#!/usr/bin/python3
#
# This file is part of FreedomBox.
#
# 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 diaspora* pod.
"""

import argparse
import augeas
import subprocess

from plinth import action_utils
from plinth.modules import diaspora

DIASPORA_YAML = "/etc/diaspora/diaspora.yml"


def parse_arguments():
    """Return parsed command line arguments as dictionary."""
    parser = argparse.ArgumentParser()
    subparsers = parser.add_subparsers(dest='subcommand', help='Sub command')
    subparsers.add_parser(
        'pre-install',
        help='Preseed debconf values before packages are installed.')

    subparsers.add_parser('enable', help='Enable diaspora* web server')
    subparsers.add_parser('disable', help='Disable diaspora* web server')
    subparsers.add_parser('enable-user-registrations', help='Allow users to' \
                          'sign up to this diaspora* pod without an invitation.')
    subparsers.add_parser('disable-user-registrations', help='Allow only, ' \
                          'users with an invitation to register to this diaspora* pod')
    subparsers.add_parser('start-diaspora', help='Start diaspora* service')
    subparsers.add_parser(
        'disable-ssl', help="Disable SSL on the diaspora* application server")
    setup = subparsers.add_parser(
        'setup', help='Set Domain name for diaspora*')
    setup.add_argument(
        '--domain-name', help='The domain name that will be used by diaspora*')

    return parser.parse_args()


def subcommand_setup(arguments):
    """Set the domain_name in diaspora configuration files"""
    domain_name = arguments.domain_name
    with open('/etc/diaspora/domain_name', 'w') as dnf:
        dnf.write(domain_name)
    set_domain_name(domain_name)
    uncomment_user_registrations()
    action_utils.webserver_enable('diaspora-plinth')


def set_domain_name(domain_name):
    """Write a new domain name to diaspora configuration files"""
    # This did not set the domain_name
    # action_utils.dpkg_reconfigure('diaspora-common',
    #                               {'url': domain_name})
    # Manually changing the domain name in the conf files.
    conf_file = '/etc/diaspora.conf'
    aug = augeas.Augeas(flags=augeas.Augeas.NO_LOAD +
                        augeas.Augeas.NO_MODL_AUTOLOAD)

    # lens for shell-script config file
    aug.set('/augeas/load/Shellvars/lens', 'Shellvars.lns')
    aug.set('/augeas/load/Shellvars/incl[last() + 1]', conf_file)
    aug.load()

    aug.set('/files/etc/diaspora.conf/SERVERNAME', '"{}"'.format(domain_name))
    aug.set('/files/etc/diaspora.conf/ENVIRONMENT_URL',
            'http://{}:3000'.format(domain_name))
    aug.save()

    diaspora.generate_apache_configuration(
        '/etc/apache2/conf-available/diaspora-plinth.conf', domain_name)

    action_utils.service_enable('diaspora')
    action_utils.service_start('diaspora')


def subcommand_disable_ssl(_):
    """
    Disable ssl in the diaspora configuration
    as the apache server takes care of ssl
    """
    # Using sed because ruamel.yaml has a bug for this kind of files
    subprocess.call([
        "sed", "-i", "s/#require_ssl: true/require_ssl: false/g", DIASPORA_YAML
    ])


def uncomment_user_registrations():
    """Uncomment the enable_registrations line which is commented by default"""
    subprocess.call([
        "sed", "-i", "s/#enable_registrations/enable_registrations/g",
        DIASPORA_YAML
    ])


def subcommand_enable_user_registrations(_):
    """Enable new user registrations on the diaspora* pod """
    subprocess.call([
        "sed", "-i",
        "s/enable_registrations: false/enable_registrations: true/g",
        DIASPORA_YAML
    ])


def subcommand_disable_user_registrations(_):
    """Disable new user registrations on the diaspora* pod """
    subprocess.call([
        "sed", "-i",
        "s/enable_registrations: true/enable_registrations: false/g",
        DIASPORA_YAML
    ])


def subcommand_pre_install(_):
    """Pre installation configuration for diaspora"""
    presets = [
        b'diaspora-common diaspora-common/url string dummy_domain_name',
        b'diaspora-common diaspora-common/dbpass note ',
        b'diaspora-common diaspora-common/enablessl boolean false',
        b'diaspora-common diaspora-common/useletsencrypt string false',
        b'diaspora-common diaspora-common/services multiselect ',
        b'diaspora-common diaspora-common/ssl boolean false',
        b'diaspora-common diaspora-common/pgsql/authmethod-admin string ident',
        b'diaspora-common diaspora-common/letsencrypt boolean false',
        b'diaspora-common diaspora-common/remote/host string localhost',
        b'diaspora-common diaspora-common/database-type string pgsql',
        b'diaspora-common diaspora-common/dbconfig-install boolean true'
    ]

    for preset in presets:
        subprocess.check_output(['debconf-set-selections'], input=preset)


def subcommand_enable(_):
    """Enable web configuration and reload."""
    action_utils.service_enable('diaspora')
    action_utils.webserver_enable('diaspora-plinth')


def subcommand_disable(_):
    """Disable web configuration and reload."""
    action_utils.webserver_disable('diaspora-plinth')
    action_utils.service_disable('diaspora')


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()