Update app.py

app.py

@@ -156,12 +156,12 @@ class SessionStateDefaults:
     
     # Chat System
     chat_ready: bool = False
-    messages: list[BaseMessage] = None  # Will be initialized as empty list
+    messages: Optional[List] = None  # Changed from list[BaseMessage]
     current_chat_id: Optional[int] = None
     
     # Document Processing
-    vector_store: Optional[FAISS] = None
-    qa_system: Optional[ConversationalRetrievalChain] = None
+    vector_store: Optional[Any] = None
+    qa_system: Optional[Any] = None
     
     # State Management
     reinitialize_chat: bool = False
@@ -170,9 +170,6 @@ class SessionStateDefaults:
 def initialize_session_state() -> None:
     """
     Initialize all session state variables with proper typing and documentation.
-    
-    This function ensures all necessary session state variables are properly initialized
-    with appropriate default values and types.
     """
     defaults = SessionStateDefaults()
     
@@ -247,10 +244,6 @@ def get_current_state() -> Dict[str, Any]:
         key: value for key, value in st.session_state.items()
         if not key.startswith('_')  # Exclude internal Streamlit states
     }
-    
-    for key, default_value in default_states.items():
-        if key not in st.session_state:
-            st.session_state[key] = default_value
 
 def display_top_bar():
     """Display the application's top navigation bar."""