pragma solidity ^0.5.7;

interface ERC20Interface {
    function allowance(address, address) external view returns (uint);
    function balanceOf(address) external view returns (uint);
    function approve(address, uint) external;
    function transfer(address, uint) external returns (bool);
    function transferFrom(address, address, uint) external returns (bool);
    function deposit() external payable;
    function withdraw(uint) external;
}

interface TubInterface {
    function open() external returns (bytes32);
    function join(uint) external;
    function exit(uint) external;
    function lock(bytes32, uint) external;
    function free(bytes32, uint) external;
    function draw(bytes32, uint) external;
    function wipe(bytes32, uint) external;
    function give(bytes32, address) external;
    function shut(bytes32) external;
    function cups(bytes32) external view returns (address, uint, uint, uint);
    function gem() external view returns (ERC20Interface);
    function gov() external view returns (ERC20Interface);
    function skr() external view returns (ERC20Interface);
    function sai() external view returns (ERC20Interface);
    function ink(bytes32) external view returns (uint);
    function tab(bytes32) external returns (uint);
    function rap(bytes32) external returns (uint);
    function per() external view returns (uint);
    function pep() external view returns (PepInterface);
}

interface PepInterface {
    function peek() external returns (bytes32, bool);
}

interface ComptrollerInterface {
    function enterMarkets(address[] calldata cTokens) external returns (uint[] memory);
    function exitMarket(address cTokenAddress) external returns (uint);
    function getAssetsIn(address account) external view returns (address[] memory);
    function getAccountLiquidity(address account) external view returns (uint, uint, uint);
}

interface CTokenInterface {
    function borrow(uint borrowAmount) external returns (uint);
    function exchangeRateCurrent() external returns (uint);

    function transfer(address, uint) external returns (bool);
    function transferFrom(address, address, uint) external returns (bool);
}

interface BridgeInterface {
    function makerToCompound(uint, uint, uint) external returns (uint);
    function compoundToMaker(uint, uint, uint) external;
}



contract DSMath {

    function add(uint x, uint y) internal pure returns (uint z) {
        require((z = x + y) >= x, "math-not-safe");
    }

    function mul(uint x, uint y) internal pure returns (uint z) {
        require(y == 0 || (z = x * y) / y == x, "math-not-safe");
    }

    uint constant WAD = 10 ** 18;
    uint constant RAY = 10 ** 27;

    function rmul(uint x, uint y) internal pure returns (uint z) {
        z = add(mul(x, y), RAY / 2) / RAY;
    }

    function rdiv(uint x, uint y) internal pure returns (uint z) {
        z = add(mul(x, RAY), y / 2) / y;
    }

    function wmul(uint x, uint y) internal pure returns (uint z) {
        z = add(mul(x, y), WAD / 2) / WAD;
    }

    function wdiv(uint x, uint y) internal pure returns (uint z) {
        z = add(mul(x, WAD), y / 2) / y;
    }

}


contract Helper is DSMath {

    /**
     * @dev get MakerDAO CDP engine
     */
    function getSaiTubAddress() public pure returns (address sai) {
        sai = 0x448a5065aeBB8E423F0896E6c5D525C040f59af3;
    }

    /**
     * @dev get Compound Comptroller Address
     */
    function getComptrollerAddress() public pure returns (address troller) {
        troller = 0x3d9819210A31b4961b30EF54bE2aeD79B9c9Cd3B;
    }

    /**
     * @dev get Compound Comptroller Address
     */
    function getDAIAddress() public pure returns (address dai) {
        dai = 0x89d24A6b4CcB1B6fAA2625fE562bDD9a23260359;
    }

    /**
     * @dev get Compound Comptroller Address
     */
    function getCDAIAddress() public pure returns (address cDai) {
        cDai = 0xF5DCe57282A584D2746FaF1593d3121Fcac444dC;
    }

    /**
     * @dev get Compound Comptroller Address
     */
    function getBridgeAddress() public pure returns (address bridge) {
        bridge = ;// <BRIDGE ADDRESS>
    }

    /**
     * @dev setting allowance to compound for the "user proxy" if required
     */
    function setApproval(address erc20, uint srcAmt, address to) internal {
        ERC20Interface erc20Contract = ERC20Interface(erc20);
        uint tokenAllowance = erc20Contract.allowance(address(this), to);
        if (srcAmt > tokenAllowance) {
            erc20Contract.approve(to, 2**255);
        }
    }

}


contract MakerHelper is Helper {

    /**
     * @dev transfer CDP ownership
     */
    function give(uint cdpNum, address nextOwner) internal {
        TubInterface(getSaiTubAddress()).give(bytes32(cdpNum), nextOwner);
    }

}


contract CompoundHelper is MakerHelper {

    function enterMarket(address cErc20) internal {
        ComptrollerInterface troller = ComptrollerInterface(getComptrollerAddress());
        address[] memory markets = troller.getAssetsIn(address(this));
        bool isEntered = false;
        for (uint i = 0; i < markets.length; i++) {
            if (markets[i] == cErc20) {
                isEntered = true;
            }
        }
        if (!isEntered) {
            address[] memory toEnter = new address[](1);
            toEnter[0] = cErc20;
            troller.enterMarkets(toEnter);
        }
    }

    /**
     * @dev borrow ETH/ERC20
     */
    function borrowDAI(uint tokenAmt) internal {
        enterMarket(getCETHAddress());
        enterMarket(getCDAIAddress());
        require(CTokenInterface(getCDAIAddress()).borrow(tokenAmt) == 0, "got collateral?");
    }

}


contract InstaBridge is CompoundHelper {

    function makerToCompound(uint cdpId, uint ethCol, uint daiDebt) public {
        give(cdpId, getBridgeAddress());
        BridgeInterface bridge = BridgeInterface(getBridgeAddress());
        uint daiAmt = bridge.makerToCompound(cdpId, ethCol, daiDebt);
        borrowDAI(daiAmt);
        setApproval(getDaiAddress(), daiAmt, getBridgeAddress());
        bridge.takeDebtBack(daiAmt);
    }

    function compoundToMaker(uint cdpId, uint ethCol, uint daiDebt) public {
        if (cdpId != 0) {
            give(cdpId, getBridgeAddress());
        }
        BridgeInterface bridge = BridgeInterface(getBridgeAddress());
        setApproval(getCEthAddress(), 2**150, getBridgeAddress());
        uint daiAmt = bridge.compoundToMaker(cdpId, ethCol, daiDebt);
    }

}