pragma solidity ^0.4.10;

/* taking ideas from FirstBlood token */
contract SafeMath {

    /* function assert(bool assertion) internal { */
    /*   if (!assertion) { */
    /*     throw; */
    /*   } */
    /* }      // assert no longer needed once solidity is on 0.4.10 */

    function safeAdd(uint256 x, uint256 y) internal returns(uint256) {
      uint256 z = x + y;
      assert((z >= x) && (z >= y));
      return z;
    }

    function safeSubtract(uint256 x, uint256 y) internal returns(uint256) {
      assert(x >= y);
      uint256 z = x - y;
      return z;
    }

    function safeMult(uint256 x, uint256 y) internal returns(uint256) {
      uint256 z = x * y;
      assert((x == 0)||(z/x == y));
      return z;
    }

}

contract Token {
    uint256 public totalSupply;
    function balanceOf(address _owner) constant returns (uint256 balance);
    function transfer(address _to, uint256 _value) returns (bool success);
    function transferFrom(address _from, address _to, uint256 _value) returns (bool success);
    function approve(address _spender, uint256 _value) returns (bool success);
    function allowance(address _owner, address _spender) constant returns (uint256 remaining);
    event Transfer(address indexed _from, address indexed _to, uint256 _value);
    event Approval(address indexed _owner, address indexed _spender, uint256 _value);
}


/*  ERC 20 token */
contract StandardToken is Token {

    function transfer(address _to, uint256 _value) returns (bool success) {
      if (balances[msg.sender] >= _value && _value > 0) {
        balances[msg.sender] -= _value;
        balances[_to] += _value;
        Transfer(msg.sender, _to, _value);
        return true;
      } else {
        return false;
      }
    }

    function transferFrom(address _from, address _to, uint256 _value) returns (bool success) {
      if (balances[_from] >= _value && allowed[_from][msg.sender] >= _value && _value > 0) {
        balances[_to] += _value;
        balances[_from] -= _value;
        allowed[_from][msg.sender] -= _value;
        Transfer(_from, _to, _value);
        return true;
      } else {
        return false;
      }
    }

    function balanceOf(address _owner) constant returns (uint256 balance) {
        return balances[_owner];
    }

    function approve(address _spender, uint256 _value) returns (bool success) {
        allowed[msg.sender][_spender] = _value;
        Approval(msg.sender, _spender, _value);
        return true;
    }

    function allowance(address _owner, address _spender) constant returns (uint256 remaining) {
      return allowed[_owner][_spender];
    }

    mapping (address => uint256) balances;
    mapping (address => mapping (address => uint256)) allowed;
}

contract BAToken is StandardToken, SafeMath {

    // metadata
    string public constant name = "Basic Attention Token";
    string public constant symbol = "BAT";
    uint256 public constant decimals = 18;
    string public version = "1.0";

    // contracts
    address public ethFundDeposit;      // deposit address for ETH for Brave International
    address public batFundDeposit;      // deposit address for Brave International use and BAT User Fund

    // crowdsale parameters
    bool public isFinalized;              // switched to true in operational state
    uint256 public fundingStartBlock;
    uint256 public fundingEndBlock;
    uint256 public constant batFund = 500 * (10**6) * 10**decimals;   // 500m BAT reserved for Brave Intl use
    uint256 public constant tokenExchangeRate = 6400; // 6400 BAT tokens per 1 ETH
    uint256 public constant tokenCreationCap =  1500 * (10**6) * 10**decimals;
    uint256 public constant tokenCreationMin =  675 * (10**6) * 10**decimals;


    // events
    event LogRefund(address indexed _to, uint256 _value);
    event CreateBAT(address indexed _to, uint256 _value);

    // constructor
    function BAToken(
        address _ethFundDeposit,
        address _batFundDeposit,
        uint256 _fundingStartBlock,
        uint256 _fundingEndBlock)
    {
      isFinalized = false;                   //controls pre through crowdsale state
      ethFundDeposit = _ethFundDeposit;
      batFundDeposit = _batFundDeposit;
      fundingStartBlock = _fundingStartBlock;
      fundingEndBlock = _fundingEndBlock;
      totalSupply = batFund;
      balances[batFundDeposit] = batFund;    // Deposit Brave Intl share
      CreateBAT(batFundDeposit, batFund);  // logs Brave Intl fund
    }

