pragma solidity ^0.5.2;

interface IERC20 {

    function transfer(address to, uint256 value) external returns (bool);

    function approve(address spender, uint256 value) external returns (bool);

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

    function totalSupply() external view returns (uint256);

    function balanceOf(address who) external view returns (uint256);

    function allowance(address owner, address spender) external view returns (uint256);

    event Transfer(address indexed from, address indexed to, uint256 value);

    event Approval(address indexed owner, address indexed spender, uint256 value);
}


library SafeMath {

    /**
     * @dev Multiplies two unsigned integers, reverts on 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-solidity/pull/522
        if (a == 0) {
            return 0;
        }

        uint256 c = a * b;
        require(c / a == b);

        return c;
    }

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

    /**
     * @dev Subtracts two unsigned integers, reverts on overflow (i.e. if subtrahend is greater than minuend).
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b <= a);
        uint256 c = a - b;

        return c;
    }

    /**
     * @dev Adds two unsigned integers, reverts on overflow.
     */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a);

        return c;
    }

    /**
     * @dev Divides two unsigned integers and returns the remainder (unsigned integer modulo),
     * reverts when dividing by zero.
     */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b != 0);
        return a % b;
    }
}

library Roles {
    struct Role {
        mapping (address => bool) bearer;
    }

    /**
     * @dev give an account access to this role
     */
    function add(Role storage role, address account) internal {
        require(account != address(0));
        require(!has(role, account));

        role.bearer[account] = true;
    }

    /**
     * @dev remove an account's access to this role
     */
    function remove(Role storage role, address account) internal {
        require(account != address(0));
        require(has(role, account));

        role.bearer[account] = false;
    }

    /**
     * @dev check if an account has this role
     * @return bool
     */
    function has(Role storage role, address account) internal view returns (bool) {
        require(account != address(0));
        return role.bearer[account];
    }
}

contract ERC20 is IERC20 {
    using SafeMath for uint256;

    mapping (address => uint256) private _balances;

    mapping (address => mapping (address => uint256)) private _allowed;

    uint256 private _totalSupply;

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

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

    /**
     * @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 Transfer token to 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) {
        _transfer(msg.sender, 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) {
        _approve(msg.sender, spender, value);
        return true;
    }

    /**
     * @dev Transfer tokens from one address to another.
     * Note that while this function emits an Approval event, this is not required as per the specification,
     * and other compliant implementations may not emit the event.
     * @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) {
        _transfer(from, to, value);
        _approve(from, msg.sender, _allowed[from][msg.sender].sub(value));
        return true;
    }

    /**
     * @dev Increase the amount of tokens that an owner allowed to a spender.
     * approve should be called when _allowed[msg.sender][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
     * Emits an Approval event.
     * @param spender The address which will spend the funds.
     * @param addedValue The amount of tokens to increase the allowance by.
     */
    function increaseAllowance(address spender, uint256 addedValue) public returns (bool) {
        _approve(msg.sender, spender, _allowed[msg.sender][spender].add(addedValue));
        return true;
    }

    /**
     * @dev Decrease the amount of tokens that an owner allowed to a spender.
     * approve should be called when _allowed[msg.sender][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
     * Emits an Approval event.
     * @param spender The address which will spend the funds.
     * @param subtractedValue The amount of tokens to decrease the allowance by.
     */
    function decreaseAllowance(address spender, uint256 subtractedValue) public returns (bool) {
        _approve(msg.sender, spender, _allowed[msg.sender][spender].sub(subtractedValue));
        return true;
    }

    /**
     * @dev Transfer token for a specified addresses
     * @param from The address to transfer from.
     * @param to The address to transfer to.
     * @param value The amount to be transferred.
     */
    function _transfer(address from, address to, uint256 value) internal {
        require(to != address(0));

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

    /**
     * @dev Internal function that mints an amount of the token and assigns it to
     * an account. This encapsulates the modification of balances such that the
     * proper events are emitted.
     * @param account The account that will receive the created tokens.
     * @param value The amount that will be created.
     */
    function _mint(address account, uint256 value) internal {
        require(account != address(0));

        _totalSupply = _totalSupply.add(value);
        _balances[account] = _balances[account].add(value);
        emit Transfer(address(0), account, value);
    }

    /**
     * @dev Internal function that burns an amount of the token of a given
     * account.
     * @param account The account whose tokens will be burnt.
     * @param value The amount that will be burnt.
     */
    function _burn(address account, uint256 value) internal {
        require(account != address(0));

        _totalSupply = _totalSupply.sub(value);
        _balances[account] = _balances[account].sub(value);
        emit Transfer(account, address(0), value);
    }

    /**
     * @dev Approve an address to spend another addresses' tokens.
     * @param owner The address that owns the tokens.
     * @param spender The address that will spend the tokens.
     * @param value The number of tokens that can be spent.
     */
    function _approve(address owner, address spender, uint256 value) internal {
        require(spender != address(0));
        require(owner != address(0));

        _allowed[owner][spender] = value;
        emit Approval(owner, spender, value);
    }

    /**
     * @dev Internal function that burns an amount of the token of a given
     * account, deducting from the sender's allowance for said account. Uses the
     * internal burn function.
     * Emits an Approval event (reflecting the reduced allowance).
     * @param account The account whose tokens will be burnt.
     * @param value The amount that will be burnt.
     */
    function _burnFrom(address account, uint256 value) internal {
        _burn(account, value);
        _approve(account, msg.sender, _allowed[account][msg.sender].sub(value));
    }
}


contract ERC20Detailed is IERC20 {
    string private _name;
    string private _symbol;
    uint8 private _decimals;

    constructor (string memory name, string memory symbol, uint8 decimals) public {
        _name = name;
        _symbol = symbol;
        _decimals = decimals;
    }

    /**
     * @return the name of the token.
     */
    function name() public view returns (string memory) {
        return _name;
    }

    /**
     * @return the symbol of the token.
     */
    function symbol() public view returns (string memory) {
        return _symbol;
    }

    /**
     * @return the number of decimals of the token.
     */
    function decimals() public view returns (uint8) {
        return _decimals;
    }
}
library Address {
    /**
     * 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 account address of the account to check
     * @return whether the target address is a contract
     */
    function isContract(address account) 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.
        // solhint-disable-next-line no-inline-assembly
        assembly { size := extcodesize(account) }
        return size > 0;
    }
}


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));
    }

    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'
        require((value == 0) || (token.allowance(address(this), spender) == 0));
        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);
        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.

        // A Solidity high level call has three parts:
        //  1. The target address is checked to verify it contains contract code
        //  2. The call itself is made, and success asserted
        //  3. The return value is decoded, which in turn checks the size of the returned data.

        require(address(token).isContract());

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = address(token).call(data);
        require(success);

        if (returndata.length > 0) { // Return data is optional
            require(abi.decode(returndata, (bool)));
        }
    }
}
contract TokenTimelock {
    using SafeERC20 for IERC20;

    // ERC20 basic token contract being held
    IERC20 private _token;

    // beneficiary of tokens after they are released
    address private _beneficiary;

    // timestamp when token release is enabled
    uint256 private _releaseTime;

    constructor (IERC20 token, address beneficiary, uint256 releaseTime) public {
        // solhint-disable-next-line not-rely-on-time
        require(releaseTime > block.timestamp);
        _token = token;
        _beneficiary = beneficiary;
        _releaseTime = releaseTime;
    }

    /**
     * @return the token being held.
     */
    function token() public view returns (IERC20) {
        return _token;
    }

    /**
     * @return the beneficiary of the tokens.
     */
    function beneficiary() public view returns (address) {
        return _beneficiary;
    }

    /**
     * @return the time when the tokens are released.
     */
    function releaseTime() public view returns (uint256) {
        return _releaseTime;
    }

    /**
     * @notice Transfers tokens held by timelock to beneficiary.
     */
    function release() public {
        // solhint-disable-next-line not-rely-on-time
        require(block.timestamp >= _releaseTime);

        uint256 amount = _token.balanceOf(address(this));
        require(amount > 0);

        _token.safeTransfer(_beneficiary, amount);
    }
}
contract MinterRole {
    using Roles for Roles.Role;

    event MinterAdded(address indexed account);
    event MinterRemoved(address indexed account);

    Roles.Role private _minters;

    constructor () internal {
        _addMinter(msg.sender);
    }

    modifier onlyMinter() {
        require(isMinter(msg.sender));
        _;
    }

    function isMinter(address account) public view returns (bool) {
        return _minters.has(account);
    }

    function addMinter(address account) public onlyMinter {
        _addMinter(account);
    }

    function renounceMinter() public {
        _removeMinter(msg.sender);
    }

    function _addMinter(address account) internal {
        _minters.add(account);
        emit MinterAdded(account);
    }

    function _removeMinter(address account) internal {
        _minters.remove(account);
        emit MinterRemoved(account);
    }
}

contract ERC20Mintable is ERC20, MinterRole {
    /**
     * @dev Function to mint tokens
     * @param to The address that will receive the minted tokens.
     * @param value The amount of tokens to mint.
     * @return A boolean that indicates if the operation was successful.
     */
    function mint(address to, uint256 value) public onlyMinter returns (bool) {
        _mint(to, value);
        return true;
    }
}

contract ERC20Burnable is ERC20 {
    /**
     * @dev Burns a specific amount of tokens.
     * @param value The amount of token to be burned.
     */
    function burn(uint256 value) public {
        _burn(msg.sender, value);
    }

    /**
     * @dev Burns a specific amount of tokens from the target address and decrements allowance
     * @param from address The account whose tokens will be burned.
     * @param value uint256 The amount of token to be burned.
     */
    function burnFrom(address from, uint256 value) public {
        _burnFrom(from, value);
    }
}

contract PauserRole {
    using Roles for Roles.Role;

    event PauserAdded(address indexed account);
    event PauserRemoved(address indexed account);

    Roles.Role private _pausers;

    constructor () internal {
        _addPauser(msg.sender);
    }

    modifier onlyPauser() {
        require(isPauser(msg.sender));
        _;
    }

    function isPauser(address account) public view returns (bool) {
        return _pausers.has(account);
    }

    function addPauser(address account) public onlyPauser {
        _addPauser(account);
    }

    function renouncePauser() public {
        _removePauser(msg.sender);
    }

    function _addPauser(address account) internal {
        _pausers.add(account);
        emit PauserAdded(account);
    }

    function _removePauser(address account) internal {
        _pausers.remove(account);
        emit PauserRemoved(account);
    }
}


contract Pausable is PauserRole {
    event Paused(address account);
    event Unpaused(address account);

    bool private _paused;

    constructor () internal {
        _paused = false;
    }

    /**
     * @return true if the contract is paused, false otherwise.
     */
    function paused() public view returns (bool) {
        return _paused;
    }

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

    /**
     * @dev Modifier to make a function callable only when the contract is paused.
     */
    modifier whenPaused() {
        require(_paused);
        _;
    }

    /**
     * @dev called by the owner to pause, triggers stopped state
     */
    function pause() public onlyPauser whenNotPaused {
        _paused = true;
        emit Paused(msg.sender);
    }

    /**
     * @dev called by the owner to unpause, returns to normal state
     */
    function unpause() public onlyPauser whenPaused {
        _paused = false;
        emit Unpaused(msg.sender);
    }
}


contract ERC20Pausable is ERC20, Pausable {
    function transfer(address to, uint256 value) public whenNotPaused returns (bool) {
        return super.transfer(to, value);
    }

    function transferFrom(address from, address to, uint256 value) public whenNotPaused returns (bool) {
        return super.transferFrom(from, to, value);
    }

    function approve(address spender, uint256 value) public whenNotPaused returns (bool) {
        return super.approve(spender, value);
    }

    function increaseAllowance(address spender, uint addedValue) public whenNotPaused returns (bool) {
        return super.increaseAllowance(spender, addedValue);
    }

    function decreaseAllowance(address spender, uint subtractedValue) public whenNotPaused returns (bool) {
        return super.decreaseAllowance(spender, subtractedValue);
    }
}

contract ACH is ERC20, ERC20Detailed, ERC20Mintable, ERC20Burnable,ERC20Pausable {
   uint private INITIAL_SUPPLY = 100e16;

    constructor () public ERC20Detailed("Alchemy", "ACH", 8) {
        _mint(msg.sender, INITIAL_SUPPLY);
        
