// Contract: CompoundSaverFlashLoan
// Target function: function drawCollateral(uint _cdpId, bytes32 _ilk, address _joinAddr, uint _amount) internal returns (uint)
(y == 0 || (z = x * y) / y == x);
    }
    function div(uint x, uint y) internal pure returns (uint z) {
        return x / y;
    }

    function min(uint x, uint y) internal pure returns (uint z) {
        return x <= y ? x : y;
    }
    function max(uint x, uint y) internal pure returns (uint z) {
        return x >= y ? x : y;
    }
    function imin(int x, int y) internal pure returns (int z) {
        return x <= y ? x : y;
    }
    function imax(int x, int y) internal pure returns (int z) {
        return x >= y ? x : y;
    }

    uint constant WAD = 10 ** 18;
    uint constant RAY = 10 ** 27;

    function wmul(uint x, uint y) internal pure returns (uint z) {
        z = add(mul(x, y), WAD / 2) / WAD;
    }
    function rmul(uint x, uint y) internal pure returns (uint z) {
        z = add(mul(x, y), RAY / 2) / RAY;
    }
    function wdiv(uint x, uint y) internal pure returns (uint z) {
        z = add(mul(x, WAD), y / 2) / y;
    }
    function rdiv(uint x, uint y) internal pure returns (uint z) {
        z = add(mul(x, RAY), y / 2) / y;
    }

    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    function rpow(uint x, uint n) internal pure returns (uint z) {
        z = n % 2 != 0 ? x : RAY;

        for (n /= 2; n != 0; n /= 2) {
            x = rmul(x, x);

            if (n % 2 != 0) {
                z = rmul(z, x);
            }
        }
    }
}

contract DSAuthority {
    function canCall(
        address src, address dst, bytes4 sig
    ) public view returns (bool);
}

contract DSAuthEvents {
    event LogSetAuthority (address indexed authority);
    event LogSetOwner     (address indexed owner);
}

contract DSAuth is DSAuthEvents {
    DSAuthority  public  authority;
    address      public  owner;

    constructor() public {
        owner = msg.sender;
        emit LogSetOwner(msg.sender);
    }

    function setOwner(address owner_)
        public
        auth
    {
        owner = owner_;
        emit LogSetOwner(owner);
    }

    function setAuthority(DSAuthority authority_)
        public
        auth
    {
        authority = authority_;
        emit LogSetAuthority(address(authority));
    }

    modifier auth {
        require(isAuthorized(msg.sender, msg.sig));
        _;
    }

    function isAuthorized(address src, bytes4 sig) internal view returns (bool) {
        if (src == address(this)) {
            return true;
        } else if (src == owner) {
            return true;
        } else if (authority == DSAuthority(0)) {
            return false;
        } else {
            return authority.canCall(src, address(this), sig);
        }
    }
}

contract DSNote {
    event LogNote(
        bytes4   indexed  sig,
        address  indexed  guy,
        bytes32  indexed  foo,
        bytes32  indexed  bar,
        uint              wad,
        bytes             fax
    ) anonymous;

    modifier note {
        bytes32 foo;
        bytes32 bar;

        assembly {
            foo := calldataload(4)
            bar := calldataload(36)
        }

        emit LogNote(msg.sig, msg.sender, foo, bar, msg.value, msg.data);

        _;
    }
}

contract DSProxy is DSAuth, DSNote {
    DSProxyCache public cache;  

    constructor(address _cacheAddr) public {
        require(setCache(_cacheAddr));
    }

    function() external payable {
    }

    
    function execute(bytes memory _code, bytes memory _data)
        public
        payable
        returns (address target, bytes32 response)
    {
        target = cache.read(_code);
        if (target == address(0)) {
            
            target = cache.write(_code);
        }

        response = execute(target, _data);
    }

    function execute(address _target, bytes memory _data)
        public
        auth
        note
        payable
        returns (bytes32 response)
    {
        require(_target != address(0));

