From bdb791e07e63a4465df2868037a583182850f90b Mon Sep 17 00:00:00 2001
From: Sowmayjain <champ.sowmay@gmail.com>
Date: Sun, 27 Jan 2019 04:19:14 +0530
Subject: [PATCH] Leverage CDP.

---
 contracts/v2/DAI2ETH.sol     |   0
 contracts/v2/InstaBank.sol   |   1 +
 contracts/v2/LeverageCDP.sol | 161 +++++++++++++++++++++++++++++++++++
 3 files changed, 162 insertions(+)
 create mode 100644 contracts/v2/DAI2ETH.sol
 create mode 100644 contracts/v2/LeverageCDP.sol

diff --git a/contracts/v2/DAI2ETH.sol b/contracts/v2/DAI2ETH.sol
new file mode 100644
index 0000000..e69de29
diff --git a/contracts/v2/InstaBank.sol b/contracts/v2/InstaBank.sol
index f4fc623..2230515 100644
--- a/contracts/v2/InstaBank.sol
+++ b/contracts/v2/InstaBank.sol
@@ -219,6 +219,7 @@ contract RepayLoan is BorrowLoan {
         );
     }
 
+    // TODO => send pethFree from frontend instead of ethFree 
     function unlockETH(uint cdpNum, uint ethFree) public isFreezed isCupOwner(cdpNum) {
         require(!freezed, "Operation Disabled");
         bytes32 cup = bytes32(cdpNum);
diff --git a/contracts/v2/LeverageCDP.sol b/contracts/v2/LeverageCDP.sol
new file mode 100644
index 0000000..7080dd8
--- /dev/null
+++ b/contracts/v2/LeverageCDP.sol
@@ -0,0 +1,161 @@
+pragma solidity 0.4.24;
+
+library SafeMath {
+
+    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
+        if (a == 0) {
+            return 0;
+        }
+        uint256 c = a * b;
+        require(c / a == b, "Assertion Failed");
+        return c;
+    }
+    
+    function div(uint256 a, uint256 b) internal pure returns (uint256) {
+        require(b > 0, "Assertion Failed");
+        uint256 c = a / b;
+        return c;
+    }
+
+}
+
+interface IERC20 {
+    function transfer(address to, uint256 value) external returns (bool);
+    function approve(address spender, uint256 value) external returns (bool);
+}
+
+interface AddressRegistry {
+    function getAddr(string name) external view returns(address);
+}
+
+interface MakerCDP {
+    function open() external returns (bytes32 cup);
+    function join(uint wad) external; // Join PETH
+    function give(bytes32 cup, address guy) external;
+    function lock(bytes32 cup, uint wad) external;
+    function draw(bytes32 cup, uint wad) external;
+    function per() external view returns (uint ray);
+}
+
+interface PriceInterface {
+    function peek() external view returns (bytes32, bool);
+}
+
+interface WETHFace {
+    function deposit() external payable;
+}
+
+interface Swap {
+    function dai2eth(uint srcDAI) external payable returns (uint destETH);
+    function expectedETH(uint srcDAI) external view returns (uint, uint);
+}
+
+
+contract Registry {
+
+    address public addressRegistry;
+    modifier onlyAdmin() {
+        require(
+            msg.sender == getAddress("admin"),
+            "Permission Denied"
+        );
+        _;
+    }
+    
+    function getAddress(string name) internal view returns(address) {
+        AddressRegistry addrReg = AddressRegistry(addressRegistry);
+        return addrReg.getAddr(name);
+    }
+
+}
+
+
+contract GlobalVar is Registry {
+
+    using SafeMath for uint;
+    using SafeMath for uint256;
+
+    address public cdpAddr; // SaiTub
+    bool public freezed;
+
+    function getETHRate() public view returns (uint) {
+        PriceInterface ethRate = PriceInterface(getAddress("ethfeed"));
+        bytes32 ethrate;
+        (ethrate, ) = ethRate.peek();
+        return uint(ethrate);
+    }
+
+    function approveERC20() public {
+        IERC20 wethTkn = IERC20(getAddress("weth"));
+        wethTkn.approve(cdpAddr, 2**256 - 1);
+        IERC20 pethTkn = IERC20(getAddress("peth"));
+        pethTkn.approve(cdpAddr, 2**256 - 1);
+        IERC20 mkrTkn = IERC20(getAddress("mkr"));
+        mkrTkn.approve(cdpAddr, 2**256 - 1);
+        IERC20 daiTkn = IERC20(getAddress("dai"));
+        daiTkn.approve(cdpAddr, 2**256 - 1);
+    }
+
+}
+
+
+contract LoopNewCDP is GlobalVar {
+
+    event LevNewCDP(uint cdpNum, uint ethLocked, uint daiMinted);
+
+    function pethPEReth(uint ethNum) public view returns (uint rPETH) {
+        MakerCDP loanMaster = MakerCDP(cdpAddr);
+        rPETH = (ethNum.mul(10 ** 27)).div(loanMaster.per());
+    }
+
+    // useETH = msg.sender + personal ETH used to assist the operation
+    function riskNewCDP(uint eth2Lock, uint dai2Mint) public payable {
+        require(!freezed, "Operation Disabled");
+
+        uint ethBal = address(this).balance;
+
+        MakerCDP loanMaster = MakerCDP(cdpAddr);
+        bytes32 cup = loanMaster.open(); // New CDP
+
+        WETHFace wethTkn = WETHFace(getAddress("weth"));
+        wethTkn.deposit.value(eth2Lock)(); // ETH to WETH
+        uint pethToLock = pethPEReth(msg.value); // PETH : ETH
+        loanMaster.join(pethToLock); // WETH to PETH
+        loanMaster.lock(cup, pethToLock); // PETH to CDP
+
+        loanMaster.draw(cup, dai2Mint);
+        IERC20 daiTkn = IERC20(getAddress("dai"));
+
+        address dai2eth = getAddress("dai2eth"); // DAI to ETH swapper
+        daiTkn.transfer(dai2eth, dai2Mint);
+        // SWAP DAI 2 ETH
+
+        uint nowBal = address(this).balance;
+        if (ethBal > nowBal) {
+            msg.sender.transfer(ethBal - nowBal);
+        }
+        require(ethBal == nowBal, "No Refund of Contract ETH");
+
+        // transfer CDP to v2 InstaBank
+
+        emit LevNewCDP(uint(cup), eth2Lock, dai2Mint);
+    }
+
+}
+
+
+contract LeverageCDP is LoopNewCDP {
+
+    constructor(address rAddr) public {
+        addressRegistry = rAddr;
+        cdpAddr = getAddress("cdp");
+        approveERC20();
+    }
+
+    function () public payable {}
+
+    function freeze(bool stop) public onlyAdmin {
+        freezed = stop;
+    }
+
+}
\ No newline at end of file