    }
    
}

// File: contracts/intf/IDODOCallee.sol
/*
    Copyright 2020 DODO ZOO.
    SPDX-License-Identifier: Apache-2.0
*/
pragma solidity 0.6.9;
pragma experimental ABIEncoderV2;
interface IDODOCallee {
    function DVMSellShareCall(
        address sender,
        uint256 burnShareAmount,
        uint256 baseAmount,
        uint256 quoteAmount,
        bytes calldata data
    ) external;
    function DVMFlashLoanCall(
        address sender,
        uint256 baseAmount,
        uint256 quoteAmount,
        bytes calldata data
    ) external;
    function DPPFlashLoanCall(
        address sender,
        uint256 baseAmount,
        uint256 quoteAmount,
        bytes calldata data
    ) external;
    function DSPFlashLoanCall(
        address sender,
        uint256 baseAmount,
        uint256 quoteAmount,
        bytes calldata data
    ) external;
    function CPCancelCall(
        address sender,
        uint256 amount,
        bytes calldata data
    ) external;
\tfunction CPClaimBidCall(
        address sender,
        uint256 baseAmount,
        uint256 quoteAmount,
        bytes calldata data
    ) external;
    function NFTRedeemCall(
        address payable assetTo,
        uint256 quoteAmount,
        bytes calldata
    ) external;
}
// File: contracts/lib/ReentrancyGuard.sol
/**
 * @title ReentrancyGuard
 * @author DODO Breeder
 *
 * @notice Protect functions from Reentrancy Attack
 */
contract ReentrancyGuard {
    // https://solidity.readthedocs.io/en/latest/control-structures.html?highlight=zero-state#scoping-and-declarations
    // zero-state of _ENTERED_ is false
    bool private _ENTERED_;
    modifier preventReentrant() {
        require(!_ENTERED_, "REENTRANT");
        _ENTERED_ = true;
        _;
        _ENTERED_ = false;
    }
}
// File: contracts/lib/SafeMath.sol
/**
 * @title SafeMath
 * @author DODO Breeder
 *
 * @notice Math operations with safety checks that revert on error
 */
library SafeMath {
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        if (a == 0) {
            return 0;
        }
        uint256 c = a * b;
        require(c / a == b, "MUL_ERROR");
        return c;
    }
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b > 0, "DIVIDING_ERROR");
        return a / b;
    }
    function divCeil(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 quotient = div(a, b);
        uint256 remainder = a - quotient * b;
        if (remainder > 0) {
            return quotient + 1;
        } else {
            return quotient;
        }
    }
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b <= a, "SUB_ERROR");
        return a - b;
    }
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "ADD_ERROR");
        return c;
    }
    function sqrt(uint256 x) internal pure returns (uint256 y) {
        uint256 z = x / 2 + 1;
        y = x;
        while (z < y) {
            y = z;
            z = (x / z + z) / 2;
        }
    }
}
// File: contracts/lib/DecimalMath.sol
/**
 * @title DecimalMath
 * @author DODO Breeder
 *
 * @notice Functions for fixed point number with 18 decimals
 */
library DecimalMath {
    using SafeMath for uint256;
    uint256 internal constant ONE = 10**18;
    uint256 internal constant ONE2 = 10**36;
    function mulFloor(uint256 target, uint256 d) internal pure returns (uint256) {
        return target.mul(d) / (10**18);
    }
    function mulCeil(uint256 target, uint256 d) internal pure returns (uint256) {
        return target.mul(d).divCeil(10**18);
    }
    function divFloor(uint256 target, uint256 d) internal pure returns (uint256) {
        return target.mul(10**18).div(d);
    }
    function divCeil(uint256 target, uint256 d) internal pure returns (uint256) {
        return target.mul(10**18).divCeil(d);
    }
    function reciprocalFloor(uint256 target) internal pure returns (uint256) {
        return uint256(10**36).div(target);
    }
    function reciprocalCeil(uint256 target) internal pure returns (uint256) {
        return uint256(10**36).divCeil(target);
    }
    function powFloor(uint256 target, uint256 e) internal pure returns (uint256) {
        if (e == 0) {
            return 10 ** 18;
        } else if (e == 1) {
            return target;
        } else {
            uint p = powFloor(target, e.div(2));
            p = p.mul(p) / (10**18);
            if (e % 2 == 1) {
                p = p.mul(target) / (10**18);
            }
            return p;
        }
    }
}
// File: contracts/lib/DODOMath.sol
/**
 * @title DODOMath
 * @author DODO Breeder
 *
 * @notice Functions for complex calculating. Including ONE Integration and TWO Quadratic solutions
 */
library DODOMath {
    using SafeMath for uint256;
    /*
        Integrate dodo curve from V1 to V2
        require V0>=V1>=V2>0
        res = (1-k)i(V1-V2)+ikV0*V0(1/V2-1/V1)
        let V1-V2=delta
        res = i*delta*(1-k+k(V0^2/V1/V2))
        i is the price of V-res trading pair
        support k=1 & k=0 case
        [round down]
    */
    function _GeneralIntegrate(
        uint256 V0,
        uint256 V1,
        uint256 V2,
        uint256 i,
        uint256 k
    ) internal pure returns (uint256) {
        require(V0 > 0, "TARGET_IS_ZERO");
        uint256 fairAmount = i.mul(V1.sub(V2)); // i*delta
        if (k == 0) {
            return fairAmount.div(DecimalMath.ONE);
        }
        uint256 V0V0V1V2 = DecimalMath.divFloor(V0.mul(V0).div(V1), V2);
        uint256 penalty = DecimalMath.mulFloor(k, V0V0V1V2); // k(V0^2/V1/V2)
        return DecimalMath.ONE.sub(k).add(penalty).mul(fairAmount).div(DecimalMath.ONE2);
    }
    /*
        Follow the integration function above
        i*deltaB = (Q2-Q1)*(1-k+kQ0^2/Q1/Q2)
        Assume Q2=Q0, Given Q1 and deltaB, solve Q0
        i is the price of delta-V trading pair
        give out target of V
        support k=1 & k=0 case
        [round down]
    */
    function _SolveQuadraticFunctionForTarget(
        uint256 V1,
        uint256 delta,
        uint256 i,
        uint256 k
    ) internal pure returns (uint256) {
        if (k == 0) {
            return V1.add(DecimalMath.mulFloor(i, delta));
        }
        // V0 = V1*(1+(sqrt-1)/2k)
        // sqrt = √(1+4kidelta/V1)
        // premium = 1+(sqrt-1)/2k
        // uint256 sqrt = (4 * k).mul(i).mul(delta).div(V1).add(DecimalMath.ONE2).sqrt();
        if (V1 == 0) {
            return 0;
        }
        uint256 sqrt;
        uint256 ki = (4 * k).mul(i);
        if (ki == 0) {
            sqrt = DecimalMath.ONE;
        } else if ((ki * delta) / ki == delta) {
            sqrt = (ki * delta).div(V1).add(DecimalMath.ONE2).sqrt();
        } else {
            sqrt = ki.div(V1).mul(delta).add(DecimalMath.ONE2).sqrt();
        }
        uint256 premium =
            DecimalMath.divFloor(sqrt.sub(DecimalMath.ONE), k * 2).add(DecimalMath.ONE);
        // V0 is greater than or equal to V1 according to the solution
        return DecimalMath.mulFloor(V1, premium);
    }
    /*
        Follow the integration expression above, we have:
        i*deltaB = (Q2-Q1)*(1-k+kQ0^2/Q1/Q2)
        Given Q1 and deltaB, solve Q2
        This is a quadratic function and the standard version is
        aQ2^2 + bQ2 + c = 0, where
        a=1-k
        -b=(1-k)Q1-kQ0^2/Q1+i*deltaB
        c=-kQ0^2 
        and Q2=(-b+sqrt(b^2+4(1-k)kQ0^2))/2(1-k)
        note: another root is negative, abondan
        if deltaBSig=true, then Q2>Q1, user sell Q and receive B
        if deltaBSig=false, then Q2<Q1, user sell B and receive Q
        return |Q1-Q2|
        as we only support sell amount as delta, the deltaB is always negative
        the input ideltaB is actually -ideltaB in the equation
        i is the price of delta-V trading pair
        support k=1 & k=0 case
        [round down]
    */
    function _SolveQuadraticFunctionForTrade(
        uint256 V0,
        uint256 V1,
        uint256 delta,
        uint256 i,
        uint256 k
    ) internal pure returns (uint256) {
        require(V0 > 0, "TARGET_IS_ZERO");
        if (delta == 0) {
            return 0;
        }
        if (k == 0) {
            return DecimalMath.mulFloor(i, delta) > V1 ? V1 : DecimalMath.mulFloor(i, delta);
        }
        if (k == DecimalMath.ONE) {
            // if k==1
            // Q2=Q1/(1+ideltaBQ1/Q0/Q0)
            // temp = ideltaBQ1/Q0/Q0
            // Q2 = Q1/(1+temp)
            // Q1-Q2 = Q1*(1-1/(1+temp)) = Q1*(temp/(1+temp))
            // uint256 temp = i.mul(delta).mul(V1).div(V0.mul(V0));
            uint256 temp;
            uint256 idelta = i.mul(delta);
            if (idelta == 0) {
                temp = 0;
            } else if ((idelta * V1) / idelta == V1) {
                temp = (idelta * V1).div(V0.mul(V0));
            } else {
                temp = delta.mul(V1).div(V0).mul(i).div(V0);
            }
            return V1.mul(temp).div(temp.add(DecimalMath.ONE));
        }
        // calculate -b value and sig
        // b = kQ0^2/Q1-i*deltaB-(1-k)Q1
        // part1 = (1-k)Q1 >=0
        // part2 = kQ0^2/Q1-i*deltaB >=0
        // bAbs = abs(part1-part2)
        // if part1>part2 => b is negative => bSig is false
        // if part2>part1 => b is positive => bSig is true
        uint256 part2 = k.mul(V0).div(V1).mul(V0).add(i.mul(delta)); // kQ0^2/Q1-i*deltaB
        uint256 bAbs = DecimalMath.ONE.sub(k).mul(V1); // (1-k)Q1
        bool bSig;
        if (bAbs >= part2) {
            bAbs = bAbs - part2;
            bSig = false;
        } else {
            bAbs = part2 - bAbs;
            bSig = true;
        }
        bAbs = bAbs.div(DecimalMath.ONE);
        // calculate sqrt
        uint256 squareRoot =
            DecimalMath.mulFloor(
                DecimalMath.ONE.sub(k).mul(4),
                DecimalMath.mulFloor(k, V0).mul(V0)
            ); // 4(1-k)kQ0^2
        squareRoot = bAbs.mul(bAbs).add(squareRoot).sqrt(); // sqrt(b*b+4(1-k)kQ0*Q0)
        // final res
        uint256 denominator = DecimalMath.ONE.sub(k).mul(2); // 2(1-k)
        uint256 numerator;
        if (bSig) {
            numerator = squareRoot.sub(bAbs);
            if (numerator == 0) {
                revert("DODOMath: should not be zero");
            }
        } else {
            numerator = bAbs.add(squareRoot);
        }
        uint256 V2 = DecimalMath.divCeil(numerator, denominator);
        if (V2 > V1) {
            return 0;
        } else {
            return V1 - V2;
        }
    }
}
// File: contracts/lib/PMMPricing.sol
/**
 * @title Pricing
 * @author DODO Breeder
 *
 * @notice DODO Pricing model
 */
library PMMPricing {
    using SafeMath for uint256;
    enum RState {ONE, ABOVE_ONE, BELOW_ONE}
    struct PMMState {
        uint256 i;
        uint256 K;
        uint256 B;
        uint256 Q;
        uint256 B0;
        uint256 Q0;
        RState R;
    }
    // ============ buy & sell ============
    function sellBaseToken(PMMState memory state, uint256 payBaseAmount)
        internal
        pure
        returns (uint256 receiveQuoteAmount, RState newR)
    {
        if (state.R == RState.ONE) {
            // case 1: R=1
            // R falls below one
            receiveQuoteAmount = _ROneSellBaseToken(state, payBaseAmount);
            newR = RState.BELOW_ONE;
        } else if (state.R == RState.ABOVE_ONE) {
            uint256 backToOnePayBase = state.B0.sub(state.B);
            uint256 backToOneReceiveQuote = state.Q.sub(state.Q0);
            // case 2: R>1
            // complex case, R status depends on trading amount
            if (payBaseAmount < backToOnePayBase) {
                // case 2.1: R status do not change
                receiveQuoteAmount = _RAboveSellBaseToken(state, payBaseAmount);
                newR = RState.ABOVE_ONE;
                if (receiveQuoteAmount > backToOneReceiveQuote) {
                    // [Important corner case!] may enter this branch when some precision problem happens. And consequently contribute to negative spare quote amount
                    // to make sure spare quote>=0, mannually set receiveQuote=backToOneReceiveQuote
                    receiveQuoteAmount = backToOneReceiveQuote;
                }
            } else if (payBaseAmount == backToOnePayBase) {
                // case 2.2: R status changes to ONE
                receiveQuoteAmount = backToOneReceiveQuote;
                newR = RState.ONE;
            } else {
                // case 2.3: R status changes to BELOW_ONE
                receiveQuoteAmount = backToOneReceiveQuote.add(
                    _ROneSellBaseToken(state, payBaseAmount.sub(backToOnePayBase))
                );
                newR = RState.BELOW_ONE;
            }
        } else {
            // state.R == RState.BELOW_ONE
            // case 3: R<1
            receiveQuoteAmount = _RBelowSellBaseToken(state, payBaseAmount);
            newR = RState.BELOW_ONE;
        }
    }
    function sellQuoteToken(PMMState memory state, uint256 payQuoteAmount)
        internal
        pure
        returns (uint256 receiveBaseAmount, RState newR)
    {
        if (state.R == RState.ONE) {
            receiveBaseAmount = _ROneSellQuoteToken(state, payQuoteAmount);
            newR = RState.ABOVE_ONE;
        } else if (state.R == RState.ABOVE_ONE) {
            receiveBaseAmount = _RAboveSellQuoteToken(state, payQuoteAmount);
            newR = RState.ABOVE_ONE;
        } else {
            uint256 backToOnePayQuote = state.Q0.sub(state.Q);
            uint256 backToOneReceiveBase = state.B.sub(state.B0);
            if (payQuoteAmount < backToOnePayQuote) {
                receiveBaseAmount = _RBelowSellQuoteToken(state, payQuoteAmount);
                newR = RState.BELOW_ONE;
                if (receiveBaseAmount > backToOneReceiveBase) {
                    receiveBaseAmount = backToOneReceiveBase;
                }
            } else if (payQuoteAmount == backToOnePayQuote) {
                receiveBaseAmount = backToOneReceiveBase;
                newR = RState.ONE;
            } else {
                receiveBaseAmount = backToOneReceiveBase.add(
                    _ROneSellQuoteToken(state, payQuoteAmount.sub(backToOnePayQuote))
                );
                newR = RState.ABOVE_ONE;
            }
        }
    }
    // ============ R = 1 cases ============
    function _ROneSellBaseToken(PMMState memory state, uint256 payBaseAmount)
        internal
        pure
        returns (
            uint256 // receiveQuoteToken
        )
    {
        // in theory Q2 <= targetQuoteTokenAmount
        // however when amount is close to 0, precision problems may cause Q2 > targetQuoteTokenAmount
        return
            DODOMath._SolveQuadraticFunctionForTrade(
                state.Q0,
                state.Q0,
                payBaseAmount,
                state.i,
                state.K
            );
    }
    function _ROneSellQuoteToken(PMMState memory state, uint256 payQuoteAmount)
        internal
        pure
        returns (
            uint256 // receiveBaseToken
        )
    {
        return
            DODOMath._SolveQuadraticFunctionForTrade(
                state.B0,
                state.B0,
                payQuoteAmount,
                DecimalMath.reciprocalFloor(state.i),
                state.K
            );
    }
    // ============ R < 1 cases ============
    function _RBelowSellQuoteToken(PMMState memory state, uint256 payQuoteAmount)
        internal
        pure
        returns (
            uint256 // receiveBaseToken
        )
    {
        return
            DODOMath._GeneralIntegrate(
                state.Q0,
                state.Q.add(payQuoteAmount),
                state.Q,
                DecimalMath.reciprocalFloor(state.i),
                state.K
            );
    }
    function _RBelowSellBaseToken(PMMState memory state, uint256 payBaseAmount)
        internal
        pure
        returns (
            uint256 // receiveQuoteToken
        )
    {
        return
            DODOMath._SolveQuadraticFunctionForTrade(
                state.Q0,
                state.Q,
                payBaseAmount,
                state.i,
                state.K
            );
    }
    // ============ R > 1 cases ============
    function _RAboveSellBaseToken(PMMState memory state, uint256 payBaseAmount)
        internal
        pure
        returns (
            uint256 // receiveQuoteToken
        )
    {
        return
            DODOMath._GeneralIntegrate(
                state.B0,
                state.B.add(payBaseAmount),
                state.B,
                state.i,
                state.K
            );
    }
    function _RAboveSellQuoteToken(PMMState memory state, uint256 payQuoteAmount)
        internal
        pure
        returns (
            uint256 // receiveBaseToken
        )
    {
        return
            DODOMath._SolveQuadraticFunctionForTrade(
                state.B0,
                state.B,
                payQuoteAmount,
                DecimalMath.reciprocalFloor(state.i),
                state.K
            );
    }
    // ============ Helper functions ============
    function adjustedTarget(PMMState memory state) internal pure {
        if (state.R == RState.BELOW_ONE) {
            state.Q0 = DODOMath._SolveQuadraticFunctionForTarget(
                state.Q,
                state.B.sub(state.B0),
                state.i,
                state.K
            );
        } else if (state.R == RState.ABOVE_ONE) {
            state.B0 = DODOMath._SolveQuadraticFunctionForTarget(
                state.B,
                state.Q.sub(state.Q0),
                DecimalMath.reciprocalFloor(state.i),
                state.K
            );
        }
    }
    function getMidPrice(PMMState memory state) internal pure returns (uint256) {
        if (state.R == RState.BELOW_ONE) {
            uint256 R = DecimalMath.divFloor(state.Q0.mul(state.Q0).div(state.Q), state.Q);
            R = DecimalMath.ONE.sub(state.K).add(DecimalMath.mulFloor(state.K, R));
            return DecimalMath.divFloor(state.i, R);
        } else {
            uint256 R = DecimalMath.divFloor(state.B0.mul(state.B0).div(state.B), state.B);
            R = DecimalMath.ONE.sub(state.K).add(DecimalMath.mulFloor(state.K, R));
            return DecimalMath.mulFloor(state.i, R);
        }
    }
}
// File: contracts/intf/IERC20.sol
// This is a file copied from https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/token/ERC20/IERC20.sol
/**
 * @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);
    function decimals() external view returns (uint8);
    function name() external view returns (string memory);
    function symbol() external view returns (string memory);
    /**
     * @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);
}
// File: contracts/lib/SafeERC20.sol
/**
 * @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 ERC20;` statement to your contract,
 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
 */
library SafeERC20 {
    using SafeMath for uint256;
    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)
        );
    }
    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));
    }
    /**
     * @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.
        // A Solidity high level call has three parts:
        //  1. The target address is checked to verify it contains contract code
        //  2. The call itself is made, and success asserted
        //  3. The return value is decoded, which in turn checks the size of the returned data.
        // solhint-disable-next-line max-line-length
        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = address(token).call(data);
        require(success, "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/lib/InitializableOwnable.sol
/**
 * @title Ownable
 * @author DODO Breeder
 *
 * @notice Ownership related functions
 */
contract InitializableOwnable {
    address public _OWNER_;
    address public _NEW_OWNER_;
    bool internal _INITIALIZED_;
    // ============ Events ============
    event OwnershipTransferPrepared(address indexed previousOwner, address indexed newOwner);
    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
    // ============ Modifiers ============
    modifier notInitialized() {
        require(!_INITIALIZED_, "DODO_INITIALIZED");
        _;
    }
    modifier onlyOwner() {
        require(msg.sender == _OWNER_, "NOT_OWNER");
        _;
    }
    // ============ Functions ============
    function initOwner(address newOwner) public notInitialized {
        _INITIALIZED_ = true;
        _OWNER_ = newOwner;
    }
    function transferOwnership(address newOwner) public onlyOwner {
        emit OwnershipTransferPrepared(_OWNER_, newOwner);
        _NEW_OWNER_ = newOwner;
    }
    function claimOwnership() public {
        require(msg.sender == _NEW_OWNER_, "INVALID_CLAIM");
        emit OwnershipTransferred(_OWNER_, _NEW_OWNER_);
        _OWNER_ = _NEW_OWNER_;
        _NEW_OWNER_ = address(0);
    }
}
// File: contracts/lib/FeeRateModel.sol
interface IFeeRateImpl {
    function getFeeRate(address pool, address trader) external view returns (uint256);
}
interface IFeeRateModel {
    function getFeeRate(address trader) external view returns (uint256);
}
contract FeeRateModel is InitializableOwnable {
    address public feeRateImpl;
    function setFeeProxy(address _feeRateImpl) public onlyOwner {
        feeRateImpl = _feeRateImpl;
    }
    
