initial commit of the SLPBondCreator contract

contracts/utils/SLPBondCreator.sol

@@ -0,0 +1,102 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+pragma solidity ^0.8.6;
+
+
+import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
+import "@uniswap/v2-periphery/contracts/interfaces/IUniswapV2Router02.sol";
+import "./../interfaces/bonds/IBondTellerErc20.sol";
+
+contract SLPBondCreator {
+
+    address public immutable sushiswapRouterAddress;
+    address public immutable usdcAddress;
+    address public immutable solaceAddress;
+    address public immutable slpAddress;
+    address public immutable slpBondingAddress;
+
+    constructor(address sushiswapRouterAddress_, address usdcAddress_, address solaceAddress_, address slpAddress_, address slpBondingAddress_) {
+        require(sushiswapRouterAddress_ != address(0x0), "zero address router");
+        require(usdcAddress_ != address(0x0), "zero address usdc");
+        require(solaceAddress_ != address(0x0), "zero address solace");
+        require(slpAddress_ != address(0x0), "zero address slp");
+        require(slpBondingAddress_ != address(0x0), "zero address slp bonding");
+        sushiswapRouterAddress = sushiswapRouterAddress_;
+        usdcAddress = usdcAddress_;
+        solaceAddress = solaceAddress_;
+        slpAddress = slpAddress_;
+        slpBondingAddress = slpBondingAddress_;
+    }
+
+    function createSLPTokens(uint256 timeNow) external returns (uint256 slp) {
+        uint256 senderUSDCBalance = IERC20(usdcAddress).balanceOf(msg.sender);
+        require(senderUSDCBalance > 0, "USDC balance = 0");
+        require(_transferAllUSDCToThisAddress(senderUSDCBalance), "USDC transfer failure");
+        uint256 halfUSDC = senderUSDCBalance/2;
+        IERC20(usdcAddress).approve(sushiswapRouterAddress, senderUSDCBalance);
+        uint256 solaceBalance = _buySolaceForUSDC(halfUSDC, timeNow)[1];
+        IERC20(solaceAddress).approve(sushiswapRouterAddress, solaceBalance);
+        uint slpBalance;
+        ( , ,slpBalance)=_addLiquidity(halfUSDC, solaceBalance, timeNow);
+        _refundDust(usdcAddress);
+        _refundDust(solaceAddress);
+        return slpBalance;
+    }
+
+    function createBondWithSLP() external {
+        uint256 slpBalance = IERC20(slpAddress).balanceOf(msg.sender);
+        require(IERC20(slpAddress).allowance(msg.sender, slpBondingAddress) >= slpBalance,
+                "Approve total SLP balance");
+        uint256 minAmountOut = IBondTellerErc20(slpBondingAddress).calculateAmountOut(slpBalance, false)*98/100;
+        IBondTellerErc20(slpBondingAddress).deposit(
+            slpBalance,
+            minAmountOut,
+            msg.sender,
+            false
+        );
+    }
+
+    function _refundDust(address token) private {
+        uint256 tokenBalance = IERC20(token).balanceOf(address(this));
+        if(tokenBalance > 0) {
+            IERC20(token).transfer(msg.sender, tokenBalance);
+        }
+    }
+
+    function _transferAllUSDCToThisAddress(uint256 usdcBalance) private returns (bool success) {
+        require(IERC20(usdcAddress).allowance(msg.sender, address(this)) >= usdcBalance,
+                 "Approve total USDC balance");
+        return IERC20(usdcAddress).transferFrom(msg.sender, address(this), usdcBalance);
+    }
+
+    function _buySolaceForUSDC(uint256 halfBalanceUSDC, uint256 timeNow) private returns (uint[] memory amounts){
+        address[] memory path = _getPathForUSDCtoSOLACE();
+        uint256 solaceMinAmount = IUniswapV2Router01(sushiswapRouterAddress).getAmountsOut(halfBalanceUSDC, path)[1]*98/100; //slippage 2%
+        return IUniswapV2Router01(sushiswapRouterAddress).swapExactTokensForTokens(
+            halfBalanceUSDC,
+            solaceMinAmount,
+            path,
+            address(this),
+            timeNow + 60
+        );
+    }
+
+    function _getPathForUSDCtoSOLACE() private view returns (address[] memory) {
+        address[] memory path = new address[](2);
+        path[0] = usdcAddress;
+        path[1] = solaceAddress;
+        return path;
+    }
+
+    function _addLiquidity(uint256 usdcToLP, uint256 solaceToLP, uint256 timeNow) private returns (uint amountA, uint amountB, uint liquidity) {
+        return IUniswapV2Router01(sushiswapRouterAddress).addLiquidity(
+            usdcAddress,
+            solaceAddress,
+            usdcToLP,
+            solaceToLP,
+            usdcToLP*98/100,
+            solaceToLP*98/100,
+            msg.sender,
+            timeNow+60
+        );
+    }
+}

package.json

@@ -40,6 +40,7 @@
     "@openzeppelin/contracts": "^4.3.2",
     "@openzeppelin/contracts-upgradeable": "^4.3.2",
     "@openzeppelin/hardhat-upgrades": "^1.13.0",
+    "@uniswap/v2-periphery": "^1.1.0-beta.0",
     "@uniswap/v3-core": "^1.0.0",
     "@uniswap/v3-periphery": "^1.1.1",
     "dotenv": "^10.0.0"