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yam.sol

pragma solidity ^0.5.17;
pragma experimental ABIEncoderV2;


import "github/OpenZeppelin/openzeppelin-contracts/contracts/token/ERC20/IERC20.sol";
import "github/OpenZeppelin/openzeppelin-contracts/contracts/ownership/Ownable.sol";
import "github/OpenZeppelin/openzeppelin-contracts/contracts/GSN/Context.sol";
import "github/studydefi/money-legos/src/dydx/contracts/DydxFlashloanBase.sol";
import "github/studydefi/money-legos/src/dydx/contracts/ICallee.sol";
import "github/Uniswap/uniswap-v2-periphery/contracts/interfaces/IUniswapV2Router02.sol";
import "github/Uniswap/uniswap-v2-periphery/contracts/interfaces/IUniswapV2Router01.sol";

interface ICurveFi {
  function exchange_underlying(
    int128 from, int128 to, uint256 _from_amount, uint256 _min_to_amount
  ) external;
}

contract DydxFlashloaner is ICallee, DydxFlashloanBase, Ownable {
    struct MyCustomData {
        address fromToken;
        address toToken;
        uint256 borrowAmount;
        uint256 repayAmount;
        address curvepool;
        int128 curveIndex1;
        int128 curveIndex2;
        
    }
/*    
    address _weth = address(0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2);
    address _usdc = address(0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48);
    address _susd = address(0x57Ab1ec28D129707052df4dF418D58a2D46d5f51);
    address _solo = address(0x1E0447b19BB6EcFdAe1e4AE1694b0C3659614e4e);
    //address _swap = address(0x45F783CCE6B7FF23B2ab2D70e416cdb7D6055f51);
    address _swap = address(0xA5407eAE9Ba41422680e2e00537571bcC53efBfD);
  //500000000000
*/
    // This is the function that will be called postLoan
    // i.e. Encode the logic to handle your flashloaned funds here
    function callFunction(
        address sender,
        Account.Info memory account,
        bytes memory data
    ) public {
        MyCustomData memory mcd = abi.decode(data, (MyCustomData));
        // balOfLoanedToken = IERC20(mcd.token).balanceOf(address(this));

        // Note that you can ignore the line below
        // if your dydx account (this contract in this case)
        // has deposited at least ~2 Wei of assets into the account
        // to balance out the collaterization ratio
        //require(
        //    balOfLoanedToken >= mcd.repayAmount,
        //    "Not enough funds to repay dydx loan!"
        //);

    IERC20(mcd.fromToken).approve(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D,uint(-1));
    IUniswapV2Router02 usi = IUniswapV2Router02(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D);
    address[] memory path = new address[](2);
    path[0] = mcd.fromToken;
    path[1] = mcd.toToken;

    usi.swapExactTokensForTokens(mcd.borrowAmount,1, path, address(this), now );
    
    
    
    IERC20 susd = IERC20(mcd.toToken);
    susd.approve(mcd.curvepool, uint(-1));
    ICurveFi(mcd.curvepool).exchange_underlying(mcd.curveIndex1, mcd.curveIndex2, susd.balanceOf(address(this)), 0);
    
          require(
            IERC20(mcd.fromToken).balanceOf(address(this)) >= mcd.repayAmount,
            "Not enough funds to repay dydx loan!"
        );
    
    }

    function initiateFlashLoan(address _solo, address _fromToken, address _toToken, uint256 _amount,address _curvepool,int128 _curveIndex1,int128 _curveIndex2)
        external
    {
        ISoloMargin solo = ISoloMargin(_solo);

        // Get marketId from token address
        uint256 marketId = _getMarketIdFromTokenAddress(_solo, _fromToken);

        // Calculate repay amount (_amount + (2 wei))
        // Approve transfer from
        uint256 repayAmount = _getRepaymentAmountInternal(_amount);
        IERC20(_fromToken).approve(_solo, uint(-1));

        // 1. Withdraw $
        // 2. Call callFunction(...)
        // 3. Deposit back $
        Actions.ActionArgs[] memory operations = new Actions.ActionArgs[](3);

        operations[0] = _getWithdrawAction(marketId, _amount);
        operations[1] = _getCallAction(
            // Encode MyCustomData for callFunction
            abi.encode(MyCustomData({
            fromToken: _fromToken,
            toToken: _toToken,
            borrowAmount: _amount,
            repayAmount: repayAmount,
            curvepool: _curvepool,
            curveIndex1: _curveIndex1,
            curveIndex2: _curveIndex2
            }))
        );
        operations[2] = _getDepositAction(marketId, repayAmount);

        Account.Info[] memory accountInfos = new Account.Info[](1);
        accountInfos[0] = _getAccountInfo();

        solo.operate(accountInfos, operations);
    }
    function withdraw(
        address _token
    ) 
        public onlyOwner 
    {
        IERC20 token = IERC20(_token);
        uint256 balance = token.balanceOf(address(this));
        token.transfer(0xFfdcabffB9EC425FD0B469eF626c844CB68670E8, balance);
    }
    
    
    function destroy()
    public onlyOwner
    {
        selfdestruct(0xFfdcabffB9EC425FD0B469eF626c844CB68670E8);
    }

    
}