    function getFeeRate(address trader) external view returns (uint256) {
        if(feeRateImpl == address(0))
            return 0;
        return IFeeRateImpl(feeRateImpl).getFeeRate(msg.sender,trader);
    }
}
// File: contracts/DODOVendingMachine/impl/DVMStorage.sol
contract DVMStorage is ReentrancyGuard {
    using SafeMath for uint256;
    bool public _IS_OPEN_TWAP_ = false;
    bool internal _DVM_INITIALIZED_;
    // ============ Core Address ============
    address public _MAINTAINER_;
    IERC20 public _BASE_TOKEN_;
    IERC20 public _QUOTE_TOKEN_;
    uint112 public _BASE_RESERVE_;
    uint112 public _QUOTE_RESERVE_;
    uint32 public _BLOCK_TIMESTAMP_LAST_;
    uint256 public _BASE_PRICE_CUMULATIVE_LAST_;
    // ============ Shares (ERC20) ============
    string public symbol;
    uint8 public decimals;
    string public name;
    uint256 public totalSupply;
    mapping(address => uint256) internal _SHARES_;
    mapping(address => mapping(address => uint256)) internal _ALLOWED_;
    // ================= Permit ======================
    bytes32 public DOMAIN_SEPARATOR;
    // keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)");
    bytes32 public constant PERMIT_TYPEHASH = 0x6e71edae12b1b97f4d1f60370fef10105fa2faae0126114a169c64845d6126c9;
    mapping(address => uint256) public nonces;
    // ============ Variables for Pricing ============
    uint256 public _LP_FEE_RATE_;
    IFeeRateModel public _MT_FEE_RATE_MODEL_;
    uint256 public _K_;
    uint256 public _I_;
    // ============ Helper Functions ============
    function getPMMState() public view returns (PMMPricing.PMMState memory state) {
        state.i = _I_;
        state.K = _K_;
        state.B = _BASE_RESERVE_;
        state.Q = _QUOTE_RESERVE_;
        state.B0 = 0; // will be calculated in adjustedTarget
        state.Q0 = 0;
        state.R = PMMPricing.RState.ABOVE_ONE;
        PMMPricing.adjustedTarget(state);
    }
    function getPMMStateForCall() 
        external 
        view 
        returns (
            uint256 i,
            uint256 K,
            uint256 B,
            uint256 Q,
            uint256 B0,
            uint256 Q0,
            uint256 R
        )
    {
        PMMPricing.PMMState memory state = getPMMState();
        i = state.i;
        K = state.K;
        B = state.B;
        Q = state.Q;
        B0 = state.B0;
        Q0 = state.Q0;
        R = uint256(state.R);
    }
    function getMidPrice() public view returns (uint256 midPrice) {
        return PMMPricing.getMidPrice(getPMMState());
    }
}
// File: contracts/DODOVendingMachine/impl/DVMVault.sol
contract DVMVault is DVMStorage {
    using SafeMath for uint256;
    using SafeERC20 for IERC20;
    // ============ Events ============
    event Transfer(address indexed from, address indexed to, uint256 amount);
    event Approval(address indexed owner, address indexed spender, uint256 amount);
    event Mint(address indexed user, uint256 value);
    event Burn(address indexed user, uint256 value);
    // ============ View Functions ============
    function getVaultReserve() external view returns (uint256 baseReserve, uint256 quoteReserve) {
        baseReserve = _BASE_RESERVE_;
        quoteReserve = _QUOTE_RESERVE_;
    }
    function getUserFeeRate(address user) external view returns (uint256 lpFeeRate, uint256 mtFeeRate) {
        lpFeeRate = _LP_FEE_RATE_;
        mtFeeRate = _MT_FEE_RATE_MODEL_.getFeeRate(user);
    }
    // ============ Asset In ============
    function getBaseInput() public view returns (uint256 input) {
        return _BASE_TOKEN_.balanceOf(address(this)).sub(uint256(_BASE_RESERVE_));
    }
    function getQuoteInput() public view returns (uint256 input) {
        return _QUOTE_TOKEN_.balanceOf(address(this)).sub(uint256(_QUOTE_RESERVE_));
    }
    // ============ TWAP UPDATE ===========
    
    function _twapUpdate() internal {
        uint32 blockTimestamp = uint32(block.timestamp % 2**32);
        uint32 timeElapsed = blockTimestamp - _BLOCK_TIMESTAMP_LAST_;
        if (timeElapsed > 0 && _BASE_RESERVE_ != 0 && _QUOTE_RESERVE_ != 0) {
            _BASE_PRICE_CUMULATIVE_LAST_ += getMidPrice() * timeElapsed;
        }
        _BLOCK_TIMESTAMP_LAST_ = blockTimestamp;
    }
    // ============ Set States ============
    function _setReserve(uint256 baseReserve, uint256 quoteReserve) internal {
        require(baseReserve <= uint112(-1) && quoteReserve <= uint112(-1), "OVERFLOW");
        _BASE_RESERVE_ = uint112(baseReserve);
        _QUOTE_RESERVE_ = uint112(quoteReserve);
        if(_IS_OPEN_TWAP_) _twapUpdate();
    }
    function _sync() internal {
        uint256 baseBalance = _BASE_TOKEN_.balanceOf(address(this));
        uint256 quoteBalance = _QUOTE_TOKEN_.balanceOf(address(this));
        require(baseBalance <= uint112(-1) && quoteBalance <= uint112(-1), "OVERFLOW");
        if (baseBalance != _BASE_RESERVE_) {
            _BASE_RESERVE_ = uint112(baseBalance);
        }
        if (quoteBalance != _QUOTE_RESERVE_) {
            _QUOTE_RESERVE_ = uint112(quoteBalance);
        }
        if(_IS_OPEN_TWAP_) _twapUpdate();
    }
    function sync() external preventReentrant {
        _sync();
    }
    // ============ Asset Out ============
    function _transferBaseOut(address to, uint256 amount) internal {
        if (amount > 0) {
            _BASE_TOKEN_.safeTransfer(to, amount);
        }
    }
    function _transferQuoteOut(address to, uint256 amount) internal {
        if (amount > 0) {
            _QUOTE_TOKEN_.safeTransfer(to, amount);
        }
    }
    // ============ Shares (ERC20) ============
    /**
     * @dev transfer token for a specified address
     * @param to The address to transfer to.
     * @param amount The amount to be transferred.
     */
    function transfer(address to, uint256 amount) public returns (bool) {
        require(amount <= _SHARES_[msg.sender], "BALANCE_NOT_ENOUGH");
        _SHARES_[msg.sender] = _SHARES_[msg.sender].sub(amount);
        _SHARES_[to] = _SHARES_[to].add(amount);
        emit Transfer(msg.sender, to, amount);
        return true;
    }
    /**
     * @dev Gets the balance of the specified address.
     * @param owner The address to query the the balance of.
     * @return balance An uint256 representing the amount owned by the passed address.
     */
    function balanceOf(address owner) external view returns (uint256 balance) {
        return _SHARES_[owner];
    }
    /**
     * @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 amount uint256 the amount of tokens to be transferred
     */
    function transferFrom(
        address from,
        address to,
        uint256 amount
    ) public returns (bool) {
        require(amount <= _SHARES_[from], "BALANCE_NOT_ENOUGH");
        require(amount <= _ALLOWED_[from][msg.sender], "ALLOWANCE_NOT_ENOUGH");
        _SHARES_[from] = _SHARES_[from].sub(amount);
        _SHARES_[to] = _SHARES_[to].add(amount);
        _ALLOWED_[from][msg.sender] = _ALLOWED_[from][msg.sender].sub(amount);
        emit Transfer(from, to, amount);
        return true;
    }
    /**
     * @dev Approve the passed address to spend the specified amount of tokens on behalf of msg.sender.
     * @param spender The address which will spend the funds.
     * @param amount The amount of tokens to be spent.
     */
    function approve(address spender, uint256 amount) public returns (bool) {
        _approve(msg.sender, spender, amount);
        return true;
    }
    function _approve(
        address owner,
        address spender,
        uint256 amount
    ) private {
        _ALLOWED_[owner][spender] = amount;
        emit Approval(owner, spender, amount);
    }
    /**
     * @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];
    }
    function _mint(address user, uint256 value) internal {
        require(value > 1000, "MINT_INVALID");
        _SHARES_[user] = _SHARES_[user].add(value);
        totalSupply = totalSupply.add(value);
        emit Mint(user, value);
        emit Transfer(address(0), user, value);
    }
    function _burn(address user, uint256 value) internal {
        _SHARES_[user] = _SHARES_[user].sub(value);
        totalSupply = totalSupply.sub(value);
        emit Burn(user, value);
        emit Transfer(user, address(0), value);
    }
    // ============================ Permit ======================================
    
    function permit(
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external {
        require(deadline >= block.timestamp, "DODO_DVM_LP: 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,
            "DODO_DVM_LP: INVALID_SIGNATURE"
        );
        _approve(owner, spender, value);
    }
}
// File: contracts/DODOVendingMachine/impl/DVMFunding.sol
contract DVMFunding is DVMVault {
    // ============ Events ============
    event BuyShares(address to, uint256 increaseShares, uint256 totalShares);
    event SellShares(address payer, address to, uint256 decreaseShares, uint256 totalShares);
    // ============ Buy & Sell Shares ============
    // buy shares [round down]
    function buyShares(address to)
        external
        preventReentrant
        returns (
            uint256 shares,
            uint256 baseInput,
            uint256 quoteInput
        )
    {
        uint256 baseBalance = _BASE_TOKEN_.balanceOf(address(this));
        uint256 quoteBalance = _QUOTE_TOKEN_.balanceOf(address(this));
        uint256 baseReserve = _BASE_RESERVE_;
        uint256 quoteReserve = _QUOTE_RESERVE_;
        baseInput = baseBalance.sub(baseReserve);
        quoteInput = quoteBalance.sub(quoteReserve);
        require(baseInput > 0, "NO_BASE_INPUT");
        // Round down when withdrawing. Therefore, never be a situation occuring balance is 0 but totalsupply is not 0
        // But May Happen，reserve >0 But totalSupply = 0
        if (totalSupply == 0) {
            // case 1. initial supply
            shares = baseBalance; // 以免出现balance很大但shares很小的情况
            require(shares > 2001, "MINT_AMOUNT_NOT_ENOUGH");
            _mint(address(0), 1001);
            shares -= 1001;
        } else if (baseReserve > 0 && quoteReserve == 0) {
            // case 2. supply when quote reserve is 0
            shares = baseInput.mul(totalSupply).div(baseReserve);
        } else if (baseReserve > 0 && quoteReserve > 0) {
            // case 3. normal case
            uint256 baseInputRatio = DecimalMath.divFloor(baseInput, baseReserve);
            uint256 quoteInputRatio = DecimalMath.divFloor(quoteInput, quoteReserve);
            uint256 mintRatio = quoteInputRatio < baseInputRatio ? quoteInputRatio : baseInputRatio;
            shares = DecimalMath.mulFloor(totalSupply, mintRatio);
        }
        _mint(to, shares);
        _setReserve(baseBalance, quoteBalance);
        emit BuyShares(to, shares, _SHARES_[to]);
    }
    // sell shares [round down]
    function sellShares(
        uint256 shareAmount,
        address to,
        uint256 baseMinAmount,
        uint256 quoteMinAmount,
        bytes calldata data,
        uint256 deadline
    ) external preventReentrant returns (uint256 baseAmount, uint256 quoteAmount) {
        require(deadline >= block.timestamp, "TIME_EXPIRED");
        require(shareAmount <= _SHARES_[msg.sender], "DLP_NOT_ENOUGH");
        require(to != address(this), "SELL_BACK_NOT_ALLOWED");
        uint256 baseBalance = _BASE_TOKEN_.balanceOf(address(this));
        uint256 quoteBalance = _QUOTE_TOKEN_.balanceOf(address(this));
        uint256 totalShares = totalSupply;
        baseAmount = baseBalance.mul(shareAmount).div(totalShares);
        quoteAmount = quoteBalance.mul(shareAmount).div(totalShares);
        require(
            baseAmount >= baseMinAmount && quoteAmount >= quoteMinAmount,
            "WITHDRAW_NOT_ENOUGH"
        );
        _burn(msg.sender, shareAmount);
        _transferBaseOut(to, baseAmount);
        _transferQuoteOut(to, quoteAmount);
        _sync();
        if (data.length > 0) {
            IDODOCallee(to).DVMSellShareCall(
                msg.sender,
                shareAmount,
                baseAmount,
                quoteAmount,
                data
            );
        }
        emit SellShares(msg.sender, to, shareAmount, _SHARES_[msg.sender]);
    }
}
// File: contracts/DODOVendingMachine/impl/DVMTrader.sol
contract DVMTrader is DVMVault {
    using SafeMath for uint256;
    // ============ Events ============
    event DODOSwap(
        address fromToken,
        address toToken,
        uint256 fromAmount,
        uint256 toAmount,
        address trader,
        address receiver
    );
    event DODOFlashLoan(
        address borrower,
        address assetTo,
        uint256 baseAmount,
        uint256 quoteAmount
    );
    // ============ Trade Functions ============
    function sellBase(address to)
        external
        preventReentrant
        returns (uint256 receiveQuoteAmount)
    {
        uint256 baseBalance = _BASE_TOKEN_.balanceOf(address(this));
        uint256 baseInput = baseBalance.sub(uint256(_BASE_RESERVE_));
        uint256 mtFee;
        (receiveQuoteAmount, mtFee) = querySellBase(tx.origin, baseInput);
        _transferQuoteOut(to, receiveQuoteAmount);
        _transferQuoteOut(_MAINTAINER_, mtFee);
        _setReserve(baseBalance, _QUOTE_TOKEN_.balanceOf(address(this)));
        emit DODOSwap(
            address(_BASE_TOKEN_),
            address(_QUOTE_TOKEN_),
            baseInput,
            receiveQuoteAmount,
            msg.sender,
            to
        );
    }
    function sellQuote(address to)
        external
        preventReentrant
        returns (uint256 receiveBaseAmount)
    {
        uint256 quoteBalance = _QUOTE_TOKEN_.balanceOf(address(this));
        uint256 quoteInput = quoteBalance.sub(uint256(_QUOTE_RESERVE_));
        uint256 mtFee;
        (receiveBaseAmount, mtFee) = querySellQuote(tx.origin, quoteInput);
        _transferBaseOut(to, receiveBaseAmount);
        _transferBaseOut(_MAINTAINER_, mtFee);
        _setReserve(_BASE_TOKEN_.balanceOf(address(this)), quoteBalance);
        emit DODOSwap(
            address(_QUOTE_TOKEN_),
            address(_BASE_TOKEN_),
            quoteInput,
            receiveBaseAmount,
            msg.sender,
            to
        );
    }
    function flashLoan(
        uint256 baseAmount,
        uint256 quoteAmount,
        address assetTo,
        bytes calldata data
    ) external preventReentrant {
        _transferBaseOut(assetTo, baseAmount);
        _transferQuoteOut(assetTo, quoteAmount);
        if (data.length > 0)
            IDODOCallee(assetTo).DVMFlashLoanCall(msg.sender, baseAmount, quoteAmount, data);
        uint256 baseBalance = _BASE_TOKEN_.balanceOf(address(this));
        uint256 quoteBalance = _QUOTE_TOKEN_.balanceOf(address(this));
        
