⚡ Optimize Product Import N+1 SKU Check

app/Http/Controllers/ProductImportController.php

@@ -180,7 +180,10 @@ public function store(Request $request)
         // (Though usually file is sorted, better safe)
         $groupedData = collect($previewData)->groupBy('name');
 
-        DB::transaction(function () use ($groupedData, &$count) {
+        $allSkus = collect($previewData)->pluck('sku')->unique()->filter()->toArray();
+        $existingSkus = ProductVariant::whereIn('sku', $allSkus)->pluck('sku')->map(fn($sku) => strtolower($sku))->flip()->toArray();
+
+        DB::transaction(function () use ($groupedData, &$count, $existingSkus) {
             foreach ($groupedData as $productName => $variants) {
                 // Use the FIRST valid row's creation data for the product
                 // Find a row that has valid product data? Or just take the first one?
@@ -218,7 +221,7 @@ public function store(Request $request)
                     if (!empty($row['errors'])) continue;
 
                     // Check duplicate SKU again to be safe
-                    if (ProductVariant::where('sku', $row['sku'])->exists()) continue;
+                    if (isset($existingSkus[strtolower($row['sku'])])) continue;
 
                     $variantImage = null; // Currently template supports 1 image per row, usually mapping to Product Image. 
                     // If user provides specific variant image logic, we'd need another column. 

tests/Feature/ProductImportPerformanceTest.php

@@ -0,0 +1,96 @@
+<?php
+
+namespace Tests\Feature;
+
+use Tests\TestCase;
+use App\Models\User;
+use App\Models\Category;
+use App\Models\SubCategory;
+use App\Models\Unit;
+use App\Models\Product;
+use App\Models\ProductVariant;
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Illuminate\Support\Facades\DB;
+
+class ProductImportPerformanceTest extends TestCase
+{
+    use RefreshDatabase;
+
+    public function test_import_performance()
+    {
+        // Setup
+        $user = User::factory()->create();
+        $this->actingAs($user);
+
+        $category = Category::create(['name' => 'Test Cat', 'code' => 'TC']);
+        $subCategory = SubCategory::create(['name' => 'Test Sub', 'category_id' => $category->id, 'code' => 'TS']);
+        $unit = Unit::create(['name' => 'Test Unit', 'short_name' => 'TU']);
+
+        // Seed some existing data to simulate a real-world scenario where check is necessary
+        $existingCount = 50;
+        for ($i = 0; $i < $existingCount; $i++) {
+            $p = Product::create([
+                'name' => "Existing Product $i",
+                'category_id' => $category->id,
+                'sub_category_id' => $subCategory->id,
+                'description' => 'Test',
+            ]);
+            ProductVariant::create([
+                'product_id' => $p->id,
+                'unit_id' => $unit->id,
+                'sku' => "SKU-$i",
+                'selling_price' => 100,
+                'quantity' => 10,
+                'unit_value' => 1,
+            ]);
+        }
+
+        // Prepare import data
+        $importCount = 500;
+        $previewData = [];
+
+        for ($i = 0; $i < $importCount; $i++) {
+            // First 50 are duplicates (SKU-0 to SKU-49)
+            // Next are new
+            $sku = "SKU-$i";
+
+            $previewData[] = [
+                'row_id' => $i,
+                'name' => "Import Product $i",
+                'category_id' => $category->id,
+                'sub_category_id' => $subCategory->id,
+                'description' => 'Desc',
+                'unit_id' => $unit->id,
+                'unit_value' => 1,
+                'sku' => $sku,
+                'selling_price' => 120,
+                'limit_price' => 110,
+                'quantity' => 20,
+                'alert_quantity' => 5,
+                'image_url' => null,
+                'errors' => []
+            ];
+        }
+
+        session(['product_import_preview_data' => $previewData]);
+
+        // Enable query logging to count queries
+        DB::enableQueryLog();
+
+        $startTime = microtime(true);
+
+        $response = $this->post(route('products.import.store'));
+
+        $endTime = microtime(true);
+        $duration = $endTime - $startTime;
+        $queryLog = DB::getQueryLog();
+        $queryCount = count($queryLog);
+
+        echo "\nPerformance Results:\n";
+        echo "Time: " . number_format($duration, 4) . " seconds\n";
+        echo "Queries: " . $queryCount . "\n";
+
+        // Assert redirect to confirm no crash
+        $response->assertRedirect(route('products.index'));
+    }
+}