#
# 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/>.
#
"""
FreedomBox app to manage users.
"""

import subprocess

from django.utils.translation import ugettext_lazy as _

from plinth import action_utils, actions
from plinth import app as app_module
from plinth import cfg, menu
from plinth.utils import format_lazy

version = 2

is_essential = True

managed_packages = [
    'ldapscripts', 'ldap-utils', 'libnss-ldapd', 'libpam-ldapd', 'nscd',
    'nslcd', 'slapd'
]

first_boot_steps = [
    {
        'id': 'users_firstboot',
        'url': 'users:firstboot',
        'order': 1
    },
]

name = _('Users and Groups')

description = [
    _('Create and managed user accounts. These accounts serve as centralized '
      'authentication mechanism for most apps. Some apps further require a '
      'user account to be part of a group to authorize the user to access the '
      'app.'),
    format_lazy(
        _('Any user may login to {box_name} web interface to see a list of '
          'apps relevant to them in the home page. However, only users of '
          'the <em>admin</em> group may alter apps or system settings.'),
        box_name=_(cfg.box_name))
]

manual_page = 'Users'

# All FreedomBox user groups
groups = dict()

app = None


class UsersApp(app_module.App):
    """FreedomBox app for users and groups management."""

    app_id = 'users'

    def __init__(self):
        """Create components for the app."""
        super().__init__()
        menu_item = menu.Menu('menu-users', name, None, 'fa-users',
                              'users:index', parent_url_name='system')
        self.add(menu_item)


def init():
    """Initialize the user module."""
    global app
    app = UsersApp()
    app.set_enabled(True)


def setup(helper, old_version=None):
    """Install and configure the module."""
    helper.install(managed_packages)
    if not old_version:
        helper.call('post', actions.superuser_run, 'users', ['first-setup'])
    helper.call('post', actions.superuser_run, 'users', ['setup'])


def diagnose():
    """Run diagnostics and return the results."""
    results = []

    results.append(action_utils.diagnose_port_listening(389, 'tcp4'))
    results.append(action_utils.diagnose_port_listening(389, 'tcp6'))

    results.append(_diagnose_ldap_entry('dc=thisbox'))
    results.append(_diagnose_ldap_entry('ou=people'))
    results.append(_diagnose_ldap_entry('ou=groups'))

    return results


def _diagnose_ldap_entry(search_item):
    """Diagnose that an LDAP entry exists."""
    result = 'failed'

    try:
        subprocess.check_output(
            ['ldapsearch', '-x', '-b', 'dc=thisbox', search_item])
        result = 'passed'
    except subprocess.CalledProcessError:
        pass

    return [
        _('Check LDAP entry "{search_item}"').format(search_item=search_item),
        result
    ]


def create_group(group):
    """Add an LDAP group."""
    actions.superuser_run('users', options=['create-group', group])


def remove_group(group):
    """Remove an LDAP group."""
    actions.superuser_run('users', options=['remove-group', group])


def register_group(group):
    groups[group[0]] = group[1]


def get_last_admin_user():
    """If there is only one admin user return its name else return None."""
    output = actions.superuser_run('users', ['get-group-users', 'admin'])
    admin_users = output.strip().split('\n')

    if len(admin_users) == 1 and admin_users[0]:
        return admin_users[0]

    return None