        // no input -> pure loss
        require(
            baseBalance >= _BASE_RESERVE_ || quoteBalance >= _QUOTE_RESERVE_,
            "FLASH_LOAN_FAILED"
        );
        // sell quote
        if (baseBalance < _BASE_RESERVE_) {
            uint256 quoteInput = quoteBalance.sub(uint256(_QUOTE_RESERVE_));
            (uint256 receiveBaseAmount, uint256 mtFee) = querySellQuote(tx.origin, quoteInput);
            require(uint256(_BASE_RESERVE_).sub(baseBalance) <= receiveBaseAmount, "FLASH_LOAN_FAILED");
            _transferBaseOut(_MAINTAINER_, mtFee);
            emit DODOSwap(
                address(_QUOTE_TOKEN_),
                address(_BASE_TOKEN_),
                quoteInput,
                receiveBaseAmount,
                msg.sender,
                assetTo
            );
        }
        // sell base
        if (quoteBalance < _QUOTE_RESERVE_) {
            uint256 baseInput = baseBalance.sub(uint256(_BASE_RESERVE_));
            (uint256 receiveQuoteAmount, uint256 mtFee) = querySellBase(tx.origin, baseInput);
            require(uint256(_QUOTE_RESERVE_).sub(quoteBalance) <= receiveQuoteAmount, "FLASH_LOAN_FAILED");
            _transferQuoteOut(_MAINTAINER_, mtFee);
            emit DODOSwap(
                address(_BASE_TOKEN_),
                address(_QUOTE_TOKEN_),
                baseInput,
                receiveQuoteAmount,
                msg.sender,
                assetTo
            );
        }
        _sync();
        
        emit DODOFlashLoan(msg.sender, assetTo, baseAmount, quoteAmount);
    }
    // ============ Query Functions ============
    function querySellBase(address trader, uint256 payBaseAmount)
        public
        view
        returns (uint256 receiveQuoteAmount, uint256 mtFee)
    {
        (receiveQuoteAmount, ) = PMMPricing.sellBaseToken(getPMMState(), payBaseAmount);
        uint256 lpFeeRate = _LP_FEE_RATE_;
        uint256 mtFeeRate = _MT_FEE_RATE_MODEL_.getFeeRate(trader);
        mtFee = DecimalMath.mulFloor(receiveQuoteAmount, mtFeeRate);
        receiveQuoteAmount = receiveQuoteAmount
            .sub(DecimalMath.mulFloor(receiveQuoteAmount, lpFeeRate))
            .sub(mtFee);
    }
    function querySellQuote(address trader, uint256 payQuoteAmount)
        public
        view
        returns (uint256 receiveBaseAmount, uint256 mtFee)
    {
        (receiveBaseAmount, ) = PMMPricing.sellQuoteToken(getPMMState(), payQuoteAmount);
        uint256 lpFeeRate = _LP_FEE_RATE_;
        uint256 mtFeeRate = _MT_FEE_RATE_MODEL_.getFeeRate(trader);
        mtFee = DecimalMath.mulFloor(receiveBaseAmount, mtFeeRate);
        receiveBaseAmount = receiveBaseAmount
            .sub(DecimalMath.mulFloor(receiveBaseAmount, lpFeeRate))
            .sub(mtFee);
    }
}
// File: contracts/DODOVendingMachine/impl/DVM.sol
/**
 * @title DODO VendingMachine
 * @author DODO Breeder
 *
 * @notice DODOVendingMachine initialization
 */
contract DVM is DVMTrader, DVMFunding {
    function init(
        address maintainer,
        address baseTokenAddress,
        address quoteTokenAddress,
        uint256 lpFeeRate,
        address mtFeeRateModel,
        uint256 i,
        uint256 k,
        bool isOpenTWAP
    ) external {
        require(!_DVM_INITIALIZED_, "DVM_INITIALIZED");
        _DVM_INITIALIZED_ = true;
        
        require(baseTokenAddress != quoteTokenAddress, "BASE_QUOTE_CAN_NOT_BE_SAME");
        _BASE_TOKEN_ = IERC20(baseTokenAddress);
        _QUOTE_TOKEN_ = IERC20(quoteTokenAddress);
        require(i > 0 && i <= 10**36);
        _I_ = i;
        require(k <= 10**18);
        _K_ = k;
        _LP_FEE_RATE_ = lpFeeRate;
        _MT_FEE_RATE_MODEL_ = IFeeRateModel(mtFeeRateModel);
        _MAINTAINER_ = maintainer;
        _IS_OPEN_TWAP_ = isOpenTWAP;
        if(isOpenTWAP) _BLOCK_TIMESTAMP_LAST_ = uint32(block.timestamp % 2**32);
        string memory connect = "_";
        string memory suffix = "DLP";
        name = string(abi.encodePacked(suffix, connect, addressToShortString(address(this))));
        symbol = "DLP";
        decimals = _BASE_TOKEN_.decimals();
        // ============================== Permit ====================================
        uint256 chainId;
        assembly {
            chainId := chainid()
        }
        DOMAIN_SEPARATOR = keccak256(
            abi.encode(
                // keccak256('EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)'),
                0x8b73c3c69bb8fe3d512ecc4cf759cc79239f7b179b0ffacaa9a75d522b39400f,
                keccak256(bytes(name)),
                keccak256(bytes("1")),
                chainId,
                address(this)
            )
        );
        // ==========================================================================
    }
    function addressToShortString(address _addr) public pure returns (string memory) {
        bytes32 value = bytes32(uint256(_addr));
        bytes memory alphabet = "0123456789abcdef";
        bytes memory str = new bytes(8);
        for (uint256 i = 0; i < 4; i++) {
            str[i * 2] = alphabet[uint8(value[i + 12] >> 4)];
            str[1 + i * 2] = alphabet[uint8(value[i + 12] & 0x0f)];
        }
        return string(str);
    }
    // ============ Version Control ============
    
    function version() external pure returns (string memory) {
        return "DVM 1.0.3";
    }
}

// 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
 of this license document, but changing it is not allowed.

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                     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: @openzeppelin/[email protected]/utils/Context.sol


// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)

pragma solidity ^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 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) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
}

// File: @openzeppelin/[email protected]/token/ERC20/IERC20.sol


// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @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);

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

// File: @openzeppelin/[email protected]/token/ERC20/extensions/IERC20Metadata.sol


// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/IERC20Metadata.sol)

pragma solidity ^0.8.0;


/**
 * @dev Interface for the optional metadata functions from the ERC20 standard.
 *
 * _Available since v4.1._
 */
interface IERC20Metadata is IERC20 {
    /**
     * @dev Returns the name of the token.
     */
    function name() external view returns (string memory);

    /**
     * @dev Returns the symbol of the token.
     */
    function symbol() external view returns (string memory);

    /**
     * @dev Returns the decimals places of the token.
     */
    function decimals() external view returns (uint8);
}

// File: @openzeppelin/[email protected]/token/ERC20/ERC20.sol


// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC20/ERC20.sol)

pragma solidity ^0.8.0;




/**
 * @dev Implementation of the {IERC20} interface.
 *
 * This implementation is agnostic to the way tokens are created. This means
 * that a supply mechanism has to be added in a derived contract using {_mint}.
 * For a generic mechanism see {ERC20PresetMinterPauser}.
 *
 * TIP: For a detailed writeup see our guide
 * https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
 * to implement supply mechanisms].
 *
 * We have followed general OpenZeppelin Contracts guidelines: functions revert
 * instead returning `false` on failure. This behavior is nonetheless
 * conventional and does not conflict with the expectations of ERC20
 * applications.
 *
 * Additionally, an {Approval} event is emitted on calls to {transferFrom}.
 * This allows applications to reconstruct the allowance for all accounts just
 * by listening to said events. Other implementations of the EIP may not emit
 * these events, as it isn't required by the specification.
 *
 * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
 * functions have been added to mitigate the well-known issues around setting
 * allowances. See {IERC20-approve}.
 */
contract ERC20 is Context, IERC20, IERC20Metadata {
    mapping(address => uint256) private _balances;

    mapping(address => mapping(address => uint256)) private _allowances;

    uint256 private _totalSupply;

    string private _name;
    string private _symbol;

    /**
     * @dev Sets the values for {name} and {symbol}.
     *
     * The default value of {decimals} is 18. To select a different value for
     * {decimals} you should overload it.
     *
     * All two of these values are immutable: they can only be set once during
     * construction.
     */
    constructor(string memory name_, string memory symbol_) {
        _name = name_;
        _symbol = symbol_;
    }

    /**
     * @dev Returns the name of the token.
     */
    function name() public view virtual override returns (string memory) {
        return _name;
    }

    /**
     * @dev Returns the symbol of the token, usually a shorter version of the
     * name.
     */
    function symbol() public view virtual override returns (string memory) {
        return _symbol;
    }

    /**
     * @dev Returns the number of decimals used to get its user representation.
     * For example, if `decimals` equals `2`, a balance of `505` tokens should
     * be displayed to a user as `5.05` (`505 / 10 ** 2`).
     *
     * Tokens usually opt for a value of 18, imitating the relationship between
     * Ether and Wei. This is the value {ERC20} uses, unless this function is
     * overridden;
     *
     * NOTE: This information is only used for _display_ purposes: it in
     * no way affects any of the arithmetic of the contract, including
     * {IERC20-balanceOf} and {IERC20-transfer}.
     */
    function decimals() public view virtual override returns (uint8) {
        return 18;
    }

    /**
     * @dev See {IERC20-totalSupply}.
     */
    function totalSupply() public view virtual override returns (uint256) {
        return _totalSupply;
    }

    /**
     * @dev See {IERC20-balanceOf}.
     */
    function balanceOf(address account) public view virtual override returns (uint256) {
        return _balances[account];
    }

    /**
     * @dev See {IERC20-transfer}.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     * - the caller must have a balance of at least `amount`.
     */
    function transfer(address to, uint256 amount) public virtual override returns (bool) {
        address owner = _msgSender();
        _transfer(owner, to, amount);
        return true;
    }

    /**
     * @dev See {IERC20-allowance}.
     */
    function allowance(address owner, address spender) public view virtual override returns (uint256) {
        return _allowances[owner][spender];
    }

    /**
     * @dev See {IERC20-approve}.
     *
     * NOTE: If `amount` is the maximum `uint256`, the allowance is not updated on
     * `transferFrom`. This is semantically equivalent to an infinite approval.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function approve(address spender, uint256 amount) public virtual override returns (bool) {
        address owner = _msgSender();
        _approve(owner, spender, amount);
        return true;
    }

    /**
     * @dev See {IERC20-transferFrom}.
     *
     * Emits an {Approval} event indicating the updated allowance. This is not
     * required by the EIP. See the note at the beginning of {ERC20}.
     *
     * NOTE: Does not update the allowance if the current allowance
     * is the maximum `uint256`.
     *
     * Requirements:
     *
     * - `from` and `to` cannot be the zero address.
     * - `from` must have a balance of at least `amount`.
     * - the caller must have allowance for ``from``'s tokens of at least
     * `amount`.
     */
    function transferFrom(
        address from,
        address to,
        uint256 amount
    ) public virtual override returns (bool) {
        address spender = _msgSender();
        _spendAllowance(from, spender, amount);
        _transfer(from, to, amount);
        return true;
    }

    /**
     * @dev Atomically increases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
        address owner = _msgSender();
        _approve(owner, spender, allowance(owner, spender) + addedValue);
        return true;
    }

    /**
     * @dev Atomically decreases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `spender` must have allowance for the caller of at least
     * `subtractedValue`.
     */
    function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
        address owner = _msgSender();
        uint256 currentAllowance = allowance(owner, spender);
        require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
        unchecked {
            _approve(owner, spender, currentAllowance - subtractedValue);
        }

        return true;
    }

    /**
     * @dev Moves `amount` of tokens from `sender` to `recipient`.
     *
     * This internal function is equivalent to {transfer}, and can be used to
     * e.g. implement automatic token fees, slashing mechanisms, etc.
     *
     * Emits a {Transfer} event.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `from` must have a balance of at least `amount`.
     */
    function _transfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {
        require(from != address(0), "ERC20: transfer from the zero address");
        require(to != address(0), "ERC20: transfer to the zero address");

        _beforeTokenTransfer(from, to, amount);

        uint256 fromBalance = _balances[from];
        require(fromBalance >= amount, "ERC20: transfer amount exceeds balance");
        unchecked {
            _balances[from] = fromBalance - amount;
        }
        _balances[to] += amount;

        emit Transfer(from, to, amount);

        _afterTokenTransfer(from, to, amount);
    }

    /** @dev Creates `amount` tokens and assigns them to `account`, increasing
     * the total supply.
     *
     * Emits a {Transfer} event with `from` set to the zero address.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     */
    function _mint(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: mint to the zero address");

        _beforeTokenTransfer(address(0), account, amount);

        _totalSupply += amount;
        _balances[account] += amount;
        emit Transfer(address(0), account, amount);

        _afterTokenTransfer(address(0), account, amount);
    }

    /**
     * @dev Destroys `amount` tokens from `account`, reducing the
     * total supply.
     *
     * Emits a {Transfer} event with `to` set to the zero address.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     * - `account` must have at least `amount` tokens.
     */
    function _burn(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: burn from the zero address");

        _beforeTokenTransfer(account, address(0), amount);

        uint256 accountBalance = _balances[account];
        require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
        unchecked {
            _balances[account] = accountBalance - amount;
        }
        _totalSupply -= amount;

        emit Transfer(account, address(0), amount);

        _afterTokenTransfer(account, address(0), amount);
    }

    /**
     * @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
     *
     * This internal function is equivalent to `approve`, and can be used to
     * e.g. set automatic allowances for certain subsystems, etc.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `owner` cannot be the zero address.
     * - `spender` cannot be the zero address.
     */
    function _approve(
        address owner,
        address spender,
        uint256 amount
    ) internal virtual {
        require(owner != address(0), "ERC20: approve from the zero address");
        require(spender != address(0), "ERC20: approve to the zero address");

        _allowances[owner][spender] = amount;
        emit Approval(owner, spender, amount);
    }

    /**
     * @dev Updates `owner` s allowance for `spender` based on spent `amount`.
     *
     * Does not update the allowance amount in case of infinite allowance.
     * Revert if not enough allowance is available.
     *
     * Might emit an {Approval} event.
     */
    function _spendAllowance(
        address owner,
        address spender,
        uint256 amount
    ) internal virtual {
        uint256 currentAllowance = allowance(owner, spender);
        if (currentAllowance != type(uint256).max) {
            require(currentAllowance >= amount, "ERC20: insufficient allowance");
            unchecked {
                _approve(owner, spender, currentAllowance - amount);
            }
        }
    }

    /**
     * @dev Hook that is called before any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * will be transferred to `to`.
     * - when `from` is zero, `amount` tokens will be minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens will be burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _beforeTokenTransfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {}

    /**
     * @dev Hook that is called after any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * has been transferred to `to`.
     * - when `from` is zero, `amount` tokens have been minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens have been burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _afterTokenTransfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {}
}

// File: contract-1de67b57d0.sol


pragma solidity ^0.8.4;


contract REDTOKEN is ERC20 {
    constructor() ERC20("RED TOKEN", "RED") {
        _mint(msg.sender, 100000000000 * 10 ** decimals());
    }
}


//red

pragma solidity ^0.5.3;

/// @title Proxy - Generic proxy contract allows to execute all transactions applying the code of a master contract.
/// @author Stefan George - <[email protected]>
/// @author Richard Meissner - <[email protected]>
contract Proxy {