        
        assembly {
            let succeeded := delegatecall(sub(gas, 5000), _target, add(_data, 0x20), mload(_data), 0, 32)
            response := mload(0)      
            switch iszero(succeeded)
            case 1 {
                
                revert(0, 0)
            }
        }
    }

    
    function setCache(address _cacheAddr)
        public
        payable
        auth
        note
        returns (bool)
    {
        require(_cacheAddr != address(0));        
        cache = DSProxyCache(_cacheAddr);  
        return true;
    }
}

contract DSProxyCache {
    mapping(bytes32 => address) cache;

    function read(bytes memory _code) public view returns (address) {
        bytes32 hash = keccak256(_code);
        return cache[hash];
    }

    function write(bytes memory _code) public returns (address target) {
        assembly {
            target := create(0, add(_code, 0x20), mload(_code))
            switch iszero(extcodesize(target))
            case 1 {
                
                revert(0, 0)
            }
        }
        bytes32 hash = keccak256(_code);
        cache[hash] = target;
    }
}

contract Manager {
    function last(address) public returns (uint);
    function cdpCan(address, uint, address) public view returns (uint);
    function ilks(uint) public view returns (bytes32);
    function owns(uint) public view returns (address);
    function urns(uint) public view returns (address);
    function vat() public view returns (address);
    function open(bytes32, address) public returns (uint);
    function give(uint, address) public;
    function cdpAllow(uint, address, uint) public;
    function urnAllow(address, uint) public;
    function frob(uint, int, int) public;
    function flux(uint, address, uint) public;
    function move(uint, address, uint) public;
    function exit(address, uint, address, uint) public;
    function quit(uint, address) public;
    function enter(address, uint) public;
    function shift(uint, uint) public;
}

contract Join {
    bytes32 public ilk;

    function dec() public returns (uint);
    function gem() public returns (Gem);
    function join(address, uint) public payable;
    function exit(address, uint) public;
}

contract DSProxyInterface {

    /// Truffle wont compile if this isn't commented
    // function execute(bytes memory _code, bytes memory _data)
    //     public
    //     payable
    //     returns (address, bytes32);

    function execute(address _target, bytes memory _data) public payable returns (bytes32);

    function setCache(address _cacheAddr) public payable returns (bool);

    function owner() public returns (address);
}

contract SaverProxyHelper is DSMath {

    
    
    
    
    function normalizeDrawAmount(uint _amount, uint _rate, uint _daiVatBalance) internal pure returns (int dart) {
        if (_daiVatBalance < mul(_amount, RAY)) {
            dart = toPositiveInt(sub(mul(_amount, RAY), _daiVatBalance) / _rate);
            dart = mul(uint(dart), _rate) < mul(_amount, RAY) ? dart + 1 : dart;
        }
    }

    
    
    function toRad(uint _wad) internal pure returns (uint) {
        return mul(_wad, 10 ** 27);
    }

    
    
    
    function convertTo18(address _joinAddr, uint256 _amount) internal returns (uint256) {
        return mul(_amount, 10 ** (18 - Join(_joinAddr).dec()));
    }

    
    
    function toPositiveInt(uint _x) internal pure returns (int y) {
        y = int(_x);
        require(y >= 0, "int-overflow");
    }

    
    
    
    
    function normalizePaybackAmount(address _vat, address _urn, bytes32 _ilk) internal view returns (int amount) {
        uint dai = Vat(_vat).dai(_urn);

        (, uint rate,,,) = Vat(_vat).ilks(_ilk);
        (, uint art) = Vat(_vat).urns(_ilk, _urn);

        amount = toPositiveInt(dai / rate);
        amount = uint(amount) <= art ? - amount : - toPositiveInt(art);
    }

    
    
    
    
    
    function getAllDebt(address _vat, address _usr, address _urn, bytes32 _ilk) internal view returns (uint daiAmount) {
        (, uint rate,,,) = Vat(_vat).ilks(_ilk);
        (, uint art) = Vat(_vat).urns(_ilk, _urn);
        uint dai = Vat(_vat).dai(_usr);

        uint rad = sub(mul(art, rate), dai);
        daiAmount = rad / RAY;

        daiAmount = mul(daiAmount, RAY) < rad ? daiAmount + 1 : daiAmount;
    }

    
    
    function getCollateralAddr(address _joinAddr) internal returns (address) {
        return address(Join(_joinAddr).gem());
    }

