app.py

import re
import json
import streamlit as st
import pandas as pd
import geopandas as gpd
import leafmap.foliumap as leafmap

# wide streamlit display
st.set_page_config(layout="wide")

file_url = st.query_params.get("file_url", None)
print(f"{file_url=}")

if file_url:
    if ("file_url" in st.session_state) and (st.session_state.file_url == file_url):
        st.toast("Using cached data")
        input_gdf = st.session_state.input_gdf
    else:
        st.session_state.file_url = file_url
        if file_url.startswith("https://drive.google.com/file/d/"):
            ID = file_url.replace("https://drive.google.com/file/d/", "").split("/")[0]
            file_url = f"https://drive.google.com/uc?id={ID}"

        input_gdf = gpd.read_file(file_url)
        input_gdf = input_gdf.to_crs(epsg=7761)  # Gujarat zone
        st.session_state.input_gdf = input_gdf
        st.toast("Data loaded and cached")

    def format_fn(x):
        return input_gdf.drop(columns=["geometry"]).loc[x].to_dict()

    input_geometry_idx = st.selectbox("Select the geometry", input_gdf.index, format_func=format_fn)
    geometry_gdf = input_gdf[input_gdf.index == input_geometry_idx]

    m = leafmap.Map()
    map_type = st.radio(
        "Select the map type",
        ["Esri Satellite Map", "Google Hybrid Map (displays place names)", "Google Satellite Map"],
    )
    if map_type == "Google Hybrid Map (displays place names)":
        st.write(
            "<h4><div style='text-align: center;'>Google Hybrid (displays place names)</div></h4>",
            unsafe_allow_html=True,
        )
        m.add_basemap("HYBRID")
    elif map_type == "Google Satellite Map":
        st.write("<h4><div style='text-align: center;'>Google Satellite</div></h4>", unsafe_allow_html=True)
        m.add_basemap("SATELLITE")
    elif map_type == "Esri Satellite Map":
        st.write("<h4><div style='text-align: center;'>Esri - 2024/10/10</div></h4>", unsafe_allow_html=True)
        m.add_wms_layer(
            "https://wayback.maptiles.arcgis.com/arcgis/rest/services/World_Imagery/WMTS/1.0.0/GoogleMapsCompatible/MapServer/tile/56450/{z}/{y}/{x}",
            layers="0",
        )
    else:
        st.error("Invalid map type")
        st.stop()
    m.add_gdf(
        geometry_gdf.to_crs(epsg=4326),
        layer_name="Geometry",
        zoom_to_layer=True,
        style_function=lambda x: {"color": "red", "fillOpacity": 0.0},
    )
    m.to_streamlit()

    # Metrics
    stats_df = pd.DataFrame()
    stats_df["Points"] = json.loads(geometry_gdf.to_crs(4326).to_json())["features"][0]["geometry"]["coordinates"]
    stats_df["Area (ha)"] = geometry_gdf.geometry.area.item() / 10000
    stats_df["Perimeter (m)"] = geometry_gdf.geometry.length.item()

    st.write("<h3><div style='text-align: center;'>Geometry Metrics</div></h3>", unsafe_allow_html=True)
    #     st.markdown(
    #         f"""| Metric | Value |
    # | --- | --- |
    # | Area (ha) | {stats_df['Area (ha)'].item():.2f} ha|
    # | Perimeter (m) | {stats_df['Perimeter (m)'].item():.2f} m |"""
    #     unsafe_allow_html=True)
    st.markdown(
        f"""
    <div style="display: flex; justify-content: center;">
        <table>
            <tr>
                <th>Metric</th>
                <th>Value</th>
            </tr>
            <tr>
                <td>Area (ha)</td>
                <td>{stats_df['Area (ha)'].item():.2f} ha</td>
            </tr>
            <tr>
                <td>Perimeter (m)</td>
                <td>{stats_df['Perimeter (m)'].item():.2f} m</td>
            </tr>
        </table>
    </div>
    """,
        unsafe_allow_html=True,
    )

    csv = stats_df.T.to_csv(index=True)
    st.download_button(
        "Download Geometry Metrics", csv, f"{file_url}_metrics.csv", "text/csv", use_container_width=True
    )

else:
    st.warning("Please provide a KML or GeoJSON URL as a query parameter, e.g., `?file_url=<your_file_url>`")