#!/usr/bin/env python

import os
import sys

from django.core.management import execute_from_command_line

from openslides import __version__ as openslides_version
from openslides.utils.main import (
    ExceptionArgumentParser,
    UnknownCommand,
    get_default_settings_path,
    get_local_settings_path,
    is_local_installation,
    setup_django_settings_module,
    start_browser,
    write_settings,
)


def main():
    """
    Main entrance to OpenSlides.
    """
    parser = get_parser()
    try:
        known_args, unknown_args = parser.parse_known_args()
    except UnknownCommand:
        unknown_command = True
    else:
        unknown_command = False

    if unknown_command:
        # Run a command, that is defined by the django management api
        local_installation = is_local_installation()
        setup_django_settings_module(local_installation=local_installation)
        execute_from_command_line(sys.argv)
    else:
        # Run a command that is defined here
        # These are commands that can not rely on an existing settings
        known_args.callback(known_args)


def get_parser():
    """
    Parses all command line arguments.
    """
    if len(sys.argv) == 1 and not is_local_installation():
        sys.argv.append('start')

    # Init parser
    description = 'Start script for OpenSlides.'
    if 'manage.py' not in sys.argv[0]:
        description += """
            If it is called without any argument, this will be treated as
            if it is called with the 'start' subcommand. That means
            OpenSlides will setup default settings and database, start the
            tornado webserver, launch the default web browser and open the
            webinterface.
            """
    epilog = """
        There are some more subcommands available. They belong to Django's
        command-line utility for administrative tasks. Type '%(prog)s help'
        (without the two hyphen-minus characters) to list them all. Type
        '%(prog)s help <subcommand>' for help on a specific subcommand.
        """
    parser = ExceptionArgumentParser(
        description=description,
        epilog=epilog)

    # Add version argument
    parser.add_argument(
        '--version',
        action='version',
        version=openslides_version,
        help='Show version number and exit.')

    # Init subparsers
    subparsers = parser.add_subparsers(
        dest='subcommand',
        title='Available subcommands',
        description="Type '%s <subcommand> --help' for help on a "
                    "specific subcommand." % parser.prog,
        help='You can choose only one subcommand at once.',
        metavar='')

    # Subcommand start
    start_help = (
        'Setup settings and database, start tornado webserver, launch the '
        'default web browser and open the webinterface. The environment '
        'variable DJANGO_SETTINGS_MODULE is ignored.')
    subcommand_start = subparsers.add_parser(
        'start',
        description=start_help,
        help=start_help)
    subcommand_start.add_argument(
        '--no-browser',
        action='store_true',
        help='Do not launch the default web browser.')
    subcommand_start.add_argument(