender, increment);
        return true;
    }

    /**
     * @notice Decrease the allowance by a given decrement
     * @param spender   Spender's address
     * @param decrement Amount of decrease in allowance
     * @return True if successful
     */
    function decreaseAllowance(address spender, uint256 decrement)
        external
        whenNotPaused
        notBlacklisted(msg.sender)
        notBlacklisted(spender)
        returns (bool)
    {
        _decreaseAllowance(msg.sender, spender, decrement);
        return true;
    }

    /**
     * @notice Execute a transfer with a signed authorization
     * @param from          Payer's address (Authorizer)
     * @param to            Payee's address
     * @param value         Amount to be transferred
     * @param validAfter    The time after which this is valid (unix time)
     * @param validBefore   The time before which this is valid (unix time)
     * @param nonce         Unique nonce
     * @param v             v of the signature
     * @param r             r of the signature
     * @param s             s of the signature
     */
    function transferWithAuthorization(
        address from,
        address to,
        uint256 value,
        uint256 validAfter,
        uint256 validBefore,
        bytes32 nonce,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external whenNotPaused notBlacklisted(from) notBlacklisted(to) {
        _transferWithAuthorization(
            from,
            to,
            value,
            validAfter,
            validBefore,
            nonce,
            v,
            r,
            s
        );
    }

    /**
     * @notice Receive a transfer with a signed authorization from the payer
     * @dev This has an additional check to ensure that the payee's address
     * matches the caller of this function to prevent front-running attacks.
     * @param from          Payer's address (Authorizer)
     * @param to            Payee's address
     * @param value         Amount to be transferred
     * @param validAfter    The time after which this is valid (unix time)
     * @param validBefore   The time before which this is valid (unix time)
     * @param nonce         Unique nonce
     * @param v             v of the signature
     * @param r             r of the signature
     * @param s             s of the signature
     */
    function receiveWithAuthorization(
        address from,
        address to,
        uint256 value,
        uint256 validAfter,
        uint256 validBefore,
        bytes32 nonce,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external whenNotPaused notBlacklisted(from) notBlacklisted(to) {
        _receiveWithAuthorization(
            from,
            to,
            value,
            validAfter,
            validBefore,
            nonce,
            v,
            r,
            s
        );
    }

    /**
     * @notice Attempt to cancel an authorization
     * @dev Works only if the authorization is not yet used.
     * @param authorizer    Authorizer's address
     * @param nonce         Nonce of the authorization
     * @param v             v of the signature
     * @param r             r of the signature
     * @param s             s of the signature
     */
    function cancelAuthorization(
        address authorizer,
        bytes32 nonce,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external whenNotPaused {
        _cancelAuthorization(authorizer, nonce, v, r, s);
    }

    /**
     * @notice Update allowance with a signed permit
     * @param owner       Token owner's address (Authorizer)
     * @param spender     Spender's address
     * @param value       Amount of allowance
     * @param deadline    Expiration time, seconds since the epoch
     * @param v           v of the signature
     * @param r           r of the signature
     * @param s           s of the signature
     */
    function permit(
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external whenNotPaused notBlacklisted(owner) notBlacklisted(spender) {
        _permit(owner, spender, value, deadline, v, r, s);
    }

    /**
     * @notice Internal function to increase the allowance by a given increment
     * @param owner     Token owner's address
     * @param spender   Spender's address
     * @param increment Amount of increase
     */
    function _increaseAllowance(
        address owner,
        address spender,
        uint256 increment
    ) internal override {
        _approve(owner, spender, allowed[owner][spender].add(increment));
    }

    /**
     * @notice Internal function to decrease the allowance by a given decrement
     * @param owner     Token owner's address
     * @param spender   Spender's address
     * @param decrement Amount of decrease
     */
    function _decreaseAllowance(
        address owner,
        address spender,
        uint256 decrement
    ) internal override {
        _approve(
            owner,
            spender,
            allowed[owner][spender].sub(
                decrement,
                "ERC20: decreased allowance below zero"
            )
        );
    }
}

// File: contracts/v2/FiatTokenV2_1.sol

/**
 * Copyright (c) 2018-2020 CENTRE SECZ
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

pragma solidity 0.6.12;

