Update app.py

app.py

@@ -16,6 +16,7 @@ from datetime import datetime
 from typing import Dict, Any, Tuple, List, Optional
 import streamlit as st
 from streamlit_folium import st_folium
+from streamlit_option_menu import option_menu
 
 # Visualization & PDF
 import matplotlib.pyplot as plt
@@ -1890,21 +1891,74 @@ if "page" not in st.session_state:
 page = st.session_state["page"]
 
 # Option menu top (main nav)
+# ===============================
+# Navigation (Option Menu)
+# ===============================
+from streamlit_option_menu import option_menu
+
+# Define all pages
+PAGES = ["Home", "Soil recognizer", "Classifier", "GSD", "OCR", "Locator", "RAG", "Reports"]
+
+# Set default page if not defined yet
+if "page" not in st.session_state:
+    st.session_state["page"] = "Home"
+
+# Build horizontal option menu
 selected = option_menu(
     None,
-    ["Home","Soil recognizer","Classifier","GSD","OCR","Locator","RAG","Reports"],
-    icons=["house","chart","journal-code","bar-chart","camera","geo-alt","robot","file-earmark-text"],
+    PAGES,
+    icons=[
+        "house", "chart", "journal-code", "bar-chart", "camera",
+        "geo-alt", "robot", "file-earmark-text"
+    ],
     menu_icon="cast",
-    default_index=["Home","Soil recognizer","Classifier","GSD","OCR","Locator","RAG","Reports"].index(page) if page in ["Home","Soil recognizer","Classifier","GSD","OCR","Locator","RAG","Reports"] else 0,
+    default_index=PAGES.index(st.session_state["page"]) if st.session_state["page"] in PAGES else 0,
     orientation="horizontal",
     styles={
-        "container": {"padding":"0px","background-color":"#0b0b0b"},
-        "nav-link": {"font-size":"14px","color":"#cfcfcf"},
-        "nav-link-selected": {"background-color":"#FF7A00","color":"white"},
+        "container": {"padding": "0px", "background-color": "#0b0b0b"},
+        "nav-link": {"font-size": "14px", "color": "#cfcfcf"},
+        "nav-link-selected": {"background-color": "#FF7A00", "color": "white"},
     }
 )
+
+# Save selection into session_state
 st.session_state["page"] = selected
-page = selected
+
+# ===============================
+# Page Routing
+# ===============================
+if selected == "Home":
+    st.title("🏠 Welcome to GeoMate")
+    st.write("Your geotechnical AI copilot.")
+
+elif selected == "Soil recognizer":
+    st.title("🔎 Soil Recognizer")
+    st.write("Upload soil images for classification.")
+
+elif selected == "Classifier":
+    st.title("📊 Soil Classifier")
+    st.write("Enter lab/field parameters for classification.")
+
+elif selected == "GSD":
+    st.title("📉 Grain Size Distribution")
+    st.write("Analyze particle size distribution.")
+
+elif selected == "OCR":
+    st.title("📷 OCR Extractor")
+    st.write("Upload lab sheets for automatic text extraction.")
+
+elif selected == "Locator":
+    st.title("🌍 Locator Tool")
+    st.write("Draw ROI on map and compute Earth Engine summaries.")
+
+elif selected == "RAG":
+    st.title("🤖 Knowledge Assistant")
+    st.write("Query soil and geotechnical references with AI.")
+
+elif selected == "Reports":
+    st.title("📑 Reports")
+    st.write("Generate classification and full reports.")
+
 
 # Display page content
 if page == "Home":