From ebdefab00faed767438bb1eda3a877c9e2601552 Mon Sep 17 00:00:00 2001
From: toniocodo <antoine@originprotocol.com>
Date: Sun, 1 Oct 2023 10:55:00 +0200
Subject: [PATCH] feat: leave 0.01ETH for gas on max click

---
 libs/shared/components/src/Inputs/TokenInput.tsx | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/libs/shared/components/src/Inputs/TokenInput.tsx b/libs/shared/components/src/Inputs/TokenInput.tsx
index 178340083..f3ebe587a 100644
--- a/libs/shared/components/src/Inputs/TokenInput.tsx
+++ b/libs/shared/components/src/Inputs/TokenInput.tsx
@@ -7,7 +7,7 @@ import {
   isNilOrEmpty,
 } from '@origin/shared/utils';
 import { useIntl } from 'react-intl';
-import { formatUnits } from 'viem';
+import { formatUnits, parseEther } from 'viem';
 
 import { BigIntInput } from './BigIntInput';
 
@@ -16,6 +16,8 @@ import type { Token } from '@origin/shared/contracts';
 
 import type { BigintInputProps } from './BigIntInput';
 
+const MIN_ETH_FOR_GAS = '0.01';
+
 export type TokenInputProps = {
   amount: bigint;
   decimals?: number;
@@ -68,10 +70,17 @@ export const TokenInput = forwardRef<HTMLInputElement, TokenInputProps>(
     const intl = useIntl();
 
     const handleMaxClick = () => {
-      onAmountChange(balance);
+      const max =
+        token.symbol === 'ETH'
+          ? balance - parseEther(MIN_ETH_FOR_GAS)
+          : balance;
+      onAmountChange(max);
     };
 
     const amountUsd = +formatUnits(amount, decimals) * tokenPriceUsd;
+    const maxVisible =
+      !hideMaxButton &&
+      (token.symbol === 'ETH' ? balance > parseEther(MIN_ETH_FOR_GAS) : true);
     const maxDisabled = disableMaxButton || !isConnected || isBalanceLoading;
 
     return (
@@ -148,7 +157,7 @@ export const TokenInput = forwardRef<HTMLInputElement, TokenInputProps>(
                       },
                     )}
                   </Typography>
-                  {!hideMaxButton && (
+                  {maxVisible && (
                     <Button
                       onClick={handleMaxClick}
                       disabled={maxDisabled}