#!/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 Mumble server
"""

import argparse
import subprocess


SERVICE_CONFIG = '/etc/default/mumble-server'


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

    # Get whether service is enabled
    subparsers.add_parser('get-enabled',
                          help='Get whether Mumble service is enabled')

    # Enable service
    subparsers.add_parser('enable', help='Enable Mumble service')

    # Disable service
    subparsers.add_parser('disable', help='Disable Mumble service')

    # Get whether daemon is running
    subparsers.add_parser('is-running',
                          help='Get whether Mumble daemon is running')

    return parser.parse_args()


def subcommand_get_enabled(_):
    """Get whether service is enabled."""
    try:
        with open(SERVICE_CONFIG, 'r') as file:
            for line in file:
                if line.startswith('MURMUR_DAEMON_START'):
                    value = line.split('=')[1].strip()
                    print('yes' if int(value) else 'no')
                    return
    except FileNotFoundError:
        pass

    print('no')


def subcommand_enable(_):
    """Start service."""
    set_service_enable(enable=True)
    subprocess.call(['service', 'mumble-server', 'start'])


def subcommand_disable(_):
    """Stop service."""
    subprocess.call(['service', 'mumble-server', 'stop'])
    set_service_enable(enable=False)


def set_service_enable(enable):
    """Enable/disable daemon; enable: boolean."""
    newline = 'MURMUR_DAEMON_START=1\n' if enable \
        else 'MURMUR_DAEMON_START=0\n'

    with open(SERVICE_CONFIG, 'r') as file:
        lines = file.readlines()
        for index, line in enumerate(lines):
            if line.startswith('MURMUR_DAEMON_START'):
                lines[index] = newline
                break

    with open(SERVICE_CONFIG, 'w') as file:
        file.writelines(lines)


def subcommand_is_running(_):
    """Get whether server is running."""
    try:
        output = subprocess.check_output(['service', 'mumble-server',
                                          'status'])
    except subprocess.CalledProcessError:
        # If daemon is not running we get a status code != 0 and a
        # 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 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()