#!/usr/bin/python3
# -*- mode: python -*-
#
# This file is part of Plinth.
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as
# published by the Free Software Foundation, either version 3 of the
# License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#

"""
Configuration helper for BitTorrent web client.
"""

import argparse
import os
import subprocess


APACHE_CONF_PATH = '/etc/apache2/conf-available/deluge-web.conf'
APACHE_CONF_ENABLED_PATH = '/etc/apache2/conf-enabled/deluge-web.conf'
APACHE_CONF = '''
##
## On all sites, provide Deluge on a default path: /deluge
##
## This file is managed and overwritten by Plinth.  If you wish to edit
## it, disable Deluge in Plinth, remove this file and manage it manually.
##
<Location /deluge>
        ProxyPass http://localhost:8112
</Location>
'''

SYSTEMD_SERVICE_PATH = '/etc/systemd/system/deluge-web.service'
SYSTEMD_SERVICE = '''
#
# This file is managed and overwritten by Plinth.  If you wish to edit
# it, disable Deluge in Plinth, remove this file and manage it manually.
#
[Unit]
Description=Deluge Web Interface
Documentation=man:deluge-web(1)
After=network.target

[Service]
ExecStart=/usr/bin/deluge-web --base=deluge
Restart=on-failure
User=debian-deluged
Group=debian-deluged

[Install]
WantedBy=multi-user.target
'''


def parse_arguments():
    """Return parsed command line arguments as dictionary."""
    parser = argparse.ArgumentParser()
    subparsers = parser.add_subparsers(dest='subcommand', help='Sub command')

    # Get whether deluge-web site is enabled
    subparsers.add_parser('get-enabled',
                          help='Get whether deluge-web site is enabled')

    # Enable deluge-web site and start deluge-web
    subparsers.add_parser('enable', help='Enable deluge-web site')

    # Disable deluge-web site and stop deluge-web
    subparsers.add_parser('disable', help='Disable deluge-web site')

    # Get whether deluge-web is running
    subparsers.add_parser('is-running',
                          help='Get whether deluge-web is running')

    return parser.parse_args()


def subcommand_get_enabled(_):
    """Get whether deluge-web site is enabled."""
    if os.path.isfile(APACHE_CONF_ENABLED_PATH) and \
       os.path.isfile(SYSTEMD_SERVICE_PATH):
        print('yes')
    else:
        print('no')


def subcommand_enable(_):
    """Enable deluge-web site and start deluge-web."""
    setup()

    start()
    subprocess.check_call(['a2enconf', 'deluge-web'])
    subprocess.check_call(['service', 'apache2', 'reload'])


def subcommand_disable(_):
    """Disable deluge-web site and stop deluge-web."""
    subprocess.check_call(['a2disconf', 'deluge-web'])
    subprocess.check_call(['service', 'apache2', 'reload'])
    stop()


def subcommand_is_running(_):
    """Get whether deluge-web is running."""
    try:
        output = subprocess.check_output(['systemctl', 'status', 'deluge-web'])
    except subprocess.CalledProcessError:
        print('no')
    else:
        running = False
        for line in output.decode().split('\n'):
            if 'Active' in line and 'running' in line:
                running = True
                break

        print('yes' if running else 'no')


def start():
    """Start deluge-web."""
    subprocess.check_call(['systemctl', 'enable', 'deluge-web'])
    subprocess.check_call(['systemctl', 'start', 'deluge-web'])


def stop():
    """Stop deluge-web."""
    try:
        subprocess.check_output(['systemctl', 'stop', 'deluge-web'])
    except subprocess.CalledProcessError:
        pass


def setup():
    """Perform initial setup for deluge-web site."""
    if not os.path.isfile(APACHE_CONF_PATH):
        with open(APACHE_CONF_PATH, 'w') as conffile:
            conffile.write(APACHE_CONF)

    if not os.path.isfile(SYSTEMD_SERVICE_PATH):
        with open(SYSTEMD_SERVICE_PATH, 'w') as file_handle:
            file_handle.write(SYSTEMD_SERVICE)

        subprocess.check_call(['systemctl', 'daemon-reload'])


def main():
    """Parse arguments and perform all duties."""
    arguments = parse_arguments()

    subcommand = arguments.subcommand.replace('-', '_')
    subcommand_method = globals()['subcommand_' + subcommand]
    subcommand_method(arguments)


if __name__ == '__main__':
    main()