    
    
    
    
    function getCdpInfo(Manager _manager, uint _cdpId, bytes32 _ilk) public view returns (uint, uint) {
        address vat = _manager.vat();
        address urn = _manager.urns(_cdpId);

        (uint collateral, uint debt) = Vat(vat).urns(_ilk, urn);
        (,uint rate,,,) = Vat(vat).ilks(_ilk);

        return (collateral, rmul(debt, rate));
    }

    
    
    
    function getOwner(Manager _manager, uint _cdpId) public view returns (address) {
        DSProxy proxy = DSProxy(uint160(_manager.owns(_cdpId)));

        return proxy.owner();
    }
}

/// @title Implements Boost and Repay for MCD CDPs
contract MCDSaverProxy is SaverProxyHelper, ExchangeHelper {

    uint public constant SERVICE_FEE = 400; // 0.25% Fee
    bytes32 public constant ETH_ILK = 0x4554482d41000000000000000000000000000000000000000000000000000000;

    Manager public constant manager = Manager(MANAGER_ADDRESS);
    Vat public constant vat = Vat(VAT_ADDRESS);
    DaiJoin public constant daiJoin = DaiJoin(DAI_JOIN_ADDRESS);
    Spotter public constant spotter = Spotter(SPOTTER_ADDRESS);

    /// @notice Checks if the collateral amount is increased after boost
    /// @param _cdpId The Id of the CDP
    modifier boostCheck(uint _cdpId) {
        bytes32 ilk = manager.ilks(_cdpId);
        address urn = manager.urns(_cdpId);

        (uint collateralBefore, ) = vat.urns(ilk, urn);

        _;

        (uint collateralAfter, ) = vat.urns(ilk, urn);

        require(collateralAfter > collateralBefore);
    }

    /// @notice Checks if ratio is increased after repay
    /// @param _cdpId The Id of the CDP
    modifier repayCheck(uint _cdpId) {
        bytes32 ilk = manager.ilks(_cdpId);

        uint beforeRatio = getRatio(_cdpId, ilk);

        _;

        uint afterRatio = getRatio(_cdpId, ilk);

        require(afterRatio > beforeRatio || afterRatio == 0);
    }

    /// @notice Repay - draws collateral, converts to Dai and repays the debt
    /// @dev Must be called by the DSProxy contract that owns the CDP
    /// @param _data Uint array [cdpId, amount, minPrice, exchangeType, gasCost, 0xPrice]
    /// @param _joinAddr Address of the join contract for the CDP collateral
    /// @param _exchangeAddress Address of 0x exchange that should be called
    /// @param _callData data to call 0x exchange with
    function repay(
        // cdpId, amount, minPrice, exchangeType, gasCost, 0xPrice
        uint[6] memory _data,
        address _joinAddr,
        address _exchangeAddress,
        bytes memory _callData
    ) public payable repayCheck(_data[0]) {

        address owner = getOwner(manager, _data[0]);
        bytes32 ilk = manager.ilks(_data[0]);

        // uint collDrawn;
        // uint daiAmount;
        // uint daiAfterFee;
        uint[3] memory temp;

        temp[0] = drawCollateral(_data[0], ilk, _joinAddr, _data[1]);

                                // collDrawn, minPrice, exchangeType, 0xPrice
        uint[4] memory swapData = [temp[0], _data[2], _data[3], _data[5]];
        temp[1] = swap(swapData, getCollateralAddr(_joinAddr), DAI_ADDRESS, _exchangeAddress, _callData);
        temp[2] = sub(temp[1], getFee(temp[1], _data[4], owner));

        paybackDebt(_data[0], ilk, temp[2], owner);

        // if there is some eth left (0x fee), return it to user
        if (address(this).balance > 0) {
            tx.origin.transfer(address(this).balance);
        }

