from __future__ import absolute_import

from django.core.exceptions import ObjectDoesNotExist
from celery import shared_task
from celery.utils.log import get_task_logger
from celery.exceptions import Reject
from ldapentities.models import (
    LdapGroup,
    LdapUser,
)


_logger = get_task_logger(__name__)


@shared_task
def create_ldap_group(groupname, gid, descr):
    try:
        ldapgroup = LdapGroup.objects.get(name=groupname)
        _logger.info(
            'ldap group with dn {0} already exists'.format(ldapgroup.dn)
        )
        ldapgroup.gid = gid
    except LdapGroup.DoesNotExist:
        ldapgroup = LdapGroup(gid=gid, name=groupname)
    ldapgroup.description = descr
    ldapgroup.save()
    return ldapgroup.dn


@shared_task
def create_ldap_user(username, uid, gid, gecos, homedir, shell, password):
    try:
        ldapuser = LdapUser.objects.get(username=username)
        _logger.info(
            'ldap user with dn {0} already exists'.format(ldapuser.dn)
        )
    except LdapUser.DoesNotExist:
        ldapuser = LdapUser(username=username)
    try:
        ldapgroup = LdapGroup.objects.get(gid=gid)
    except ObjectDoesNotExist as exc:
        _logger.info('ldap group with gid {0} does not exist')
        raise Reject(exc, requeue=False)
    ldapuser.uid = uid
    ldapuser.group = gid
    ldapuser.gecos = gecos
    ldapuser.home_directory = homedir
    ldapuser.login_shell = shell
    ldapuser.username = username
    ldapuser.common_name = username
    if password is not None:
        ldapuser.set_password(password)
    if ldapuser.username in ldapgroup.members:
        _logger.info('user {0} is already member of {1}'.format(
            ldapuser.username, ldapgroup.dn)
        )
    else:
        ldapgroup.members.append(ldapuser.username)
        ldapgroup.save()
    ldapuser.save()
    return ldapuser.dn


@shared_task(bind=True)
def add_ldap_user_to_group(self, username, groupname):
    try:
        ldapgroup = LdapGroup.objects.get(name=groupname)
        ldapuser = LdapUser.objects.get(username=username)
    except LdapGroup.DoesNotExist:
        _logger.error('ldap group {0} does not exist'.format(groupname))
    except LdapUser.DoesNotExist as exc:
        _logger.error('ldap user {0} does not exist'.format(username))
        self.retry(exc=exc, time_limit=5)
    else:
        if not ldapuser.username in ldapgroup.members:
            ldapgroup.members.append(ldapuser.username)
            ldapgroup.save()
        else:
            _logger.info('ldap user {0} is already in group {1}'.format(
                ldapuser.username, ldapgroup.dn)
            )


@shared_task
def remove_ldap_user_from_group(username, groupname):
    ldapgroup = LdapGroup.objects.get(name=groupname)
    ldapuser = LdapUser.objects.get(username=username)
    if ldapuser.username in ldapgroup.members:
        ldapgroup.members.remove(ldapuser.username)
    ldapgroup.save()


@shared_task
def delete_ldap_user(username):
    try:
        ldapuser = LdapUser.objects.get(username=username)
    except LdapUser.DoesNotExist:
        _logger.info('there is no ldap user with uid {0}'.format(
            username)
        )
    else:
        try:
            ldapgroup = LdapGroup.objects.get(gid=ldapuser.group)
        except LdapGroup.DoesNotExist:
            _logger.info('group {0} for user {1} does not exist'.format(
                ldapuser.group, ldapuser.username)
            )
        else:
            if ldapuser.username in ldapgroup.members:
                ldapgroup.members.remove(ldapuser.username)
                ldapgroup.save()
        ldapuser.delete()


@shared_task
def delete_ldap_group_if_empty(groupname):
    try:
        ldapgroup = LdapGroup.objects.get(name=groupname)
    except LdapGroup.DoesNotExist:
        _logger.info('ldap group with name {0} does not exist'.format(
            groupname)
        )
    else:
        if len(ldapgroup.members) == 0:
            ldapgroup.delete()
        else:
            _logger.info('ldap group {0} still has {1} members'.format(
                ldapgroup.dn, len(ldapgroup.members))
            )