fix(scanner): execute GetFolderUpdateInfo in batches to avoid "Expression tree is too large (maximum depth 1000)"

Signed-off-by: Deluan <deluan@navidrome.org>

persistence/folder_repository.go

@@ -95,24 +95,57 @@ func (r folderRepository) CountAll(opt ...model.QueryOptions) (int64, error) {
 }
 
 func (r folderRepository) GetFolderUpdateInfo(lib model.Library, targetPaths ...string) (map[string]model.FolderUpdateInfo, error) {
+	// If no specific paths, return all folders in the library
+	if len(targetPaths) == 0 {
+		return r.getFolderUpdateInfoAll(lib)
+	}
+
+	// Check if any path is root (return all folders)
+	for _, targetPath := range targetPaths {
+		if targetPath == "" || targetPath == "." {
+			return r.getFolderUpdateInfoAll(lib)
+		}
+	}
+
+	// Process paths in batches to avoid SQLite's expression tree depth limit (max 1000).
+	// Each path generates ~3 conditions, so batch size of 100 keeps us well under the limit.
+	const batchSize = 100
+	result := make(map[string]model.FolderUpdateInfo)
+
+	for batch := range slices.Chunk(targetPaths, batchSize) {
+		batchResult, err := r.getFolderUpdateInfoBatch(lib, batch)
+		if err != nil {
+			return nil, err
+		}
+		for id, info := range batchResult {
+			result[id] = info
+		}
+	}
+
+	return result, nil
+}
+
+// getFolderUpdateInfoAll returns update info for all non-missing folders in the library
+func (r folderRepository) getFolderUpdateInfoAll(lib model.Library) (map[string]model.FolderUpdateInfo, error) {
+	where := And{
+		Eq{"library_id": lib.ID},
+		Eq{"missing": false},
+	}
+	return r.queryFolderUpdateInfo(where)
+}
+
+// getFolderUpdateInfoBatch returns update info for a batch of target paths and their descendants
+func (r folderRepository) getFolderUpdateInfoBatch(lib model.Library, targetPaths []string) (map[string]model.FolderUpdateInfo, error) {
 	where := And{
 		Eq{"library_id": lib.ID},
 		Eq{"missing": false},
 	}
 
-	// If specific paths are requested, include those folders and all their descendants
-	if len(targetPaths) > 0 {
 	// Collect folder IDs for exact target folders and path conditions for descendants
 	folderIDs := make([]string, 0, len(targetPaths))
 	pathConditions := make(Or, 0, len(targetPaths)*2)
 
 	for _, targetPath := range targetPaths {
-			if targetPath == "" || targetPath == "." {
-				// Root path - include everything in this library
-				pathConditions = Or{}
-				folderIDs = nil
-				break
-			}
 		// Clean the path to normalize it. Paths stored in the folder table do not have leading/trailing slashes.
 		cleanPath := strings.TrimPrefix(targetPath, string(os.PathSeparator))
 		cleanPath = filepath.Clean(cleanPath)
@@ -132,8 +165,12 @@ func (r folderRepository) GetFolderUpdateInfo(lib model.Library, targetPaths ...
 	} else if len(pathConditions) > 0 {
 		where = append(where, pathConditions)
 	}
-	}
 
+	return r.queryFolderUpdateInfo(where)
+}
+
+// queryFolderUpdateInfo executes the query and returns the result map
+func (r folderRepository) queryFolderUpdateInfo(where And) (map[string]model.FolderUpdateInfo, error) {
 	sq := r.newSelect().Columns("id", "updated_at", "hash").Where(where)
 	var res []struct {
 		ID        string