// solhint-disable func-name-mixedcase

/**
 * @title FiatToken V2.1
 * @notice ERC20 Token backed by fiat reserves, version 2.1
 */
contract FiatTokenV2_1 is FiatTokenV2 {
    /**
     * @notice Initialize v2.1
     * @param lostAndFound  The address to which the locked funds are sent
     */
    function initializeV2_1(address lostAndFound) external {
        // solhint-disable-next-line reason-string
        require(_initializedVersion == 1);

        uint256 lockedAmount = balances[address(this)];
        if (lockedAmount > 0) {
            _transfer(address(this), lostAndFound, lockedAmount);
        }
        blacklisted[address(this)] = true;

        _initializedVersion = 2;
    }

    /**
     * @notice Version string for the EIP712 domain separator
     * @return Version string
     */
    function version() external view returns (string memory) {
        return "2";
    }
}

// File: contracts/uniswapv2/interfaces/IUniswapV2Factory.sol

pragma solidity >=0.5.0;

interface IUniswapV2Factory {
    event PairCreated(address indexed token0, address indexed token1, address pair, uint);

    function feeTo() external view returns (address);
    function feeToSetter() external view returns (address);
    function migrator() external view returns (address);

    function getPair(address tokenA, address tokenB) external view returns (address pair);
    function allPairs(uint) external view returns (address pair);
    function allPairsLength() external view returns (uint);

    function createPair(address tokenA, address tokenB) external returns (address pair);

    function setFeeTo(address) external;
    function setFeeToSetter(address) external;
    function setMigrator(address) external;
}

// File: contracts/uniswapv2/libraries/SafeMath.sol

pragma solidity =0.6.12;

// a library for performing overflow-safe math, courtesy of DappHub (https://github.com/dapphub/ds-math)

library SafeMathUniswap {
    function add(uint x, uint y) internal pure returns (uint z) {
        require((z = x + y) >= x, 'ds-math-add-overflow');
    }

    function sub(uint x, uint y) internal pure returns (uint z) {
        require((z = x - y) <= x, 'ds-math-sub-underflow');
    }

    function mul(uint x, uint y) internal pure returns (uint z) {
        require(y == 0 || (z = x * y) / y == x, 'ds-math-mul-overflow');
    }
}

// File: contracts/uniswapv2/UniswapV2ERC20.sol

pragma solidity =0.6.12;


contract UniswapV2ERC20 {
    using SafeMathUniswap for uint;

    string public constant name = 'SushiSwap LP Token';
    string public constant symbol = 'SLP';
    uint8 public constant decimals = 18;
    uint  public totalSupply;
    mapping(address => uint) public balanceOf;
    mapping(address => mapping(address => uint)) public allowance;

    bytes32 public DOMAIN_SEPARATOR;
    // keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)");
    bytes32 public constant PERMIT_TYPEHASH = 0x6e71edae12b1b97f4d1f60370fef10105fa2faae0126114a169c64845d6126c9;
    mapping(address => uint) public nonces;

    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    constructor() public {
        uint chainId;
        assembly {
            chainId := chainid()
        }
        DOMAIN_SEPARATOR = keccak256(
            abi.encode(
                keccak256('EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)'),
                keccak256(bytes(name)),
                keccak256(bytes('1')),
                chainId,
                address(this)
            )
        );
    }

    function _mint(address to, uint value) internal {
        totalSupply = totalSupply.add(value);
        balanceOf[to] = balanceOf[to].add(value);
        emit Transfer(address(0), to, value);
    }

    function _burn(address from, uint value) internal {
        balanceOf[from] = balanceOf[from].sub(value);
        totalSupply = totalSupply.sub(value);
        emit Transfer(from, address(0), value);
    }

    function _approve(address owner, address spender, uint value) private {
        allowance[owner][spender] = value;
        emit Approval(owner, spender, value);
    }

    function _transfer(address from, address to, uint value) private {
        balanceOf[from] = balanceOf[from].sub(value);
        balanceOf[to] = balanceOf[to].add(value);
        emit Transfer(from, to, value);
    }

    function approve(address spender, uint value) external returns (bool) {
        _approve(msg.sender, spender, value);
        return true;
    }

    function transfer(address to, uint value) external returns (bool) {
        _transfer(msg.sender, to, value);
        return true;
    }

    function transferFrom(address from, address to, uint value) external returns (bool) {
        if (allowance[from][msg.sender] != uint(-1)) {
            allowance[from][msg.sender] = allowance[from][msg.sender].sub(value);
        }
        _transfer(from, to, value);
        return true;
    }

