from flask import (Flask, render_template, flash, redirect,
                   url_for, request, send_from_directory)
from flask_bootstrap import Bootstrap
from flask_wtf import FlaskForm
from wtforms import DateTimeField, DecimalField, SubmitField
from wtforms.validators import DataRequired, NumberRange

from datetime import datetime, timedelta

from config import Config


app = Flask(__name__)
app.config.from_object(Config)
Bootstrap(app)


class DownloadForm(FlaskForm):
    start_time = DateTimeField('Start time', validators=[DataRequired()])
    length = DecimalField('Length', validators=[DataRequired(),
                                                NumberRange(min=1, max=app.config['MAX_LENGTH'])])
    submit = SubmitField('Download')


@app.route('/', methods=['GET', 'POST'])
def download():
    form = DownloadForm()
    if request.method == 'GET':
        form.start_time.data = datetime.now() - timedelta(hours=1)
        form.length.data = 60
    elif form.validate_on_submit():
        output_filename = prepare_download(form)
        if output_filename:
            flash('The download should start immediately.', 'success')
            return render_template('download.html', form=form, filename=output_filename)
        else:
            flash('Error preparing download!', 'warning')
    else:
        flash('Error in form!', 'warning')
    return render_template('download.html', form=form)


@app.route('/download_file/<path:filename>')
def download_file(filename):
    return send_from_directory(app.config['DATA_DIR'], filename,
                               as_attachment=True)


def prepare_download(form):
    return 'test.mp3'


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