import streamlit as st
import pandas as pd
import plotly.express as px
import plotly.graph_objects as go
import base64

# Function to create a download link
def create_download_link(file_path, link_title):
    with open(file_path, 'rb') as file:
        csv_data = file.read()
    b64 = base64.b64encode(csv_data).decode()
    return f'<a href="data:file/csv;base64,{b64}" download="{link_title}.csv">{link_title}</a>'

# Function to plot the map
def plot_map(data):
    fig = px.choropleth(locations=data['State'], locationmode="USA-states", scope="usa")
    grouped_data = data.groupby('State')
    for state, group in grouped_data:
        top_corp = group.nlargest(1, 'Revenue')
        text_label = f"{top_corp['Corporation'].iloc[0]} - ${top_corp['Revenue'].iloc[0]}B"
        lon = group['Longitude'].mean()
        lat = group['Latitude'].mean()
        fig.add_trace(go.Scattergeo(
            lon=[lon],
            lat=[lat],
            text=text_label,
            mode='text',
        ))
    fig.update_layout(title="Top Corporation by State in the United States")
    return fig

st.title('Top Corporation by State in the United States 🏢')

# Upload CSV
uploaded_files = st.file_uploader("Choose a CSV file", accept_multiple_files=True, type="csv")

# Display map button
display_map_button = st.button('Display Map of CSV Data 🗺️')

if display_map_button:
    if uploaded_files:
        for uploaded_file in uploaded_files:
            data = pd.read_csv(uploaded_file)
            st.write(f"Map for {uploaded_file.name} 🌐")
            st.plotly_chart(plot_map(data))
    else:
        st.write("Please upload a CSV file to proceed. 📑")

# Download link for the CSV file
csv_file_path = 'top_corporation_per_state.csv'
download_link = create_download_link(csv_file_path, "Top Corporations by State")
st.markdown(download_link, unsafe_allow_html=True)