first commit

src/Meezi.API/Services/OrderService.cs

@@ -55,6 +55,12 @@ public interface IOrderService
         string targetTableId,
         CancellationToken cancellationToken = default);
     Task<OrderDto?> UpdateStatusAsync(string cafeId, string orderId, OrderStatus status, CancellationToken cancellationToken = default);
+    Task<OrderServiceResult<OrderDto>> CancelOrderAsync(
+        string cafeId,
+        string orderId,
+        string? reason,
+        string? cancelledByEmployeeId,
+        CancellationToken cancellationToken = default);
     Task<OrderServiceResult<IReadOnlyList<PaymentDto>>> RecordPaymentsAsync(
         string cafeId,
         string orderId,
@@ -957,6 +963,53 @@ public class OrderService : IOrderService
         return await GetOrderAsync(cafeId, orderId, cancellationToken);
     }
 
+    public async Task<OrderServiceResult<OrderDto>> CancelOrderAsync(
+        string cafeId,
+        string orderId,
+        string? reason,
+        string? cancelledByEmployeeId,
+        CancellationToken cancellationToken = default)
+    {
+        var order = await _db.Orders
+            .Include(o => o.Payments)
+            .FirstOrDefaultAsync(o => o.Id == orderId && o.CafeId == cafeId, cancellationToken);
+
+        if (order is null)
+            return new OrderServiceResult<OrderDto>(false, null, "ORDER_NOT_FOUND");
+
+        if (order.Status == OrderStatus.Cancelled)
+            return new OrderServiceResult<OrderDto>(false, null, "ORDER_ALREADY_CANCELLED");
+
+        if (!OpenForPaymentStatuses.Contains(order.Status))
+            return new OrderServiceResult<OrderDto>(false, null, "ORDER_NOT_OPEN");
+
+        // A paid order must be refunded through the payment flow first — cancelling it
+        // here would silently strip the recorded money. Block and surface the reason.
+        if (order.Payments.Any(p => p.DeletedAt == null))
+            return new OrderServiceResult<OrderDto>(false, null, "ORDER_HAS_PAYMENTS");
+
+        order.Status = OrderStatus.Cancelled;
+        order.StatusUpdatedAt = DateTime.UtcNow;
+        order.CancelledAt = DateTime.UtcNow;
+        order.CancelReason = string.IsNullOrWhiteSpace(reason) ? null : reason.Trim();
+        order.CancelledByEmployeeId = cancelledByEmployeeId;
+        await _db.SaveChangesAsync(cancellationToken);
+
+        await _kdsNotifier.NotifyOrderStatusChangedAsync(cafeId, orderId, OrderStatus.Cancelled, cancellationToken);
+        if (!string.IsNullOrEmpty(order.TableId))
+            await _kdsNotifier.NotifyTableStatusChangedAsync(cafeId, cancellationToken);
+
+        await _deliverySync.SyncInternalStatusAsync(cafeId, orderId, OrderStatus.Cancelled, cancellationToken);
+
+        var loaded = await LoadOrderAsync(cafeId, orderId, cancellationToken);
+        if (loaded is not null)
+            await _orderNotifications.NotifyOrderStatusChangedAsync(loaded, cancellationToken);
+
+        return loaded is null
+            ? new OrderServiceResult<OrderDto>(false, null, "ORDER_NOT_FOUND")
+            : new OrderServiceResult<OrderDto>(true, MapOrder(loaded));
+    }
+
     public async Task<OrderServiceResult<IReadOnlyList<PaymentDto>>> RecordPaymentsAsync(
         string cafeId,
         string orderId,