    // masterCopy always needs to be first declared variable, to ensure that it is at the same location in the contracts to which calls are delegated.
    // To reduce deployment costs this variable is internal and needs to be retrieved via `getStorageAt`
    address internal masterCopy;

    /// @dev Constructor function sets address of master copy contract.
    /// @param _masterCopy Master copy address.
    constructor(address _masterCopy)
        public
    {
        require(_masterCopy != address(0), "Invalid master copy address provided");
        masterCopy = _masterCopy;
    }

    /// @dev Fallback function forwards all transactions and returns all received return data.
    function ()
        external
        payable
    {
        // solium-disable-next-line security/no-inline-assembly
        assembly {
            let masterCopy := and(sload(0), 0xffffffffffffffffffffffffffffffffffffffff)
            // 0xa619486e == keccak("masterCopy()"). The value is right padded to 32-bytes with 0s
            if eq(calldataload(0), 0xa619486e00000000000000000000000000000000000000000000000000000000) {
                mstore(0, masterCopy)
                return(0, 0x20)
            }
            calldatacopy(0, 0, calldatasize())
            let success := delegatecall(gas, masterCopy, 0, calldatasize(), 0, 0)
            returndatacopy(0, 0, returndatasize())
            if eq(success, 0) { revert(0, returndatasize()) }
            return(0, returndatasize())
        }
    }
}

/**
 *Submitted for verification at BscScan.com on 2023-06-26
*/

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

// OpenZeppelin Contracts v4.4.1 (access/Ownable.sol)

// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)

// OpenZeppelin Contracts v4.4.1 (proxy/utils/Initializable.sol)

// OpenZeppelin Contracts v4.4.1 (utils/Address.sol)

/**
 * @dev Collection of functions related to the address type
 */
library AddressUpgradeable {
    /**
     * @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) {
        // This method relies on extcodesize, which returns 0 for contracts in
        // construction, since the code is only stored at the end of the
        // constructor execution.

        uint256 size;
        assembly {
            size := extcodesize(account)
        }
        return size > 0;
    }

    /**
     * @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");

        (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");
        require(isContract(target), "Address: call to non-contract");

        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        return functionStaticCall(target, data, "Address: low-level static call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        require(isContract(target), "Address: static call to non-contract");

        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason using the provided one.
     *
     * _Available since v4.3._
     */
    function verifyCallResult(
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal pure returns (bytes memory) {
        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

                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}

/**
 * @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed
 * behind a proxy. Since a proxied contract can't have a constructor, it's common to move constructor logic to an
 * external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer
 * function so it can only be called once. The {initializer} modifier provided by this contract will have this effect.
 *
 * TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as
 * possible by providing the encoded function call as the `_data` argument to {ERC1967Proxy-constructor}.
 *
 * CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure
 * that all initializers are idempotent. This is not verified automatically as constructors are by Solidity.
 *
 * [CAUTION]
 * ====
 * Avoid leaving a contract uninitialized.
 *
 * An uninitialized contract can be taken over by an attacker. This applies to both a proxy and its implementation
 * contract, which may impact the proxy. To initialize the implementation contract, you can either invoke the
 * initializer manually, or you can include a constructor to automatically mark it as initialized when it is deployed:
 *
 * [.hljs-theme-light.nopadding]
 * ```
 * /// @custom:oz-upgrades-unsafe-allow constructor
 * constructor() initializer {}
 * ```
 * ====
 */
abstract contract Initializable {
    /**
     * @dev Indicates that the contract has been initialized.
     */
    bool private _initialized;

    /**
     * @dev Indicates that the contract is in the process of being initialized.
     */
    bool private _initializing;

    /**
     * @dev Modifier to protect an initializer function from being invoked twice.
     */
    modifier initializer() {
        // If the contract is initializing we ignore whether _initialized is set in order to support multiple
        // inheritance patterns, but we only do this in the context of a constructor, because in other contexts the
        // contract may have been reentered.
        require(_initializing ? _isConstructor() : !_initialized, "Initializable: contract is already initialized");

        bool isTopLevelCall = !_initializing;
        if (isTopLevelCall) {
            _initializing = true;
            _initialized = true;
        }

        _;

        if (isTopLevelCall) {
            _initializing = false;
        }
    }

    /**
     * @dev Modifier to protect an initialization function so that it can only be invoked by functions with the
     * {initializer} modifier, directly or indirectly.
     */
    modifier onlyInitializing() {
        require(_initializing, "Initializable: contract is not initializing");
        _;
    }

    function _isConstructor() private view returns (bool) {
        return !AddressUpgradeable.isContract(address(this));
    }
}

/**
 * @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 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 ContextUpgradeable is Initializable {
    function __Context_init() internal onlyInitializing {
        __Context_init_unchained();
    }

    function __Context_init_unchained() internal onlyInitializing {
    }
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
    uint256[50] private __gap;
}

/**
 * @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 OwnableUpgradeable is Initializable, ContextUpgradeable {
    address private _owner;

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

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    function __Ownable_init() internal onlyInitializing {
        __Context_init_unchained();
        __Ownable_init_unchained();
    }

    function __Ownable_init_unchained() internal onlyInitializing {
        _transferOwnership(_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 {
        _transferOwnership(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");
        _transferOwnership(newOwner);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Internal function without access restriction.
     */
    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
    uint256[49] private __gap;
}

interface IERC20 {
    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);
}

library SafeMath {
    uint256 constant WAD = 10 ** 18;
    uint256 constant RAY = 10 ** 27;

    function wad() public pure returns (uint256) {
        return WAD;
    }

    function ray() public pure returns (uint256) {
        return RAY;
    }

    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");

        return c;
    }

    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        return sub(a, b, "SafeMath: subtraction overflow");
    }

    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b <= a, errorMessage);
        uint256 c = a - b;

        return c;
    }

    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;
    }

    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        return div(a, b, "SafeMath: division by zero");
    }

    function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        // Solidity only automatically asserts when dividing by 0
        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;
    }

    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        return mod(a, b, "SafeMath: modulo by zero");
    }

    function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b != 0, errorMessage);
        return a % b;
    }

    function min(uint256 a, uint256 b) internal pure returns (uint256) {
        return a <= b ? a : b;
    }

    function max(uint256 a, uint256 b) internal pure returns (uint256) {
        return a >= b ? a : b;
    }

    function sqrt(uint256 a) internal pure returns (uint256 b) {
        if (a > 3) {
            b = a;
            uint256 x = a / 2 + 1;
            while (x < b) {
                b = x;
                x = (a / x + x) / 2;
            }
        } else if (a != 0) {
            b = 1;
        }
    }

    function wmul(uint256 a, uint256 b) internal pure returns (uint256) {
        return mul(a, b) / WAD;
    }

    function wmulRound(uint256 a, uint256 b) internal pure returns (uint256) {
        return add(mul(a, b), WAD / 2) / WAD;
    }

    function rmul(uint256 a, uint256 b) internal pure returns (uint256) {
        return mul(a, b) / RAY;
    }

    function rmulRound(uint256 a, uint256 b) internal pure returns (uint256) {
        return add(mul(a, b), RAY / 2) / RAY;
    }

    function wdiv(uint256 a, uint256 b) internal pure returns (uint256) {
        return div(mul(a, WAD), b);
    }

    function wdivRound(uint256 a, uint256 b) internal pure returns (uint256) {
        return add(mul(a, WAD), b / 2) / b;
    }

    function rdiv(uint256 a, uint256 b) internal pure returns (uint256) {
        return div(mul(a, RAY), b);
    }

    function rdivRound(uint256 a, uint256 b) internal pure returns (uint256) {
        return add(mul(a, RAY), b / 2) / b;
    }

    function wpow(uint256 x, uint256 n) internal pure returns (uint256) {
        uint256 result = WAD;
        while (n > 0) {
            if (n % 2 != 0) {
                result = wmul(result, x);
            }
            x = wmul(x, x);
            n /= 2;
        }
        return result;
    }

    function rpow(uint256 x, uint256 n) internal pure returns (uint256) {
        uint256 result = RAY;
        while (n > 0) {
            if (n % 2 != 0) {
                result = rmul(result, x);
            }
            x = rmul(x, x);
            n /= 2;
        }
        return result;
    }

    function divCeil(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 quotient = div(a, b);
        uint256 remainder = a - quotient * b;
        if (remainder > 0) {
            return quotient + 1;
        } else {
            return quotient;
        }
    }
}

/**
 * @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 Converts an `address` into `address payable`. Note that this is
     * simply a type cast: the actual underlying value is not changed.
     *
     * _Available since v2.4.0._
     */
    function toPayable(address account) internal pure returns (address payable) {
        return payable(account);
    }

    /**
     * @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].
     *
     * _Available since v2.4.0._
     */
    function sendValue(address recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

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

/**
 * @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 ERC20;` 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));
    }

    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.

        // A Solidity high level call has three parts:
        //  1. The target address is checked to verify it contains contract code
        //  2. The call itself is made, and success asserted
        //  3. The return value is decoded, which in turn checks the size of the returned data.
        // solhint-disable-next-line max-line-length
        require(address(token).isContract(), "SafeERC20: call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = address(token).call(data);
        require(success, "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");
        }
    }
}

/// @title Handle authorizations in dex platform
/// @notice Explain to an end user what this does
/// @dev Explain to a developer any extra details
contract TokenApprove is OwnableUpgradeable {
  using SafeERC20 for IERC20;

  address public tokenApproveProxy;

  function initialize(address _tokenApproveProxy) public initializer {
    __Ownable_init();
    tokenApproveProxy = _tokenApproveProxy;
  }

  //-------------------------------
  //------- Events ----------------
  //-------------------------------

  event ProxyUpdate(address indexed oldProxy, address indexed newProxy);

  //-------------------------------
  //------- Modifier --------------
  //-------------------------------

  //--------------------------------
  //------- Internal Functions -----
  //--------------------------------

  //---------------------------------
  //------- Admin functions ---------
  //---------------------------------

  function setApproveProxy(address _newTokenApproveProxy) external onlyOwner {
    tokenApproveProxy = _newTokenApproveProxy;
    emit ProxyUpdate(tokenApproveProxy, _newTokenApproveProxy);
  }

  //---------------------------------
  //-------  Users Functions --------
  //---------------------------------

  function claimTokens(
    address _token,
    address _who,
    address _dest,
    uint256 _amount
  ) external {
    require(msg.sender == tokenApproveProxy, "TokenApprove: Access restricted");
    if (_amount > 0) {
      IERC20(_token).safeTransferFrom(_who, _dest, _amount);
    }
  }
}

