Update app.py

app.py

@@ -142,6 +142,36 @@ def display_top_bar():
         if st.session_state.current_collection:
             st.info(f"📁 Active Collection: {st.session_state.current_collection['name']}")
 
+def initialize_chat_from_existing():
+    """Initialize chat system from existing documents in database."""
+    if not st.session_state.get('chat_ready'):
+        try:
+            documents = get_all_documents(st.session_state.db_conn)
+            if documents:
+                # Initialize vector store and QA system with existing documents
+                embeddings = get_embeddings_model()
+                chunks = []
+                for doc in documents:
+                    doc_chunks = text_splitter.split_text(doc['content'])
+                    for chunk in doc_chunks:
+                        chunks.append({
+                            'content': chunk,
+                            'metadata': {'source': doc['name'], 'document_id': doc['id']}
+                        })
+                
+                vector_store = FAISS.from_texts(
+                    [chunk['content'] for chunk in chunks],
+                    embeddings,
+                    [chunk['metadata'] for chunk in chunks]
+                )
+                
+                st.session_state.vector_store = vector_store
+                st.session_state.qa_system = initialize_qa_system(vector_store)
+                st.session_state.chat_ready = True
+                return True
+        except Exception as e:
+            st.error(f"Error initializing chat: {e}")
+    return False
 
 def display_collection_sidebar():
     """Display the document management sidebar."""