Update app.py

app.py

@@ -1,5 +1,5 @@
 """
-Universal RAG PDF Chatbot with Enhanced Safety Checks and Improved Context Management - COMPLETE UPDATED VERSION
+Universal RAG PDF Chatbot with Enhanced Safety Checks and Improved Context Management - COMPLETE UPDATED VERSION WITH PASSWORD PROTECTION
 
 This is a general-purpose RAG (Retrieval-Augmented Generation) chatbot that can work with any set of PDF documents.
 It includes comprehensive safety checks and can provide educational responses even when information isn't in the documents.
@@ -50,6 +50,11 @@ SAFETY_CONFIG = {
     'educational_alternatives': True,      # Always provide educational alternatives
     'allow_general_knowledge': True        # Allow answers from general knowledge when appropriate
 }
+
+# ====== PASSWORD AUTHENTICATION CONFIGURATION ======
+# Password can be set in Streamlit secrets or environment variable
+CHATBOT_PASSWORD = st.secrets.get("CHATBOT_PASSWORD", os.getenv("CHATBOT_PASSWORD", "edu123"))
+
 # ====== END CONFIGURATION SECTION ======
 
 # Set environment variables
@@ -63,6 +68,101 @@ np.float_ = np.float64
 # Streamlit Page Config
 st.set_page_config(page_title=APP_TITLE, layout=APP_LAYOUT)
 
+# ====== PASSWORD AUTHENTICATION SYSTEM ======
+def check_password():
+    """Check password and manage authentication."""
+    
+    # Initialize authentication state
+    if "authenticated" not in st.session_state:
+        st.session_state.authenticated = False
+    
+    if "login_attempts" not in st.session_state:
+        st.session_state.login_attempts = 0
+    
+    # If already authenticated, return True
+    if st.session_state.authenticated:
+        return True
+    
+    # Display login screen
+    st.markdown("""
+    <div style='text-align: center; padding: 2rem; background: linear-gradient(135deg, #667eea 0%, #764ba2 100%); border-radius: 10px; margin-bottom: 2rem;'>
+        <h1 style='color: white; margin-bottom: 1rem;'>🔒 Educational PDF Chatbot</h1>
+        <p style='color: white; font-size: 1.1em;'>This educational assistant requires authentication for access.</p>
+    </div>
+    """, unsafe_allow_html=True)
+    
+    # Check for too many failed attempts
+    if st.session_state.login_attempts >= 5:
+        st.error("Too many failed login attempts. Please wait a few minutes before trying again.")
+        st.info("If you continue to have trouble, please contact the administrator.")
+        st.stop()
+    
+    # Login form
+    with st.form("login_form"):
+        st.subheader("🔑 Enter Password to Continue")
+        password = st.text_input(
+            "Password", 
+            type="password", 
+            placeholder="Enter your access password...",
+            help="Enter the password provided to you for accessing this educational chatbot"
+        )
+        submit_button = st.form_submit_button("🚀 Access Chatbot", use_container_width=True)
+        
+        if submit_button:
+            if password == CHATBOT_PASSWORD:
+                st.session_state.authenticated = True
+                st.session_state.login_attempts = 0
+                st.success("✅ Access granted! Loading your educational assistant...")
+                st.rerun()
+            else:
+                st.session_state.login_attempts += 1
+                remaining_attempts = 5 - st.session_state.login_attempts
+                
+                if remaining_attempts > 0:
+                    st.error(f"❌ Incorrect password. Attempts remaining: {remaining_attempts}")
+                else:
+                    st.error("🚫 Too many failed attempts. Access temporarily blocked.")
+    
+    # Additional information in sidebar
+    st.sidebar.markdown("""
+    ### 📋 Access Information
+    
+    **To access this educational chatbot:**
+    - Enter the provided access password
+    - Maximum 5 attempts allowed
+    - Contact administrator if you need help
+    
+    **Features available after login:**
+    - PDF document analysis
+    - Educational Q&A system  
+    - Context-aware responses
+    - Safe content filtering
+    - Conversation management
+    """)
+    
+    st.sidebar.markdown("---")
+    st.sidebar.info("🛡️ This system includes comprehensive safety features and educational content filtering.")
+    
+    return False
+
+# Check authentication before loading the rest of the application
+if not check_password():
+    st.stop()
+
+# ====== AUTHENTICATED USER INTERFACE ======
+
+# Add logout functionality in sidebar
+st.sidebar.markdown("---")
+st.sidebar.success("✅ Access Authorized")
+st.sidebar.write("Welcome to your educational assistant!")
+
+if st.sidebar.button("🚪 Logout", use_container_width=True):
+    st.session_state.authenticated = False
+    st.session_state.messages = []
+    st.session_state.conversation_id = 0
+    st.success("👋 Successfully logged out!")
+    st.rerun()
+
 # Initialize essential session state variables only
 if "messages" not in st.session_state:
     st.session_state.messages = []
@@ -1235,22 +1335,25 @@ def process_query(prompt, context_docs):
 st.title(APP_TITLE)
 
 # Sidebar info
-st.sidebar.title("System Info")
-st.sidebar.info("Educational Assistant with Safety Features")
-st.sidebar.write("Documents loaded:")
+st.sidebar.title("System Information")
+st.sidebar.info("Educational Assistant with Advanced Security")
+
+st.sidebar.markdown("---")
+st.sidebar.write("**Documents loaded:**")
 for pdf in PDF_FILES:
     display_name = os.path.basename(pdf)
-    st.sidebar.write(f"- {display_name}")
+    st.sidebar.write(f"• {display_name}")
 
 # Safety configuration display
 st.sidebar.markdown("---")
-st.sidebar.write("Safety Features:")
-st.sidebar.write("- Content filtering enabled")
-st.sidebar.write("- Educational focus maintained")
+st.sidebar.write("**Security Features:**")
+st.sidebar.write("✓ Content filtering enabled")
+st.sidebar.write("✓ Educational focus maintained")
+st.sidebar.write("✓ Password protection active")
 if SAFETY_CONFIG['allow_general_knowledge']:
-    st.sidebar.write("- General knowledge fallback available")
+    st.sidebar.write("✓ General knowledge fallback available")
 if SAFETY_CONFIG['educational_alternatives']:
-    st.sidebar.write("- Alternative topic suggestions")
+    st.sidebar.write("✓ Alternative topic suggestions")
 
 # Initialize welcome message
 if not st.session_state.messages:
@@ -1268,13 +1371,13 @@ if not st.session_state.messages:
     else:
         topic_preview = ""
     
-    welcome_msg = f"Hello! I'm your educational assistant with built-in safety features.{topic_preview} I can answer questions using the uploaded documents or provide general educational information when appropriate. What would you like to explore today?"
+    welcome_msg = f"Hello! I'm your secure educational assistant with built-in safety features.{topic_preview} I can answer questions using the uploaded documents or provide general educational information when appropriate. What would you like to explore today?"
     st.session_state.messages.append({"role": "assistant", "content": welcome_msg})
 
 # Clear conversation button
 col1, col2 = st.columns([4, 1])
 with col2:
-    if st.button("New Conversation"):
+    if st.button("🆕 New Conversation", use_container_width=True):
         st.session_state.conversation_id += 1
         st.session_state.messages = []
         
@@ -1312,7 +1415,7 @@ if retriever:
     
         # Generate response
         with st.chat_message("assistant"):
-            with st.spinner("Thinking..."):
+            with st.spinner("Processing your question..."):
                 try:
                     # Process query with enhanced safety checks
                     retrieved_docs = retriever.get_relevant_documents(prompt)