// File: contracts/intf/IDODOCallee.sol
/*
    Copyright 2020 DODO ZOO.
    SPDX-License-Identifier: Apache-2.0
*/
pragma solidity 0.6.9;
pragma experimental ABIEncoderV2;
interface IDODOCallee {
    function DVMSellShareCall(
        address sender,
        uint256 burnShareAmount,
        uint256 baseAmount,
        uint256 quoteAmount,
        bytes calldata data
    ) external;
    function DVMFlashLoanCall(
        address sender,
        uint256 baseAmount,
        uint256 quoteAmount,
        bytes calldata data
    ) external;
    function DPPFlashLoanCall(
        address sender,
        uint256 baseAmount,
        uint256 quoteAmount,
        bytes calldata data
    ) external;
    function DSPFlashLoanCall(
        address sender,
        uint256 baseAmount,
        uint256 quoteAmount,
        bytes calldata data
    ) external;
    function CPCancelCall(
        address sender,
        uint256 amount,
        bytes calldata data
    ) external;
\tfunction CPClaimBidCall(
        address sender,
        uint256 baseAmount,
        uint256 quoteAmount,
        bytes calldata data
    ) external;
    function NFTRedeemCall(
        address payable assetTo,
        uint256 quoteAmount,
        bytes calldata
    ) external;
}
// File: contracts/lib/ReentrancyGuard.sol
/**
 * @title ReentrancyGuard
 * @author DODO Breeder
 *
 * @notice Protect functions from Reentrancy Attack
 */
contract ReentrancyGuard {
    // https://solidity.readthedocs.io/en/latest/control-structures.html?highlight=zero-state#scoping-and-declarations
    // zero-state of _ENTERED_ is false
    bool private _ENTERED_;
    modifier preventReentrant() {
        require(!_ENTERED_, "REENTRANT");
        _ENTERED_ = true;
        _;
        _ENTERED_ = false;
    }
}
// File: contracts/lib/SafeMath.sol
/**
 * @title SafeMath
 * @author DODO Breeder
 *
 * @notice Math operations with safety checks that revert on error
 */
library SafeMath {
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        if (a == 0) {
            return 0;
        }
        uint256 c = a * b;
        require(c / a == b, "MUL_ERROR");
        return c;
    }
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b > 0, "DIVIDING_ERROR");
        return a / b;
    }
    function divCeil(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 quotient = div(a, b);
        uint256 remainder = a - quotient * b;
        if (remainder > 0) {
            return quotient + 1;
        } else {
            return quotient;
        }
    }
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b <= a, "SUB_ERROR");
        return a - b;
    }
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "ADD_ERROR");
        return c;
    }
    function sqrt(uint256 x) internal pure returns (uint256 y) {
        uint256 z = x / 2 + 1;
        y = x;
        while (z < y) {
            y = z;
            z = (x / z + z) / 2;
        }
    }
}
// File: contracts/lib/DecimalMath.sol
/**
 * @title DecimalMath
 * @author DODO Breeder
 *
 * @notice Functions for fixed point number with 18 decimals
 */
library DecimalMath {
    using SafeMath for uint256;
    uint256 internal constant ONE = 10**18;
    uint256 internal constant ONE2 = 10**36;
    function mulFloor(uint256 target, uint256 d) internal pure returns (uint256) {
        return target.mul(d) / (10**18);
    }
    function mulCeil(uint256 target, uint256 d) internal pure returns (uint256) {
        return target.mul(d).divCeil(10**18);
    }
    function divFloor(uint256 target, uint256 d) internal pure returns (uint256) {
        return target.mul(10**18).div(d);
    }
    function divCeil(uint256 target, uint256 d) internal pure returns (uint256) {
        return target.mul(10**18).divCeil(d);
    }
    function reciprocalFloor(uint256 target) internal pure returns (uint256) {
        return uint256(10**36).div(target);
    }
    function reciprocalCeil(uint256 target) internal pure returns (uint256) {
        return uint256(10**36).divCeil(target);
    }
    function powFloor(uint256 target, uint256 e) internal pure returns (uint256) {
        if (e == 0) {
            return 10 ** 18;
        } else if (e == 1) {
            return target;
        } else {
            uint p = powFloor(target, e.div(2));
            p = p.mul(p) / (10**18);
            if (e % 2 == 1) {
                p = p.mul(target) / (10**18);
            }
            return p;
        }
    }
}
// File: contracts/lib/DODOMath.sol
/**
 * @title DODOMath
 * @author DODO Breeder
 *
 * @notice Functions for complex calculating. Including ONE Integration and TWO Quadratic solutions
 */
library DODOMath {
    using SafeMath for uint256;
    /*
        Integrate dodo curve from V1 to V2
        require V0>=V1>=V2>0
        res = (1-k)i(V1-V2)+ikV0*V0(1/V2-1/V1)
        let V1-V2=delta
        res = i*delta*(1-k+k(V0^2/V1/V2))
        i is the price of V-res trading pair
        support k=1 & k=0 case
        [round down]
    */
    function _GeneralIntegrate(
        uint256 V0,
        uint256 V1,
        uint256 V2,
        uint256 i,
        uint256 k
    ) internal pure returns (uint256) {
        require(V0 > 0, "TARGET_IS_ZERO");
        uint256 fairAmount = i.mul(V1.sub(V2)); // i*delta
        if (k == 0) {
            return fairAmount.div(DecimalMath.ONE);
        }
        uint256 V0V0V1V2 = DecimalMath.divFloor(V0.mul(V0).div(V1), V2);
        uint256 penalty = DecimalMath.mulFloor(k, V0V0V1V2); // k(V0^2/V1/V2)
        return DecimalMath.ONE.sub(k).add(penalty).mul(fairAmount).div(DecimalMath.ONE2);
    }
    /*
        Follow the integration function above
        i*deltaB = (Q2-Q1)*(1-k+kQ0^2/Q1/Q2)
        Assume Q2=Q0, Given Q1 and deltaB, solve Q0
        i is the price of delta-V trading pair
        give out target of V
        support k=1 & k=0 case
        [round down]
    */
    function _SolveQuadraticFunctionForTarget(
        uint256 V1,
        uint256 delta,
        uint256 i,
        uint256 k
    ) internal pure returns (uint256) {
        if (k == 0) {
            return V1.add(DecimalMath.mulFloor(i, delta));
        }
        // V0 = V1*(1+(sqrt-1)/2k)
        // sqrt = √(1+4kidelta/V1)
        // premium = 1+(sqrt-1)/2k
        // uint256 sqrt = (4 * k).mul(i).mul(delta).div(V1).add(DecimalMath.ONE2).sqrt();
        if (V1 == 0) {
            return 0;
        }
        uint256 sqrt;
        uint256 ki = (4 * k).mul(i);
        if (ki == 0) {
            sqrt = DecimalMath.ONE;
        } else if ((ki * delta) / ki == delta) {
            sqrt = (ki * delta).div(V1).add(DecimalMath.ONE2).sqrt();
        } else {
            sqrt = ki.div(V1).mul(delta).add(DecimalMath.ONE2).sqrt();
        }
        uint256 premium =
            DecimalMath.divFloor(sqrt.sub(DecimalMath.ONE), k * 2).add(DecimalMath.ONE);
        // V0 is greater than or equal to V1 according to the solution
        return DecimalMath.mulFloor(V1, premium);
    }
    /*
        Follow the integration expression above, we have:
        i*deltaB = (Q2-Q1)*(1-k+kQ0^2/Q1/Q2)
        Given Q1 and deltaB, solve Q2
        This is a quadratic function and the standard version is
        aQ2^2 + bQ2 + c = 0, where
        a=1-k
        -b=(1-k)Q1-kQ0^2/Q1+i*deltaB
        c=-kQ0^2 
        and Q2=(-b+sqrt(b^2+4(1-k)kQ0^2))/2(1-k)
        note: another root is negative, abondan
        if deltaBSig=true, then Q2>Q1, user sell Q and receive B
        if deltaBSig=false, then Q2<Q1, user sell B and receive Q
        return |Q1-Q2|
        as we only support sell amount as delta, the deltaB is always negative
        the input ideltaB is actually -ideltaB in the equation
        i is the price of delta-V trading pair
        support k=1 & k=0 case
        [round down]
    */
    function _SolveQuadraticFunctionForTrade(
        uint256 V0,
        uint256 V1,
        uint256 delta,
        uint256 i,
        uint256 k
    ) internal pure returns (uint256) {
        require(V0 > 0, "TARGET_IS_ZERO");
        if (delta == 0) {
            return 0;
        }
        if (k == 0) {
            return DecimalMath.mulFloor(i, delta) > V1 ? V1 : DecimalMath.mulFloor(i, delta);
        }
        if (k == DecimalMath.ONE) {
            // if k==1
            // Q2=Q1/(1+ideltaBQ1/Q0/Q0)
            // temp = ideltaBQ1/Q0/Q0
            // Q2 = Q1/(1+temp)
            // Q1-Q2 = Q1*(1-1/(1+temp)) = Q1*(temp/(1+temp))
            // uint256 temp = i.mul(delta).mul(V1).div(V0.mul(V0));
            uint256 temp;
            uint256 idelta = i.mul(delta);
            if (idelta == 0) {
                temp = 0;
            } else if ((idelta * V1) / idelta == V1) {
                temp = (idelta * V1).div(V0.mul(V0));
            } else {
                temp = delta.mul(V1).div(V0).mul(i).div(V0);
            }
            return V1.mul(temp).div(temp.add(DecimalMath.ONE));
        }
        // calculate -b value and sig
        // b = kQ0^2/Q1-i*deltaB-(1-k)Q1
        // part1 = (1-k)Q1 >=0
        // part2 = kQ0^2/Q1-i*deltaB >=0
        // bAbs = abs(part1-part2)
        // if part1>part2 => b is negative => bSig is false
        // if part2>part1 => b is positive => bSig is true
        uint256 part2 = k.mul(V0).div(V1).mul(V0).add(i.mul(delta)); // kQ0^2/Q1-i*deltaB
        uint256 bAbs = DecimalMath.ONE.sub(k).mul(V1); // (1-k)Q1
        bool bSig;
        if (bAbs >= part2) {
            bAbs = bAbs - part2;
            bSig = false;
        } else {
            bAbs = part2 - bAbs;
            bSig = true;
        }
        bAbs = bAbs.div(DecimalMath.ONE);
        // calculate sqrt
        uint256 squareRoot =
            DecimalMath.mulFloor(
                DecimalMath.ONE.sub(k).mul(4),
                DecimalMath.mulFloor(k, V0).mul(V0)
            ); // 4(1-k)kQ0^2
        squareRoot = bAbs.mul(bAbs).add(squareRoot).sqrt(); // sqrt(b*b+4(1-k)kQ0*Q0)
        // final res
        uint256 denominator = DecimalMath.ONE.sub(k).mul(2); // 2(1-k)
        uint256 numerator;
        if (bSig) {
            numerator = squareRoot.sub(bAbs);
            if (numerator == 0) {
                revert("DODOMath: should not be zero");
            }
        } else {
            numerator = bAbs.add(squareRoot);
        }
        uint256 V2 = DecimalMath.divCeil(numerator, denominator);
        if (V2 > V1) {
            return 0;
        } else {
            return V1 - V2;
        }
    }
}
// File: contracts/lib/PMMPricing.sol
/**
 * @title Pricing
 * @author DODO Breeder
 *
 * @notice DODO Pricing model
 */
library PMMPricing {
    using SafeMath for uint256;
    enum RState {ONE, ABOVE_ONE, BELOW_ONE}
    struct PMMState {
        uint256 i;
        uint256 K;
        uint256 B;
        uint256 Q;
        uint256 B0;
        uint256 Q0;
        RState R;
    }
    // ============ buy & sell ============
    function sellBaseToken(PMMState memory state, uint256 payBaseAmount)
        internal
        pure
        returns (uint256 receiveQuoteAmount, RState newR)
    {
        if (state.R == RState.ONE) {
            // case 1: R=1
            // R falls below one
            receiveQuoteAmount = _ROneSellBaseToken(state, payBaseAmount);
            newR = RState.BELOW_ONE;
        } else if (state.R == RState.ABOVE_ONE) {
            uint256 backToOnePayBase = state.B0.sub(state.B);
            uint256 backToOneReceiveQuote = state.Q.sub(state.Q0);
            // case 2: R>1
            // complex case, R status depends on trading amount
            if (payBaseAmount < backToOnePayBase) {
                // case 2.1: R status do not change
                receiveQuoteAmount = _RAboveSellBaseToken(state, payBaseAmount);
                newR = RState.ABOVE_ONE;
                if (receiveQuoteAmount > backToOneReceiveQuote) {
                    // [Important corner case!] may enter this branch when some precision problem happens. And consequently contribute to negative spare quote amount
                    // to make sure spare quote>=0, mannually set receiveQuote=backToOneReceiveQuote
                    receiveQuoteAmount = backToOneReceiveQuote;
                }
            } else if (payBaseAmount == backToOnePayBase) {
                // case 2.2: R status changes to ONE
                receiveQuoteAmount = backToOneReceiveQuote;
                newR = RState.ONE;
            } else {
                // case 2.3: R status changes to BELOW_ONE
                receiveQuoteAmount = backToOneReceiveQuote.add(
                    _ROneSellBaseToken(state, payBaseAmount.sub(backToOnePayBase))
                );
                newR = RState.BELOW_ONE;
            }
        } else {
            // state.R == RState.BELOW_ONE
            // case 3: R<1
            receiveQuoteAmount = _RBelowSellBaseToken(state, payBaseAmount);
            newR = RState.BELOW_ONE;
        }
    }
    function sellQuoteToken(PMMState memory state, uint256 payQuoteAmount)
        internal
        pure
        returns (uint256 receiveBaseAmount, RState newR)
    {
        if (state.R == RState.ONE) {
            receiveBaseAmount = _ROneSellQuoteToken(state, payQuoteAmount);
            newR = RState.ABOVE_ONE;
        } else if (state.R == RState.ABOVE_ONE) {
            receiveBaseAmount = _RAboveSellQuoteToken(state, payQuoteAmount);
            newR = RState.ABOVE_ONE;
        } else {
            uint256 backToOnePayQuote = state.Q0.sub(state.Q);
            uint256 backToOneReceiveBase = state.B.sub(state.B0);
            if (payQuoteAmount < backToOnePayQuote) {
                receiveBaseAmount = _RBelowSellQuoteToken(state, payQuoteAmount);
                newR = RState.BELOW_ONE;
                if (receiveBaseAmount > backToOneReceiveBase) {
                    receiveBaseAmount = backToOneReceiveBase;
                }
            } else if (payQuoteAmount == backToOnePayQuote) {
                receiveBaseAmount = backToOneReceiveBase;
                newR = RState.ONE;
            } else {
                receiveBaseAmount = backToOneReceiveBase.add(
                    _ROneSellQuoteToken(state, payQuoteAmount.sub(backToOnePayQuote))
                );
                newR = RState.ABOVE_ONE;
            }
        }
    }
    // ============ R = 1 cases ============
    function _ROneSellBaseToken(PMMState memory state, uint256 payBaseAmount)
        internal
        pure
        returns (
            uint256 // receiveQuoteToken
        )
    {
        // in theory Q2 <= targetQuoteTokenAmount
        // however when amount is close to 0, precision problems may cause Q2 > targetQuoteTokenAmount
        return
            DODOMath._SolveQuadraticFunctionForTrade(
                state.Q0,
                state.Q0,
                payBaseAmount,
                state.i,
                state.K
            );
    }
    function _ROneSellQuoteToken(PMMState memory state, uint256 payQuoteAmount)
        internal
        pure
        returns (
            uint256 // receiveBaseToken
        )
    {
        return
            DODOMath._SolveQuadraticFunctionForTrade(
                state.B0,
                state.B0,
                payQuoteAmount,
                DecimalMath.reciprocalFloor(state.i),
                state.K
            );
    }
    // ============ R < 1 cases ============
    function _RBelowSellQuoteToken(PMMState memory state, uint256 payQuoteAmount)
        internal
        pure
        returns (
            uint256 // receiveBaseToken
        )
    {
        return
            DODOMath._GeneralIntegrate(
                state.Q0,
                state.Q.add(payQuoteAmount),
                state.Q,
                DecimalMath.reciprocalFloor(state.i),
                state.K
            );
    }
    function _RBelowSellBaseToken(PMMState memory state, uint256 payBaseAmount)
        internal
        pure
        returns (
            uint256 // receiveQuoteToken
        )
    {
        return
            DODOMath._SolveQuadraticFunctionForTrade(
                state.Q0,
                state.Q,
                payBaseAmount,
                state.i,
                state.K
            );
    }
    // ============ R > 1 cases ============
    function _RAboveSellBaseToken(PMMState memory state, uint256 payBaseAmount)
        internal
        pure
        returns (
            uint256 // receiveQuoteToken
        )
    {
        return
            DODOMath._GeneralIntegrate(
                state.B0,
                state.B.add(payBaseAmount),
                state.B,
                state.i,
                state.K
            );
    }
    function _RAboveSellQuoteToken(PMMState memory state, uint256 payQuoteAmount)
        internal
        pure
        returns (
            uint256 // receiveBaseToken
        )
    {
        return
            DODOMath._SolveQuadraticFunctionForTrade(
                state.B0,
                state.B,
                payQuoteAmount,
                DecimalMath.reciprocalFloor(state.i),
                state.K
            );
    }
    // ============ Helper functions ============
    function adjustedTarget(PMMState memory state) internal pure {
        if (state.R == RState.BELOW_ONE) {
            state.Q0 = DODOMath._SolveQuadraticFunctionForTarget(
                state.Q,
                state.B.sub(state.B0),
                state.i,
                state.K
            );
        } else if (state.R == RState.ABOVE_ONE) {
            state.B0 = DODOMath._SolveQuadraticFunctionForTarget(
                state.B,
                state.Q.sub(state.Q0),
                DecimalMath.reciprocalFloor(state.i),
                state.K
            );
        }
    }
    function getMidPrice(PMMState memory state) internal pure returns (uint256) {
        if (state.R == RState.BELOW_ONE) {
            uint256 R = DecimalMath.divFloor(state.Q0.mul(state.Q0).div(state.Q), state.Q);
            R = DecimalMath.ONE.sub(state.K).add(DecimalMath.mulFloor(state.K, R));
            return DecimalMath.divFloor(state.i, R);
        } else {
            uint256 R = DecimalMath.divFloor(state.B0.mul(state.B0).div(state.B), state.B);
            R = DecimalMath.ONE.sub(state.K).add(DecimalMath.mulFloor(state.K, R));
            return DecimalMath.mulFloor(state.i, R);
        }
    }
}
// File: contracts/intf/IERC20.sol
// This is a file copied from https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/token/ERC20/IERC20.sol
/**
 * @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);
    function decimals() external view returns (uint8);
    function name() external view returns (string memory);
    function symbol() external view returns (string memory);
    /**
     * @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);
}
// File: contracts/lib/SafeERC20.sol
/**
 * @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 ERC20;` statement to your contract,
 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
 */
library SafeERC20 {
    using SafeMath for uint256;
    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)
        );
    }
    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));
    }
    /**
     * @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.
        // A Solidity high level call has three parts:
        //  1. The target address is checked to verify it contains contract code
        //  2. The call itself is made, and success asserted
        //  3. The return value is decoded, which in turn checks the size of the returned data.
        // solhint-disable-next-line max-line-length
        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = address(token).call(data);
        require(success, "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/lib/InitializableOwnable.sol
/**
 * @title Ownable
 * @author DODO Breeder
 *
 * @notice Ownership related functions
 */
contract InitializableOwnable {
    address public _OWNER_;
    address public _NEW_OWNER_;
    bool internal _INITIALIZED_;
    // ============ Events ============
    event OwnershipTransferPrepared(address indexed previousOwner, address indexed newOwner);
    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
    // ============ Modifiers ============
    modifier notInitialized() {
        require(!_INITIALIZED_, "DODO_INITIALIZED");
        _;
    }
    modifier onlyOwner() {
        require(msg.sender == _OWNER_, "NOT_OWNER");
        _;
    }
    // ============ Functions ============
    function initOwner(address newOwner) public notInitialized {
        _INITIALIZED_ = true;
        _OWNER_ = newOwner;
    }
    function transferOwnership(address newOwner) public onlyOwner {
        emit OwnershipTransferPrepared(_OWNER_, newOwner);
        _NEW_OWNER_ = newOwner;
    }
    function claimOwnership() public {
        require(msg.sender == _NEW_OWNER_, "INVALID_CLAIM");
        emit OwnershipTransferred(_OWNER_, _NEW_OWNER_);
        _OWNER_ = _NEW_OWNER_;
        _NEW_OWNER_ = address(0);
    }
}
// File: contracts/lib/FeeRateModel.sol
interface IFeeRateImpl {
    function getFeeRate(address pool, address trader) external view returns (uint256);
}
interface IFeeRateModel {
    function getFeeRate(address trader) external view returns (uint256);
}
contract FeeRateModel is InitializableOwnable {
    address public feeRateImpl;
    function setFeeProxy(address _feeRateImpl) public onlyOwner {
        feeRateImpl = _feeRateImpl;
    }
    
