// SPDX-License-Identifier: MIT
import "../Interfaces.sol";
pragma solidity >=0.8.0;

contract SwapHelperTest {
	// returns sorted token addresses, used to handle return values from pairs sorted in this order
	function sortTokens(address tokenA, address tokenB)
		internal
		pure
		returns (address token0, address token1)
	{
		require(tokenA != tokenB, "UniswapV2Library: IDENTICAL_ADDRESSES");
		(token0, token1) = tokenA < tokenB
			? (tokenA, tokenB)
			: (tokenB, tokenA);
		require(token0 != address(0), "UniswapV2Library: ZERO_ADDRESS");
	}

	// fetches and sorts the reserves for a pair
	function getReserves(
		address factory,
		address tokenA,
		address tokenB
	) public view returns (uint256 reserveA, uint256 reserveB) {
		(address token0, ) = sortTokens(tokenA, tokenB);
		(uint256 reserve0, uint256 reserve1, ) = UniswapPair(
			pairFor(factory, tokenA, tokenB)
		).getReserves();
		(reserveA, reserveB) = tokenA == token0
			? (reserve0, reserve1)
			: (reserve1, reserve0);
	}

	// calculates the CREATE2 address for a pair without making any external calls
	function pairFor(
		address factory,
		address tokenA,
		address tokenB
	) internal pure returns (address pair) {
		(address token0, address token1) = sortTokens(tokenA, tokenB);
		pair = address(
			uint160(
				uint256(
					keccak256(
						abi.encodePacked(
							hex"ff",
							factory,
							keccak256(abi.encodePacked(token0, token1)),
							hex"96e8ac4277198ff8b6f785478aa9a39f403cb768dd02cbee326c3e7da348845f" // init code hash
						)
					)
				)
			)
		);
	}
}