Feature: Adding Product Service to Lunar

This commit introduces a Product service to Lunar. This product service calls Meilisearch to fetch an indexed product. The indexer has been updated to also include the collection and the price of the product.

A product search service has also been created to be used by the frontend's search

src/Search/ProductIndexer.php

@@ -2,26 +2,62 @@
 
 namespace Modules\Core\Search;
 
+use Illuminate\Database\Eloquent\Builder;
 use Illuminate\Database\Eloquent\Model;
+use Lunar\Models\Currency;
+use Lunar\Models\Product;
 use Lunar\Search\ProductIndexer as BaseProductIndexer;
 
 /**
- * Lunar's own indexer puts raw attribute HTML (e.g. name_en, description_en) into
- * the search index, which pollutes relevance ranking and highlighting with markup.
- * Strip tags from string fields before they reach Meilisearch.
+ * Extends Lunar's own indexer to add fields needed for storefront listing/filtering
+ * (Modules\Core\Catalog\ProductService) that aren't part of Lunar's default document:
+ * collection membership and a comparable price. Neither is filterable in Meilisearch
+ * until `php artisan lunar:meilisearch:setup` re-syncs index settings and the index is
+ * refreshed — see docs/product-listing.md.
  */
 class ProductIndexer extends BaseProductIndexer
 {
+    public function getFilterableFields(): array
+    {
+        return [
+            ...parent::getFilterableFields(),
+            'brand',
+            'collections',
+            'price',
+        ];
+    }
+
+    public function makeAllSearchableUsing(Builder $query): Builder
+    {
+        return parent::makeAllSearchableUsing($query)->with(['collections', 'variants.prices']);
+    }
+
     public function toSearchableArray(Model $model): array
     {
+        /** @var Product $model */
         $data = parent::toSearchableArray($model);
 
-        foreach ($data as $key => $value) {
-            if (is_string($value)) {
-                $data[$key] = trim(strip_tags($value));
-            }
-        }
+        $data['collections'] = $model->collections->pluck('id')->map(fn ($id) => (string) $id)->all();
+        $data['price'] = $this->cheapestPrice($model);
 
         return $data;
     }
+
+    /**
+     * The cheapest variant's base price (no customer group) in the default currency,
+     * as a float in major units — e.g. 19.99, not 1999. Null if the product has no
+     * variant with a price in that currency yet, so it's excluded from price filters
+     * rather than sorting to the bottom as if it were free.
+     */
+    private function cheapestPrice(Product $model): ?float
+    {
+        $currency = Currency::getDefault();
+
+        $price = $model->variants
+            ->flatMap(fn ($variant) => $variant->prices)
+            ->filter(fn ($price) => $price->currency_id === $currency->id && $price->customer_group_id === null)
+            ->min(fn ($price) => $price->price->value);
+
+        return $price !== null ? $price / (10 ** $currency->decimal_places) : null;
+    }
 }