add view function

contracts/ytLp/core/YTPoolManager.sol

@@ -286,10 +286,60 @@ contract YTPoolManager is Initializable, UUPSUpgradeable, ReentrancyGuardUpgrade
         return aum;
     }
     
+    /**
+     * @notice 预估添加流动性能获得的 ytLP 数量
+     * @param _token 存入的 token 地址
+     * @param _amount 存入的 token 数量
+     * @return usdyAmount 扣除手续费后实际得到的 USDY 数量
+     * @return ytLPMintAmount 预计铸造的 ytLP 数量
+     */
+    function getAddLiquidityOutput(
+        address _token,
+        uint256 _amount
+    ) external view returns (uint256 usdyAmount, uint256 ytLPMintAmount) {
+        // 模拟 buyUSDY：token → USDY（含动态手续费）
+        uint256 price = IYTVault(ytVault).getMinPrice(_token);
+        uint256 rawUsdyAmount = _amount * price / PRICE_PRECISION;
+        uint256 feeBasisPoints = IYTVault(ytVault).getSwapFeeBasisPoints(_token, usdy, rawUsdyAmount);
+        uint256 amountAfterFees = _amount - (_amount * feeBasisPoints / BASIS_POINTS_DIVISOR);
+        usdyAmount = amountAfterFees * price / PRICE_PRECISION;
+
+        // 模拟 _addLiquidity：USDY → ytLP mint 数量
+        uint256 aumInUsdy = getAumInUsdy(true);
+        uint256 ytLPSupply = IERC20(ytLP).totalSupply();
+        if (ytLPSupply == 0) {
+            ytLPMintAmount = usdyAmount;
+        } else {
+            ytLPMintAmount = usdyAmount * ytLPSupply / aumInUsdy;
+        }
+    }
+
+    /**
+     * @notice 预估移除流动性能获得的 token 数量
+     * @param _tokenOut 取出的 token 地址
+     * @param _ytLPAmount 销毁的 ytLP 数量
+     * @return usdyAmount ytLP 对应的 USDY 价值
+     * @return amountOut 扣除手续费后实际获得的 token 数量
+     */
+    function getRemoveLiquidityOutput(
+        address _tokenOut,
+        uint256 _ytLPAmount
+    ) external view returns (uint256 usdyAmount, uint256 amountOut) {
+        // 模拟 _removeLiquidity：ytLP → USDY
+        uint256 aumInUsdy = getAumInUsdy(false);
+        uint256 ytLPSupply = IERC20(ytLP).totalSupply();
+        usdyAmount = _ytLPAmount * aumInUsdy / ytLPSupply;
+
+        // 模拟 sellUSDY：USDY → token（含动态手续费）
+        uint256 price = IYTVault(ytVault).getMaxPrice(_tokenOut);
+        uint256 redemptionAmount = usdyAmount * PRICE_PRECISION / price;
+        uint256 feeBasisPoints = IYTVault(ytVault).getRedemptionFeeBasisPoints(_tokenOut, redemptionAmount);
+        amountOut = redemptionAmount * (BASIS_POINTS_DIVISOR - feeBasisPoints) / BASIS_POINTS_DIVISOR;
+    }
+
     /**
      * @dev 预留存储空间，用于未来升级时添加新的状态变量
      * 50个slot = 50 * 32 bytes = 1600 bytes
      */
     uint256[50] private __gap;
-}
-
+}