    function getFeeRate(address trader) external view returns (uint256) {
        if(feeRateImpl == address(0))
            return 0;
        return IFeeRateImpl(feeRateImpl).getFeeRate(msg.sender,trader);
    }
}
// File: contracts/DODOVendingMachine/impl/DVMStorage.sol
contract DVMStorage is ReentrancyGuard {
    using SafeMath for uint256;
    bool public _IS_OPEN_TWAP_ = false;
    bool internal _DVM_INITIALIZED_;
    // ============ Core Address ============
    address public _MAINTAINER_;
    IERC20 public _BASE_TOKEN_;
    IERC20 public _QUOTE_TOKEN_;
    uint112 public _BASE_RESERVE_;
    uint112 public _QUOTE_RESERVE_;
    uint32 public _BLOCK_TIMESTAMP_LAST_;
    uint256 public _BASE_PRICE_CUMULATIVE_LAST_;
    // ============ Shares (ERC20) ============
    string public symbol;
    uint8 public decimals;
    string public name;
    uint256 public totalSupply;
    mapping(address => uint256) internal _SHARES_;
    mapping(address => mapping(address => uint256)) internal _ALLOWED_;
    // ================= Permit ======================
    bytes32 public DOMAIN_SEPARATOR;
    // keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)");
    bytes32 public constant PERMIT_TYPEHASH = 0x6e71edae12b1b97f4d1f60370fef10105fa2faae0126114a169c64845d6126c9;
    mapping(address => uint256) public nonces;
    // ============ Variables for Pricing ============
    uint256 public _LP_FEE_RATE_;
    IFeeRateModel public _MT_FEE_RATE_MODEL_;
    uint256 public _K_;
    uint256 public _I_;
    // ============ Helper Functions ============
    function getPMMState() public view returns (PMMPricing.PMMState memory state) {
        state.i = _I_;
        state.K = _K_;
        state.B = _BASE_RESERVE_;
        state.Q = _QUOTE_RESERVE_;
        state.B0 = 0; // will be calculated in adjustedTarget
        state.Q0 = 0;
        state.R = PMMPricing.RState.ABOVE_ONE;
        PMMPricing.adjustedTarget(state);
    }
    function getPMMStateForCall() 
        external 
        view 
        returns (
            uint256 i,
            uint256 K,
            uint256 B,
            uint256 Q,
            uint256 B0,
            uint256 Q0,
            uint256 R
        )
    {
        PMMPricing.PMMState memory state = getPMMState();
        i = state.i;
        K = state.K;
        B = state.B;
        Q = state.Q;
        B0 = state.B0;
        Q0 = state.Q0;
        R = uint256(state.R);
    }
    function getMidPrice() public view returns (uint256 midPrice) {
        return PMMPricing.getMidPrice(getPMMState());
    }
}
// File: contracts/DODOVendingMachine/impl/DVMVault.sol
contract DVMVault is DVMStorage {
    using SafeMath for uint256;
    using SafeERC20 for IERC20;
    // ============ Events ============
    event Transfer(address indexed from, address indexed to, uint256 amount);
    event Approval(address indexed owner, address indexed spender, uint256 amount);
    event Mint(address indexed user, uint256 value);
    event Burn(address indexed user, uint256 value);
    // ============ View Functions ============
    function getVaultReserve() external view returns (uint256 baseReserve, uint256 quoteReserve) {
        baseReserve = _BASE_RESERVE_;
        quoteReserve = _QUOTE_RESERVE_;
    }
    function getUserFeeRate(address user) external view returns (uint256 lpFeeRate, uint256 mtFeeRate) {
        lpFeeRate = _LP_FEE_RATE_;
        mtFeeRate = _MT_FEE_RATE_MODEL_.getFeeRate(user);
    }
    // ============ Asset In ============
    function getBaseInput() public view returns (uint256 input) {
        return _BASE_TOKEN_.balanceOf(address(this)).sub(uint256(_BASE_RESERVE_));
    }
    function getQuoteInput() public view returns (uint256 input) {
        return _QUOTE_TOKEN_.balanceOf(address(this)).sub(uint256(_QUOTE_RESERVE_));
    }
    // ============ TWAP UPDATE ===========
    
    function _twapUpdate() internal {
        uint32 blockTimestamp = uint32(block.timestamp % 2**32);
        uint32 timeElapsed = blockTimestamp - _BLOCK_TIMESTAMP_LAST_;
        if (timeElapsed > 0 && _BASE_RESERVE_ != 0 && _QUOTE_RESERVE_ != 0) {
            _BASE_PRICE_CUMULATIVE_LAST_ += getMidPrice() * timeElapsed;
        }
        _BLOCK_TIMESTAMP_LAST_ = blockTimestamp;
    }
    // ============ Set States ============
    function _setReserve(uint256 baseReserve, uint256 quoteReserve) internal {
        require(baseReserve <= uint112(-1) && quoteReserve <= uint112(-1), "OVERFLOW");
        _BASE_RESERVE_ = uint112(baseReserve);
        _QUOTE_RESERVE_ = uint112(quoteReserve);
        if(_IS_OPEN_TWAP_) _twapUpdate();
    }
    function _sync() internal {
        uint256 baseBalance = _BASE_TOKEN_.balanceOf(address(this));
        uint256 quoteBalance = _QUOTE_TOKEN_.balanceOf(address(this));
        require(baseBalance <= uint112(-1) && quoteBalance <= uint112(-1), "OVERFLOW");
        if (baseBalance != _BASE_RESERVE_) {
            _BASE_RESERVE_ = uint112(baseBalance);
        }
        if (quoteBalance != _QUOTE_RESERVE_) {
            _QUOTE_RESERVE_ = uint112(quoteBalance);
        }
        if(_IS_OPEN_TWAP_) _twapUpdate();
    }
    function sync() external preventReentrant {
        _sync();
    }
    // ============ Asset Out ============
    function _transferBaseOut(address to, uint256 amount) internal {
        if (amount > 0) {
            _BASE_TOKEN_.safeTransfer(to, amount);
        }
    }
    function _transferQuoteOut(address to, uint256 amount) internal {
        if (amount > 0) {
            _QUOTE_TOKEN_.safeTransfer(to, amount);
        }
    }
    // ============ Shares (ERC20) ============
    /**
     * @dev transfer token for a specified address
     * @param to The address to transfer to.
     * @param amount The amount to be transferred.
     */
    function transfer(address to, uint256 amount) public returns (bool) {
        require(amount <= _SHARES_[msg.sender], "BALANCE_NOT_ENOUGH");
        _SHARES_[msg.sender] = _SHARES_[msg.sender].sub(amount);
        _SHARES_[to] = _SHARES_[to].add(amount);
        emit Transfer(msg.sender, to, amount);
        return true;
    }
    /**
     * @dev Gets the balance of the specified address.
     * @param owner The address to query the the balance of.
     * @return balance An uint256 representing the amount owned by the passed address.
     */
    function balanceOf(address owner) external view returns (uint256 balance) {
        return _SHARES_[owner];
    }
    /**
     * @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 amount uint256 the amount of tokens to be transferred
     */
    function transferFrom(
        address from,
        address to,
        uint256 amount
    ) public returns (bool) {
        require(amount <= _SHARES_[from], "BALANCE_NOT_ENOUGH");
        require(amount <= _ALLOWED_[from][msg.sender], "ALLOWANCE_NOT_ENOUGH");
        _SHARES_[from] = _SHARES_[from].sub(amount);
        _SHARES_[to] = _SHARES_[to].add(amount);
        _ALLOWED_[from][msg.sender] = _ALLOWED_[from][msg.sender].sub(amount);
        emit Transfer(from, to, amount);
        return true;
    }
    /**
     * @dev Approve the passed address to spend the specified amount of tokens on behalf of msg.sender.
     * @param spender The address which will spend the funds.
     * @param amount The amount of tokens to be spent.
     */
    function approve(address spender, uint256 amount) public returns (bool) {
        _approve(msg.sender, spender, amount);
        return true;
    }
    function _approve(
        address owner,
        address spender,
        uint256 amount
    ) private {
        _ALLOWED_[owner][spender] = amount;
        emit Approval(owner, spender, amount);
    }
    /**
     * @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];
    }
    function _mint(address user, uint256 value) internal {
        require(value > 1000, "MINT_INVALID");
        _SHARES_[user] = _SHARES_[user].add(value);
        totalSupply = totalSupply.add(value);
        emit Mint(user, value);
        emit Transfer(address(0), user, value);
    }
    function _burn(address user, uint256 value) internal {
        _SHARES_[user] = _SHARES_[user].sub(value);
        totalSupply = totalSupply.sub(value);
        emit Burn(user, value);
        emit Transfer(user, address(0), value);
    }
    // ============================ Permit ======================================
    
    function permit(
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external {
        require(deadline >= block.timestamp, "DODO_DVM_LP: 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,
            "DODO_DVM_LP: INVALID_SIGNATURE"
        );
        _approve(owner, spender, value);
    }
}
// File: contracts/DODOVendingMachine/impl/DVMFunding.sol
contract DVMFunding is DVMVault {
    // ============ Events ============
    event BuyShares(address to, uint256 increaseShares, uint256 totalShares);
    event SellShares(address payer, address to, uint256 decreaseShares, uint256 totalShares);
    // ============ Buy & Sell Shares ============
    // buy shares [round down]
    function buyShares(address to)
        external
        preventReentrant
        returns (
            uint256 shares,
            uint256 baseInput,
            uint256 quoteInput
        )
    {
        uint256 baseBalance = _BASE_TOKEN_.balanceOf(address(this));
        uint256 quoteBalance = _QUOTE_TOKEN_.balanceOf(address(this));
        uint256 baseReserve = _BASE_RESERVE_;
        uint256 quoteReserve = _QUOTE_RESERVE_;
        baseInput = baseBalance.sub(baseReserve);
        quoteInput = quoteBalance.sub(quoteReserve);
        require(baseInput > 0, "NO_BASE_INPUT");
        // Round down when withdrawing. Therefore, never be a situation occuring balance is 0 but totalsupply is not 0
        // But May Happen，reserve >0 But totalSupply = 0
        if (totalSupply == 0) {
            // case 1. initial supply
            shares = baseBalance; // 以免出现balance很大但shares很小的情况
            require(shares > 2001, "MINT_AMOUNT_NOT_ENOUGH");
            _mint(address(0), 1001);
            shares -= 1001;
        } else if (baseReserve > 0 && quoteReserve == 0) {
            // case 2. supply when quote reserve is 0
            shares = baseInput.mul(totalSupply).div(baseReserve);
        } else if (baseReserve > 0 && quoteReserve > 0) {
            // case 3. normal case
            uint256 baseInputRatio = DecimalMath.divFloor(baseInput, baseReserve);
            uint256 quoteInputRatio = DecimalMath.divFloor(quoteInput, quoteReserve);
            uint256 mintRatio = quoteInputRatio < baseInputRatio ? quoteInputRatio : baseInputRatio;
            shares = DecimalMath.mulFloor(totalSupply, mintRatio);
        }
        _mint(to, shares);
        _setReserve(baseBalance, quoteBalance);
        emit BuyShares(to, shares, _SHARES_[to]);
    }
    // sell shares [round down]
    function sellShares(
        uint256 shareAmount,
        address to,
        uint256 baseMinAmount,
        uint256 quoteMinAmount,
        bytes calldata data,
        uint256 deadline
    ) external preventReentrant returns (uint256 baseAmount, uint256 quoteAmount) {
        require(deadline >= block.timestamp, "TIME_EXPIRED");
        require(shareAmount <= _SHARES_[msg.sender], "DLP_NOT_ENOUGH");
        require(to != address(this), "SELL_BACK_NOT_ALLOWED");
        uint256 baseBalance = _BASE_TOKEN_.balanceOf(address(this));
        uint256 quoteBalance = _QUOTE_TOKEN_.balanceOf(address(this));
        uint256 totalShares = totalSupply;
        baseAmount = baseBalance.mul(shareAmount).div(totalShares);
        quoteAmount = quoteBalance.mul(shareAmount).div(totalShares);
        require(
            baseAmount >= baseMinAmount && quoteAmount >= quoteMinAmount,
            "WITHDRAW_NOT_ENOUGH"
        );
        _burn(msg.sender, shareAmount);
        _transferBaseOut(to, baseAmount);
        _transferQuoteOut(to, quoteAmount);
        _sync();
        if (data.length > 0) {
            IDODOCallee(to).DVMSellShareCall(
                msg.sender,
                shareAmount,
                baseAmount,
                quoteAmount,
                data
            );
        }
        emit SellShares(msg.sender, to, shareAmount, _SHARES_[msg.sender]);
    }
}
// File: contracts/DODOVendingMachine/impl/DVMTrader.sol
contract DVMTrader is DVMVault {
    using SafeMath for uint256;
    // ============ Events ============
    event DODOSwap(
        address fromToken,
        address toToken,
        uint256 fromAmount,
        uint256 toAmount,
        address trader,
        address receiver
    );
    event DODOFlashLoan(
        address borrower,
        address assetTo,
        uint256 baseAmount,
        uint256 quoteAmount
    );
    // ============ Trade Functions ============
    function sellBase(address to)
        external
        preventReentrant
        returns (uint256 receiveQuoteAmount)
    {
        uint256 baseBalance = _BASE_TOKEN_.balanceOf(address(this));
        uint256 baseInput = baseBalance.sub(uint256(_BASE_RESERVE_));
        uint256 mtFee;
        (receiveQuoteAmount, mtFee) = querySellBase(tx.origin, baseInput);
        _transferQuoteOut(to, receiveQuoteAmount);
        _transferQuoteOut(_MAINTAINER_, mtFee);
        _setReserve(baseBalance, _QUOTE_TOKEN_.balanceOf(address(this)));
        emit DODOSwap(
            address(_BASE_TOKEN_),
            address(_QUOTE_TOKEN_),
            baseInput,
            receiveQuoteAmount,
            msg.sender,
            to
        );
    }
    function sellQuote(address to)
        external
        preventReentrant
        returns (uint256 receiveBaseAmount)
    {
        uint256 quoteBalance = _QUOTE_TOKEN_.balanceOf(address(this));
        uint256 quoteInput = quoteBalance.sub(uint256(_QUOTE_RESERVE_));
        uint256 mtFee;
        (receiveBaseAmount, mtFee) = querySellQuote(tx.origin, quoteInput);
        _transferBaseOut(to, receiveBaseAmount);
        _transferBaseOut(_MAINTAINER_, mtFee);
        _setReserve(_BASE_TOKEN_.balanceOf(address(this)), quoteBalance);
        emit DODOSwap(
            address(_QUOTE_TOKEN_),
            address(_BASE_TOKEN_),
            quoteInput,
            receiveBaseAmount,
            msg.sender,
            to
        );
    }
    function flashLoan(
        uint256 baseAmount,
        uint256 quoteAmount,
        address assetTo,
        bytes calldata data
    ) external preventReentrant {
        _transferBaseOut(assetTo, baseAmount);
        _transferQuoteOut(assetTo, quoteAmount);
        if (data.length > 0)
            IDODOCallee(assetTo).DVMFlashLoanCall(msg.sender, baseAmount, quoteAmount, data);
        uint256 baseBalance = _BASE_TOKEN_.balanceOf(address(this));
        uint256 quoteBalance = _QUOTE_TOKEN_.balanceOf(address(this));
        
