feat: add filtering for product detail attribute options based on available variant values

app/Domains/Catalog/Services/ProductService.php

@@ -293,6 +293,8 @@ class ProductService
             'variants.definitions.productAttribute.attribute.options',
         ]);
 
+        $this->filterProductDetailAttributeOptions($product);
+
         $selectedVariant = $variantId !== null
             ? $product->variants->firstWhere('id', $variantId)
             : $product->variants->first(fn (ProductVariant $variant) => $variant->stock > 0);
@@ -313,4 +315,36 @@ class ProductService
 
         return $product;
     }
+
+    protected function filterProductDetailAttributeOptions(Product $product): void
+    {
+        $availableValuesByAttributeId = [];
+
+        foreach ($product->variants as $variant) {
+            foreach ($variant->definitions as $definition) {
+                $attributeId = $definition->productAttribute?->attribute_id;
+
+                if ($attributeId === null || $definition->value === null) {
+                    continue;
+                }
+
+                $availableValuesByAttributeId[$attributeId][$definition->value] = true;
+            }
+        }
+
+        foreach ($product->attributes as $attribute) {
+            if (! $attribute->relationLoaded('options')) {
+                continue;
+            }
+
+            $availableValues = $availableValuesByAttributeId[$attribute->id] ?? [];
+
+            $attribute->setRelation(
+                'options',
+                $attribute->options
+                    ->filter(fn ($option): bool => array_key_exists($option->value, $availableValues))
+                    ->values()
+            );
+        }
+    }
 }