stock check, variants in cart, variant buttons in product page

app/Http/Controllers/ProductController.php

@@ -4,7 +4,10 @@
 
 use App\Catalog\ProductListing;
 use App\Catalog\ProductListingPage;
+use Illuminate\Http\JsonResponse;
+use Illuminate\Http\Request;
 use Illuminate\Http\Response;
+use Lunar\Models\ProductVariant;
 use Modules\Core\Catalog\Services\ProductService;
 
 class ProductController extends Controller
@@ -42,11 +45,48 @@ public function show(string $locale, int $id)
         $firstVariant = $product['variants'][0] ?? null;
         $option = $firstVariant['options'][0]['option'] ?? null;
 
+        // The "Color" option type is the only one that writes a hex code into
+        // meta (see boboko/core's ColorOptionType) — its presence is how we
+        // tell a color option (swatches) from any other option (buttons).
+        $optionIsColor = collect($product['variants'])
+            ->contains(fn (array $variant) => !empty($variant['options'][0]['meta']['hex'] ?? null));
+
         return view('product.show', [
             'collection' => $collection,
             'product' => $product,
             'option' => $option,
+            'optionIsColor' => $optionIsColor,
             'variantsData' => $variantsData,
         ]);
     }
+
+    /**
+     * A storefront-owned, checkout-module-independent stock check — the
+     * product page's "Add to cart" calls this first and only submits to the
+     * checkout module's own add-to-cart endpoint once this says `ok`. Reads
+     * the live Eloquent ProductVariant directly (not the Meilisearch index
+     * ProductService otherwise reads from, which can lag behind an actual
+     * sale until the next reindex) via the SAME method Lunar's own
+     * CartLineStock validator calls, so this can never disagree with what
+     * the module's own server-side check would decide.
+     */
+    public function checkStock(string $locale, Request $request): JsonResponse
+    {
+        $data = $request->validate([
+            'variant' => ['required', 'integer'],
+            'quantity' => ['nullable', 'integer', 'min:1'],
+        ]);
+
+        $variant = ProductVariant::find($data['variant']);
+        $quantity = $data['quantity'] ?? 1;
+
+        if ($variant === null) {
+            return response()->json(['ok' => true]);
+        }
+
+        return response()->json([
+            'ok' => $variant->canBeFulfilledAtQuantity($quantity),
+            'stock' => $variant->purchasable === 'always' ? null : $variant->getTotalInventory(),
+        ]);
+    }
 }