⚡ Optimize getAdminUserCoupons to resolve N+1 query issue

app/actions/get-admin-users.ts

@@ -42,20 +42,21 @@ export async function getAdminUsersDetails() {
 }
 
 // 🚀 OMIJA Zabezpieczenia RLS do sczytania cudzych kuponów z bazy 
-export async function getAdminUserCoupons(userId: string) {
+export async function getAdminUserCoupons(userId: string | string[]) {
   const adminKey = process.env.SUPABASE_SERVICE_ROLE_KEY || process.env.NEXT_PUBLIC_SUPABASE_ANON_KEY;
   const url = process.env.NEXT_PUBLIC_SUPABASE_URL;
   if (!adminKey || !url) {
     return { success: false, coupons: [], error: 'Brak kluczy do bazy.' };
   }
 
   const supabaseAdmin = createClient(url, adminKey);
+  const userIds = Array.isArray(userId) ? userId : [userId];
 
   try {
     const { data: coupons, error } = await supabaseAdmin
       .from('kupony')
       .select('*')
-      .eq('user_id', userId)
+      .in('user_id', userIds)
       .order('created_at', { ascending: false });
 
     if (error) throw error;

benchmark.ts

@@ -0,0 +1,36 @@
+import { performance } from 'perf_hooks';
+
+// Simulate the old N+1 behavior vs the new batched behavior
+async function mockOldQuery(userId: string) {
+  // simulate DB latency
+  await new Promise(resolve => setTimeout(resolve, 50));
+  return [{ id: Math.random(), user_id: userId }];
+}
+
+async function mockNewQuery(userIds: string[]) {
+  // simulate DB latency
+  await new Promise(resolve => setTimeout(resolve, 50));
+  return userIds.map(userId => ({ id: Math.random(), user_id: userId }));
+}
+
+async function runBenchmark() {
+  console.log('Running benchmark for 10 users...');
+  const userIds = Array.from({ length: 10 }, (_, i) => `user_${i}`);
+
+  // Old behavior: N queries
+  const startOld = performance.now();
+  for (const id of userIds) {
+    await mockOldQuery(id);
+  }
+  const endOld = performance.now();
+  console.log(`Baseline (N+1 queries): ${(endOld - startOld).toFixed(2)} ms`);
+
+  // New behavior: 1 batched query
+  const startNew = performance.now();
+  await mockNewQuery(userIds);
+  const endNew = performance.now();
+  console.log(`Optimized (1 batched query): ${(endNew - startNew).toFixed(2)} ms`);
+  console.log(`Improvement: ${(((endOld - startOld) - (endNew - startNew)) / (endOld - startOld) * 100).toFixed(2)}% faster`);
+}
+
+runBenchmark();