Defi Saver

1pragma solidity ^0.5.0;
2​
3import "./interfaces/ERC20.sol";
4import "./ReentrancyGuard.sol";
5import "./DS/DSMath.sol";
6import "./constants/ConstantAddresses.sol";
7​
8contract CTokenInterface is ERC20 {
9    function mint(uint mintAmount) external returns (uint);
10    function redeem(uint redeemTokens) external returns (uint);
11    function redeemUnderlying(uint redeemAmount) external returns (uint);
12    function borrow(uint borrowAmount) external returns (uint);
13    function repayBorrow(uint repayAmount) external returns (uint);
14    function repayBorrowBehalf(address borrower, uint repayAmount) external returns (uint);
15    function exchangeRateCurrent() external returns (uint);
16}
17​
18contract SaverProxy {
19    function repay(bytes32 _cup, uint _amount, uint _minAmount) public;
20    function boost(bytes32 _cup, uint _amount, uint _minAmount) public;
21}
22​
23/// @title Contract will hold cDai and use it for users to borrow and return in the sam tx
24contract DecenterLending is ReentrancyGuard, DSMath, ConstantAddresses {
25​
26    //Kovan
27    CTokenInterface public cDai = CTokenInterface(CDAI_ADDRESS);
28    ERC20 public Dai = ERC20(COMPOUND_DAI_ADDRESS);
29​
30    modifier onlyOwner() {
31        require(msg.sender == owner);
32        _;
33    }
34​
35    address public owner;
36    address public feeAddress;
37    uint public feeAmount;
38    uint public sanityBalance;
39    address public sanityContractAddress;
40​
41    constructor(address _owner, uint _feeAmount, address _feeAddress) public {
42        owner = _owner;
43        feeAmount = _feeAmount;
44        feeAddress = _feeAddress;
45    }
46​
47    function borrow(uint _amountToBorrow, uint _type, bytes32 _cup, uint _amount, uint _minAmount) public nonReentrant {
48​
49        require(cDai.redeemUnderlying(_amountToBorrow) == 0, "Reedem failed");
50​
51        uint prevDaiBalance = Dai.balanceOf(address(this));
52​
53        //Send money
54        Dai.transfer(msg.sender, _amountToBorrow);
55​
56        if (_type == 1) {
57            SaverProxy(msg.sender).repay(_cup, _amount, _minAmount);
58        } else {
59            SaverProxy(msg.sender).boost(_cup, _amount, _minAmount);
60        }
61​
62​
63        uint currentDaiBalance = Dai.balanceOf(address(this));
64​
65        // if feeAmount is 0, feeEarned will be 0
66        uint feeEarned = _amountToBorrow / feeAmount;
67​
68        //Where my money bitch
69        require(currentDaiBalance >= add(prevDaiBalance, feeEarned));
70​
71        // Transfer the fee earned to the feeAddress
72        Dai.transfer(feeAddress, feeEarned);
73​
74        require(Dai.balanceOf(sanityContractAddress) >= sanityBalance, "Sanity check against hackers");
75​
76        require(cDai.mint(_amountToBorrow) == 0, "Mint failed");
77    }
78​
79​
80    / ADMIN ONLY
81​
82    / Owner can get his money back
83    function withdraw(uint _amount, address _tokenAddress) public onlyOwner {
84        ERC20(_tokenAddress).transfer(owner, _amount);
85    }
86​
87    function changeFee(uint _newFee) public onlyOwner {
88        feeAmount = _newFee;
89    }
90​
91    function setSanityAmount(uint _sanityAmount) public onlyOwner {
92        sanityBalance = _sanityAmount;
93    }
94​
95    function setSanityContractAddress(address _contractAddress) public onlyOwner {
96        sanityContractAddress = _contractAddress;
97    }
98}

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