from __future__ import absolute_import
from __future__ import print_function

import sys
import argparse

from django.core.management.base import BaseCommand, CommandError
from django.core.exceptions import ValidationError
from django.db.utils import IntegrityError
from django.core import validators

from zerver.models import Realm, get_realm, email_to_username
from zerver.lib.actions import do_create_user
from zerver.views import notify_new_user
from zerver.lib.initial_password import initial_password
from six.moves import input

class Command(BaseCommand):
    help = """Create the specified user with a default initial password.

A user MUST have ALREADY accepted the Terms of Service before creating their
account this way.

Omit both <email> and <full name> for interactive user creation.
"""

    def add_arguments(self, parser):
        parser.add_argument('--this-user-has-accepted-the-tos',
                            dest='tos',
                            action="store_true",
                            default=False,
                            help='Acknowledgement that the user has already accepted the ToS.')
        parser.add_argument('--domain',
                            dest='domain',
                            type=str,
                            help='The name of the existing realm to which to add the user.')
        parser.add_argument('email', metavar='<email>', type=str, nargs='?', default=argparse.SUPPRESS,
                            help='email address of new user')
        parser.add_argument('full_name', metavar='<full name>', type=str, nargs='?', default=argparse.SUPPRESS,
                            help='full name of new user')

    def handle(self, *args, **options):
        if not options["tos"]:
            raise CommandError("""You must confirm that this user has accepted the
Terms of Service by passing --this-user-has-accepted-the-tos.""")

        if not options["domain"]:
            raise CommandError("""Please specify a realm by passing --domain.""")

        try:
            realm = get_realm(options["domain"])
        except Realm.DoesNotExist:
            raise CommandError("Realm does not exist.")

        try:
            email = options['email']
            full_name = options['full_name']
            try:
                validators.validate_email(email)
            except ValidationError:
                raise CommandError("Invalid email address.")
        except KeyError:
            if 'email' in options or 'full_name' in options:
                raise CommandError("""Either specify an email and full name as two
parameters, or specify no parameters for interactive user creation.""")
            else:
                while True:
                    email = input("Email: ")
                    try:
                        validators.validate_email(email)
                        break
                    except ValidationError:
                        print("Invalid email address.", file=sys.stderr)
                full_name = input("Full name: ")

        try:
            notify_new_user(do_create_user(email, initial_password(email),
                realm, full_name, email_to_username(email)),
                internal=True)
        except IntegrityError:
            raise CommandError("User already exists.")