import dash
from dash import dcc, html, Input, Output, State, dash_table
import pandas as pd
import os
import datetime
import base64
import io

from google_sheet import fetch_leaderboard
from google_drive import upload_to_drive

# Make sure submissions folder exists
os.makedirs("submissions", exist_ok=True)

app = dash.Dash(__name__)
app.title = "🏆 Hackathon Leaderboard"

app.layout = html.Div([
    html.H2("🏆 Hackathon Leaderboard"),

    dcc.Upload(
        id='upload-data',
        children=html.Div([
            '📁 Drag and drop or click to upload a .zip file'
        ]),
        style={
            'width': '50%',
            'height': '60px',
            'lineHeight': '60px',
            'borderWidth': '1px',
            'borderStyle': 'dashed',
            'borderRadius': '10px',
            'textAlign': 'center',
            'margin': '20px'
        },
        multiple=False,
        accept='.zip'
    ),
    html.Button('Submit', id='submit-btn', n_clicks=0),

    html.Div(id='upload-status', style={'margin': '20px', 'fontWeight': 'bold'}),
    html.H3("Leaderboard"),
    html.Div(id='leaderboard-table', style={'margin': '20px'})
])

def save_file_and_upload(content, filename):
    timestamp = datetime.datetime.now().isoformat().replace(':', '_')
    saved_filename = f"{timestamp}_{filename}"
    path = os.path.join("submissions", saved_filename)

    # Decode and save the file
    content_string = content.split(',')[1]
    decoded = base64.b64decode(content_string)

    with open(path, 'wb') as f:
        f.write(decoded)

    # Upload to Google Drive
    try:
        drive_file_id = upload_to_drive(path, saved_filename)
        return f"✅ Uploaded to Google Drive [File ID: {drive_file_id}]"
    except Exception as e:
        return f"⚠️ Failed to upload to Google Drive: {e}"

def generate_leaderboard():
    try:
        df = fetch_leaderboard()
        if df.empty:
            return html.Div("No submissions yet.")
        df_sorted = df.sort_values(by="score", ascending=False)
        return dash_table.DataTable(
            data=df_sorted.to_dict("records"),
            columns=[{"name": i, "id": i} for i in df_sorted.columns],
            style_table={'overflowX': 'auto'},
            style_cell={'textAlign': 'left', 'padding': '5px'},
            style_header={'backgroundColor': 'lightgrey', 'fontWeight': 'bold'}
        )
    except Exception as e:
        return html.Div(f"Could not load leaderboard: {e}")

@app.callback(
    Output('upload-status', 'children'),
    Output('leaderboard-table', 'children'),
    Input('submit-btn', 'n_clicks'),
    State('upload-data', 'contents'),
    State('upload-data', 'filename'),
    prevent_initial_call=True
)
def handle_submission(n_clicks, contents, filename):
    if contents is None:
        return "❌ No file uploaded.", generate_leaderboard()
    
    status = save_file_and_upload(contents, filename)
    leaderboard = generate_leaderboard()
    return status, leaderboard

if __name__ == '__main__':
    app.run(debug=True)