import logging
from argparse import ArgumentParser
from typing import Any, Collection

from django.conf import settings
from django.core.management.base import CommandError
from django.db import transaction

from zerver.lib.logging_util import log_to_file
from zerver.lib.management import ZulipBaseCommand
from zerver.models import UserProfile
from zproject.backends import ZulipLDAPError, sync_user_from_ldap

## Setup ##
logger = logging.getLogger("zulip.sync_ldap_user_data")
log_to_file(logger, settings.LDAP_SYNC_LOG_PATH)


# Run this on a cron job to pick up on name changes.
@transaction.atomic
def sync_ldap_user_data(
    user_profiles: Collection[UserProfile], deactivation_protection: bool = True
) -> None:
    logger.info("Starting update.")
    try:
        realms = {u.realm.string_id for u in user_profiles}

        for u in user_profiles:
            # This will save the user if relevant, and will do nothing if the user
            # does not exist.
            try:
                sync_user_from_ldap(u, logger)
            except ZulipLDAPError as e:
                logger.error("Error attempting to update user %s:", u.delivery_email)
                logger.error(e.args[0])

        if deactivation_protection:
            if not UserProfile.objects.filter(is_bot=False, is_active=True).exists():
                raise Exception(
                    "LDAP sync would have deactivated all users. This is most likely due "
                    "to a misconfiguration of LDAP settings. Rolling back...\n"
                    "Use the --force option if the mass deactivation is intended."
                )
            for string_id in realms:
                if not UserProfile.objects.filter(
                    is_bot=False,
                    is_active=True,
                    realm__string_id=string_id,
                    role=UserProfile.ROLE_REALM_OWNER,
                ).exists():
                    raise Exception(
                        f"LDAP sync would have deactivated all owners of realm {string_id}. "
                        "This is most likely due "
                        "to a misconfiguration of LDAP settings. Rolling back...\n"
                        "Use the --force option if the mass deactivation is intended."
                    )
    except Exception:
        logger.exception("LDAP sync failed")
        raise

    logger.info("Finished update.")


class Command(ZulipBaseCommand):
    def add_arguments(self, parser: ArgumentParser) -> None:
        parser.add_argument(
            "-f",
            "--force",
            action="store_true",
            help="Disable the protection against deactivating all users.",
        )

        self.add_realm_args(parser)
        self.add_user_list_args(parser)

    def handle(self, *args: Any, **options: Any) -> None:
        if options.get("realm_id") is not None:
            realm = self.get_realm(options)
            user_profiles = self.get_users(options, realm, is_bot=False, include_deactivated=True)
        else:
            user_profile_query = UserProfile.objects.select_related("realm").filter(is_bot=False)

            if not user_profile_query.exists():
                # This case provides a special error message if one
                # tries setting up LDAP sync before creating a realm.
                raise CommandError("Zulip server contains no users. Have you created a realm?")
            user_profiles = list(user_profile_query)

        if len(user_profiles) == 0:
            # We emphasize that this error is purely about the
            # command-line parameters, since this has nothing to do
            # with your LDAP configuration.
            raise CommandError("Zulip server contains no users matching command-line parameters.")

        sync_ldap_user_data(user_profiles, not options["force"])