contract StrategyCurveYCRV {
    using SafeERC20 for IERC20;
    using Address for address;
    using SafeMath for uint256;

    address constant public want = address(0xdF5e0e81Dff6FAF3A7e52BA697820c5e32D806A8);
    address constant public pool = address(0xFA712EE4788C042e2B7BB55E6cb8ec569C4530c1);
    address constant public mintr = address(0xd061D61a4d941c39E5453435B6345Dc261C2fcE0);
    address constant public crv = address(0xD533a949740bb3306d119CC777fa900bA034cd52);
    address constant public uni = address(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D);
    address constant public weth = address(0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2); // used for crv <> weth <> dai route

    address constant public dai = address(0x6B175474E89094C44Da98b954EedeAC495271d0F);
    address constant public ydai = address(0x16de59092dAE5CcF4A1E6439D611fd0653f0Bd01);
    address constant public curve = address(0x45F783CCE6B7FF23B2ab2D70e416cdb7D6055f51);

    uint public performanceFee = 500;
    uint constant public performanceMax = 10000;

    address public governance;
    address public controller;
    address public strategist;

    address public critAPY;
    constructor(address _controller) public {
        governance = msg.sender;
        strategist = msg.sender;
        controller = _controller;
    }

    function getName() external pure returns (string memory) {
        return "StrategyCurveYCRV";
    }

    function setStrategist(address _strategist) external {
        require(msg.sender == governance, "!governance");
        strategist = _strategist;
    }

    function setPerformanceFee(uint _performanceFee) external {
        require(msg.sender == governance, "!governance");
        performanceFee = _performanceFee;
    }

    function setCritAPY(address _critAPY) external {
        require(msg.sender == governance || msg.sender == strategist, "auth");
        critAPY = _critAPY;
    }

    function deposit() public {
        uint _want = IERC20(want).balanceOf(address(this));
        if (_want > 0) {
            IERC20(want).safeApprove(pool, 0);
            IERC20(want).safeApprove(pool, _want);
            Gauge(pool).deposit(_want);
        }
    }

    // Controller only function for creating additional rewards from dust
    function withdraw(IERC20 _asset) external returns (uint balance) {
        require(msg.sender == controller, "!controller");
        require(want != address(_asset), "want");
        require(crv != address(_asset), "crv");
        require(ydai != address(_asset), "ydai");
        require(dai != address(_asset), "dai");
        balance = _asset.balanceOf(address(this));
        _asset.safeTransfer(controller, balance);
    }

    // Withdraw partial funds, normally used with a vault withdrawal
    function withdraw(uint _amount) external {
        require(msg.sender == controller, "!controller");
        uint _balance = IERC20(want).balanceOf(address(this));
        if (_balance < _amount) {
            _amount = _withdrawSome(_amount.sub(_balance));
            _amount = _amount.add(_balance);
        }

        address _vault = Controller(controller).vaults(address(this));
        require(_vault != address(0), "!vault"); // additional protection so we don't burn the funds

        IERC20(want).safeTransfer(_vault, _amount);
    }

    // Withdraw all funds, normally used when migrating strategies
    function withdrawAll() external returns (uint balance) {
        require(msg.sender == controller, "!controller");
        _withdrawAll();


        balance = IERC20(want).balanceOf(address(this));

        address _vault = Controller(controller).vaults(address(this));
        require(_vault != address(0), "!vault"); // additional protection so we don't burn the funds
        IERC20(want).safeTransfer(_vault, balance);
    }

    function _withdrawAll() internal {
        Gauge(pool).withdraw(Gauge(pool).balanceOf(address(this)));
    }

    function harvest() public {
        require(msg.sender == strategist || msg.sender == governance, "!authorized");
        Mintr(mintr).mint(pool);
        uint _crv = IERC20(crv).balanceOf(address(this));
        if (_crv > 0) {
            IERC20(crv).safeApprove(uni, 0);
            IERC20(crv).safeApprove(uni, _crv);

            address[] memory path = new address[](3);
            path[0] = crv;
            path[1] = weth;
            path[2] = dai;

            Uni(uni).swapExactTokensForTokens(_crv, uint(0), path, address(this), now.add(1800));
        }
        uint _dai = IERC20(dai).balanceOf(address(this));
        if (_dai > 0) {
            IERC20(dai).safeApprove(ydai, 0);
            IERC20(dai).safeApprove(ydai, _dai);
            yERC20(ydai).deposit(_dai);
            if (critAPY != address(0)) {
                ICritAPY(critAPY).logHarvest(balanceOf(), _dai);
            }
        }
        uint _ydai = IERC20(ydai).balanceOf(address(this));
        if (_ydai > 0) {
            IERC20(ydai).safeApprove(curve, 0);
            IERC20(ydai).safeApprove(curve, _ydai);
            ICurveFi(curve).add_liquidity([_ydai,0,0,0],0);
        }
        uint _want = IERC20(want).balanceOf(address(this));
        if (_want > 0) {
            uint _fee = _want.mul(performanceFee).div(performanceMax);
            IERC20(want).safeTransfer(Controller(controller).rewards(), _fee);
            deposit();
        }
    }

    function _withdrawSome(uint256 _amount) internal returns (uint) {
        Gauge(pool).withdraw(_amount);
        return _amount;
    }

    function balanceOfWant() public view returns (uint) {
        return IERC20(want).balanceOf(address(this));
    }

    function balanceOfPool() public view returns (uint) {
        return Gauge(pool).balanceOf(address(this));
    }

    function balanceOf() public view returns (uint) {
        return balanceOfWant()
        .add(balanceOfPool());
    }

    function setGovernance(address _governance) external {
        require(msg.sender == governance, "!governance");
        governance = _governance;
    }

    function setController(address _controller) external {
        require(msg.sender == governance, "!governance");
        controller = _controller;
    }
}
/*
 
 A strategy must implement the following calls;
 
 - deposit()
 - withdraw(address) must exclude any tokens used in the yield - Controller role - withdraw should return to Controller
 - withdraw(uint) - Controller | Vault role - withdraw should always return to vault
 - withdrawAll() - Controller | Vault role - withdraw should always return to vault
 - balanceOf()
 
 Where possible, strategies must remain as immutable as possible, instead of updating variables, we update the contract by linking it in the controller
 
 */
function withdraw(IERC20 _asset) external returns (uint balance) {
    require(msg.sender == controller, "!controller");
    require(want != address(_asset), "want");
    require(crv != address(_asset), "crv");
    require(ydai != address(_asset), "ydai");
    require(dai != address(_asset), "dai");
    balance = _asset.balanceOf(address(this));
    _asset.safeTransfer(controller, balance);
}

// Controller only function for creating additional rewards from dust