// 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 0.5.12;
pragma experimental ABIEncoderV2;


contract PoolInterface {
    function swapExactAmountIn(address, uint, address, uint, uint) external returns (uint, uint);
    function swapExactAmountOut(address, uint, address, uint, uint) external returns (uint, uint);
}

contract TokenInterface {
    function balanceOf(address) public returns (uint);
    function allowance(address, address) public returns (uint);
    function approve(address, uint) public returns (bool);
    function transfer(address, uint) public returns (bool);
    function transferFrom(address, address, uint) public returns (bool);
    function deposit() public payable;
    function withdraw(uint) public;
}

contract ExchangeProxy {

    struct Swap {
        address pool;
        uint    tokenInParam; // tokenInAmount / maxAmountIn / limitAmountIn
        uint    tokenOutParam; // minAmountOut / tokenAmountOut / limitAmountOut
        uint    maxPrice;
    }

    event LOG_CALL(
        bytes4  indexed sig,
        address indexed caller,
        bytes           data
    ) anonymous;

    modifier _logs_() {
        emit LOG_CALL(msg.sig, msg.sender, msg.data);
        _;
    }

    modifier _lock_() {
        require(!_mutex, "ERR_REENTRY");
        _mutex = true;
        _;
        _mutex = false;
    }

    bool private _mutex;
    TokenInterface weth;

    constructor(address _weth) public {
        weth = TokenInterface(_weth);
    }

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

    function batchSwapExactIn(
        Swap[] memory swaps,
        address tokenIn,
        address tokenOut,
        uint totalAmountIn,
        uint minTotalAmountOut
    )   
        public
        _logs_
        _lock_
        returns (uint totalAmountOut)
    {
        TokenInterface TI = TokenInterface(tokenIn);
        TokenInterface TO = TokenInterface(tokenOut);
        require(TI.transferFrom(msg.sender, address(this), totalAmountIn), "ERR_TRANSFER_FAILED");
        for (uint i = 0; i < swaps.length; i++) {
            Swap memory swap = swaps[i];
            
            PoolInterface pool = PoolInterface(swap.pool);
            if (TI.allowance(address(this), swap.pool) < totalAmountIn) {
                TI.approve(swap.pool, uint(-1));
            }
            (uint tokenAmountOut,) = pool.swapExactAmountIn(
                                        tokenIn,
                                        swap.tokenInParam,
                                        tokenOut,
                                        swap.tokenOutParam,
                                        swap.maxPrice
                                    );
            totalAmountOut = add(tokenAmountOut, totalAmountOut);
        }
        require(totalAmountOut >= minTotalAmountOut, "ERR_LIMIT_OUT");
        require(TO.transfer(msg.sender, TO.balanceOf(address(this))), "ERR_TRANSFER_FAILED");
        require(TI.transfer(msg.sender, TI.balanceOf(address(this))), "ERR_TRANSFER_FAILED");
        return totalAmountOut;
    }

    function batchSwapExactOut(
        Swap[] memory swaps,
        address tokenIn,
        address tokenOut,
        uint maxTotalAmountIn
    )
        public
        _logs_
        _lock_
        returns (uint totalAmountIn)
    {
        TokenInterface TI = TokenInterface(tokenIn);
        TokenInterface TO = TokenInterface(tokenOut);
        require(TI.transferFrom(msg.sender, address(this), maxTotalAmountIn), "ERR_TRANSFER_FAILED");
        for (uint i = 0; i < swaps.length; i++) {
            Swap memory swap = swaps[i];
            PoolInterface pool = PoolInterface(swap.pool);
            if (TI.allowance(address(this), swap.pool) < maxTotalAmountIn) {
                TI.approve(swap.pool, uint(-1));
            }
            (uint tokenAmountIn,) = pool.swapExactAmountOut(
                                        tokenIn,
                                        swap.tokenInParam,
                                        tokenOut,
                                        swap.tokenOutParam,
                                        swap.maxPrice
                                    );
            totalAmountIn = add(tokenAmountIn, totalAmountIn);
        }
        require(totalAmountIn <= maxTotalAmountIn, "ERR_LIMIT_IN");
        require(TO.transfer(msg.sender, TO.balanceOf(address(this))), "ERR_TRANSFER_FAILED");
        require(TI.transfer(msg.sender, TI.balanceOf(address(this))), "ERR_TRANSFER_FAILED");
        return totalAmountIn;
    }

