from argparse import ArgumentParser
from typing import Any

from django.core.management.base import CommandError

from confirmation.models import Confirmation, create_confirmation_link
from zerver.lib.email_validation import email_allowed_for_realm
from zerver.lib.management import ZulipBaseCommand
from zerver.models import DomainNotAllowedForRealmError, PreregistrationUser


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

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

    def handle(self, *args: Any, **options: Any) -> None:
        duplicates = False
        realm = self.get_realm(options)
        assert realm is not None  # Should be ensured by parser

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

        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']:
            try:
                email_allowed_for_realm(email, realm)
            except DomainNotAllowedForRealmError:
                if not options["force"]:
                    raise CommandError("You've asked to add an external user '{}' to a "
                                       "closed realm '{}'.\nAre you sure? To do this, "
                                       "pass --force.".format(email, realm.string_id))

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