Update app.py

app.py

@@ -1,37 +1,39 @@
 import streamlit as st
-
-# ✅ Must be the first command
-st.set_page_config(page_title="TransPolymer", layout="wide", page_icon="🧪")
-
-# ✅ Import your page modules
+from login import login
+from signup import signup
 import home
-import prediction 
+import prediction
 import about
 import contact
 
-# ✅ Navigation Sidebar
-st.sidebar.title("🔗 Navigation")
-page = st.sidebar.radio("Select a Page", ["Home", "Predictions", "About", "Help"])
+# Initialize session state
+if 'logged_in' not in st.session_state:
+    st.session_state.logged_in = False
+if 'signup' not in st.session_state:
+    st.session_state.signup = False
+
+# Sign-up flow
+if st.session_state.signup:
+    signup()
+
+# Logged-in flow
+elif st.session_state.logged_in:
+    st.sidebar.title("Navigation")
+    page = st.sidebar.radio("Go to", ("Home", "Prediction", "About", "Contact"))
 
-# ✅ Optional: Override via URL (?page=Contact)
-query_params = st.query_params
-if "page" in query_params:
-    param_page = query_params["page"][0].capitalize()
-    if param_page in ["Home", "Predictions", "About", "Help"]:
-        page = param_page
+    if st.sidebar.button("Logout"):
+        st.session_state.logged_in = False
 
-# ✅ Page loading logic
-def load_page(page_name):
-    if page_name == "Home":
+    if page == "Home":
         home.show()
-    elif page_name == "Predictions":
+    elif page == "Prediction":
         prediction.show()
-    elif page_name == "About":
+    elif page == "About":
         about.show()
-    elif page_name == "Help":
+    elif page == "Contact":
         contact.show()
-    else:
-        st.error("Page not found.")
 
-# ✅ Load the selected page
-load_page(page)
+# Login flow
+else:
+    if login():  # This now returns True when credentials are correct
+        st.session_state.logged_in = True