From 99e55902ac3c55bb683f1b9dc46be83c37d95a42 Mon Sep 17 00:00:00 2001
From: Konstantinos Arvanitakis <arvanitakis@radical-elements.com>
Date: Thu, 10 Sep 2026 01:34:30 +0300
Subject: [PATCH] Feat: Updating OrderPlaced Listeners to Decrement Stock,
 Creating Notifications

---
 .../order/notifications/placed.blade.php      | 11 ++++
 src/Catalog/Services/ProductIndexer.php       |  8 ++-
 .../Listeners/DecrementStockOnOrderPlaced.php | 64 +++++++++++++++++++
 .../Notifications/OrderPlacedNotification.php | 62 ++++++++++++++++++
 src/Providers/OrderServiceProvider.php        |  5 ++
 5 files changed, 148 insertions(+), 2 deletions(-)
 create mode 100644 resources/views/order/notifications/placed.blade.php
 create mode 100644 src/Order/Listeners/DecrementStockOnOrderPlaced.php
 create mode 100644 src/Order/Notifications/OrderPlacedNotification.php

diff --git a/resources/views/order/notifications/placed.blade.php b/resources/views/order/notifications/placed.blade.php
new file mode 100644
index 0000000..0e1b7aa
--- /dev/null
+++ b/resources/views/order/notifications/placed.blade.php
@@ -0,0 +1,11 @@
+<p>Hi,</p>
+
+<p>Thanks for your order! Your order <strong>{{ $reference }}</strong> is confirmed.</p>
+
+<ul>
+    @foreach ($lines as $line)
+        <li>{{ $line->quantity }} &times; {{ $line->description }} — {{ $line->total?->formatted }}</li>
+    @endforeach
+</ul>
+
+<p>Total: <strong>{{ $total }}</strong></p>
diff --git a/src/Catalog/Services/ProductIndexer.php b/src/Catalog/Services/ProductIndexer.php
index bf97f38..0ed4516 100644
--- a/src/Catalog/Services/ProductIndexer.php
+++ b/src/Catalog/Services/ProductIndexer.php
@@ -47,8 +47,12 @@ use Spatie\MediaLibrary\MediaCollections\Models\Media;
  *     quantity 1, via ProductVariant::canBeFulfilledAtQuantity() (Lunar's own
  *     purchasability rule: `purchasable === 'always'` is always true regardless of
  *     stock, `in_stock` checks stock alone, anything else checks stock+backorder).
- *     Reflects stock as of the last reindex only — nothing currently reindexes a
- *     product when an order decrements its stock (see docs/product-listing.md).
+ *     Modules\Core\Order\Listeners\DecrementStockOnOrderPlaced reindexes a product
+ *     the moment an order placed against it decrements its stock — see that
+ *     class's own docblock for why only `purchasable === 'in_stock'`
+ *     variants are ever touched. Any other stock edit (a manual admin
+ *     change, a future inventory-sync integration) still only reflects here
+ *     as of the next reindex (see docs/product-listing.md).
  *
  *   - recommendations (recommendations.id filterable): [{id, name, price, image}, ...]
  *     up to 4 other products to show alongside this one (a "related products"
diff --git a/src/Order/Listeners/DecrementStockOnOrderPlaced.php b/src/Order/Listeners/DecrementStockOnOrderPlaced.php
new file mode 100644
index 0000000..67e497f
--- /dev/null
+++ b/src/Order/Listeners/DecrementStockOnOrderPlaced.php
@@ -0,0 +1,64 @@
+<?php
+
+namespace Modules\Core\Order\Listeners;
+
+use Illuminate\Support\Facades\DB;
+use Lunar\Models\Product;
+use Lunar\Models\ProductVariant;
+use Modules\Core\Checkout\Events\OrderPlaced;
+
+/**
+ * The only place ProductVariant::stock is written as a result of an order —
+ * fires once per order regardless of capture_mode/driver, same reasoning as
+ * Modules\Core\Order\Notifications\OrderPlacedNotification: OrderPlaced is
+ * dispatched exactly once, from the one place an order's placed_at
+ * actually gets set (Modules\Core\Order\Listeners\ApplyResolvedPaymentStatus),
+ * so this can't double-decrement across a capture/authorize/refund sequence
+ * the way listening to PaymentCaptured directly could.
+ *
+ * Only decrements for `purchasable === 'in_stock'` variants — 'always' and
+ * 'backorder' variants are deliberately allowed to sell past (or without
+ * regard to) their stock count already (see ProductVariant::
+ * canBeFulfilledAtQuantity()), so decrementing their stock would just make
+ * that column an inaccurate, decreasingly-negative number with no purchasing
+ * consequence. Only `OrderLine::type === 'physical'` lines are considered —
+ * a digital line has no stock to decrement (ProductVariant::getType()).
+ *
+ * A single UPDATE per variant (`DB::table(...)->decrement()`), not a
+ * read-then-write on the Eloquent model — avoids a lost-update race between
+ * two orders decrementing the same variant concurrently, and skips
+ * Modules\Core\Catalog\Services\ProductIndexer::stock's staleness gap for
+ * the DB value itself even though the search index still only refreshes on
+ * the next reindex event/nightly job (see that class's own docblock).
+ *
+ * Never lets stock go negative (`GREATEST(stock - qty, 0)` via a raw
+ * expression) — an order can still be placed against a variant whose stock
+ * was already fully consumed by another concurrent order (Lunar has no
+ * stock-reservation step at cart/checkout time), so this is a best-effort
+ * count, not a hard inventory guarantee.
+ */
+class DecrementStockOnOrderPlaced
+{
