from __future__ import absolute_import
from __future__ import print_function

from typing import Any

from argparse import ArgumentParser
from django.core.management.base import CommandError
from confirmation.models import Confirmation, create_confirmation_link
from zerver.lib.management import ZulipBaseCommand
from zerver.models import PreregistrationUser, email_allowed_for_realm

class Command(ZulipBaseCommand):
    help = "Generate activation links for users and print them to stdout."

    def add_arguments(self, parser):
        # type: (ArgumentParser) -> None
        parser.add_argument('--force',
                            dest='force',
                            action="store_true",
                            default=False,
                            help='Override that the domain is restricted to external users.')
        parser.add_argument('emails', metavar='<email>', type=str, nargs='*',
                            help='email of users to generate an activation link for')
        self.add_realm_args(parser, True)

    def handle(self, *args, **options):
        # type: (*Any, **Any) -> None
        duplicates = False
        realm = self.get_realm(options)

        if not options['emails']:
            self.print_help("./manage.py", "generate_invite_links")
            exit(1)

        for email in options['emails']:
            try:
                self.get_user(email, realm)
                print(email + ": There is already a user registered with that address.")
                duplicates = True
                continue
            except CommandError:
                pass

        if duplicates:
            return

        for email in options['emails']:
            if not email_allowed_for_realm(email, realm) and not options["force"]:
                print("You've asked to add an external user '%s' to a closed realm '%s'." % (
                    email, realm.string_id))
                print("Are you sure? To do this, pass --force.")
                exit(1)

            prereg_user = PreregistrationUser(email=email, realm=realm)
            prereg_user.save()
            print(email + ": " + create_confirmation_link(prereg_user, realm.host,
                                                          Confirmation.INVITATION))