Nested folders: Provide count of all descendant dashboards and folders (#67184)

* Add a method for getting descendant folders
* Include dashboard count for descendant folders
* Return subfolder count
* Replace references to children with descendants
* Update openapi specs
* Add test for descendant counts
* Add logging to GetDescendantCounts

pkg/services/folder/folderimpl/folder.go

@@ -20,6 +20,7 @@ import (
 	"github.com/grafana/grafana/pkg/services/org"
 	"github.com/grafana/grafana/pkg/services/sqlstore"
 	"github.com/grafana/grafana/pkg/services/sqlstore/migrator"
+	"github.com/grafana/grafana/pkg/services/store/entity"
 	"github.com/grafana/grafana/pkg/services/user"
 	"github.com/grafana/grafana/pkg/setting"
 	"github.com/grafana/grafana/pkg/util"
@@ -623,7 +624,8 @@ func (s *Service) nestedFolderDelete(ctx context.Context, cmd *folder.DeleteFold
 	return result, nil
 }
 
-func (s *Service) GetChildrenCounts(ctx context.Context, cmd *folder.GetChildrenCountsQuery) (folder.ChildrenCounts, error) {
+func (s *Service) GetDescendantCounts(ctx context.Context, cmd *folder.GetDescendantCountsQuery) (folder.DescendantCounts, error) {
+	logger := s.log.FromContext(ctx)
 	if cmd.SignedInUser == nil {
 		return nil, folder.ErrBadRequest.Errorf("missing signed-in user")
 	}
@@ -634,15 +636,47 @@ func (s *Service) GetChildrenCounts(ctx context.Context, cmd *folder.GetChildren
 		return nil, folder.ErrBadRequest.Errorf("invalid orgID")
 	}
 
-	countsMap := make(folder.ChildrenCounts, len(s.registry))
+	result := []string{*cmd.UID}
+	countsMap := make(folder.DescendantCounts, len(s.registry)+1)
+	if s.features.IsEnabled(featuremgmt.FlagNestedFolders) {
+		subfolders, err := s.getNestedFolders(ctx, cmd.OrgID, *cmd.UID)
+		if err != nil {
+			logger.Error("failed to get subfolders", "error", err)
+			return nil, err
+		}
+		result = append(result, subfolders...)
+		countsMap[entity.StandardKindFolder] = int64(len(subfolders))
+	}
+
 	for _, v := range s.registry {
-		c, err := v.CountInFolder(ctx, cmd.OrgID, *cmd.UID, cmd.SignedInUser)
+		for _, folder := range result {
+			c, err := v.CountInFolder(ctx, cmd.OrgID, folder, cmd.SignedInUser)
+			if err != nil {
+				logger.Error("failed to count folder descendants", "error", err)
+				return nil, err
+			}
+			countsMap[v.Kind()] += c
+		}
+	}
+	return countsMap, nil
+}
+
+func (s *Service) getNestedFolders(ctx context.Context, orgID int64, uid string) ([]string, error) {
+	result := []string{}
+	folders, err := s.store.GetChildren(ctx, folder.GetChildrenQuery{UID: uid, OrgID: orgID})
+	if err != nil {
+		return nil, err
+	}
+
+	for _, f := range folders {
+		result = append(result, f.UID)
+		subfolders, err := s.getNestedFolders(ctx, f.OrgID, f.UID)
 		if err != nil {
 			return nil, err
 		}
-		countsMap[v.Kind()] += c
+		result = append(result, subfolders...)
 	}
-	return countsMap, nil
+	return result, nil
 }
 
 // MakeUserAdmin is copy of DashboardServiceImpl.MakeUserAdmin