    function batchEthInSwapExactIn(
        Swap[] memory swaps,
        address tokenOut,
        uint minTotalAmountOut
    )
        public payable
        _logs_
        _lock_
        returns (uint totalAmountOut)
    {
        TokenInterface TO = TokenInterface(tokenOut);
        weth.deposit.value(msg.value)();
        for (uint i = 0; i < swaps.length; i++) {
            Swap memory swap = swaps[i];
            PoolInterface pool = PoolInterface(swap.pool);
            if (weth.allowance(address(this), swap.pool) < msg.value) {
                weth.approve(swap.pool, uint(-1));
            }
            (uint tokenAmountOut,) = pool.swapExactAmountIn(
                                        address(weth),
                                        swap.tokenInParam,
                                        tokenOut,
                                        swap.tokenOutParam,
                                        swap.maxPrice
                                    );
            totalAmountOut = add(tokenAmountOut, totalAmountOut);
        }
        require(totalAmountOut >= minTotalAmountOut, "ERR_LIMIT_OUT");
        require(TO.transfer(msg.sender, TO.balanceOf(address(this))), "ERR_TRANSFER_FAILED");
        uint wethBalance = weth.balanceOf(address(this));
        if (wethBalance > 0) {
            weth.withdraw(wethBalance);
            (bool xfer,) = msg.sender.call.value(wethBalance)("");
            require(xfer, "ERR_ETH_FAILED");
        }
        return totalAmountOut;
    }

    function batchEthOutSwapExactIn(
        Swap[] memory swaps,
        address tokenIn,
        uint totalAmountIn,
        uint minTotalAmountOut
    )
        public
        _logs_
        _lock_
        returns (uint totalAmountOut)
    {
        TokenInterface TI = TokenInterface(tokenIn);
        require(TI.transferFrom(msg.sender, address(this), totalAmountIn), "ERR_TRANSFER_FAILED");
        for (uint i = 0; i < swaps.length; i++) {
            Swap memory swap = swaps[i];
            PoolInterface pool = PoolInterface(swap.pool);
            if (TI.allowance(address(this), swap.pool) < totalAmountIn) {
                TI.approve(swap.pool, uint(-1));
            }
            (uint tokenAmountOut,) = pool.swapExactAmountIn(
                                        tokenIn,
                                        swap.tokenInParam,
                                        address(weth),
                                        swap.tokenOutParam,
                                        swap.maxPrice
                                    );

            totalAmountOut = add(tokenAmountOut, totalAmountOut);
        }
        require(totalAmountOut >= minTotalAmountOut, "ERR_LIMIT_OUT");
        uint wethBalance = weth.balanceOf(address(this));
        weth.withdraw(wethBalance);
        (bool xfer,) = msg.sender.call.value(wethBalance)("");
        require(xfer, "ERR_ETH_FAILED");
        require(TI.transfer(msg.sender, TI.balanceOf(address(this))), "ERR_TRANSFER_FAILED");
        return totalAmountOut;
    }

    function batchEthInSwapExactOut(
        Swap[] memory swaps,
        address tokenOut
    )
        public payable
        _logs_
        _lock_
        returns (uint totalAmountIn)
    {
        TokenInterface TO = TokenInterface(tokenOut);
        weth.deposit.value(msg.value)();
        for (uint i = 0; i < swaps.length; i++) {
            Swap memory swap = swaps[i];
            PoolInterface pool = PoolInterface(swap.pool);
            if (weth.allowance(address(this), swap.pool) < msg.value) {
                weth.approve(swap.pool, uint(-1));
            }
            (uint tokenAmountIn,) = pool.swapExactAmountOut(
                                        address(weth),
                                        swap.tokenInParam,
                                        tokenOut,
                                        swap.tokenOutParam,
                                        swap.maxPrice
                                    );

