add function to add item

internal/services/v2/inprogress_order/in_progress_order.go

@@ -14,9 +14,11 @@ type InProgressOrderService interface {
 	Save(ctx mycontext.Context, order *entity.OrderRequest) (*entity.Order, error)
 	GetOrdersByPartnerID(ctx mycontext.Context, partnerID int64, limit, offset int) ([]*entity.Order, error)
 	GetOrderByOrderAndPartnerID(ctx mycontext.Context, partnerID int64, orderID int64) (*entity.Order, error)
+	AddItems(ctx mycontext.Context, orderID int64, newItems []entity.OrderItemRequest) (*entity.Order, error)
 }
 
 type OrderRepository interface {
+	FindByID(ctx mycontext.Context, id int64) (*entity.Order, error)
 	CreateOrUpdate(ctx mycontext.Context, order *entity.Order) (*entity.Order, error)
 	GetListByPartnerID(ctx mycontext.Context, partnerID int64, limit, offset int, status string) ([]*entity.Order, error)
 	FindByIDAndPartnerID(ctx mycontext.Context, id int64, partnerID int64) (*entity.Order, error)
@@ -124,6 +126,50 @@ func (s *inProgressOrderSvc) GetOrdersByPartnerID(ctx mycontext.Context, partner
 	return orders, nil
 }
 
+func (s *inProgressOrderSvc) AddItems(ctx mycontext.Context, orderID int64, newItems []entity.OrderItemRequest) (*entity.Order, error) {
+	existingOrder, err := s.repo.FindByID(ctx, orderID)
+	if err != nil {
+		return nil, errors.Wrapf(err, "failed to fetch order %d", orderID)
+	}
+
+	itemMap := make(map[int64]entity.OrderItemRequest, len(existingOrder.OrderItems)+len(newItems))
+
+	for _, oi := range existingOrder.OrderItems {
+		itemMap[oi.ItemID] = entity.OrderItemRequest{
+			ProductID: oi.ItemID,
+			Quantity:  oi.Quantity,
+		}
+	}
+
+	for _, ni := range newItems {
+		if existing, found := itemMap[ni.ProductID]; found {
+			existing.Quantity += ni.Quantity
+			itemMap[ni.ProductID] = existing
+		} else {
+			itemMap[ni.ProductID] = ni
+		}
+	}
+
+	mergedItems := make([]entity.OrderItemRequest, 0, len(itemMap))
+	for _, item := range itemMap {
+		mergedItems = append(mergedItems, item)
+	}
+
+	req := &entity.OrderRequest{
+		ID:           existingOrder.ID,
+		PartnerID:    existingOrder.PartnerID,
+		CustomerID:   existingOrder.CustomerID,
+		CustomerName: existingOrder.CustomerName,
+		CreatedBy:    existingOrder.CreatedBy,
+		TableNumber:  existingOrder.TableNumber,
+		OrderType:    existingOrder.OrderType,
+		Source:       existingOrder.Source,
+		OrderItems:   mergedItems,
+	}
+
+	return s.Save(ctx, req)
+}
+
 func (s *inProgressOrderSvc) GetOrderByOrderAndPartnerID(ctx mycontext.Context, partnerID int64, orderID int64) (*entity.Order, error) {
 	orders, err := s.repo.FindByIDAndPartnerID(ctx, orderID, partnerID)
 	if err != nil {