From 0ce063ee0ee1a95a4f02cf83d5dc071ce0bed7c5 Mon Sep 17 00:00:00 2001
From: crispymangoes <crispymangoes@gmail.com>
Date: Thu, 16 Jun 2022 16:25:15 -0700
Subject: [PATCH] feat(SwapRouter): Add UniV2 and UniV3 swap options

---
 src/SwapRouter.sol | 81 ++++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 74 insertions(+), 7 deletions(-)

diff --git a/src/SwapRouter.sol b/src/SwapRouter.sol
index 39ed46f7e..95b09678a 100644
--- a/src/SwapRouter.sol
+++ b/src/SwapRouter.sol
@@ -4,17 +4,35 @@ pragma solidity 0.8.13;
 import { ERC20 } from "@solmate/tokens/ERC20.sol";
 import { SafeTransferLib } from "@solmate/utils/SafeTransferLib.sol";
 import { IAggregationRouterV4 as AggregationRouterV4 } from "./interfaces/IAggregationRouterV4.sol";
+import { IUniswapV2Router02 as UniswapV2Router } from "./interfaces/IUniswapV2Router02.sol";
+import { IUniswapV3Router as UniswapV3Router } from "./interfaces/IUniswapV3Router.sol";
 
 contract SwapRouter {
     using SafeTransferLib for ERC20;
 
     enum Exchanges {
-        ONEINCH
+        UNIV2,
+        UNIV3
     }
-
+    /** @notice Planned additions 
+        BALANCERV2,
+        CURVE,
+        ONEINCH
+    */
     mapping(Exchanges => bytes4) public idToSelector;
 
     // ========================================== CONSTRUCTOR ==========================================
+
+    /**
+     * @notice Uniswap V2 swap router contract. Used for swapping if pool fees are not specified.
+     */
+    UniswapV2Router public immutable uniswapV2Router; // 0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D
+
+    /**
+     * @notice Uniswap V3 swap router contract. Used for swapping if pool fees are specified.
+     */
+    UniswapV3Router public immutable uniswapV3Router; // 0xE592427A0AEce92De3Edee1F18E0157C05861564
+
     /**
      * @notice 1Inch Dex Aggregation Router
      */
@@ -23,22 +41,71 @@ contract SwapRouter {
     /**
      * @param _aggRouterV4 1 Inch Router Address
      */
-    constructor(AggregationRouterV4 _aggRouterV4) {
-        //set up all aggregators
+    constructor(
+        AggregationRouterV4 _aggRouterV4,
+        UniswapV2Router _uniswapV2Router,
+        UniswapV3Router _uniswapV3Router
+    ) {
+        //set up all exchanges
         aggRouterV4 = _aggRouterV4;
+        uniswapV2Router = _uniswapV2Router;
+        uniswapV3Router = _uniswapV3Router;
 
         //set up mapping between ids and selectors
-        idToSelector[Exchanges.ONEINCH] = SwapRouter(this).swapWith1Inch.selector;
+        idToSelector[Exchanges.UNIV2] = SwapRouter(this).swapWithUniV2.selector;
+        idToSelector[Exchanges.UNIV3] = SwapRouter(this).swapWithUniV3.selector;
     }
 
     // ======================================= SWAP OPERATIONS =======================================
 
     function swap(Exchanges id, bytes memory swapData) external returns (uint256 swapOutAmount) {
-        //TODO should we add a require here to make sure id is valid? Otherwise it calls the 0x0000 function in this contract which I'm not sure what that would be
         (bool success, bytes memory result) = address(this).call(abi.encodeWithSelector(idToSelector[id], swapData));
         require(success, "Failed to perform swap");
         swapOutAmount = abi.decode(result, (uint256));
     }
 
-    function swapWith1Inch(bytes memory swapData) public returns (uint256 swapOutAmount) {}
+    function swapWithUniV2(bytes memory swapData) public returns (uint256 swapOutAmount) {
+        (address[] memory path, uint256 assets, uint256 assetsOutMin, address recipient) = abi.decode(
+            swapData,
+            (address[], uint256, uint256, address)
+        );
+        ERC20 assetIn = ERC20(path[0]);
+        // Approve assets to be swapped through the router.
+        assetIn.safeApprove(address(uniswapV2Router), assets);
+
+        // Execute the swap.
+        uint256[] memory amountsOut = uniswapV2Router.swapExactTokensForTokens(
+            assets,
+            assetsOutMin,
+            path,
+            recipient,
+            block.timestamp + 60
+        );
+        swapOutAmount = amountsOut[1];
+    }
+
+    function swapWithUniV3(bytes memory swapData) public returns (uint256 swapOutAmount) {
+        (address[] memory path, uint24[] memory poolFees, uint256 assets, uint256 assetsOutMin, address recipient) = abi
+            .decode(swapData, (address[], uint24[], uint256, uint256, address));
+        ERC20 assetIn = ERC20(path[0]);
+
+        // Approve assets to be swapped through the router.
+        assetIn.safeApprove(address(uniswapV3Router), assets);
+
+        // Encode swap parameters.
+        bytes memory encodePackedPath = abi.encodePacked(address(assetIn));
+        for (uint256 i = 1; i < path.length; i++)
+            encodePackedPath = abi.encodePacked(encodePackedPath, poolFees[i - 1], path[i]);
+
+        // Execute the swap.
+        swapOutAmount = uniswapV3Router.exactInput(
+            UniswapV3Router.ExactInputParams({
+                path: encodePackedPath,
+                recipient: recipient,
+                deadline: block.timestamp + 60,
+                amountIn: assets,
+                amountOutMinimum: assetsOutMin
+            })
+        );
+    }
 }