    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external {
        require(deadline >= block.timestamp, 'UniswapV2: EXPIRED');
        bytes32 digest = keccak256(
            abi.encodePacked(
                '\x19\x01',
                DOMAIN_SEPARATOR,
                keccak256(abi.encode(PERMIT_TYPEHASH, owner, spender, value, nonces[owner]++, deadline))
            )
        );
        address recoveredAddress = ecrecover(digest, v, r, s);
        require(recoveredAddress != address(0) && recoveredAddress == owner, 'UniswapV2: INVALID_SIGNATURE');
        _approve(owner, spender, value);
    }
}

// File: contracts/uniswapv2/libraries/Math.sol

pragma solidity =0.6.12;

// a library for performing various math operations

library Math {
    function min(uint x, uint y) internal pure returns (uint z) {
        z = x < y ? x : y;
    }

    // babylonian method (https://en.wikipedia.org/wiki/Methods_of_computing_square_roots#Babylonian_method)
    function sqrt(uint y) internal pure returns (uint z) {
        if (y > 3) {
            z = y;
            uint x = y / 2 + 1;
            while (x < z) {
                z = x;
                x = (y / x + x) / 2;
            }
        } else if (y != 0) {
            z = 1;
        }
    }
}

// File: contracts/uniswapv2/libraries/UQ112x112.sol

pragma solidity =0.6.12;

// a library for handling binary fixed point numbers (https://en.wikipedia.org/wiki/Q_(number_format))

// range: [0, 2**112 - 1]
// resolution: 1 / 2**112

library UQ112x112 {
    uint224 constant Q112 = 2**112;

    // encode a uint112 as a UQ112x112
    function encode(uint112 y) internal pure returns (uint224 z) {
        z = uint224(y) * Q112; // never overflows
    }

    // divide a UQ112x112 by a uint112, returning a UQ112x112
    function uqdiv(uint224 x, uint112 y) internal pure returns (uint224 z) {
        z = x / uint224(y);
    }
}

// File: contracts/uniswapv2/interfaces/IERC20.sol

pragma solidity >=0.5.0;

interface IERC20Uniswap {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external view returns (string memory);
    function symbol() external view returns (string memory);
    function decimals() external view returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);
}

// File: contracts/uniswapv2/interfaces/IUniswapV2Callee.sol

pragma solidity >=0.5.0;

interface IUniswapV2Callee {
    function uniswapV2Call(address sender, uint amount0, uint amount1, bytes calldata data) external;
}

// File: contracts/uniswapv2/UniswapV2Pair.sol

pragma solidity =0.6.12;








interface IMigrator {
    // Return the desired amount of liquidity token that the migrator wants.
    function desiredLiquidity() external view returns (uint256);
}

contract UniswapV2Pair is UniswapV2ERC20 {
    using SafeMathUniswap  for uint;
    using UQ112x112 for uint224;

    uint public constant MINIMUM_LIQUIDITY = 10**3;
    bytes4 private constant SELECTOR = bytes4(keccak256(bytes('transfer(address,uint256)')));

    address public factory;
    address public token0;
    address public token1;

    uint112 private reserve0;           // uses single storage slot, accessible via getReserves
    uint112 private reserve1;           // uses single storage slot, accessible via getReserves
    uint32  private blockTimestampLast; // uses single storage slot, accessible via getReserves

    uint public price0CumulativeLast;
    uint public price1CumulativeLast;
    uint public kLast; // reserve0 * reserve1, as of immediately after the most recent liquidity event

    uint private unlocked = 1;
    modifier lock() {
        require(unlocked == 1, 'UniswapV2: LOCKED');
        unlocked = 0;
        _;
        unlocked = 1;
    }

    function getReserves() public view returns (uint112 _reserve0, uint112 _reserve1, uint32 _blockTimestampLast) {
        _reserve0 = reserve0;
        _reserve1 = reserve1;
        _blockTimestampLast = blockTimestampLast;
    }

    function _safeTransfer(address token, address to, uint value) private {
        (bool success, bytes memory data) = token.call(abi.encodeWithSelector(SELECTOR, to, value));
        require(success && (data.length == 0 || abi.decode(data, (bool))), 'UniswapV2: TRANSFER_FAILED');
    }

