From f8858d482f6aac5b1f0c0977feb4a043bd25100f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micha=C5=82=20Leszczyk?= <michal.leszczyk@avalabs.org>
Date: Wed, 18 Dec 2024 15:32:21 +0100
Subject: [PATCH] fix: make swap reverse work

---
 src/components/common/BNInput.tsx             |  5 ++++-
 src/pages/Swap/hooks/useSwap.tsx              |  1 +
 src/pages/Swap/hooks/useSwapStateFunctions.ts | 22 ++++++++++++++-----
 3 files changed, 21 insertions(+), 7 deletions(-)

diff --git a/src/components/common/BNInput.tsx b/src/components/common/BNInput.tsx
index 2ad44ef7..5c671109 100644
--- a/src/components/common/BNInput.tsx
+++ b/src/components/common/BNInput.tsx
@@ -60,7 +60,10 @@ export function BNInput({
       return;
     }
 
-    if (value === 0n && Number(valStr) === 0) {
+    if (value === 0n) {
+      if (Number(valStr) !== 0) {
+        setValStr('');
+      }
       return;
     }
 
diff --git a/src/pages/Swap/hooks/useSwap.tsx b/src/pages/Swap/hooks/useSwap.tsx
index 8faee9ea..0a85ca30 100644
--- a/src/pages/Swap/hooks/useSwap.tsx
+++ b/src/pages/Swap/hooks/useSwap.tsx
@@ -163,6 +163,7 @@ export function useSwap() {
   return {
     setValuesDebouncedSubject,
     swapError,
+    setSwapError,
     isSwapLoading,
     optimalRate,
     swapGasLimit,
diff --git a/src/pages/Swap/hooks/useSwapStateFunctions.ts b/src/pages/Swap/hooks/useSwapStateFunctions.ts
index 1d3c983d..870dde1d 100644
--- a/src/pages/Swap/hooks/useSwapStateFunctions.ts
+++ b/src/pages/Swap/hooks/useSwapStateFunctions.ts
@@ -48,6 +48,7 @@ export function useSwapStateFunctions() {
     swapGasLimit,
     destAmount,
     setDestAmount,
+    setSwapError,
   } = useSwap();
 
   const calculateTokenValueToInput = useCallback(
@@ -186,15 +187,24 @@ export function useSwapStateFunctions() {
       );
       return;
     }
+    setSwapError({ message: '' });
     setSelectedFromToken(toToken);
     setSelectedToToken(fromToken);
     setIsReversed((reversed) => reversed);
-    calculateSwapValue({
-      fromToken: toToken,
-      toToken: fromToken,
-      fromValue: undefined,
-      toValue: undefined,
-    });
+
+    if (!toToken || !fromToken || !destAmount) {
+      return;
+    }
+
+    const fromValue = {
+      amount: bigIntToString(BigInt(destAmount), toToken.decimals),
+      bigint: BigInt(destAmount),
+    };
+    setDestAmount('');
+    setFromTokenValue(fromValue);
+    setFromDefaultValue(fromValue.bigint);
+    setToTokenValue(undefined);
+    calculateTokenValueToInput(BigInt(destAmount), 'to', toToken, fromToken);
   };
 
   const onTokenChange = ({