            totalAmountIn = add(tokenAmountIn, totalAmountIn);
        }
        require(TO.transfer(msg.sender, TO.balanceOf(address(this))), "ERR_TRANSFER_FAILED");
        uint wethBalance = weth.balanceOf(address(this));
        if (wethBalance > 0) {
            weth.withdraw(wethBalance);
            (bool xfer,) = msg.sender.call.value(wethBalance)("");
            require(xfer, "ERR_ETH_FAILED");
        }
        return totalAmountIn;
    }

    function batchEthOutSwapExactOut(
        Swap[] memory swaps,
        address tokenIn,
        uint maxTotalAmountIn
    )
        public
        _logs_
        _lock_
        returns (uint totalAmountIn)
    {
        TokenInterface TI = TokenInterface(tokenIn);
        require(TI.transferFrom(msg.sender, address(this), maxTotalAmountIn), "ERR_TRANSFER_FAILED");
        for (uint i = 0; i < swaps.length; i++) {
            Swap memory swap = swaps[i];
            PoolInterface pool = PoolInterface(swap.pool);
            if (TI.allowance(address(this), swap.pool) < maxTotalAmountIn) {
                TI.approve(swap.pool, uint(-1));
            }
            (uint tokenAmountIn,) = pool.swapExactAmountOut(
                                        tokenIn,
                                        swap.tokenInParam,
                                        address(weth),
                                        swap.tokenOutParam,
                                        swap.maxPrice
                                    );

            totalAmountIn = add(tokenAmountIn, totalAmountIn);
        }
        require(totalAmountIn <= maxTotalAmountIn, "ERR_LIMIT_IN");
        require(TI.transfer(msg.sender, TI.balanceOf(address(this))), "ERR_TRANSFER_FAILED");
        uint wethBalance = weth.balanceOf(address(this));
        weth.withdraw(wethBalance);
        (bool xfer,) = msg.sender.call.value(wethBalance)("");
        require(xfer, "ERR_ETH_FAILED");
        return totalAmountIn;
    }

    function() external payable {}
}

pragma solidity ^0.5.16;

interface IERC20 {
    function totalSupply() external view returns (uint);
    function balanceOf(address account) external view returns (uint);
    function transfer(address recipient, uint amount) external returns (bool);
    function allowance(address owner, address spender) external view returns (uint);
    function approve(address spender, uint amount) external returns (bool);
    function transferFrom(address sender, address recipient, uint amount) external returns (bool);
    event Transfer(address indexed from, address indexed to, uint value);
    event Approval(address indexed owner, address indexed spender, uint value);
}

contract Context {
    constructor () internal { }
    // solhint-disable-previous-line no-empty-blocks

    function _msgSender() internal view returns (address payable) {
        return msg.sender;
    }
}

contract ERC20 is Context, IERC20 {
    using SafeMath for uint;

    mapping (address => uint) private _balances;

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

    uint private _totalSupply;
    function totalSupply() public view returns (uint) {
        return _totalSupply;
    }
    function balanceOf(address account) public view returns (uint) {
        return _balances[account];
    }
    function transfer(address recipient, uint amount) public returns (bool) {
        _transfer(_msgSender(), recipient, amount);
        return true;
    }
    function allowance(address owner, address spender) public view returns (uint) {
        return _allowances[owner][spender];
    }
    function approve(address spender, uint amount) public returns (bool) {
        _approve(_msgSender(), spender, amount);
        return true;
    }
    function transferFrom(address sender, address recipient, uint amount) public returns (bool) {
        _transfer(sender, recipient, amount);
        _approve(sender, _msgSender(), _allowances[sender][_msgSender()].sub(amount, "ERC20: transfer amount exceeds allowance"));
        return true;
    }
    function increaseAllowance(address spender, uint addedValue) public returns (bool) {
        _approve(_msgSender(), spender, _allowances[_msgSender()][spender].add(addedValue));
        return true;
    }
    function decreaseAllowance(address spender, uint subtractedValue) public returns (bool) {
        _approve(_msgSender(), spender, _allowances[_msgSender()][spender].sub(subtractedValue, "ERC20: decreased allowance below zero"));
        return true;
    }
    function _transfer(address sender, address recipient, uint amount) internal {
        require(sender != address(0), "ERC20: transfer from the zero address");
        require(recipient != address(0), "ERC20: transfer to the zero address");

