#!/usr/bin/python3
# SPDX-License-Identifier: AGPL-3.0-or-later
"""
Configuration helper for MediaWiki.
"""

import argparse
import os
import subprocess
import sys
import tempfile

from plinth.utils import generate_password

MAINTENANCE_SCRIPTS_DIR = "/usr/share/mediawiki/maintenance"
CONF_FILE = '/etc/mediawiki/FreedomBoxSettings.php'
LOCAL_SETTINGS_CONF = '/etc/mediawiki/LocalSettings.php'


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('setup', help='Setup MediaWiki')
    subparsers.add_parser('update', help='Run MediaWiki update script')

    help_pub_reg = 'Enable/Disable/Status public user registration.'
    pub_reg = subparsers.add_parser('public-registrations', help=help_pub_reg)
    pub_reg.add_argument('command', choices=('enable', 'disable', 'status'),
                         help=help_pub_reg)

    help_private_mode = 'Enable/Disable/Status private mode.'
    private_mode = subparsers.add_parser('private-mode',
                                         help=help_private_mode)
    private_mode.add_argument('command',
                              choices=('enable', 'disable', 'status'),
                              help=help_private_mode)

    change_password = subparsers.add_parser('change-password',
                                            help='Change user password')
    change_password.add_argument('--username', default='admin',
                                 help='name of the MediaWiki user')
    change_password.add_argument('--password',
                                 help='new password for the MediaWiki user')

    default_skin = subparsers.add_parser('set-default-skin',
                                         help='Set the default skin')
    default_skin.add_argument('skin', help='name of the skin')

    server_url = subparsers.add_parser(
        'set-server-url', help='Set the value of $wgServer for this server')
    server_url.add_argument('server_url', help='value of $wgServer')

    subparsers.required = True
    return parser.parse_args()


def _get_php_command():
    """Return the PHP command that should be used on CLI.

    This is workaround for /usr/bin/php pointing to a different version than
    what php-defaults (and php-mbstring, php-xml) point to. See:
    https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=959742

    """
    version = ''

    try:
        process = subprocess.run(['dpkg', '-s', 'php'], stdout=subprocess.PIPE,
                                 check=True)
        for line in process.stdout.decode().splitlines():
            if line.startswith('Version:'):
                version = line.split(':')[-1].split('+')[0].strip()
    except subprocess.CalledProcessError:
        pass

    return f'php{version}'


def subcommand_setup(_):
    """Run the installer script to create database and configuration file."""
    data_dir = '/var/lib/mediawiki-db/'
    if not os.path.exists(data_dir):
        os.mkdir(data_dir)

    if not os.path.exists(os.path.join(data_dir, 'my_wiki.sqlite')) or \
       not os.path.exists(LOCAL_SETTINGS_CONF):
        install_script = os.path.join(MAINTENANCE_SCRIPTS_DIR, 'install.php')
        password = generate_password()
        with tempfile.NamedTemporaryFile() as password_file_handle:
            password_file_handle.write(password.encode())
            password_file_handle.flush()
            subprocess.check_call([
                _get_php_command(), install_script,
                '--confpath=/etc/mediawiki', '--dbtype=sqlite',
                '--dbpath=' + data_dir, '--scriptpath=/mediawiki',
                '--passfile', password_file_handle.name, 'Wiki', 'admin'
            ])
    subprocess.run(['chmod', '-R', 'o-rwx', data_dir], check=True)
    subprocess.run(['chown', '-R', 'www-data:www-data', data_dir], check=True)
    include_custom_config()
    _fix_non_private_mode()


def include_custom_config():
    """Include FreedomBox specific configuration in LocalSettings.php."""
    with open(LOCAL_SETTINGS_CONF, 'r') as conf_file:
        lines = conf_file.readlines()

    static_settings_index = None
    settings_index = None
    for line_number, line in enumerate(lines):
        if 'FreedomBoxSettings.php' in line:
            settings_index = line_number

        if 'FreedomBoxStaticSettings.php' in line:
            static_settings_index = line_number

    if settings_index is None:
        settings_index = len(lines)
        lines.append('include dirname(__FILE__)."/FreedomBoxSettings.php";\n')

    if static_settings_index is None:
        lines.insert(
            settings_index,
            'include dirname(__FILE__)."/FreedomBoxStaticSettings.php";\n')

    with open(LOCAL_SETTINGS_CONF, 'w') as conf_file:
        conf_file.writelines(lines)


def _fix_non_private_mode():
    """Drop the line that allows editing by anonymous users.

