diff --git a/app/Livewire/Forms/Studio/Manage/PurchaseForm.php b/app/Livewire/Forms/Studio/Manage/PurchaseForm.php
index 0b1ed38..9d6ec00 100644
--- a/app/Livewire/Forms/Studio/Manage/PurchaseForm.php
+++ b/app/Livewire/Forms/Studio/Manage/PurchaseForm.php
@@ -87,14 +87,30 @@ public function store(): void
 
         $purchaseItems = $this->loadPurchaseItems();
 
-        DB::transaction(function () use ($purchaseItems) {
-            $purchase = Purchase::create($this->prepareSavedData());
+        // Recalculate total to ensure data integrity
+        $calculatedTotal = $purchaseItems->sum(function ($item) {
+            return $item->unit_price * $item->quantity;
+        });
+
+        // Override the total input with the calculated one to prevent mismatches
+        $this->total = formatCurrencyNumber($calculatedTotal);
+
+        DB::transaction(function () use ($purchaseItems, $calculatedTotal) {
+            $data = $this->prepareSavedData();
+            $data['total'] = $calculatedTotal; // Use strict calculated total
+
+            $purchase = Purchase::create($data);
 
             $purchase->load('outlet');
 
             $this->uploadMedia($this->image, $purchase, 'image');
 
             foreach ($purchaseItems as $item) {
+                // Ensure item integrity before linking
+                if ($item->quantity <= 0 || $item->unit_price <= 0) {
+                    continue; // Or throw exception
+                }
+
                 $item->update(['purchase_id' => $purchase->id]);
 
                 $this->increaseOutletStock($purchase->outlet, $item);
@@ -106,8 +122,15 @@ public function update(): void
     {
         $this->validate();
 
-        DB::transaction(function () {
-            $this->purchase->update($this->prepareSavedData());
+        // Ensure total calculation integrity from existing items
+        $calculatedTotal = $this->purchase->items()->sum(DB::raw('unit_price * quantity'));
+        $this->total = formatCurrencyNumber($calculatedTotal);
+
+        DB::transaction(function () use ($calculatedTotal) {
+            $data = $this->prepareSavedData();
+            $data['total'] = $calculatedTotal; // Enforce calculated total
+
+            $this->purchase->update($data);
 
             $this->syncMedia($this->image, $this->purchase, 'image');
             $this->uploadMedia($this->image, $this->purchase, 'image');
diff --git a/app/Livewire/Studio/Manage/Purchase/Create.php b/app/Livewire/Studio/Manage/Purchase/Create.php
index b2bb6b5..e78a155 100644
--- a/app/Livewire/Studio/Manage/Purchase/Create.php
+++ b/app/Livewire/Studio/Manage/Purchase/Create.php
@@ -40,11 +40,11 @@ public function mount(): void
     {
         $this->outlets = auth()->user()->outlets->pluck('name', 'id')->toArray();
 
-        $this->perfumes = Perfume::orderBy('name')->pluck('name', 'id')->toArray();
+        $this->perfumes = Perfume::whereHas('outlets', fn ($query) => $query->where('outlets.id', $this->form->outlet_id))->orderBy('name')->pluck('name', 'id')->toArray();
 
-        $this->bottles = Bottle::orderBy('size')->pluck('name', 'id')->toArray();
+        $this->bottles = Bottle::whereHas('outlets', fn ($query) => $query->where('outlets.id', $this->form->outlet_id))->orderBy('size')->pluck('name', 'id')->toArray();
 
-        $this->products = Product::orderBy('name')->pluck('name', 'id')->toArray();
+        $this->products = Product::whereHas('outlets', fn ($query) => $query->where('outlets.id', $this->form->outlet_id))->orderBy('name')->pluck('name', 'id')->toArray();
 
         $this->purchaseItems = $this->loadPurchaseItems();
 
@@ -70,6 +70,13 @@ public function save(): void
         $this->redirectRoute('studio.manage.purchase.index');
     }
 
+    public function updatedFormOutletId($value): void
+    {
+        $this->perfumes = Perfume::whereHas('outlets', fn ($query) => $query->where('outlets.id', $value))->orderBy('name')->pluck('name', 'id')->toArray();
+        $this->bottles = Bottle::whereHas('outlets', fn ($query) => $query->where('outlets.id', $value))->orderBy('size')->pluck('name', 'id')->toArray();
+        $this->products = Product::whereHas('outlets', fn ($query) => $query->where('outlets.id', $value))->orderBy('name')->pluck('name', 'id')->toArray();
+    }
+
     public function render(): View
     {
         return view('livewire.studio.manage.purchase.form', [
diff --git a/app/Livewire/Studio/Manage/Purchase/Index.php b/app/Livewire/Studio/Manage/Purchase/Index.php
index ad9c8f4..6659d78 100644
--- a/app/Livewire/Studio/Manage/Purchase/Index.php
+++ b/app/Livewire/Studio/Manage/Purchase/Index.php
@@ -11,6 +11,7 @@
 use App\Traits\Purchase\WithUpdateStock;
 use Flux\Flux;
 use Illuminate\Contracts\View\View;
+use Illuminate\Support\Facades\DB;
 use Livewire\Attributes\Title;
 use Livewire\Component;
 
@@ -23,11 +24,13 @@ public function delete(Purchase $purchase): void
     {
         $this->canOrAbort('delete purchase');
 
-        foreach ($purchase->items as $item) {
-            $this->decreaseOutletStock($purchase->outlet, $item);
-        }
+        DB::transaction(function () use ($purchase) {
+            foreach ($purchase->items as $item) {
+                $this->decreaseOutletStock($purchase->outlet, $item);
+            }
 
