app.py

import streamlit as st
st.set_page_config(page_title="India Map Visualizer", layout="centered")
from streamlit_folium import st_folium
import folium
import random
from utils import add_hover_tooltips
import geopandas as gpd
import matplotlib.pyplot as plt
from shapely.geometry import Point
from utils import plot_full_india_map, draw_map_lines_with_labels
import io
import os

# === Load GeoJSONs ===
state_path = os.path.join("data", "in.json")
district_path = os.path.join("data", "output.geojson")

states = gpd.read_file(state_path).rename(columns={"name": "State"}).to_crs(epsg=4326)
states["State"] = states["State"].str.strip()

# Title
st.title("🗺️ India Map Visualizer")
st.markdown("Select states or districts and optionally draw connection lines.")

# Show full India map
fig_full = plot_full_india_map(states)
st.pyplot(fig_full)

# Download full map
buf = io.BytesIO()
fig_full.savefig(buf, format="png")
st.download_button("📥 Download India Map", data=buf.getvalue(), file_name="india_map.png", mime="image/png")

# --- Selection ---
st.markdown("---")
st.header("🔗 Select Regions & Draw Connections")

mode = st.radio("Choose connection type:", ["State-to-State", "District-to-District"])
line_type = st.selectbox("Choose line style", ["Straight", "Dashed", "Curved"])
show_boundaries = st.checkbox("Show boundaries of other states/districts", value=True)

# Target point input (optional)
st.markdown("### 📍 Optional: Click on map to add target points")
clicks = st.session_state.get("clicks", [])

if st.button("Clear Clicks"):
    st.session_state["clicks"] = []
    clicks = []

if "clicks" not in st.session_state:
    st.session_state["clicks"] = []

clicked_lon = st.number_input("Click Longitude", value=77.0)
clicked_lat = st.number_input("Click Latitude", value=28.0)
if st.button("Add Target Point"):
    st.session_state["clicks"].append((clicked_lon, clicked_lat))
    clicks = st.session_state["clicks"]

st.markdown(f"**Current Target Points:** {st.session_state['clicks']}")

# --- Region selection ---
selected_data = None

if mode == "State-to-State":
    state_options = states["State"].sort_values().unique().tolist()
    selected_states = st.multiselect("Select State(s)", state_options, default=["Madhya Pradesh"])
    selected_data = states[states["State"].isin(selected_states)]

else:
    try:
        districts = gpd.read_file(district_path).to_crs(epsg=4326)
        if 'district' not in districts.columns and 'dtname' in districts.columns:
            districts = districts.rename(columns={"dtname": "district"})
        if 'district' not in districts.columns:
            st.warning("⚠️ 'district' column not found in district data.")
            st.write("Available columns:", list(districts.columns))
        districts["district"] = districts["district"].str.strip()
        district_options = districts["district"].sort_values().unique().tolist()
        selected_districts = st.multiselect("Select District(s)", district_options)
        selected_data = districts[districts["district"].isin(selected_districts)]
    except Exception as e:
        st.error("❌ Could not load district GeoJSON.")
        st.exception(e)
        st.stop()

# --- Draw button ---
# --- Draw button ---
if st.button("🖍️ Generate Map") and selected_data is not None:
    fig = draw_map_lines_with_labels(
        geo_data=states if mode == "State-to-State" else districts,
        selected_data=selected_data,
        target_coords=clicks if clicks else None,
        line_style=line_type,
        label_field='State' if mode == 'State-to-State' else 'district',
        show_boundaries=show_boundaries
    )
    st.session_state["generated_fig"] = fig  # Save figure in session state

# --- Display map & download ---
if "generated_fig" in st.session_state:
    fig = st.session_state["generated_fig"]
    st.pyplot(fig)

    buf = io.BytesIO()
    fig.savefig(buf, format="png")
    st.download_button("📥 Download Map", data=buf.getvalue(), file_name="map_with_lines.png", mime="image/png")


# --- Interactive Folium Map ---
st.markdown("---")
st.header("🗺️ Interactive Map with Hover Tooltips & Coloring")

folium_mode = st.radio("Select interactive map type", ["State Map (Population Color)", "District Map (Index Color)"])

@st.cache_data
def get_population(_states_df):
    return [random.randint(1_000_000, 50_000_000) for _ in range(len(_states_df))]

if folium_mode == "State Map (Population Color)":
    states["Population"] = get_population(states)

    m = folium.Map(location=[22.0, 78.0], zoom_start=5, tiles="cartodbpositron")
    add_hover_tooltips(
        m,
        states,
        field_to_color="Population",
        tooltip_fields=["State", "Population"],
        tooltip_aliases=["State:", "Population:"]
    )

    st_folium(m, width=1000, height=600)

elif folium_mode == "District Map (Index Color)":
    try:
        districts = gpd.read_file(district_path).to_crs(epsg=4326)
        if 'district' not in districts.columns and 'dtname' in districts.columns:
            districts = districts.rename(columns={"dtname": "district"})
        districts["district"] = districts["district"].str.strip()
        districts["Index"] = list(range(len(districts)))  # dummy data

        m = folium.Map(location=[22.0, 78.0], zoom_start=5, tiles="cartodbpositron")
        add_hover_tooltips(
            m,
            districts,
            field_to_color="Index",
            tooltip_fields=["district", "Index"],
            tooltip_aliases=["District:", "Index:"]
        )

        st_folium(m, width=1000, height=600)
    except Exception as e:
        st.error("❌ Could not load district GeoJSON.")
        st.exception(e)