Update app.py

app.py

@@ -10,10 +10,10 @@ import uuid
 st.set_page_config(
     page_title="Chat Flow 🕷",
     page_icon="💬",
-    initial_sidebar_state="collapsed"
+    initial_sidebar_state="expanded"  # Changed to show chat history by default
 )
 
-# White background
+# Enhanced CSS with chat history styling
 st.markdown("""
 <style>
     .stApp {
@@ -39,6 +39,44 @@ st.markdown("""
         font-size: 0.8em;
         font-style: italic;
     }
+    
+    /* Chat history styling */
+    .chat-history-item {
+        padding: 8px 12px;
+        margin: 4px 0;
+        border-radius: 8px;
+        border: 1px solid #e0e0e0;
+        background: #f8f9fa;
+        cursor: pointer;
+        transition: all 0.2s;
+    }
+    
+    .chat-history-item:hover {
+        background: #e9ecef;
+        border-color: #28a745;
+    }
+    
+    .chat-history-item.active {
+        background: #28a745;
+        color: white;
+        border-color: #28a745;
+    }
+    
+    .chat-title {
+        font-weight: 500;
+        font-size: 0.9em;
+        margin-bottom: 2px;
+    }
+    
+    .chat-date {
+        font-size: 0.75em;
+        opacity: 0.7;
+    }
+    
+    .new-chat-btn {
+        width: 100%;
+        margin-bottom: 16px;
+    }
 </style>
 """, unsafe_allow_html=True)
 
@@ -46,6 +84,8 @@ st.markdown("""
 HISTORY_FILE = "chat_history.json"
 # NEW: File to store online users
 USERS_FILE = "online_users.json"
+# NEW: File to store chat sessions
+SESSIONS_FILE = "chat_sessions.json"
 
 
 def load_chat_history():
@@ -77,9 +117,100 @@ def clear_chat_history():
     except Exception as e:
         st.error(f"Error clearing chat history: {e}")
 
-# NEW: User tracking functions
+
+# NEW: Chat Sessions Management
+def load_chat_sessions():
+    """Load all chat sessions"""
+    try:
+        if os.path.exists(SESSIONS_FILE):
+            with open(SESSIONS_FILE, 'r', encoding='utf-8') as f:
+                return json.load(f)
+    except Exception as e:
+        st.error(f"Error loading chat sessions: {e}")
+    return {}
+
+
+def save_chat_sessions(sessions):
+    """Save chat sessions to file"""
+    try:
+        with open(SESSIONS_FILE, 'w', encoding='utf-8') as f:
+            json.dump(sessions, f, ensure_ascii=False, indent=2)
+    except Exception as e:
+        st.error(f"Error saving chat sessions: {e}")
+
+
+def get_session_id():
+    """Get or create session ID"""
+    if 'session_id' not in st.session_state:
+        st.session_state.session_id = str(uuid.uuid4())
+    return st.session_state.session_id
+
+
+def get_chat_title(messages):
+    """Generate a title for the chat based on first user message"""
+    if not messages:
+        return "New Chat"
+    
+    for msg in messages:
+        if msg["role"] == "user":
+            content = msg["content"]
+            # Take first 30 characters and add ellipsis if longer
+            if len(content) > 30:
+                return content[:30] + "..."
+            return content
+    return "New Chat"
+
+
+def save_current_session():
+    """Save current chat session"""
+    if not st.session_state.messages:
+        return
+        
+    sessions = load_chat_sessions()
+    session_id = get_session_id()
+    
+    sessions[session_id] = {
+        "title": get_chat_title(st.session_state.messages),
+        "messages": st.session_state.messages,
+        "created_at": datetime.now().isoformat(),
+        "updated_at": datetime.now().isoformat()
+    }
+    
+    save_chat_sessions(sessions)
+
+
+def load_session(session_id):
+    """Load a specific chat session"""
+    sessions = load_chat_sessions()
+    if session_id in sessions:
+        st.session_state.messages = sessions[session_id]["messages"]
+        st.session_state.session_id = session_id
+        return True
+    return False
+
+
+def delete_session(session_id):
+    """Delete a chat session"""
+    sessions = load_chat_sessions()
+    if session_id in sessions:
+        del sessions[session_id]
+        save_chat_sessions(sessions)
+        return True
+    return False
 
 
+def start_new_chat():
+    """Start a new chat session"""
+    # Save current session if it has messages
+    if st.session_state.messages:
+        save_current_session()
+    
+    # Clear current chat and create new session
+    st.session_state.messages = []
+    st.session_state.session_id = str(uuid.uuid4())
+
+
+# NEW: User tracking functions
 def get_user_id():
     """Get unique ID for this user session"""
     if 'user_id' not in st.session_state:
@@ -147,6 +278,10 @@ def get_online_count():
 if "messages" not in st.session_state:
     st.session_state.messages = load_chat_history()
 
+# Initialize session ID
+if "session_id" not in st.session_state:
+    st.session_state.session_id = str(uuid.uuid4())
+
 # Get API key
 OPENROUTER_API_KEY = os.environ.get("OPENROUTER_API_KEY")
 
@@ -245,8 +380,82 @@ def get_ai_response(messages, model="openai/gpt-3.5-turbo"):
 st.title("Chat Flow 🕷")
 st.caption("10 powerful Models, one simple chat.")
 
-# Sidebar
+# Sidebar with Chat History
 with st.sidebar:
+    # NEW: Chat History Section at the top
+    st.header("💬 Chat History")
+    
+    # New Chat Button
+    if st.button("➕ New Chat", use_container_width=True, type="primary"):
+        start_new_chat()
+        st.rerun()
+    
+    st.divider()
+    
+    # Load and display chat sessions
+    sessions = load_chat_sessions()
+    current_session_id = get_session_id()
+    
+    if sessions:
+        st.subheader("Previous Chats")
+        
+        # Sort sessions by updated_at (most recent first)
+        sorted_sessions = sorted(
+            sessions.items(), 
+            key=lambda x: x[1].get("updated_at", x[1].get("created_at", "")), 
+            reverse=True
+        )
+        
+        for session_id, session_data in sorted_sessions:
+            # Create container for each chat item
+            chat_container = st.container()
+            
+            with chat_container:
+                # Show current chat with different styling
+                if session_id == current_session_id:
+                    st.markdown(f"🔹 **{session_data['title']}**")
+                else:
+                    col_load, col_delete = st.columns([3, 1])
+                    
+                    with col_load:
+                        if st.button(
+                            f"💭 {session_data['title']}", 
+                            key=f"load_{session_id}",
+                            use_container_width=True
+                        ):
+                            # Save current session before switching
+                            if st.session_state.messages:
+                                save_current_session()
+                            
+                            # Load selected session
+                            load_session(session_id)
+                            st.rerun()
+                    
+                    with col_delete:
+                        if st.button("🗑️", key=f"delete_{session_id}"):
+                            delete_session(session_id)
+                            # If deleted session was current, start new chat
+                            if session_id == current_session_id:
+                                start_new_chat()
+                            st.rerun()
+                
+                # Show session info
+                if "updated_at" in session_data:
+                    update_time = datetime.fromisoformat(session_data["updated_at"])
+                    st.caption(f"Updated: {update_time.strftime('%m/%d %H:%M')}")
+                
+                st.markdown("---")
+    
+    else:
+        st.info("No previous chats yet")
+    
+    # Auto-save current session periodically
+    if st.session_state.messages:
+        save_current_session()
+    
+    st.divider()
+
+    # Settings Section
     st.header("Settings")
 
     # API Status