    event Mint(address indexed sender, uint amount0, uint amount1);
    event Burn(address indexed sender, uint amount0, uint amount1, address indexed to);
    event Swap(
        address indexed sender,
        uint amount0In,
        uint amount1In,
        uint amount0Out,
        uint amount1Out,
        address indexed to
    );
    event Sync(uint112 reserve0, uint112 reserve1);

    constructor() public {
        factory = msg.sender;
    }

    // called once by the factory at time of deployment
    function initialize(address _token0, address _token1) external {
        require(msg.sender == factory, 'UniswapV2: FORBIDDEN'); // sufficient check
        token0 = _token0;
        token1 = _token1;
    }

    // update reserves and, on the first call per block, price accumulators
    function _update(uint balance0, uint balance1, uint112 _reserve0, uint112 _reserve1) private {
        require(balance0 <= uint112(-1) && balance1 <= uint112(-1), 'UniswapV2: OVERFLOW');
        uint32 blockTimestamp = uint32(block.timestamp % 2**32);
        uint32 timeElapsed = blockTimestamp - blockTimestampLast; // overflow is desired
        if (timeElapsed > 0 && _reserve0 != 0 && _reserve1 != 0) {
            // * never overflows, and + overflow is desired
            price0CumulativeLast += uint(UQ112x112.encode(_reserve1).uqdiv(_reserve0)) * timeElapsed;
            price1CumulativeLast += uint(UQ112x112.encode(_reserve0).uqdiv(_reserve1)) * timeElapsed;
        }
        reserve0 = uint112(balance0);
        reserve1 = uint112(balance1);
        blockTimestampLast = blockTimestamp;
        emit Sync(reserve0, reserve1);
    }

    // if fee is on, mint liquidity equivalent to 1/6th of the growth in sqrt(k)
    function _mintFee(uint112 _reserve0, uint112 _reserve1) private returns (bool feeOn) {
        address feeTo = IUniswapV2Factory(factory).feeTo();
        feeOn = feeTo != address(0);
        uint _kLast = kLast; // gas savings
        if (feeOn) {
            if (_kLast != 0) {
                uint rootK = Math.sqrt(uint(_reserve0).mul(_reserve1));
                uint rootKLast = Math.sqrt(_kLast);
                if (rootK > rootKLast) {
                    uint numerator = totalSupply.mul(rootK.sub(rootKLast));
                    uint denominator = rootK.mul(5).add(rootKLast);
                    uint liquidity = numerator / denominator;
                    if (liquidity > 0) _mint(feeTo, liquidity);
                }
            }
        } else if (_kLast != 0) {
            kLast = 0;
        }
    }

    // this low-level function should be called from a contract which performs important safety checks
    function mint(address to) external lock returns (uint liquidity) {
        (uint112 _reserve0, uint112 _reserve1,) = getReserves(); // gas savings
        uint balance0 = IERC20Uniswap(token0).balanceOf(address(this));
        uint balance1 = IERC20Uniswap(token1).balanceOf(address(this));
        uint amount0 = balance0.sub(_reserve0);
        uint amount1 = balance1.sub(_reserve1);

        bool feeOn = _mintFee(_reserve0, _reserve1);
        uint _totalSupply = totalSupply; // gas savings, must be defined here since totalSupply can update in _mintFee
        if (_totalSupply == 0) {
            address migrator = IUniswapV2Factory(factory).migrator();
            if (msg.sender == migrator) {
                liquidity = IMigrator(migrator).desiredLiquidity();
                require(liquidity > 0 && liquidity != uint256(-1), "Bad desired liquidity");
            } else {
                require(migrator == address(0), "Must not have migrator");
                liquidity = Math.sqrt(amount0.mul(amount1)).sub(MINIMUM_LIQUIDITY);
                _mint(address(0), MINIMUM_LIQUIDITY); // permanently lock the first MINIMUM_LIQUIDITY tokens
            }
        } else {
            liquidity = Math.min(amount0.mul(_totalSupply) / _reserve0, amount1.mul(_totalSupply) / _reserve1);
        }
        require(liquidity > 0, 'UniswapV2: INSUFFICIENT_LIQUIDITY_MINTED');
        _mint(to, liquidity);

