feat: add stock availability validation during order processing and display specific error messages in POS form

app/Services/Manage/OrderService.php

@@ -199,6 +199,12 @@ public function syncDraftItem(array $validated, User $user): array
         }
 
         $quantity = (int) $validated['quantity'];
+        if ($quantity > $variant->stock) {
+            throw ValidationException::withMessages([
+                'quantity' => "Stok tidak mencukupi. Stok saat ini: {$variant->stock} pcs.",
+            ]);
+        }
+
         $unitPrice = (int) $price->price;
         $subtotal = $unitPrice * $quantity;
 
@@ -311,6 +317,17 @@ public function create(array $validated, User $user): Order
             ]);
 
             foreach ($draftItems as $item) {
+                $variant = ProductVariant::query()->with('product')->lockForUpdate()->find($item->product_variant_id);
+                if ($variant === null) {
+                    throw ValidationException::withMessages([
+                        'items' => 'Varian produk tidak ditemukan.',
+                    ]);
+                }
+                if ($variant->stock < $item->quantity) {
+                    throw ValidationException::withMessages([
+                        'items' => "Stok produk {$variant->product->name} ({$variant->name}) tidak mencukupi. Stok saat ini: {$variant->stock} pcs.",
+                    ]);
+                }
                 $item->order_id = $order->id;
                 $item->save();
                 $this->decrementStock($item);
@@ -371,6 +388,17 @@ public function update(Order $order, array $validated): void
             $order->save();
 
             foreach ($lineItems as $itemData) {
+                $variant = ProductVariant::query()->with('product')->lockForUpdate()->find($itemData['product_variant_id']);
+                if ($variant === null) {
+                    throw ValidationException::withMessages([
+                        'items' => 'Varian produk tidak ditemukan.',
+                    ]);
+                }
+                if ($variant->stock < $itemData['quantity']) {
+                    throw ValidationException::withMessages([
+                        'items' => "Stok produk {$variant->product->name} ({$variant->name}) tidak mencukupi. Stok saat ini: {$variant->stock} pcs.",
+                    ]);
+                }
                 $orderItem = $order->items()->create($itemData);
                 $this->decrementStock($orderItem);
             }

resources/js/components/admin/manage/orders/OrderPosForm.vue

@@ -349,8 +349,9 @@ function submit() {
 
     form.transform(() => payload).post(props.submitUrl, {
         forceFormData: true,
-        onError: () => {
+        onError: (errors) => {
-            toast.error('Gagal menyimpan data. Periksa kembali formulir.');
+            const firstError = Object.values(errors)[0];
+            toast.error(firstError || 'Gagal menyimpan data. Periksa kembali formulir.');
         },
     });
 }