fix: 编辑订单时恢复旧库存并扣减新库存

src/main/java/com/example/building/service/impl/OrderServiceImpl.java

@@ -366,10 +366,17 @@ public class OrderServiceImpl implements OrderService {
         // 重新计算金额
         BigDecimal totalAmount = BigDecimal.ZERO;
         
+        // 删除旧的订单明细前，先恢复库存
+        List<OrderItem> oldItems = orderItemMapper.selectList(new LambdaQueryWrapper<OrderItem>()
+                .eq(OrderItem::getOrderId, orderId));
+        for (OrderItem oldItem : oldItems) {
+            increaseStock(oldItem.getProductId(), oldItem.getQuantity(), orderId, operatorId);
+        }
+        
         // 删除旧的订单明细
         orderItemMapper.delete(new LambdaQueryWrapper<OrderItem>().eq(OrderItem::getOrderId, orderId));
         
-        // 重新创建订单明细
+        // 重新创建订单明细，并扣减库存
         List<OrderItem> orderItems = new ArrayList<>();
         for (CreateOrderRequest.OrderItemDTO itemDTO : request.getItems()) {
             Product product = productMapper.selectById(itemDTO.getProductId());
@@ -403,6 +410,8 @@ public class OrderServiceImpl implements OrderService {
             item.setSubtotal(subtotal);
             orderItems.add(item);
             orderItemMapper.insert(item);
+            // 扣减库存
+            decreaseStock(product.getProductId(), itemDTO.getQuantity(), orderId, operatorId);
         }
         
         order.setTotalAmount(totalAmount);