fix(pifs): roll back add-created folders

pageindex/filesystem/store.py

@@ -1063,6 +1063,48 @@ class SQLiteFileSystemStore:
             conn.execute("DELETE FROM metadata_values WHERE file_ref = ?", (file_ref,))
             conn.execute("DELETE FROM files WHERE file_ref = ?", (file_ref,))
 
+    def folder_exists(self, path: str) -> bool:
+        path = normalize_path(path)
+        with self.connect() as conn:
+            row = conn.execute(
+                "SELECT 1 FROM folders WHERE path = ?",
+                (path,),
+            ).fetchone()
+        return row is not None
+
+    def delete_empty_folder(self, path: str) -> bool:
+        path = normalize_path(path)
+        if path == "/":
+            return False
+        with self.connect() as conn:
+            folder = self._folder_by_path(conn, path)
+            if folder is None:
+                return False
+            has_files = conn.execute(
+                """
+                SELECT 1
+                FROM file_folders
+                WHERE folder_id = ?
+                LIMIT 1
+                """,
+                (folder["folder_id"],),
+            ).fetchone()
+            if has_files is not None:
+                return False
+            has_children = conn.execute(
+                """
+                SELECT 1
+                FROM folders
+                WHERE parent_id = ?
+                LIMIT 1
+                """,
+                (folder["folder_id"],),
+            ).fetchone()
+            if has_children is not None:
+                return False
+            conn.execute("DELETE FROM folders WHERE folder_id = ?", (folder["folder_id"],))
+            return True
+
     def resolve_file_ref(self, target: str) -> str:
         with self.connect() as conn:
             return self._resolve_file_ref(conn, target)