refactor(catalog): Complete catalog refactor to simplify its data model and its querying.

source commits: refactor/catalog

app/Domains/Cart/Models/CartItem.php

@@ -2,7 +2,8 @@
 
 namespace App\Domains\Cart\Models;
 
-use App\Domains\Catalog\Models\ProductVariant;
+use App\Domains\Catalog\Models\CatalogItem;
+use App\Domains\Catalog\Models\Variant;
 use Illuminate\Database\Eloquent\Attributes\Fillable;
 use Illuminate\Database\Eloquent\Factories\HasFactory;
 use Illuminate\Database\Eloquent\Model;
@@ -10,8 +11,8 @@ use Illuminate\Database\Eloquent\Relations\BelongsTo;
 
 #[Fillable([
     'cart_id',
-    'buyable_id',
-    'buyable_type',
+    'catalog_item_id',
+    'variant_id',
     'cantidad',
 ])]
 class CartItem extends Model
@@ -24,8 +25,8 @@ class CartItem extends Model
     {
         return [
             'cart_id' => 'integer',
-            'buyable_id' => 'integer',
-            'buyable_type' => 'string',
+            'catalog_item_id' => 'integer',
+            'variant_id' => 'integer',
             'cantidad' => 'integer',
         ];
     }
@@ -38,11 +39,20 @@ class CartItem extends Model
         return $this->belongsTo(Cart::class, 'cart_id');
     }
 
-    /**
-     * @return \Illuminate\Database\Eloquent\Relations\MorphTo
-     */
-    public function buyable()
+    /** @return BelongsTo<CatalogItem, $this> */
+    public function catalogItem(): BelongsTo
     {
-        return $this->morphTo();
+        return $this->belongsTo(CatalogItem::class);
+    }
+
+    /** @return BelongsTo<Variant, $this> */
+    public function variant(): BelongsTo
+    {
+        return $this->belongsTo(Variant::class);
+    }
+
+    public function selectedItem(): CatalogItem|Variant|null
+    {
+        return $this->variant ?? $this->catalogItem;
     }
 }