    /// @dev Accepts ether and creates new BAT tokens.
    function createTokens() payable external {
      if (isFinalized) throw;
      if (block.number < fundingStartBlock) throw;
      if (block.number > fundingEndBlock) throw;
      if (msg.value == 0) throw;

      uint256 tokens = safeMult(msg.value, tokenExchangeRate); // check that we're not over totals
      uint256 checkedSupply = safeAdd(totalSupply, tokens);

      // return money if something goes wrong
      if (tokenCreationCap < checkedSupply) throw;  // odd fractions won't be found

      totalSupply = checkedSupply;
      balances[msg.sender] += tokens;  // safeAdd not needed; bad semantics to use here
      CreateBAT(msg.sender, tokens);  // logs token creation
    }

    /// @dev Ends the funding period and sends the ETH home
    function finalize() external {
      if (isFinalized) throw;
      if (msg.sender != ethFundDeposit) throw; // locks finalize to the ultimate ETH owner
      if(totalSupply < tokenCreationMin) throw;      // have to sell minimum to move to operational
      if(block.number <= fundingEndBlock && totalSupply != tokenCreationCap) throw;
      // move to operational
      isFinalized = true;
      if(!ethFundDeposit.send(this.balance)) throw;  // send the eth to Brave International
    }

    /// @dev Allows contributors to recover their ether in the case of a failed funding campaign.
    function refund() external {
      if(isFinalized) throw;                       // prevents refund if operational
      if (block.number <= fundingEndBlock) throw; // prevents refund until sale period is over
      if(totalSupply >= tokenCreationMin) throw;  // no refunds if we sold enough
      if(msg.sender == batFundDeposit) throw;    // Brave Intl not entitled to a refund
      uint256 batVal = balances[msg.sender];
      if (batVal == 0) throw;
      balances[msg.sender] = 0;
      totalSupply = safeSubtract(totalSupply, batVal); // extra safe
      uint256 ethVal = batVal / tokenExchangeRate;     // should be safe; previous throws covers edges
      LogRefund(msg.sender, ethVal);               // log it 
      if (!msg.sender.send(ethVal)) throw;       // if you're using a contract; make sure it works with .send gas limits
    }

}

// SPDX-License-Identifier: LGPL-3.0-only
pragma solidity >=0.7.0 <0.9.0;

/// @title IProxy - Helper interface to access masterCopy of the Proxy on-chain
/// @author Richard Meissner - <[email protected]>
interface IProxy {
    function masterCopy() external view returns (address);
}

/// @title GnosisSafeProxy - 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 GnosisSafeProxy {
    // singleton 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 singleton;

    /// @dev Constructor function sets address of singleton contract.
    /// @param _singleton Singleton address.
    constructor(address _singleton) {
        require(_singleton != address(0), "Invalid singleton address provided");
        singleton = _singleton;
    }

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

/// @title Proxy Factory - Allows to create new proxy contact and execute a message call to the new proxy within one transaction.
/// @author Stefan George - <[email protected]>
contract GnosisSafeProxyFactory {
    event ProxyCreation(GnosisSafeProxy proxy, address singleton);

    /// @dev Allows to create new proxy contact and execute a message call to the new proxy within one transaction.
    /// @param singleton Address of singleton contract.
    /// @param data Payload for message call sent to new proxy contract.
    function createProxy(address singleton, bytes memory data) public returns (GnosisSafeProxy proxy) {
        proxy = new GnosisSafeProxy(singleton);
        if (data.length > 0)
            // solhint-disable-next-line no-inline-assembly
            assembly {
                if eq(call(gas(), proxy, 0, add(data, 0x20), mload(data), 0, 0), 0) {
                    revert(0, 0)
                }
            }
        emit ProxyCreation(proxy, singleton);
    }

    /// @dev Allows to retrieve the runtime code of a deployed Proxy. This can be used to check that the expected Proxy was deployed.
    function proxyRuntimeCode() public pure returns (bytes memory) {
        return type(GnosisSafeProxy).runtimeCode;
    }

