From cad7ae42170aaf1576fbd7e0bca421091068bbbd Mon Sep 17 00:00:00 2001
From: Mubaris NK <mubaris@instadapp.io>
Date: Sun, 21 Mar 2021 18:15:29 +0530
Subject: [PATCH] Add calculateAmtMinusFee in fee connector

---
 contracts/connectors/fee/main.sol | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/contracts/connectors/fee/main.sol b/contracts/connectors/fee/main.sol
index b09c2684..e08a1bdf 100644
--- a/contracts/connectors/fee/main.sol
+++ b/contracts/connectors/fee/main.sol
@@ -6,6 +6,11 @@ import { Basic } from "../../common/basic.sol";
 abstract contract FeeResolver is DSMath, Basic {
     /**
      * @dev Calculate fee
+     * @param amount token amount to caculate fee.
+     * @param fee fee percentage. Eg: 1% => 1e17, 100% => 1e18.
+     * @param getId Get token amount at this ID from `InstaMemory` Contract.
+     * @param setId Set total amount at this ID in `InstaMemory` Contract.
+     * @param setIdFee Set only fee amount at this ID in `InstaMemory` Contract.
      */
     function calculateFee(
         uint amount,
@@ -23,6 +28,30 @@ abstract contract FeeResolver is DSMath, Basic {
         setUint(setId, totalAmt);
         setUint(setIdFee, feeAmt);
     }
+
+    /**
+     * @dev Calculate amount minus fee
+     * @param amount token amount to caculate fee.
+     * @param fee fee percentage. Eg: 1% => 1e17, 100% => 1e18.
+     * @param getId Get token amount at this ID from `InstaMemory` Contract.
+     * @param setIdAmtMinusFee Set amount minus fee amount at this ID in `InstaMemory` Contract.
+     * @param setIdFee Set only fee amount at this ID in `InstaMemory` Contract.
+     */
+    function calculateAmtMinusFee(
+        uint amount,
+        uint fee,
+        uint getId,
+        uint setIdAmtMinusFee,
+        uint setIdFee
+    ) external payable {
+        uint _amt = getUint(getId, amount);
+
+        uint feeAmt = wmul(_amt, fee);
+        uint amountMinusFee = sub(_amt, feeAmt);
+
+        setUint(setIdAmtMinusFee, amountMinusFee);
+        setUint(setIdFee, feeAmt);
+    }
 }
 
 contract ConnectV2Fee is FeeResolver {