Feature: Adding Facets, Updating Indexers

docs/collections.md

@@ -21,6 +21,8 @@ nowhere near enough for a storefront category page or a nav tree.
 | `collection_group_id` | `$model->collection_group_id` | Filterable. Mirrors `Collection::scopeInGroup()`. |
 | `slugs` | `$model->urls->pluck('slug')` | Filterable. Every locale's `Url::slug`, so `getBySlug()` resolves purely from the index. |
 | `thumbnail` | `$model->getThumbnailImage()` | Display only. `null` if the collection has no thumbnail image. |
+| `ancestors` | `$model->ancestors` | Display only. Array of `{id, name}`, ordered root-first — a breadcrumb (`Home > Apparel > Keychains`) can render directly from a single `getById()`/`getBySlug()` call, no extra queries. Empty array for a top-level collection. |
+| `product_count` | Queried from the *product* Meilisearch index at collection-index time | Display only. How many products are in this collection **or any of its descendants** — matches what `ProductService::list(ProductFilters(collectionId: ...))` would return, not just direct assignment. Computed via `Product::search('')->options(['filter' => "collection_ids = \"{id}\""])`, so it depends on the product index already being current — reindex products *before* collections (see "Gotchas" below). |
 
 `name`/`description` (and any other `TranslatedText` attribute) are indexed per-locale
 by Lunar's base indexer and resolved by `CollectionService` exactly like
@@ -87,6 +89,19 @@ lunar:meilisearch:setup` re-syncs index settings, and existing documents need
 the queue worker also needs restarting after deploying changes to the indexer class —
 see `docs/lunar.md` "Gotchas".
 
+**`product_count` needs the product index reindexed first.** `config/lunar/search.php`'s
+`indexers` array is typically ordered `Collection` before `Product`, so a plain
+`lunar:search:index --refresh` computes `product_count` against whatever the product
+index held *before* this run — stale if products changed too. `lunar:search:index`
+takes an explicit model list as its argument (`--ignore` restricts it to only those),
+so reindex products first, then collections, when both need a fresh `--refresh` in the
+same deploy:
+
+```
+php artisan lunar:search:index "Lunar\Models\Product" --ignore --refresh
+php artisan lunar:search:index "Lunar\Models\Collection" --ignore --refresh
+```
+
 ---
 
 ## When to still use Eloquent directly

docs/product-listing.md

@@ -33,9 +33,9 @@ $service = app(ProductService::class);
 // "Meilisearch driver quirk" below), so it behaves like any other Laravel paginator.
 $products = $service->list(perPage: 24, page: 1);
 
-// Filter by collection, brand, and/or price range
+// Filter by collection, brand, price range, and/or stock
 $products = $service->list(
-    filters: new ProductFilters(collectionId: 17, minPrice: 10.0, maxPrice: 50.0),
+    filters: new ProductFilters(collectionId: 17, minPrice: 10.0, maxPrice: 50.0, inStockOnly: true),
     perPage: 24,
     page: 1,
 );
@@ -56,10 +56,41 @@ $product = $service->getById(367);   // array, or null if not found
 
 // Single product, by URL slug (any locale — slugs are indexed across all languages)
 $product = $service->getBySlug('erotika-mprelok');   // array, or null if not found
+
+// Facet counts for a sidebar — value => matching product count, scoped to whatever
+// $filters is passed. Does NOT exclude the faceted field itself from $filters — see
+// facets()'s docblock for why, and how to build a standard "every option's count,
+// unaffected by that option's own currently-selected value" sidebar.
+$brandCounts = $service->facets('brand', filters: new ProductFilters(collectionId: 17));
+// ['3Dealer.gr - 3D printed creations' => 48, 'Kraniou Topos - 3D printed creations' => 135]
+
+// Min/max price across matching products, for sizing a price-range slider.
+// minPrice/maxPrice are ALWAYS excluded from the filter driving this (unlike
+// facets(), which doesn't auto-exclude) — the slider's own bounds shouldn't shrink
+// to whatever range is currently selected on it. Other filters (collectionId,
+// brand, inStockOnly) still apply normally.
+$range = $service->priceRange(new ProductFilters(collectionId: 17));
+// ['min' => 0.0, 'max' => 120.0]
 ```
 
 All `ProductFilters` fields are optional; only the ones set are added to the Meilisearch query.
 
+`facets()` only makes sense on discrete-value filterable fields (`brand`, `in_stock`) — a numeric
+field like `price` would return one "facet" per exact price, not a usable range bucket. Use
+`priceRange()` for `price` instead, which reads Meilisearch's `facetStats` (min/max), a different
+feature from `facetDistribution`.
+
+---
+
+## Stock goes stale between orders
+
+`in_stock` reflects `ProductVariant::stock`/`purchasable` as of the **last reindex**, not live
+inventory. Nothing in this codebase currently reindexes a product when an order decrements its
+stock — that's a cart/checkout concern, not something `ProductIndexer` can solve on its own (see
+`Modules\Core\Catalog\Observers\ProductOptionReindexObserver` for the equivalent pattern once an
+order → stock → reindex pipeline exists to hook into). Until then, `in_stock`/`product_count` can
+drift from the database the same way every other indexed field already can between writes.
+
 ---
 
 ## Fields this depends on: `Modules\Core\Catalog\Services\ProductIndexer`
@@ -81,6 +112,7 @@ needs, listing and detail alike:
 | `media` | `$product->media` | Full gallery (id/url/thumb per image), not just the single thumbnail Lunar's base indexer sends. |
 | `variants` | `$product->variants` | Per variant: `id`, `sku`, `stock`, `purchasable`, `options` (option/value names, in the current locale), `prices` (per currency/customer group), `media` (variant-specific images). |
 | `reviews` | `Modules\Core\Review\Models\ProductReview` | `{items, count, average_rating}` — see "Reviews" below. |
+| `in_stock` | `$model->variants` | Filterable boolean. `true` if ANY variant currently passes `ProductVariant::canBeFulfilledAtQuantity(1)` — Lunar's own purchasability rule (`purchasable === 'always'` ignores stock entirely; `in_stock` checks `stock` alone; anything else checks `stock + backorder`). Only as fresh as the last reindex — see "Stock goes stale" below. |
 
 `name`/`description` (and any other `TranslatedText` attribute) are indexed per-locale — see
 "Locale resolution" below for how `ProductService` resolves them down to one value per request.