Update app.py

app.py

@@ -1,30 +1,87 @@
 import streamlit as st
 
-# Initialize session state
+# Initialize session state for user data and authentication
+if "users" not in st.session_state:
+    st.session_state.users = {}  # Store registered users (username: password)
 if "logged_in" not in st.session_state:
     st.session_state.logged_in = False
+if "current_user" not in st.session_state:
+    st.session_state.current_user = None
 
-# Callback for login
-def login_callback():
-    username = st.session_state.username_input
-    password = st.session_state.password_input
-    if username == "admin" and password == "password":  # Replace with your credentials
+# Registration function
+def register(username, password):
+    if username in st.session_state.users:
+        st.error("Username already exists. Please choose a different username.")
+    else:
+        st.session_state.users[username] = password
+        st.success("Registration successful! Please log in.")
+
+# Login function
+def login(username, password):
+    if username in st.session_state.users and st.session_state.users[username] == password:
         st.session_state.logged_in = True
+        st.session_state.current_user = username
+        st.success("Logged in successfully!")
     else:
-        st.error("Invalid username or password")
+        st.error("Invalid username or password.")
 
-# Callback for logout
-def logout_callback():
+# Logout function
+def logout():
     st.session_state.logged_in = False
+    st.session_state.current_user = None
+    st.info("Logged out successfully!")
+
+# Registration form
+def registration_form():
+    with st.form("Registration"):
+        st.subheader("Register")
+        username = st.text_input("Username (min 5 characters)", key="reg_username")
+        password = st.text_input("Password (min 6 characters)", type="password", key="reg_password")
+        submit_button = st.form_submit_button("Register")
+
+        if submit_button:
+            if len(username) < 5:
+                st.error("Username must be at least 5 characters long.")
+            elif len(password) < 6:
+                st.error("Password must be at least 6 characters long.")
+            else:
+                register(username, password)
 
 # Login form
-if not st.session_state.logged_in:
-    st.subheader("Login")
-    st.text_input("Username", key="username_input")
-    st.text_input("Password", type="password", key="password_input")
-    st.button("Login", on_click=login_callback)
+def login_form():
+    with st.form("Login"):
+        st.subheader("Login")
+        username = st.text_input("Username", key="login_username")
+        password = st.text_input("Password", type="password", key="login_password")
+        submit_button = st.form_submit_button("Login")
+
+        if submit_button:
+            if len(username) < 5:
+                st.error("Username must be at least 5 characters long.")
+            elif len(password) < 6:
+                st.error("Password must be at least 6 characters long.")
+            else:
+                login(username, password)
+
+# Main app screen (after login)
+def main_app():
+    st.subheader(f"Welcome, {st.session_state.current_user}!")
+    st.write("Enter a name below to get a greeting.")
+
+    # Input field for name
+    name = st.text_input("Enter a name", key="name_input")
+
+    # Display greeting in real-time
+    if name:
+        st.write(f"Hi {name}!")
+
+    # Logout button
+    if st.button("Logout"):
+        logout()
 
-# Logout button
+# Render the appropriate screen based on login status
 if st.session_state.logged_in:
-    st.subheader("Welcome to the App!")
-    st.button("Logout", on_click=logout_callback)
+    main_app()
+else:
+    registration_form()
+    login_form()