feat(cart): implement cart management with add, update, and remove item functionalities

app/Domains/Cart/Models/Cart.php

@@ -3,6 +3,7 @@
 namespace App\Domains\Cart\Models;
 
 use App\Domains\Catalog\Models\ProductVariant;
+use App\Domains\Tenant\Models\Tenant;
 use App\Models\User;
 use Illuminate\Database\Eloquent\Attributes\Fillable;
 use Illuminate\Database\Eloquent\Factories\HasFactory;
@@ -11,8 +12,10 @@ use Illuminate\Database\Eloquent\Relations\BelongsTo;
 use Illuminate\Database\Eloquent\Relations\HasMany;
 use Illuminate\Support\Facades\DB;
 use Illuminate\Validation\ValidationException;
+use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
 
 #[Fillable([
+    'tenant_codigo',
     'user_id',
     'guest_token',
     'status',
@@ -30,6 +33,14 @@ class Cart extends Model
         ];
     }
 
+    /**
+     * @return BelongsTo<Tenant, $this>
+     */
+    public function tenant(): BelongsTo
+    {
+        return $this->belongsTo(Tenant::class, 'tenant_codigo', 'codigo');
+    }
+
     /**
      * @return BelongsTo<User, $this>
      */
@@ -54,11 +65,8 @@ class Cart extends Model
             ]);
         }
 
-        return DB::transaction(function () use ($productVariantId, $quantity) {
-            /** @var ProductVariant $variant */
-            $variant = ProductVariant::query()
-                ->lockForUpdate()
-                ->findOrFail($productVariantId);
+        return DB::transaction(function () use ($productVariantId, $quantity): CartItem {
+            $variant = $this->resolveScopedVariant($productVariantId, true);
 
             if ($variant->stock < $quantity) {
                 throw ValidationException::withMessages([
@@ -68,18 +76,18 @@ class Cart extends Model
 
             /** @var CartItem|null $item */
             $item = $this->items()
-                ->where('producto_variante_id', $productVariantId)
+                ->where('producto_variante_id', $variant->getKey())
                 ->lockForUpdate()
                 ->first();
 
-            if ($item) {
-                $item->cantidad += $quantity;
-                $item->save();
-            } else {
+            if ($item === null) {
                 $item = $this->items()->create([
-                    'producto_variante_id' => $productVariantId,
+                    'producto_variante_id' => $variant->getKey(),
                     'cantidad' => $quantity,
                 ]);
+            } else {
+                $item->cantidad += $quantity;
+                $item->save();
             }
 
             $variant->decrement('stock', $quantity);
@@ -96,18 +104,14 @@ class Cart extends Model
             ]);
         }
 
-        return DB::transaction(function () use ($productVariantId, $quantity) {
+        return DB::transaction(function () use ($productVariantId, $quantity): CartItem {
             /** @var CartItem $item */
             $item = $this->items()
                 ->where('producto_variante_id', $productVariantId)
                 ->lockForUpdate()
                 ->firstOrFail();
 
-            /** @var ProductVariant $variant */
-            $variant = ProductVariant::query()
-                ->lockForUpdate()
-                ->findOrFail($productVariantId);
-
+            $variant = $this->resolveScopedVariant($productVariantId, true);
             $delta = $quantity - $item->cantidad;
 
             if ($delta > 0 && $variant->stock < $delta) {
@@ -133,20 +137,36 @@ class Cart extends Model
 
     public function removeItem(int $productVariantId): void
     {
-        DB::transaction(function () use ($productVariantId) {
+        DB::transaction(function () use ($productVariantId): void {
             /** @var CartItem $item */
             $item = $this->items()
                 ->where('producto_variante_id', $productVariantId)
                 ->lockForUpdate()
                 ->firstOrFail();
 
-            /** @var ProductVariant $variant */
-            $variant = ProductVariant::query()
-                ->lockForUpdate()
-                ->findOrFail($productVariantId);
-
+            $variant = $this->resolveScopedVariant($productVariantId, true);
             $variant->increment('stock', $item->cantidad);
             $item->delete();
         });
     }
+
+    protected function resolveScopedVariant(int $productVariantId, bool $lockForUpdate = false): ProductVariant
+    {
+        $query = ProductVariant::query()
+            ->whereKey($productVariantId)
+            ->whereHas('product', fn ($query) => $query->where('tenant_codigo', $this->tenant_codigo));
+
+        if ($lockForUpdate) {
+            $query->lockForUpdate();
+        }
+
+        /** @var ProductVariant|null $variant */
+        $variant = $query->first();
+
+        if ($variant === null) {
+            throw new NotFoundHttpException('Product variant not found for tenant.');
+        }
+
+        return $variant;
+    }
 }