        _update(balance0, balance1, _reserve0, _reserve1);
        if (feeOn) kLast = uint(reserve0).mul(reserve1); // reserve0 and reserve1 are up-to-date
        emit Mint(msg.sender, amount0, amount1);
    }

    // this low-level function should be called from a contract which performs important safety checks
    function burn(address to) external lock returns (uint amount0, uint amount1) {
        (uint112 _reserve0, uint112 _reserve1,) = getReserves(); // gas savings
        address _token0 = token0;                                // gas savings
        address _token1 = token1;                                // gas savings
        uint balance0 = IERC20Uniswap(_token0).balanceOf(address(this));
        uint balance1 = IERC20Uniswap(_token1).balanceOf(address(this));
        uint liquidity = balanceOf[address(this)];

        bool feeOn = _mintFee(_reserve0, _reserve1);
        uint _totalSupply = totalSupply; // gas savings, must be defined here since totalSupply can update in _mintFee
        amount0 = liquidity.mul(balance0) / _totalSupply; // using balances ensures pro-rata distribution
        amount1 = liquidity.mul(balance1) / _totalSupply; // using balances ensures pro-rata distribution
        require(amount0 > 0 && amount1 > 0, 'UniswapV2: INSUFFICIENT_LIQUIDITY_BURNED');
        _burn(address(this), liquidity);
        _safeTransfer(_token0, to, amount0);
        _safeTransfer(_token1, to, amount1);
        balance0 = IERC20Uniswap(_token0).balanceOf(address(this));
        balance1 = IERC20Uniswap(_token1).balanceOf(address(this));

        _update(balance0, balance1, _reserve0, _reserve1);
        if (feeOn) kLast = uint(reserve0).mul(reserve1); // reserve0 and reserve1 are up-to-date
        emit Burn(msg.sender, amount0, amount1, to);
    }

    // this low-level function should be called from a contract which performs important safety checks
    function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external lock {
        require(amount0Out > 0 || amount1Out > 0, 'UniswapV2: INSUFFICIENT_OUTPUT_AMOUNT');
        (uint112 _reserve0, uint112 _reserve1,) = getReserves(); // gas savings
        require(amount0Out < _reserve0 && amount1Out < _reserve1, 'UniswapV2: INSUFFICIENT_LIQUIDITY');

        uint balance0;
        uint balance1;
        { // scope for _token{0,1}, avoids stack too deep errors
        address _token0 = token0;
        address _token1 = token1;
        require(to != _token0 && to != _token1, 'UniswapV2: INVALID_TO');
        if (amount0Out > 0) _safeTransfer(_token0, to, amount0Out); // optimistically transfer tokens
        if (amount1Out > 0) _safeTransfer(_token1, to, amount1Out); // optimistically transfer tokens
        if (data.length > 0) IUniswapV2Callee(to).uniswapV2Call(msg.sender, amount0Out, amount1Out, data);
        balance0 = IERC20Uniswap(_token0).balanceOf(address(this));
        balance1 = IERC20Uniswap(_token1).balanceOf(address(this));
        }
        uint amount0In = balance0 > _reserve0 - amount0Out ? balance0 - (_reserve0 - amount0Out) : 0;
        uint amount1In = balance1 > _reserve1 - amount1Out ? balance1 - (_reserve1 - amount1Out) : 0;
        require(amount0In > 0 || amount1In > 0, 'UniswapV2: INSUFFICIENT_INPUT_AMOUNT');
        { // scope for reserve{0,1}Adjusted, avoids stack too deep errors
        uint balance0Adjusted = balance0.mul(1000).sub(amount0In.mul(3));
        uint balance1Adjusted = balance1.mul(1000).sub(amount1In.mul(3));
        require(balance0Adjusted.mul(balance1Adjusted) >= uint(_reserve0).mul(_reserve1).mul(1000**2), 'UniswapV2: K');
        }

        _update(balance0, balance1, _reserve0, _reserve1);
        emit Swap(msg.sender, amount0In, amount1In, amount0Out, amount1Out, to);
    }

    // force balances to match reserves
    function skim(address to) external lock {
        address _token0 = token0; // gas savings
        address _token1 = token1; // gas savings
        _safeTransfer(_token0, to, IERC20Uniswap(_token0).balanceOf(address(this)).sub(reserve0));
        _safeTransfer(_token1, to, IERC20Uniswap(_token1).balanceOf(address(this)).sub(reserve1));
    }

