Contract Source Code:

// SPDX-License-Identifier: GPL-3.0-or-later

pragma solidity ^0.8.6;

import "@uniswap/v2-periphery/contracts/interfaces/IUniswapV2Router02.sol";
import "@uniswap/v2-periphery/contracts/interfaces/IERC20.sol";
import "../../interfaces/IUniswapV2Swap.sol";

/**
 * @title QuickswapSwapBridge
 * @author DeFi Basket
 *
 * @notice Swaps using the Quickswap contract in Polygon.
 *
 * @dev This contract swaps ERC20 tokens to ERC20 tokens. Please notice that there are no payable functions.
 *
 */

contract QuickswapSwapBridge is IUniswapV2Swap {
    address constant routerAddress = 0xa5E0829CaCEd8fFDD4De3c43696c57F7D7A678ff;
    /**
      * @notice Swaps from ERC20 token to ERC20 token.
      *
      * @dev Wraps the swap and generate the necessary events to communicate with DeFi Basket's UI and back-end.
      *
      * @param amountInPercentage Percentage of the balance of the input ERC20 token that will be swapped
      * @param amountOutMin Minimum amount of the output token required to execute swap
      * @param path The swap route determined by the path. The first element of path is the input token, the last is
      * the output token, and any intermediate elements represent intermediate pairs to trade through (if, for example,
      * a direct pair does not exist)
      */
    function swapTokenToToken(
        uint256 amountInPercentage,
        uint256 amountOutMin,
        address[] calldata path
    ) external override {
        IUniswapV2Router02 router = IUniswapV2Router02(routerAddress);

        uint256 amountIn = IERC20(path[0]).balanceOf(address(this)) * amountInPercentage / 100000;

        // Approve 0 first as a few ERC20 tokens are requiring this pattern.
        IERC20(path[0]).approve(routerAddress, 0);
        IERC20(path[0]).approve(routerAddress, amountIn);

        uint[] memory amounts = router.swapExactTokensForTokens(
            amountIn,
            amountOutMin,
            path,
            address(this),
            block.timestamp + 100000
        );

        emit DEFIBASKET_UNISWAPV2_SWAP(amounts);
    }
}

pragma solidity >=0.6.2;

import './IUniswapV2Router01.sol';

interface IUniswapV2Router02 is IUniswapV2Router01 {
    function removeLiquidityETHSupportingFeeOnTransferTokens(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external returns (uint amountETH);
    function removeLiquidityETHWithPermitSupportingFeeOnTransferTokens(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external returns (uint amountETH);

    function swapExactTokensForTokensSupportingFeeOnTransferTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external;
    function swapExactETHForTokensSupportingFeeOnTransferTokens(
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external payable;
    function swapExactTokensForETHSupportingFeeOnTransferTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external;
}

pragma solidity >=0.5.0;

interface IERC20 {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external view returns (string memory);
    function symbol() external view returns (string memory);
    function decimals() external view returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);
}

// SPDX-License-Identifier: GPL-3.0-or-later

pragma solidity ^0.8.6;

interface IUniswapV2Swap {
    event DEFIBASKET_UNISWAPV2_SWAP(
        uint256[] amounts
    );

    function swapTokenToToken(
        uint256 amountInPercentage,
        uint256 amountOutMin,
        address[] calldata path
    ) external;
}

pragma solidity >=0.6.2;

interface IUniswapV2Router01 {
    function factory() external pure returns (address);
    function WETH() external pure returns (address);

    function addLiquidity(
        address tokenA,
        address tokenB,
        uint amountADesired,
        uint amountBDesired,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline
    ) external returns (uint amountA, uint amountB, uint liquidity);
    function addLiquidityETH(
        address token,
        uint amountTokenDesired,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external payable returns (uint amountToken, uint amountETH, uint liquidity);
    function removeLiquidity(
        address tokenA,
        address tokenB,
        uint liquidity,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline
    ) external returns (uint amountA, uint amountB);
    function removeLiquidityETH(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external returns (uint amountToken, uint amountETH);
    function removeLiquidityWithPermit(
        address tokenA,
        address tokenB,
        uint liquidity,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external returns (uint amountA, uint amountB);
    function removeLiquidityETHWithPermit(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external returns (uint amountToken, uint amountETH);
    function swapExactTokensForTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external returns (uint[] memory amounts);
    function swapTokensForExactTokens(
        uint amountOut,
        uint amountInMax,
        address[] calldata path,
        address to,
        uint deadline
    ) external returns (uint[] memory amounts);
    function swapExactETHForTokens(uint amountOutMin, address[] calldata path, address to, uint deadline)
        external
        payable
        returns (uint[] memory amounts);
    function swapTokensForExactETH(uint amountOut, uint amountInMax, address[] calldata path, address to, uint deadline)
        external
        returns (uint[] memory amounts);
    function swapExactTokensForETH(uint amountIn, uint amountOutMin, address[] calldata path, address to, uint deadline)
        external
        returns (uint[] memory amounts);
    function swapETHForExactTokens(uint amountOut, address[] calldata path, address to, uint deadline)
        external
        payable
        returns (uint[] memory amounts);

    function quote(uint amountA, uint reserveA, uint reserveB) external pure returns (uint amountB);
    function getAmountOut(uint amountIn, uint reserveIn, uint reserveOut) external pure returns (uint amountOut);
    function getAmountIn(uint amountOut, uint reserveIn, uint reserveOut) external pure returns (uint amountIn);
    function getAmountsOut(uint amountIn, address[] calldata path) external view returns (uint[] memory amounts);
    function getAmountsIn(uint amountOut, address[] calldata path) external view returns (uint[] memory amounts);
}