add legend

app.py

@@ -197,7 +197,17 @@ if selected_geometry.type != "Polygon":
 selected_geometry = selected_geometry.__geo_interface__
 ee_geometry = ee.Geometry(selected_geometry)
 ee_feature_collection = ee.FeatureCollection(ee_geometry)
-feature_collection = geojson.FeatureCollection([{"type": "Feature", "geometry": selected_geometry, "properties": {}}])
+feature_collection = geojson.FeatureCollection([{"type": "Feature", "geometry": selected_geometry, "properties": {"name": "Selected Geometry"}}])
+
+# visualize the geometry
+m = leaf_folium.Map()
+keys = list(wayback_mapping.keys())
+latest_date = sorted(keys, key=lambda x: pd.to_datetime(x))[-1]
+m.add_tile_layer(wayback_mapping[latest_date], name=f"Esri Wayback - {latest_date}", attribution="Esri")
+m.add_geojson(feature_collection)
+write_info(f"Visual Esri Wayback Basemap - {latest_date}")
+m.to_streamlit()
+
 
 # Input: Satellite Sources
 st.write("Select the satellite sources:")
@@ -292,7 +302,7 @@ if "result" in st.session_state:
             mosaic = df.loc[pd.to_datetime(date), f"Mosaic_{satellite}"]
             with col:
                 maps = [leaf_folium.Map(), leaf_folium.Map()]
-                ndvi_layer = gee_folium.ee_tile_layer(mosaic, {"bands": ["NDVI"], "min": 0, "max": 1})
+                ndvi_layer = gee_folium.ee_tile_layer(mosaic, {"bands": ["NDVI"], "min": -0.2, "max": 1})
                 
                 if satellite == "COPERNICUS/S2_SR_HARMONIZED":
                     min_all = 0
@@ -304,6 +314,8 @@ if "result" in st.session_state:
                 maps[0].add_layer(
                     ndvi_layer,
                 )
+                # add colorbar
+                maps[0].add_colorbar(colors=["#000000", "#FFFFFF"], vmin=-0.2, vmax=1.0, caption="NDVI")
                     
                 maps[1].add_layer(
                     visual_layer,