initial exchange re-write

add initialization function to exchanges add mint function in erc20
2019-10-25 15:06:06 -04:00
parent d48b5f5a44
commit e5b8db9df1
4 changed files with 165 additions and 147 deletions
--- a/contracts/UniswapV2Helper.sol.unreviewed
+++ b/contracts/UniswapV2Helper.sol.unreviewed
@ -0,0 +1,131 @@
+// TODO ema oracle, review
+pragma solidity 0.5.12;
+
+import "./libraries/Math.sol";
+import "./libraries/SafeMath.sol";
+
+import "./UniswapV2Factory.sol";
+import "./UniswapV2.sol";
+
+contract UniswapV2Helper {
+    using SafeMath for uint256;
+
+    event Swap(address inputToken, address outputToken, address indexed buyer, address recipient, uint256 amountSold, uint256 amountBought);
+
+    address factory;                  // Uniswap ERC20 factory
+
+    constructor(address _factory) public  {
+        factory = _factory;
+    }
+
+    bool private reentrancyLock = false;
+
+    modifier nonReentrant() {
+        require(!reentrancyLock, "REENTRANCY_FORBIDDEN");
+        reentrancyLock = true;
+        _;
+        reentrancyLock = false;
+    }
+
+    function _send(
+        address inputToken,
+        address outputToken,
+        uint256 amountSold,
+        address recipient
+    ) internal returns (uint256) {
+        address exchange = UniswapV2Factory(factory).getExchange(inputToken, outputToken);
+        require(exchange != address(0), "NO_EXCHANGE");
+        if (amountSold != 0) {
+        require(IERC20(inputToken).transferFrom(msg.sender, exchange, amountSold), "TRANSFER_FAILED");
+        }
+        return UniswapV2(exchange).swap(inputToken, recipient);
+    }
+
+    function send(
+        address inputToken,
+        address outputToken,
+        uint256 amountSold,
+        uint256 minBought,
+        uint256 deadline,
+        address recipient
+    ) public nonReentrant returns (uint256) {
+        require(block.timestamp <= deadline, "DEADLINE_PASSED");
+        uint256 amountBought = _send(inputToken, outputToken, amountSold, recipient);
+        require(amountBought >= minBought, "INSUFFICIENT_AMOUNT_BOUGHT");
+        emit Swap(inputToken, outputToken, msg.sender, recipient, amountSold, amountBought);
+        return amountBought;
+    }
+
+    function sendIndirect(
+        address inputToken,
+        address intermediateToken,
+        address outputToken,
+        uint256 amountSold,
+        uint256 minBought,
+        uint256 deadline,
+        address recipient
+    ) public nonReentrant returns (uint256) {
+        require(block.timestamp <= deadline, "DEADLINE_PASSED");
+        // send intermediate amount directly to the next contract
+        uint256 intermediateAmountBought = _send(inputToken, intermediateToken, amountSold, outputToken);
+        emit Swap(inputToken, intermediateToken, msg.sender, msg.sender, amountSold, intermediateAmountBought);
+        uint256 amountBought = _send(inputToken, intermediateToken, 0, recipient);
+        emit Swap(intermediateToken, outputToken, msg.sender, recipient, intermediateAmountBought, amountBought);
+        require(amountBought >= minBought, "INSUFFICIENT_AMOUNT_BOUGHT");
+        return amountBought;
+    }
+
+    function swap(
+        address inputToken,
+        address outputToken,
+        uint256 amountSold,
+        uint256 minBought,
+        uint256 deadline
+    ) public nonReentrant returns (uint256) {
+        return send(inputToken, outputToken, amountSold, minBought, deadline, msg.sender);
+    }
+
+    function _addLiquidity(
+        address token1,
+        address token2,
+        uint256 amount1,
+        uint256 amount2,
+        address exchange,
+        address recipient
+    ) public nonReentrant returns (uint256) {
+        require(IERC20(token1).transferFrom(msg.sender, exchange, amount1), "TRANSFER_FAILED");
+        require(IERC20(token2).transferFrom(msg.sender, exchange, amount2), "TRANSFER_FAILED");
+        return UniswapV2(exchange).addLiquidity(recipient);
+    }
+
+    function addLiquidity(
+        address token1,
+        address token2,
+        uint256 amount1,
+        uint256 minBought,
+        address recipient,
+        uint256 deadline
+    ) public nonReentrant returns (uint256) {
+        require(block.timestamp <= deadline, "DEADLINE_PASSED");
+        address exchange = UniswapV2Factory(factory).getExchange(token1, token2);
+        require(exchange != address(0), "NO_EXCHANGE");
+        (uint256 reserve1,) = UniswapV2(exchange).dataForToken(token1);
+        (uint256 reserve2,) = UniswapV2(exchange).dataForToken(token2);
+        uint256 amount2 = amount1.mul(reserve2).div(reserve1);
+        uint256 amountBought = _addLiquidity(token1, token2, amount1, amount2, exchange, recipient);
+        require(amountBought >= minBought, "INSUFFICIENT_AMOUNT_BOUGHT");
+    }
+
+    function removeLiquidity(
+        address token1,
+        address token2,
+        uint256 amount,
+        address recipient,
+        uint256 deadline
+    ) public nonReentrant returns (uint256, uint256) {
+        require(block.timestamp <= deadline, "DEADLINE_PASSED");
+        address exchange = UniswapV2Factory(factory).getExchange(token1, token2);
+        require(exchange != address(0), "NO_EXCHANGE");
+        return UniswapV2(exchange).removeLiquidity(amount, recipient);
+    }
+}