Optimistic updates for +/- buttons, UI responds instantly

src/components/PrintingRow/PrintingRow.jsx

@@ -1,24 +1,21 @@
-import React, { useContext, useState } from 'react';
+import React, { useContext } from 'react';
 import { CardContext } from '../../context/CardContext';
 import { updateCardAmount } from '../../services/api';
 
 function PrintingRow({ card_id, printing, cols, zebra }) {
   const { ownedAmounts, updateAmount } = useContext(CardContext);
-  const [loading, setLoading] = useState(false);
 
   const key = `${printing.set_id}-${printing.rarity_id}`;
   const current = ownedAmounts[card_id]?.[key] ?? printing.amount_owned ?? 0;
 
   const save = async (next) => {
     if (card_id == null || printing.set_id == null || printing.rarity_id == null) return;
-    setLoading(true);
+    updateAmount(card_id, key, next);
     try {
       await updateCardAmount(card_id, printing.set_id, printing.rarity_id, next);
-      updateAmount(card_id, key, next);
     } catch (err) {
       console.error('Failed to update amount', err);
-    } finally {
-      setLoading(false);
+      updateAmount(card_id, key, current);
     }
   };
 
@@ -26,7 +23,7 @@ function PrintingRow({ card_id, printing, cols, zebra }) {
     <div style={{
       display: 'grid', gridTemplateColumns: cols,
       gap: '8px', padding: '7px 16px 7px 32px',
-      alignItems: 'center', opacity: loading ? 0.5 : 1,
+      alignItems: 'center',
       background: zebra ? '#1e1e1e' : '#161616',
     }}>
       <span style={{ fontFamily: 'monospace', fontSize: '11px', color: '#555' }}>
@@ -35,19 +32,11 @@ function PrintingRow({ card_id, printing, cols, zebra }) {
       <span style={{ fontSize: '12px', color: '#888' }}>{printing.set_name}</span>
       <span style={{ fontSize: '12px', color: '#aaa' }}>{printing.rarity_name}</span>
       <div style={{ display: 'flex', alignItems: 'center', gap: '6px' }}>
-        <button
-          className="icon-btn"
-          onClick={() => current > 0 && save(current - 1)}
-          disabled={loading || current === 0}
-        >−</button>
+        <button className="icon-btn" onClick={() => current > 0 && save(current - 1)} disabled={current === 0}>−</button>
         <span style={{ minWidth: '20px', textAlign: 'center', color: '#e0e0e0', fontSize: '13px' }}>
           {current}
         </span>
-        <button
-          className="icon-btn"
-          onClick={() => save(current + 1)}
-          disabled={loading}
-        >+</button>
+        <button className="icon-btn" onClick={() => save(current + 1)}>+</button>
       </div>
     </div>
   );