From 5fa4567da544a16d7227e096131a7dfc3be5d1bc Mon Sep 17 00:00:00 2001
From: clemlak <clementlakhal@gmail.com>
Date: Thu, 16 Nov 2023 14:05:32 +0400
Subject: [PATCH] feat: add computeAmountInGivenAmountOut

---
 contracts/strategies/G3MStrategyLib.sol | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/contracts/strategies/G3MStrategyLib.sol b/contracts/strategies/G3MStrategyLib.sol
index b57d74e3..979a97e6 100644
--- a/contracts/strategies/G3MStrategyLib.sol
+++ b/contracts/strategies/G3MStrategyLib.sol
@@ -117,4 +117,20 @@ library G3MStrategyLib {
                 )
         );
     }
+
+    function computeAmountInGivenAmountOut(
+        uint256 amountOut,
+        uint256 reserveIn,
+        uint256 weightIn,
+        uint256 reserveOut,
+        uint256 weightOut
+    ) internal pure returns (uint256 amountIn) {
+        amountIn = reserveIn.mulWadUp(
+            uint256(
+                int256(reserveOut.divWadUp(reserveOut - amountOut)).powWad(
+                    int256(weightOut.divWadUp(weightIn))
+                )
+            ) - FixedPointMathLib.WAD
+        );
+    }
 }