        SaverLogger(LOGGER_ADDRESS).LogRepay(_data[0], owner, temp[0], temp[1]);
    }

    /// @notice Boost - draws Dai, converts to collateral and adds to CDP
    /// @dev Must be called by the DSProxy contract that owns the CDP
    /// @param _data Uint array [cdpId, daiAmount, minPrice, exchangeType, gasCost, 0xPrice]
    /// @param _joinAddr Address of the join contract for the CDP collateral
    /// @param _exchangeAddress Address of 0x exchange that should be called
    /// @param _callData data to call 0x exchange with
    function boost(
        // cdpId, daiAmount, minPrice, exchangeType, gasCost, 0xPrice
        uint[6] memory _data,
        address _joinAddr,
        address _exchangeAddress,
        bytes memory _callData
    ) public payable boostCheck(_data[0]) {
        address owner = getOwner(manager, _data[0]);
        bytes32 ilk = manager.ilks(_data[0]);

        // uint daiDrawn;
        // uint daiAfterFee;
        // uint collateralAmount;
        uint[3] memory temp;

        temp[0] = drawDai(_data[0], ilk, _data[1]);
        temp[1] = sub(temp[0], getFee(temp[0], _data[4], owner));
                                // daiAfterFee, minPrice, exchangeType, 0xPrice
        uint[4] memory swapData = [temp[1], _data[2], _data[3], _data[5]];
        temp[2] = swap(swapData, DAI_ADDRESS, getCollateralAddr(_joinAddr), _exchangeAddress, _callData);

        addCollateral(_data[0], _joinAddr, temp[2]);

        // if there is some eth left (0x fee), return it to user
        if (address(this).balance > 0) {
            tx.origin.transfer(address(this).balance);
        }

        SaverLogger(LOGGER_ADDRESS).LogBoost(_data[0], owner, temp[0], temp[2]);
    }

    /// @notice Draws Dai from the CDP
    /// @dev If _daiAmount is bigger than max available we'll draw max
    /// @param _cdpId Id of the CDP
    /// @param _ilk Ilk of the CDP
    /// @param _daiAmount Amount of Dai to draw
    function drawDai(uint _cdpId, bytes32 _ilk, uint _daiAmount) internal returns (uint) {
        uint rate = Jug(JUG_ADDRESS).drip(_ilk);
        uint daiVatBalance = vat.dai(manager.urns(_cdpId));

        uint maxAmount = getMaxDebt(_cdpId, _ilk);

        if (_daiAmount >= maxAmount) {
            _daiAmount = sub(maxAmount, 1);
        }

        manager.frob(_cdpId, int(0), normalizeDrawAmount(_daiAmount, rate, daiVatBalance));
        manager.move(_cdpId, address(this), toRad(_daiAmount));

        if (vat.can(address(this), address(DAI_JOIN_ADDRESS)) == 0) {
            vat.hope(DAI_JOIN_ADDRESS);
        }

        DaiJoin(DAI_JOIN_ADDRESS).exit(address(this), _daiAmount);

        return _daiAmount;
    }

    /// @notice Adds collateral to the CDP
    /// @param _cdpId Id of the CDP
    /// @param _joinAddr Address of the join contract for the CDP collateral
    /// @param _amount Amount of collateral to add
    function addCollateral(uint _cdpId, address _joinAddr, uint _amount) internal {
        int convertAmount = 0;

        if (_joinAddr == ETH_JOIN_ADDRESS) {
            Join(_joinAddr).gem().deposit.value(_amount)();
            convertAmount = toPositiveInt(_amount);
        } else {
            convertAmount = toPositiveInt(convertTo18(_joinAddr, _amount));
        }

        Join(_joinAddr).gem().approve(_joinAddr, _amount);
        Join(_joinAddr).join(address(this), _amount);

        vat.frob(
            manager.ilks(_cdpId),
            manager.urns(_cdpId),
            address(this),
            address(this),
            convertAmount,
            0
        );

    }