"""App

This script allows connects and interacts with Flask and Dash components.

This script requires that `flask` and 'dash' be installed within the Python
environment you are running this script in.

This file can also be imported as a module and contains the following
functions:

    * dataframe_return - list of Dataframes from dataframe_visualizer
    * root - returns the index page
"""
from flask import Flask, render_template, request
import dash_bootstrap_components as dbc
import dash
from dash import html
from libs.dataframe_visualizer import dataframe_visualizer


app = Flask(__name__)
app.config['MAX_CONTENT_LENGTH'] = 1024 * 1024
app = Flask(__name__)
app.config['SECRET_KEY'] = 'secret!'
app.config['DEBUG'] = True


DASH_APP = dash.Dash(
    routes_pathname_prefix='/visualizer/',
    server=app,
    external_scripts=[
        'https://cdnjs.cloudflare.com/ajax/libs/codemirror/5.52.2/codemirror.min.js',
        'custom-script.js'
    ],
    external_stylesheets=[
        'https://fonts.googleapis.com/css?family=Lato',
        'https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.min.css',
        'https://cdnjs.cloudflare.com/ajax/libs/codemirror/5.52.2/theme/monokai.min.css',
        'https://cdnjs.cloudflare.com/ajax/libs/codemirror/5.52.2/codemirror.min.css',
        'styles.css',
        dbc.themes.BOOTSTRAP
    ],
    name='CSV Visualizer',
    title='CSV Visualizer'
)


DASH_APP.config.suppress_callback_exceptions = True

DASH_APP.validation_layout = html.Div()

DASH_APP.layout = html.Div()

@app.route('/DataVisualizer', methods=['POST', 'GET'])
def dataframe_return():
    """returns list of Dataframes from dataframe_visualizer

    Returns:
        string: list of datafrmaes
    """
    # pylint: disable=W0603
    global DASH_APP
    list_dataframe, DASH_APP = dataframe_visualizer(request.form, DASH_APP)
    return str(list_dataframe)


@app.route('/', methods=['POST', 'GET'])
def root():
    """renders undex.html

    Returns:
        _render: rendered html
    """
    return render_template('index.html')


if __name__ == '__main__':
    app.run(host='0.0.0.0')