        // no input -> pure loss
        require(
            baseBalance >= _BASE_RESERVE_ || quoteBalance >= _QUOTE_RESERVE_,
            "FLASH_LOAN_FAILED"
        );
        // sell quote
        if (baseBalance < _BASE_RESERVE_) {
            uint256 quoteInput = quoteBalance.sub(uint256(_QUOTE_RESERVE_));
            (uint256 receiveBaseAmount, uint256 mtFee) = querySellQuote(tx.origin, quoteInput);
            require(uint256(_BASE_RESERVE_).sub(baseBalance) <= receiveBaseAmount, "FLASH_LOAN_FAILED");
            _transferBaseOut(_MAINTAINER_, mtFee);
            emit DODOSwap(
                address(_QUOTE_TOKEN_),
                address(_BASE_TOKEN_),
                quoteInput,
                receiveBaseAmount,
                msg.sender,
                assetTo
            );
        }
        // sell base
        if (quoteBalance < _QUOTE_RESERVE_) {
            uint256 baseInput = baseBalance.sub(uint256(_BASE_RESERVE_));
            (uint256 receiveQuoteAmount, uint256 mtFee) = querySellBase(tx.origin, baseInput);
            require(uint256(_QUOTE_RESERVE_).sub(quoteBalance) <= receiveQuoteAmount, "FLASH_LOAN_FAILED");
            _transferQuoteOut(_MAINTAINER_, mtFee);
            emit DODOSwap(
                address(_BASE_TOKEN_),
                address(_QUOTE_TOKEN_),
                baseInput,
                receiveQuoteAmount,
                msg.sender,
                assetTo
            );
        }
        _sync();
        
        emit DODOFlashLoan(msg.sender, assetTo, baseAmount, quoteAmount);
    }
    // ============ Query Functions ============
    function querySellBase(address trader, uint256 payBaseAmount)
        public
        view
        returns (uint256 receiveQuoteAmount, uint256 mtFee)
    {
        (receiveQuoteAmount, ) = PMMPricing.sellBaseToken(getPMMState(), payBaseAmount);
        uint256 lpFeeRate = _LP_FEE_RATE_;
        uint256 mtFeeRate = _MT_FEE_RATE_MODEL_.getFeeRate(trader);
        mtFee = DecimalMath.mulFloor(receiveQuoteAmount, mtFeeRate);
        receiveQuoteAmount = receiveQuoteAmount
            .sub(DecimalMath.mulFloor(receiveQuoteAmount, lpFeeRate))
            .sub(mtFee);
    }
    function querySellQuote(address trader, uint256 payQuoteAmount)
        public
        view
        returns (uint256 receiveBaseAmount, uint256 mtFee)
    {
        (receiveBaseAmount, ) = PMMPricing.sellQuoteToken(getPMMState(), payQuoteAmount);
        uint256 lpFeeRate = _LP_FEE_RATE_;
        uint256 mtFeeRate = _MT_FEE_RATE_MODEL_.getFeeRate(trader);
        mtFee = DecimalMath.mulFloor(receiveBaseAmount, mtFeeRate);
        receiveBaseAmount = receiveBaseAmount
            .sub(DecimalMath.mulFloor(receiveBaseAmount, lpFeeRate))
            .sub(mtFee);
    }
}
// File: contracts/DODOVendingMachine/impl/DVM.sol
/**
 * @title DODO VendingMachine
 * @author DODO Breeder
 *
 * @notice DODOVendingMachine initialization
 */
contract DVM is DVMTrader, DVMFunding {
    function init(
        address maintainer,
        address baseTokenAddress,
        address quoteTokenAddress,
        uint256 lpFeeRate,
        address mtFeeRateModel,
        uint256 i,
        uint256 k,
        bool isOpenTWAP
    ) external {
        require(!_DVM_INITIALIZED_, "DVM_INITIALIZED");
        _DVM_INITIALIZED_ = true;
        
        require(baseTokenAddress != quoteTokenAddress, "BASE_QUOTE_CAN_NOT_BE_SAME");
        _BASE_TOKEN_ = IERC20(baseTokenAddress);
        _QUOTE_TOKEN_ = IERC20(quoteTokenAddress);
        require(i > 0 && i <= 10**36);
        _I_ = i;
        require(k <= 10**18);
        _K_ = k;
        _LP_FEE_RATE_ = lpFeeRate;
        _MT_FEE_RATE_MODEL_ = IFeeRateModel(mtFeeRateModel);
        _MAINTAINER_ = maintainer;
        _IS_OPEN_TWAP_ = isOpenTWAP;
        if(isOpenTWAP) _BLOCK_TIMESTAMP_LAST_ = uint32(block.timestamp % 2**32);
        string memory connect = "_";
        string memory suffix = "DLP";
        name = string(abi.encodePacked(suffix, connect, addressToShortString(address(this))));
        symbol = "DLP";
        decimals = _BASE_TOKEN_.decimals();
        // ============================== Permit ====================================
        uint256 chainId;
        assembly {
            chainId := chainid()
        }
        DOMAIN_SEPARATOR = keccak256(
            abi.encode(
                // keccak256('EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)'),
                0x8b73c3c69bb8fe3d512ecc4cf759cc79239f7b179b0ffacaa9a75d522b39400f,
                keccak256(bytes(name)),
                keccak256(bytes("1")),
                chainId,
                address(this)
            )
        );
        // ==========================================================================
    }
    function addressToShortString(address _addr) public pure returns (string memory) {
        bytes32 value = bytes32(uint256(_addr));
        bytes memory alphabet = "0123456789abcdef";
        bytes memory str = new bytes(8);
        for (uint256 i = 0; i < 4; i++) {
            str[i * 2] = alphabet[uint8(value[i + 12] >> 4)];
            str[1 + i * 2] = alphabet[uint8(value[i + 12] & 0x0f)];
        }
        return string(str);
    }
    // ============ Version Control ============
    
    function version() external pure returns (string memory) {
        return "DVM 1.0.3";
    }
}

// File: contracts/lib/InitializableOwnable.sol

/*

    Copyright 2020 DODO ZOO.
    SPDX-License-Identifier: Apache-2.0

*/

pragma solidity 0.6.9;
pragma experimental ABIEncoderV2;

/**
 * @title Ownable
 * @author DODO Breeder
 *
 * @notice Ownership related functions
 */
contract InitializableOwnable {
    address public _OWNER_;
    address public _NEW_OWNER_;
    bool internal _INITIALIZED_;

    // ============ Events ============

    event OwnershipTransferPrepared(address indexed previousOwner, address indexed newOwner);

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

    // ============ Modifiers ============

    modifier notInitialized() {
        require(!_INITIALIZED_, "DODO_INITIALIZED");
        _;
    }

    modifier onlyOwner() {
        require(msg.sender == _OWNER_, "NOT_OWNER");
        _;
    }

    // ============ Functions ============

    function initOwner(address newOwner) public notInitialized {
        _INITIALIZED_ = true;
        _OWNER_ = newOwner;
    }

    function transferOwnership(address newOwner) public onlyOwner {
        emit OwnershipTransferPrepared(_OWNER_, newOwner);
        _NEW_OWNER_ = newOwner;
    }

    function claimOwnership() public {
        require(msg.sender == _NEW_OWNER_, "INVALID_CLAIM");
        emit OwnershipTransferred(_OWNER_, _NEW_OWNER_);
        _OWNER_ = _NEW_OWNER_;
        _NEW_OWNER_ = address(0);
    }
}

// File: contracts/lib/FeeRateModel.sol


interface IFeeRateImpl {
    function getFeeRate(address pool, address trader) external view returns (uint256);
}

interface IFeeRateModel {
    function getFeeRate(address trader) external view returns (uint256);
}

contract FeeRateModel is InitializableOwnable {
    address public feeRateImpl;

    function setFeeProxy(address _feeRateImpl) public onlyOwner {
        feeRateImpl = _feeRateImpl;
    }
    
    function getFeeRate(address trader) external view returns (uint256) {
        if(feeRateImpl == address(0))
            return 0;
        return IFeeRateImpl(feeRateImpl).getFeeRate(msg.sender,trader);
    }
}

// File: contracts/lib/InitializableOwnable.sol

/*

    Copyright 2020 DODO ZOO.
    SPDX-License-Identifier: Apache-2.0

*/

pragma solidity 0.6.9;
pragma experimental ABIEncoderV2;

/**
 * @title Ownable
 * @author DODO Breeder
 *
 * @notice Ownership related functions
 */
contract InitializableOwnable {
    address public _OWNER_;
    address public _NEW_OWNER_;
    bool internal _INITIALIZED_;

    // ============ Events ============

    event OwnershipTransferPrepared(address indexed previousOwner, address indexed newOwner);

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

    // ============ Modifiers ============

    modifier notInitialized() {
        require(!_INITIALIZED_, "DODO_INITIALIZED");
        _;
    }

    modifier onlyOwner() {
        require(msg.sender == _OWNER_, "NOT_OWNER");
        _;
    }

    // ============ Functions ============

    function initOwner(address newOwner) public notInitialized {
        _INITIALIZED_ = true;
        _OWNER_ = newOwner;
    }

    function transferOwnership(address newOwner) public onlyOwner {
        emit OwnershipTransferPrepared(_OWNER_, newOwner);
        _NEW_OWNER_ = newOwner;
    }

    function claimOwnership() public {
        require(msg.sender == _NEW_OWNER_, "INVALID_CLAIM");
        emit OwnershipTransferred(_OWNER_, _NEW_OWNER_);
        _OWNER_ = _NEW_OWNER_;
        _NEW_OWNER_ = address(0);
    }
}

// File: contracts/intf/IERC20.sol


/**
 * @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);

    function decimals() external view returns (uint8);

    function name() external view returns (string memory);

    function symbol() external view returns (string memory);

    /**
     * @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);
}

// File: contracts/lib/SafeMath.sol



/**
 * @title SafeMath
 * @author DODO Breeder
 *
 * @notice Math operations with safety checks that revert on error
 */
library SafeMath {
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        if (a == 0) {
            return 0;
        }

        uint256 c = a * b;
        require(c / a == b, "MUL_ERROR");

        return c;
    }

    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b > 0, "DIVIDING_ERROR");
        return a / b;
    }

    function divCeil(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 quotient = div(a, b);
        uint256 remainder = a - quotient * b;
        if (remainder > 0) {
            return quotient + 1;
        } else {
            return quotient;
        }
    }

    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b <= a, "SUB_ERROR");
        return a - b;
    }

    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "ADD_ERROR");
        return c;
    }

    function sqrt(uint256 x) internal pure returns (uint256 y) {
        uint256 z = x / 2 + 1;
        y = x;
        while (z < y) {
            y = z;
            z = (x / z + z) / 2;
        }
    }
}

// File: contracts/DODOFee/FeeRateDIP3Impl.sol


interface ICrowdPooling {
    function _QUOTE_RESERVE_() external view returns (uint256);
    function getShares(address user) external view returns (uint256);
}

interface IFee {
    function getUserFee(address user) external view returns (uint256);
}

interface IQuota {
    function getUserQuota(address user) external view returns (int);
}

interface IPool {
    function version() external pure returns (string memory);
    function _LP_FEE_RATE_() external view returns (uint256);
    function _BASE_RESERVE_() external view returns (uint);
    function _QUOTE_RESERVE_() external view returns (uint);
    function _K_() external view returns (uint);
}

contract FeeRateDIP3Impl is InitializableOwnable {
    using SafeMath for uint256;

    // ============ Storage  ============

    uint256 public _LP_MT_RATIO_ = 25;

    struct CPPoolInfo {
        address quoteToken;
        int globalQuota;
        address feeAddr;
        address quotaAddr;
    }

    mapping(address => CPPoolInfo) cpPools;
    mapping(address => uint256) public specPoolList;


    // ============ Ownable Functions ============
    
    function addCpPoolInfo(address cpPool, address quoteToken, int globalQuota, address feeAddr, address quotaAddr) external onlyOwner {
        CPPoolInfo memory cpPoolInfo =  CPPoolInfo({
            quoteToken: quoteToken,
            feeAddr: feeAddr,
            quotaAddr: quotaAddr,
            globalQuota: globalQuota
        });
        cpPools[cpPool] = cpPoolInfo;
    }

    function setCpPoolInfo(address cpPool, address quoteToken, int globalQuota, address feeAddr, address quotaAddr) external onlyOwner {
        cpPools[cpPool].quoteToken = quoteToken;
        cpPools[cpPool].feeAddr = feeAddr;
        cpPools[cpPool].quotaAddr = quotaAddr;
        cpPools[cpPool].globalQuota = globalQuota;
    }

    function setLpMtRatio(uint256 newLpMtRatio) external onlyOwner {
        _LP_MT_RATIO_ = newLpMtRatio;
    }


    function setSpecPoolList (address poolAddr, uint256 mtFeeRate) public onlyOwner {
        specPoolList[poolAddr] = mtFeeRate;
    }

    // ============ View Functions ============

    function getFeeRate(address pool, address user) external view returns (uint256) {
        try IPool(pool).version() returns (string memory poolVersion) {
            bytes32 hashPoolVersion = keccak256(abi.encodePacked(poolVersion));
            if(_kjudge(hashPoolVersion)) {
                uint k = IPool(pool)._K_();
                uint baseReserve = IPool(pool)._BASE_RESERVE_();
                uint quoteReserve = IPool(pool)._QUOTE_RESERVE_();
                require(!(k==0 && (baseReserve ==0 || quoteReserve == 0)), "KJUDGE_ERROR");
            }

            if(specPoolList[pool] != 0) {
                return specPoolList[pool];
            }

            if(_cp(hashPoolVersion)) {
                CPPoolInfo memory cpPoolInfo = cpPools[pool];
                address quoteToken = cpPoolInfo.quoteToken;
                if(quoteToken == address(0)) {
                    return 0;
                }else {
                    uint256 userInput = IERC20(quoteToken).balanceOf(pool).sub(ICrowdPooling(pool)._QUOTE_RESERVE_());
                    uint256 userStake = ICrowdPooling(pool).getShares(user);
                    address feeAddr = cpPoolInfo.feeAddr;
                    address quotaAddr = cpPoolInfo.quotaAddr;
                    int curQuota = cpPoolInfo.globalQuota;
                    if(quotaAddr != address(0))
                        curQuota = IQuota(quotaAddr).getUserQuota(user);

                    require(curQuota == -1 || (curQuota != -1 && int(userInput.add(userStake)) <= curQuota), "DODOFeeImpl: EXCEED_YOUR_QUOTA");

                    if(feeAddr == address(0)) {
                        return 0;
                    } else {
                        return IFee(feeAddr).getUserFee(user);
                    }
                }
            } else if(_dip3dvm(hashPoolVersion) || _dip3dsp(hashPoolVersion)) {
                uint256 lpFeeRate = IPool(pool)._LP_FEE_RATE_();
                uint256 mtFeeRate = lpFeeRate.mul(_LP_MT_RATIO_).div(100);
                if(lpFeeRate.add(mtFeeRate) >= 10**18) {
                    return 0;
                } else {
                    return mtFeeRate;
                }
            } else {
                return 0;
            }
        } catch (bytes memory) {
            return 0;
        }
    }

    function getCPInfoByUser(address pool, address user) external view returns (bool isHaveCap, int curQuota, uint256 userFee) {
        CPPoolInfo memory cpPoolInfo = cpPools[pool];
        if(cpPoolInfo.quoteToken == address(0)) {
            isHaveCap = false;
            curQuota = -1;
            userFee = 0;
        }else {
            address quotaAddr = cpPoolInfo.quotaAddr;
            curQuota = cpPoolInfo.globalQuota;
            if(quotaAddr != address(0))
                curQuota = IQuota(quotaAddr).getUserQuota(user);
        
            if(curQuota == -1) {
                isHaveCap = false;
            }else {
                isHaveCap = true;
                uint256 userStake = ICrowdPooling(pool).getShares(user);
                curQuota = int(uint256(curQuota).sub(userStake));
            }

            address feeAddr = cpPoolInfo.feeAddr;
            if(feeAddr == address(0)) {
                userFee =  0;
            } else {
                userFee = IFee(feeAddr).getUserFee(user);
            }
        }
    }

    function _cp(bytes32 _hashPoolVersion) internal pure returns (bool) {
        return (_hashPoolVersion == keccak256(abi.encodePacked("CP 1.0.0")) || _hashPoolVersion == keccak256(abi.encodePacked("CP 2.0.0")));
    }

    function _dip3dvm(bytes32 _hashPoolVersion) internal pure returns (bool){
        return (_hashPoolVersion == keccak256(abi.encodePacked("DVM 1.0.2")) || _hashPoolVersion == keccak256(abi.encodePacked("DVM 1.0.3")));
    }

    function _dip3dsp(bytes32 _hashPoolVersion) internal pure returns (bool){
        return (_hashPoolVersion == keccak256(abi.encodePacked("DSP 1.0.1")) || _hashPoolVersion == keccak256(abi.encodePacked("DSP 1.0.2")));
    }

    function _kjudge(bytes32 _hashPoolVersion) internal pure returns (bool) {
        return (_hashPoolVersion == keccak256(abi.encodePacked("DVM 1.0.2")) || _hashPoolVersion == keccak256(abi.encodePacked("DSP 1.0.1")) || _hashPoolVersion == keccak256(abi.encodePacked("DPP 1.0.0")));
    }
}