    Remove this fix after the release of Debian 11.

    """
    with open(CONF_FILE, 'r') as conf_file:
        lines = conf_file.readlines()

    with open(CONF_FILE, 'w') as conf_file:
        for line in lines:
            if not line.startswith("$wgGroupPermissions['*']['edit']"):
                conf_file.write(line)


def subcommand_change_password(arguments):
    """Change the password for a given user"""
    new_password = ''.join(sys.stdin)
    change_password_script = os.path.join(MAINTENANCE_SCRIPTS_DIR,
                                          'changePassword.php')

    subprocess.check_call([
        _get_php_command(), change_password_script, '--user',
        arguments.username, '--password', new_password
    ])


def subcommand_update(_):
    """Run update.php maintenance script when version upgrades happen."""
    update_script = os.path.join(MAINTENANCE_SCRIPTS_DIR, 'update.php')
    subprocess.check_call([_get_php_command(), update_script, '--quick'])


def subcommand_public_registrations(arguments):
    """Enable or Disable public registrations for MediaWiki."""

    with open(CONF_FILE, 'r') as conf_file:
        lines = conf_file.readlines()

    def is_pub_reg_line(line):
        return line.startswith("$wgGroupPermissions['*']['createaccount']")

    if arguments.command == 'status':
        conf_lines = list(filter(is_pub_reg_line, lines))
        if conf_lines:
            print('enabled' if 'true' in conf_lines[0] else 'disabled')
        else:
            print('disabled')
    else:
        with open(CONF_FILE, 'w') as conf_file:
            for line in lines:
                if is_pub_reg_line(line):
                    words = line.split()
                    if arguments.command == 'enable':
                        words[-1] = 'true;'
                    else:
                        words[-1] = 'false;'
                    conf_file.write(" ".join(words) + '\n')
                else:
                    conf_file.write(line)


def subcommand_private_mode(arguments):
    """Enable or Disable Private mode for wiki"""
    with open(CONF_FILE, 'r') as conf_file:
        lines = conf_file.readlines()

    def is_read_line(line):
        return line.startswith("$wgGroupPermissions['*']['read']")

    read_conf_lines = list(filter(is_read_line, lines))
    if arguments.command == 'status':
        if read_conf_lines and 'false' in read_conf_lines[0]:
            print('enabled')
        else:
            print('disabled')
    else:
        with open(CONF_FILE, 'w') as conf_file:
            conf_value = 'false;' if arguments.command == 'enable' else 'true;'
            for line in lines:
                if is_read_line(line):
                    words = line.split()
                    words[-1] = conf_value
                    conf_file.write(" ".join(words) + '\n')
                else:
                    conf_file.write(line)

            if not read_conf_lines:
                conf_file.write("$wgGroupPermissions['*']['read'] = " +
                                conf_value + '\n')


def _update_setting(setting_name, setting_line):
    """Update the value of one setting in the config file."""
    with open(CONF_FILE, 'r') as conf_file:
        lines = conf_file.readlines()

        inserted = False
        for i, line in enumerate(lines):
            if line.strip().startswith(setting_name):
                lines[i] = setting_line
                inserted = True
                break

        if not inserted:
            lines.append(setting_line)

    with open(CONF_FILE, 'w') as conf_file:
        conf_file.writelines(lines)


def subcommand_set_default_skin(arguments):
    """Set a default skin."""
    skin = arguments.skin
    _update_setting('$wgDefaultSkin ', f'$wgDefaultSkin = "{skin}";\n')


def subcommand_set_server_url(arguments):
    """Set the value of $wgServer for this MediaWiki server."""
    # This is a required setting from MediaWiki 1.34
    _update_setting('$wgServer', f'$wgServer = "{arguments.server_url}";\n')


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()