+    public function handle(OrderPlaced $event): void
+    {
+        $lines = $event->order->lines()
+            ->where('type', 'physical')
+            ->where('purchasable_type', ProductVariant::morphName())
+            ->get(['purchasable_id', 'quantity']);
+
+        foreach ($lines as $line) {
+            DB::table((new ProductVariant())->getTable())
+                ->where('id', $line->purchasable_id)
+                ->where('purchasable', 'in_stock')
+                ->update([
+                    'stock' => DB::raw('GREATEST(stock - '.(int) $line->quantity.', 0)'),
+                ]);
+        }
+
+        $productIds = ProductVariant::whereIn('id', $lines->pluck('purchasable_id'))
+            ->pluck('product_id')
+            ->unique();
+
+        Product::whereIn('id', $productIds)->get()->each->searchable();
+    }
+}
diff --git a/src/Order/Notifications/OrderPlacedNotification.php b/src/Order/Notifications/OrderPlacedNotification.php
new file mode 100644
index 0000000..b2138c3
--- /dev/null
+++ b/src/Order/Notifications/OrderPlacedNotification.php
@@ -0,0 +1,62 @@
+<?php
+
+namespace Modules\Core\Order\Notifications;
+
+use Illuminate\Notifications\AnonymousNotifiable;
+use Illuminate\Notifications\Messages\MailMessage;
+use Illuminate\Support\Facades\Notification as NotificationFacade;
+use Modules\Core\Checkout\Events\OrderPlaced;
+use Modules\Core\Notification\BaseNotification;
+
+/**
+ * The order confirmation email — fires once, for every capture_mode and
+ * driver alike (Stripe, offline, bank-transfer), since OrderPlaced is
+ * dispatched from the one place an order's placed_at actually gets set
+ * (Modules\Core\Order\Listeners\ApplyResolvedPaymentStatus), not from a
+ * driver-specific event like OrderCaptured. Before this existed, an
+ * offline/bank-transfer order got no placement email at all — only a
+ * Stripe (auto-captured) order did, via OrderCapturedNotification, which is
+ * a different concern (payment confirmation, not order confirmation) that
+ * happens to fire at the same moment for that one driver.
+ */
+class OrderPlacedNotification extends BaseNotification
+{
+    public function __construct(private readonly OrderPlaced $event) {}
+
+    public static function getKey(): string
+    {
+        return 'order.placed.customer.mail';
+    }
+
+    public static function listensTo(): string
+    {
+        return OrderPlaced::class;
+    }
+
+    public function via(object $notifiable): array
+    {
+        return ['mail'];
+    }
+
+    public function notifiable(): AnonymousNotifiable
+    {
+        $order = $this->event->order;
+
+        $email = $order->billingAddress?->contact_email ?? $order->shippingAddress?->contact_email;
+
+        return NotificationFacade::route('mail', $email);
+    }
+
+    public function toMail(object $notifiable): MailMessage
+    {
+        $order = $this->event->order;
+
+        return (new MailMessage)
+            ->subject(__('Your order :reference is confirmed', ['reference' => $order->reference]))
+            ->view('core::order.notifications.placed', [
+                'reference' => $order->reference,
+                'total' => $order->total->formatted,
+                'lines' => $order->lines,
+            ]);
+    }
+}
diff --git a/src/Providers/OrderServiceProvider.php b/src/Providers/OrderServiceProvider.php
index 764847c..7566e8c 100644
--- a/src/Providers/OrderServiceProvider.php
+++ b/src/Providers/OrderServiceProvider.php
@@ -6,12 +6,15 @@ use Illuminate\Support\Facades\Event;
 use Illuminate\Support\ServiceProvider;
 use Lunar\Models\Order;
 use Lunar\Models\Transaction;
+use Modules\Core\Checkout\Events\OrderPlaced;
 use Modules\Core\Notification\NotificationRegistry;
 use Modules\Core\Order\Listeners\ApplyResolvedPaymentStatus;
+use Modules\Core\Order\Listeners\DecrementStockOnOrderPlaced;
 use Modules\Core\Order\Listeners\DeriveOrderDeliveredFromShipment;
 use Modules\Core\Order\Listeners\RecordPaymentTransaction;
 use Modules\Core\Order\Notifications\OrderCapturedNotification;
 use Modules\Core\Order\Notifications\OrderDeliveredNotification;
+use Modules\Core\Order\Notifications\OrderPlacedNotification;
 use Modules\Core\Order\Notifications\OrderRefundedNotification;
 use Modules\Core\Order\Notifications\OrderStatusUpdatedNotification;
 use Modules\Core\Order\Observers\OrderObserver;
@@ -41,12 +44,14 @@ class OrderServiceProvider extends ServiceProvider
         Event::listen(PaymentAuthorized::class, RecordPaymentTransaction::class);
         Event::listen(PaymentVoided::class, RecordPaymentTransaction::class);
         Event::listen(PaymentRefunded::class, RecordPaymentTransaction::class);
+        Event::listen(OrderPlaced::class, DecrementStockOnOrderPlaced::class);
 
         NotificationRegistry::get()->register([
             OrderDeliveredNotification::class,
             OrderStatusUpdatedNotification::class,
             OrderRefundedNotification::class,
             OrderCapturedNotification::class,
+            OrderPlacedNotification::class,
         ]);
 
         // Lets the consuming app override copy/markup without forking core