    // force reserves to match balances
    function sync() external lock {
        _update(IERC20Uniswap(token0).balanceOf(address(this)), IERC20Uniswap(token1).balanceOf(address(this)), reserve0, reserve1);
    }
}

// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0 <0.8.0;
import "../utils/Context.sol";
/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. This
 * can later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
abstract contract Ownable is Context {
    address private _owner;
    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor () internal {
        address msgSender = _msgSender();
        _owner = msgSender;
        emit OwnershipTransferred(address(0), msgSender);
    }
    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view virtual returns (address) {
        return _owner;
    }
    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
        _;
    }
    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions anymore. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby removing any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        emit OwnershipTransferred(_owner, address(0));
        _owner = address(0);
    }
    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
    }
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0 <0.8.0;
/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);
    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);
    /**
     * @dev Moves `amount` tokens from the caller's account to `recipient`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address recipient, uint256 amount) external returns (bool);
    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);
    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);
    /**
     * @dev Moves `amount` tokens from `sender` to `recipient` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);
    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);
    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0 <0.8.0;
/*
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with GSN meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address payable) {
        return msg.sender;
    }
    function _msgData() internal view virtual returns (bytes memory) {
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        return msg.data;
    }
}
pragma solidity =0.6.6;
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
import "./libraries/TransferHelper.sol";
import "./interfaces/IWETH.sol";
contract FeeReceiverMultichain is Ownable {
    address public WETH;
    constructor(address _WETH) public {
        WETH = _WETH;
    }
    /// @dev converts WETH to ETH
    function unwrapWETH() public {
        uint256 balance = IWETH(WETH).balanceOf(address(this));
        require(balance > 0, "FeeReceiver: Nothing to unwrap");
        IWETH(WETH).withdraw(balance);
    }
    /// @dev lets the owner withdraw ETH from the contract
    function withdrawETH(address payable to, uint256 amount) external onlyOwner {
        to.transfer(amount);
    }
    /// @dev lets the owner withdraw any ERC20 Token from the contract
    function withdrawERC20Token(
        address token,
        address to,
        uint256 amount
    ) external onlyOwner {
        IERC20(token).transfer(to, amount);
    }
    /// @dev allows to receive ETH on this contract
    receive() external payable {}
}
pragma solidity >=0.5.0;
interface IWETH {
    function deposit() external payable;
    function transfer(address to, uint256 value) external returns (bool);
    function withdraw(uint256) external;
    function approve(address _spender, uint256 _amount) external returns (bool);
    function balanceOf(address _account) external view returns (uint256);
}
pragma solidity =0.6.6;
// helper methods for interacting with ERC20 tokens and sending ETH that do not consistently return true/false
library TransferHelper {
    function safeApprove(
        address token,
        address to,
        uint256 value
    ) internal {
        // bytes4(keccak256(bytes('approve(address,uint256)')));
        (bool success, bytes memory data) = token.call(abi.encodeWithSelector(0x095ea7b3, to, value));
        require(success && (data.length == 0 || abi.decode(data, (bool))), "TransferHelper: APPROVE_FAILED");
    }
    function safeTransfer(
        address token,
        address to,
        uint256 value
    ) internal {
        // bytes4(keccak256(bytes('transfer(address,uint256)')));
        (bool success, bytes memory data) = token.call(abi.encodeWithSelector(0xa9059cbb, to, value));
        require(success && (data.length == 0 || abi.decode(data, (bool))), "TransferHelper: TRANSFER_FAILED");
    }
    function safeTransferFrom(
        address token,
        address from,
        address to,
        uint256 value
    ) internal {
        // bytes4(keccak256(bytes('transferFrom(address,address,uint256)')));
        (bool success, bytes memory data) = token.call(abi.encodeWithSelector(0x23b872dd, from, to, value));
        require(success && (data.length == 0 || abi.decode(data, (bool))), "TransferHelper: TRANSFER_FROM_FAILED");
    }
    function safeTransferETH(address to, uint256 value) internal {
        (bool success, ) = to.call{value: value}(new bytes(0));
        require(success, "TransferHelper: ETH_TRANSFER_FAILED");
    }
}