improve interface

Author: haider-rs

src/oracle/IOracle.sol

@@ -4,5 +4,5 @@
 pragma solidity >=0.8.0;
 
 interface IOracle {
-    function getNativePrice() external view returns (uint256, uint256);
+    function getPrice(address token) external view returns (uint256, uint256);
 }

src/oracle/UniswapV2Oracle.sol

@@ -22,56 +22,40 @@ interface IERC20 {
 
 contract UniswapV2Oracle is IOracle {
     address public immutable factory;
-    address public immutable WETH;
     address public immutable USDT;
 
-    constructor(address _factory, address _weth, address _usdt) {
+    constructor(address _factory, address _usdt) {
         factory = _factory;
-        WETH = _weth;
         USDT = _usdt;
     }
 
-    function getNativePrice() external view override returns (uint256, uint256) {
-        return getTokenPrice(WETH, USDT, 1 ether);
+    function getPrice(address token) external view returns (uint256, uint256) {
+        return getTokenValueInUSDT(token, 10 ** IERC20(token).decimals());
     }
 
-    function getTokenPrice(address tokenA, address tokenB, uint256 amount) public view returns (uint256, uint256) {
-        address pairAddress = IUniswapV2Factory(factory).getPair(tokenA, tokenB);
-        console.log("pair address: ", pairAddress);
+    function getTokenValueInUSDT(address token, uint256 amount) public view returns (uint256, uint256) {
+        address pairAddress = IUniswapV2Factory(factory).getPair(token, USDT);
         require(pairAddress != address(0), "Pair does not exist");
 
         IUniswapV2Pair pair = IUniswapV2Pair(pairAddress);
-
         (uint112 reserve0, uint112 reserve1,) = pair.getReserves();
         require(reserve0 > 0 && reserve1 > 0, "Insufficient liquidity");
-        console.log("reserve0 is, ", reserve0);
-        console.log("reserve1 is, ", reserve1);
-
-        address token0 = pair.token0();
-        // address token1 = pair.token1();
-
-        uint256 reserveA;
-        uint256 reserveB;
 
-        if (tokenA == token0) {
-            reserveA = uint256(reserve0);
-            reserveB = uint256(reserve1);
-        } else {
-            reserveA = uint256(reserve1);
-            reserveB = uint256(reserve0);
-        }
+        (uint256 reserveToken, uint256 reserveUSDT) =
+            pair.token0() == USDT ? (reserve1, reserve0) : (reserve0, reserve1);
 
-        uint8 decimalsA = IERC20(tokenA).decimals();
-        console.log("decimal a", decimalsA);
-        uint8 decimalsB = IERC20(tokenB).decimals();
-        console.log("decimal b", decimalsB);
+        uint8 tokenDecimals = IERC20(token).decimals();
+        uint8 usdtDecimals = IERC20(USDT).decimals(); // address token1 = pair.token1();
 
         // e.g. lets say we wanna get price fo 1eth
         // and pool have 10 eth and 30000 usd then
-        //                1e18  * 30000USD *  10 ** 1e18        / 10eth     *  10 ** 1e6
-        uint256 price = (amount * reserveB * (10 ** decimalsA)) / (reserveA * (10 ** decimalsB));
+        //                1e18  * 30000USD    * 10 ** 1e18             / 10eth         * 10 ** 1e6
+        uint256 price = (amount * reserveUSDT * (10 ** tokenDecimals)) / (reserveToken * (10 ** usdtDecimals));
+        console.log("price: {}", price);
+        console.log("reserve0: {}", reserve0);
+        console.log("reserve1: {}", reserve1);
 
-        uint256 scale = 10 ** decimalsA;
+        uint256 scale = 10 ** tokenDecimals;
         uint256 integer_part = price / scale;
         uint256 fraction = price % scale;
         return (integer_part, fraction);

test/UniswapV2Oracle.t.sol

@@ -17,11 +17,11 @@ contract UniswapV2OracleTest is Test {
 
     function setUp() public {
         vm.createSelectFork({urlOrAlias: "https://eth.meowrpc.com"});
-        oracle = new UniswapV2Oracle(FACTORY, WETH, USDT);
+        oracle = new UniswapV2Oracle(FACTORY, USDT);
     }
 
     function testGetNativePrice() public view {
-        (uint256 ints, uint256 fraction) = oracle.getNativePrice();
+        (uint256 ints, uint256 fraction) = oracle.getPrice(WETH);
         console.log("WETH/USDT Price:", ints, fraction);
     }
 }