Standardize tenant DB directory to db with legacy migration

backend/services/database.py

@@ -53,16 +53,57 @@ WORKSPACE_DIR = os.path.join(ROOT_DIR, 'workspace')
 # Engine cache for multi-tenant support
 _user_engines = {}
 
+
+def _sanitize_user_id(user_id: str) -> str:
+    """Sanitize user_id to be safe for filesystem."""
+    return "".join(c for c in user_id if c.isalnum() or c in ('-', '_'))
+
+
+def ensure_user_workspace_db_directory(user_id: str) -> str:
+    """Ensure modern `db/` directory exists, migrating legacy `database/` when safe."""
+    safe_user_id = _sanitize_user_id(user_id)
+    user_workspace = os.path.join(WORKSPACE_DIR, f"workspace_{safe_user_id}")
+    db_dir = os.path.join(user_workspace, 'db')
+    legacy_db_dir = os.path.join(user_workspace, 'database')
+
+    if os.path.isdir(legacy_db_dir) and not os.path.exists(db_dir):
+        try:
+            os.rename(legacy_db_dir, db_dir)
+            logger.info(f"Migrated legacy database directory to db/: {user_workspace}")
+        except OSError as rename_error:
+            logger.warning(
+                f"Could not rename legacy database directory for {user_workspace}: {rename_error}"
+            )
+            os.makedirs(db_dir, exist_ok=True)
+            for filename in os.listdir(legacy_db_dir):
+                src = os.path.join(legacy_db_dir, filename)
+                dst = os.path.join(db_dir, filename)
+                if os.path.isfile(src) and not os.path.exists(dst):
+                    try:
+                        os.link(src, dst)
+                    except OSError:
+                        # Fall back to copy when hard-linking is not possible.
+                        import shutil
+                        shutil.copy2(src, dst)
+    else:
+        os.makedirs(db_dir, exist_ok=True)
+
+    return db_dir
+
 def get_user_db_path(user_id: str) -> str:
     """Get the database path for a specific user."""
-    # Sanitize user_id to be safe for filesystem
-    safe_user_id = "".join(c for c in user_id if c.isalnum() or c in ('-', '_'))
+    safe_user_id = _sanitize_user_id(user_id)
     user_workspace = os.path.join(WORKSPACE_DIR, f"workspace_{safe_user_id}")
+    db_dir = ensure_user_workspace_db_directory(user_id)
     
     # Check for legacy naming convention first (to support existing data)
     # Some older workspaces might have 'alwrity.db' instead of 'alwrity_{user_id}.db'
-    legacy_db_path = os.path.join(user_workspace, 'db', 'alwrity.db')
-    specific_db_path = os.path.join(user_workspace, 'db', f'alwrity_{safe_user_id}.db')
+    legacy_db_path = os.path.join(db_dir, 'alwrity.db')
+    specific_db_path = os.path.join(db_dir, f'alwrity_{safe_user_id}.db')
+
+    # Backward compatibility when filesystem migration couldn't run yet.
+    legacy_dir_path = os.path.join(user_workspace, 'database', f'alwrity_{safe_user_id}.db')
+    legacy_dir_default = os.path.join(user_workspace, 'database', 'alwrity.db')
     
     # If the specific one exists, use it (preferred)
     if os.path.exists(specific_db_path):
@@ -71,6 +112,12 @@ def get_user_db_path(user_id: str) -> str:
     # If legacy exists and specific doesn't, use legacy
     if os.path.exists(legacy_db_path):
         return legacy_db_path
+
+    if os.path.exists(legacy_dir_path):
+        return legacy_dir_path
+
+    if os.path.exists(legacy_dir_default):
+        return legacy_dir_default
         
     # Default to specific for new databases
     return specific_db_path