-        $purchase->delete();
+            $purchase->delete();
+        });
 
         $this->dispatch('refreshDatatable');
 
diff --git a/app/Traits/Purchase/WithAddItem.php b/app/Traits/Purchase/WithAddItem.php
index 5fc1d31..fba535f 100644
--- a/app/Traits/Purchase/WithAddItem.php
+++ b/app/Traits/Purchase/WithAddItem.php
@@ -84,7 +84,7 @@ public function addItem(string $type): void
                 'total_price' => $costPrice * $quantity,
             ]);
 
-            $this->purchaseItems->push($item);
+            $this->purchaseItems->prepend($item);
 
             $this->toast(Str::ucfirst($type).' ditambahkan ke keranjang.', 'Berhasil');
         }
diff --git a/app/Traits/Purchase/WithUpdateItem.php b/app/Traits/Purchase/WithUpdateItem.php
index 231276b..91e4b4c 100644
--- a/app/Traits/Purchase/WithUpdateItem.php
+++ b/app/Traits/Purchase/WithUpdateItem.php
@@ -27,11 +27,25 @@ public function closeModal()
 
     public function updateItem(): void
     {
+        $quantity = parseRupiahToInt($this->form->quantity_edit);
+
+        if ($quantity <= 0) {
+            $this->toast('Jumlah item tidak valid.', 'Gagal', 'danger');
+
+            return;
+        }
+
         $item = PurchaseItem::find($this->form->item_id);
 
+        if (! $item) {
+            $this->toast('Item tidak found.', 'Gagal', 'danger');
+
+            return;
+        }
+
         $item->update([
-            'quantity' => parseRupiahToInt($this->form->quantity_edit),
-            'total_price' => (int) $item->purchasable->cost_price * (int) parseRupiahToInt($this->form->quantity_edit),
+            'quantity' => $quantity,
+            'total_price' => (int) $item->purchasable->cost_price * $quantity,
         ]);
 
         $item->refresh();
diff --git a/app/Traits/Purchase/WithUpdateStock.php b/app/Traits/Purchase/WithUpdateStock.php
index 307a599..56ab602 100644
--- a/app/Traits/Purchase/WithUpdateStock.php
+++ b/app/Traits/Purchase/WithUpdateStock.php
@@ -27,7 +27,12 @@ public function increaseOutletStock($outlet, $item): void
                 return;
         }
 
-        $existing = $outlet->{$relation}()->withPivot('stock')->where("{$relation}.id", $item->purchasable_id)->first();
+        // Lock the row to prevent race conditions
+        $existing = $outlet->{$relation}()
+            ->where("{$relation}.id", $item->purchasable_id)
+            ->lockForUpdate()
+            ->withPivot('stock')
+            ->first();
 
         if ($existing) {
             $previousStock = $existing->pivot->stock ?? 0;
@@ -76,7 +81,11 @@ public function decreaseOutletStock($outlet, $item): void
                 return;
         }
 
-        $existing = $outlet->{$relation}()->withPivot('stock')->where("{$relation}.id", $item->purchasable_id)->first();
+        $existing = $outlet->{$relation}()
+            ->where("{$relation}.id", $item->purchasable_id)
+            ->lockForUpdate()
+            ->withPivot('stock')
+            ->first();
 
         if ($existing) {
             $currentStock = $existing->pivot->stock ?? 0;
@@ -84,6 +93,11 @@ public function decreaseOutletStock($outlet, $item): void
             $outlet->{$relation}()->updateExistingPivot($item->purchasable_id, [
                 'stock' => $newStock,
             ]);
+        } else {
+            // Handle case where stock doesn't exist but we are decreasing?
+            // Should not happen in normal flow, but good to handle.
+            $currentStock = 0;
+            $newStock = 0;
         }
 
         StockActivityLogService::log(
diff --git a/resources/views/livewire/studio/manage/order/form.blade.php b/resources/views/livewire/studio/manage/order/form.blade.php
index 7d5bc78..708ea40 100644
--- a/resources/views/livewire/studio/manage/order/form.blade.php
+++ b/resources/views/livewire/studio/manage/order/form.blade.php
@@ -15,7 +15,7 @@
             <div class="grid grid-cols-1 md:grid-cols-4 gap-6">
                 <flux:field>
                     <flux:label>Outlet <span class="text-red-500 ms-1">*</span></flux:label>
-                    <flux:select variant="listbox" searchable placeholder="Pilih Outlet" wire:model="form.outlet_id">
+                    <flux:select variant="listbox" searchable placeholder="Pilih Outlet" wire:model.live="form.outlet_id">
                         @foreach ($outlets as $key => $value)
                             <flux:select.option value="{{ $key }}">
                                 {{ $value }}
diff --git a/resources/views/livewire/studio/manage/purchase/form.blade.php b/resources/views/livewire/studio/manage/purchase/form.blade.php
index b2e5050..9a77f46 100644
--- a/resources/views/livewire/studio/manage/purchase/form.blade.php
+++ b/resources/views/livewire/studio/manage/purchase/form.blade.php
@@ -50,7 +50,7 @@
                         <flux:field>
                             <flux:label>Outlet <span class="text-red-500 ms-1">*</span></flux:label>
                             <flux:select variant="listbox" searchable placeholder="Pilih Outlet"
-                                wire:model="form.outlet_id">
+                                wire:model.live="form.outlet_id">
                                 @foreach ($outlets as $key => $value)
                                     <flux:select.option value="{{ $key }}">{{ $value }}
                                     </flux:select.option>