feat(catalog): expose product unavailability messages

app/Domains/Catalog/Resources/CatalogItemDetailResource.php

@@ -42,11 +42,15 @@ class CatalogItemDetailResource extends JsonResource
                 $selectedVariant === null,
                 fn () => $this->maximumAddable($this->availableStock()),
             ),
+            'unavailable_message' => $this->when(
+                $selectedVariant === null,
+                fn () => $this->unavailableMessage($this->availableStock()),
+            ),
             'images' => $this->when(
                 $selectedVariant === null,
                 fn () => $this->imageUrls($this->attachments),
             ),
-            'variants' => $this->visibleVariants()
+            'variants' => $this->variants
                 ->map(fn (Variant $variant): array => $this->variantData($variant))
                 ->values(),
             'selected_variant' => $this->when(
@@ -159,6 +163,7 @@ class CatalogItemDetailResource extends JsonResource
     {
         $values = $variant->selectionOptions($this->itemAttributes);
         $eventDates = $variant->selectedEventDates();
+        $variantStock = $this->variantStock($variant);
 
         return [
             'id' => $variant->id,
@@ -168,7 +173,8 @@ class CatalogItemDetailResource extends JsonResource
             'event_dates' => $eventDates->map(fn ($eventDate): string => $eventDate->date->format('Y-m-d'))->values(),
             'descripcion' => $variant->getDescription(),
             'precio' => number_format($variant->getPrice(), 2, '.', ''),
-            'maximum_addable_quantity' => $this->maximumAddable($this->variantStock($variant)),
+            'maximum_addable_quantity' => $this->maximumAddable($variantStock),
+            'unavailable_message' => $this->unavailableMessage($variantStock),
             'values' => $values,
         ];
     }
@@ -195,4 +201,12 @@ class CatalogItemDetailResource extends JsonResource
             $this->getAttribute('remaining_user_quota'),
         );
     }
+
+    private function unavailableMessage(?int $stock): ?string
+    {
+        return app(CatalogItemAllowanceService::class)->unavailableMessage(
+            $stock,
+            $this->getAttribute('remaining_user_quota'),
+        );
+    }
 }