        _balances[sender] = _balances[sender].sub(amount, "ERC20: transfer amount exceeds balance");
        _balances[recipient] = _balances[recipient].add(amount);
        emit Transfer(sender, recipient, amount);
    }
    function _mint(address account, uint amount) internal {
        require(account != address(0), "ERC20: mint to the zero address");

        _totalSupply = _totalSupply.add(amount);
        _balances[account] = _balances[account].add(amount);
        emit Transfer(address(0), account, amount);
    }
    function _burn(address account, uint amount) internal {
        require(account != address(0), "ERC20: burn from the zero address");

        _balances[account] = _balances[account].sub(amount, "ERC20: burn amount exceeds balance");
        _totalSupply = _totalSupply.sub(amount);
        emit Transfer(account, address(0), amount);
    }
    function _approve(address owner, address spender, uint amount) internal {
        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);
    }
}

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;
    }
    function name() public view returns (string memory) {
        return _name;
    }
    function symbol() public view returns (string memory) {
        return _symbol;
    }
    function decimals() public view returns (uint8) {
        return _decimals;
    }
}

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

        return c;
    }
    function sub(uint a, uint b) internal pure returns (uint) {
        return sub(a, b, "SafeMath: subtraction overflow");
    }
    function sub(uint a, uint b, string memory errorMessage) internal pure returns (uint) {
        require(b <= a, errorMessage);
        uint c = a - b;

        return c;
    }
    function mul(uint a, uint b) internal pure returns (uint) {
        if (a == 0) {
            return 0;
        }

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

        return c;
    }
    function div(uint a, uint b) internal pure returns (uint) {
        return div(a, b, "SafeMath: division by zero");
    }
    function div(uint a, uint b, string memory errorMessage) internal pure returns (uint) {
        // Solidity only automatically asserts when dividing by 0
        require(b > 0, errorMessage);
        uint c = a / b;

        return c;
    }
}

library Address {
    function isContract(address account) internal view returns (bool) {
        bytes32 codehash;
        bytes32 accountHash = 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470;
        // solhint-disable-next-line no-inline-assembly
        assembly { codehash := extcodehash(account) }
        return (codehash != 0x0 && codehash != accountHash);
    }
}

library SafeERC20 {
    using SafeMath for uint;
    using Address for address;

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

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

    function safeApprove(IERC20 token, address spender, uint value) internal {
        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 callOptionalReturn(IERC20 token, bytes memory data) private {
        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");
        }
    }
}

contract YFII is ERC20, ERC20Detailed {
  using SafeERC20 for IERC20;
  using Address for address;
  using SafeMath for uint;
  
  
  address public governance;
  mapping (address => bool) public minters;

  constructor () public ERC20Detailed("YFII.finance", "YFII", 18) {
      governance = tx.origin;
  }

  function mint(address account, uint256 amount) public {
      require(minters[msg.sender], "!minter");
      _mint(account, amount);
  }
  
  function setGovernance(address _governance) public {
      require(msg.sender == governance, "!governance");
      governance = _governance;
  }
  
  function addMinter(address _minter) public {
      require(msg.sender == governance, "!governance");
      minters[_minter] = true;
  }
  
  function removeMinter(address _minter) public {
      require(msg.sender == governance, "!governance");
      minters[_minter] = false;
  }
}