fix top menu

app/service/menuService/menuService.go

@@ -99,32 +99,40 @@ func (a ByPosition) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }
 func (a ByPosition) Less(i, j int) bool { return a[i].Position < a[j].Position }
 
 func (s *MenuService) GetTopMenu(id uint) ([]model.B2BTopMenu, error) {
-	menuMap := make(map[int]*model.B2BTopMenu)
-	var roots []model.B2BTopMenu
-
 	items, err := s.routesRepo.GetTopMenu(id)
 	if err != nil {
 		return nil, err
 	}
 
-	// Build the map first
-	for i := range items {
-		items[i].Children = []model.B2BTopMenu{}
-		menuMap[items[i].MenuID] = &items[i]
+	if len(items) == 0 {
+		return []model.B2BTopMenu{}, nil
 	}
 
-	// Then link children to parents
-	for _, item := range menuMap {
-		if item.ParentID != nil && *item.ParentID != 0 {
-			parent, exists := menuMap[*item.ParentID]
-			if exists {
-				parent.Children = append(parent.Children, *item)
-			}
+	// Build a map with empty children slices
+	itemMap := make(map[int]model.B2BTopMenu, len(items))
+	for i := range items {
+		items[i].Children = []model.B2BTopMenu{}
+		itemMap[items[i].MenuID] = items[i]
+	}
+
+	// Build the tree
+	var roots []model.B2BTopMenu
+	for _, item := range itemMap {
+		if item.ParentID == nil || *item.ParentID == 0 {
+			roots = append(roots, itemMap[item.MenuID])
 		} else {
-			// This is a root item
-			roots = append(roots, *item)
+			parentID := *item.ParentID
+			if parent, exists := itemMap[parentID]; exists {
+				parent.Children = append(parent.Children, item)
+				itemMap[parentID] = parent
+			}
 		}
 	}
 
+	// Update roots with children
+	for i := range roots {
+		roots[i] = itemMap[roots[i].MenuID]
+	}
+
 	return roots, nil
 }