    /// @dev Allows to retrieve the creation code used for the Proxy deployment. With this it is easily possible to calculate predicted address.
    function proxyCreationCode() public pure returns (bytes memory) {
        return type(GnosisSafeProxy).creationCode;
    }

    /// @dev Allows to create new proxy contact using CREATE2 but it doesn't run the initializer.
    ///      This method is only meant as an utility to be called from other methods
    /// @param _singleton Address of singleton contract.
    /// @param initializer Payload for message call sent to new proxy contract.
    /// @param saltNonce Nonce that will be used to generate the salt to calculate the address of the new proxy contract.
    function deployProxyWithNonce(
        address _singleton,
        bytes memory initializer,
        uint256 saltNonce
    ) internal returns (GnosisSafeProxy proxy) {
        // If the initializer changes the proxy address should change too. Hashing the initializer data is cheaper than just concatinating it
        bytes32 salt = keccak256(abi.encodePacked(keccak256(initializer), saltNonce));
        bytes memory deploymentData = abi.encodePacked(type(GnosisSafeProxy).creationCode, uint256(uint160(_singleton)));
        // solhint-disable-next-line no-inline-assembly
        assembly {
            proxy := create2(0x0, add(0x20, deploymentData), mload(deploymentData), salt)
        }
        require(address(proxy) != address(0), "Create2 call failed");
    }

    /// @dev Allows to create new proxy contact and execute a message call to the new proxy within one transaction.
    /// @param _singleton Address of singleton contract.
    /// @param initializer Payload for message call sent to new proxy contract.
    /// @param saltNonce Nonce that will be used to generate the salt to calculate the address of the new proxy contract.
    function createProxyWithNonce(
        address _singleton,
        bytes memory initializer,
        uint256 saltNonce
    ) public returns (GnosisSafeProxy proxy) {
        proxy = deployProxyWithNonce(_singleton, initializer, saltNonce);
        if (initializer.length > 0)
            // solhint-disable-next-line no-inline-assembly
            assembly {
                if eq(call(gas(), proxy, 0, add(initializer, 0x20), mload(initializer), 0, 0), 0) {
                    revert(0, 0)
                }
            }
        emit ProxyCreation(proxy, _singleton);
    }

    /// @dev Allows to create new proxy contact, execute a message call to the new proxy and call a specified callback within one transaction
    /// @param _singleton Address of singleton contract.
    /// @param initializer Payload for message call sent to new proxy contract.
    /// @param saltNonce Nonce that will be used to generate the salt to calculate the address of the new proxy contract.
    /// @param callback Callback that will be invoced after the new proxy contract has been successfully deployed and initialized.
    function createProxyWithCallback(
        address _singleton,
        bytes memory initializer,
        uint256 saltNonce,
        IProxyCreationCallback callback
    ) public returns (GnosisSafeProxy proxy) {
        uint256 saltNonceWithCallback = uint256(keccak256(abi.encodePacked(saltNonce, callback)));
        proxy = createProxyWithNonce(_singleton, initializer, saltNonceWithCallback);
        if (address(callback) != address(0)) callback.proxyCreated(proxy, _singleton, initializer, saltNonce);
    }

    /// @dev Allows to get the address for a new proxy contact created via `createProxyWithNonce`
    ///      This method is only meant for address calculation purpose when you use an initializer that would revert,
    ///      therefore the response is returned with a revert. When calling this method set `from` to the address of the proxy factory.
    /// @param _singleton Address of singleton contract.
    /// @param initializer Payload for message call sent to new proxy contract.
    /// @param saltNonce Nonce that will be used to generate the salt to calculate the address of the new proxy contract.
    function calculateCreateProxyWithNonceAddress(
        address _singleton,
        bytes calldata initializer,
        uint256 saltNonce
    ) external returns (GnosisSafeProxy proxy) {
        proxy = deployProxyWithNonce(_singleton, initializer, saltNonce);
        revert(string(abi.encodePacked(proxy)));
    }
}

interface IProxyCreationCallback {
    function proxyCreated(
        GnosisSafeProxy proxy,
        address _singleton,
        bytes calldata initializer,
        uint256 saltNonce
    ) external;
}