from __future__ import absolute_import

import logging
from typing import Any, Dict, List, Optional, Text

from argparse import ArgumentParser
from django.core.management.base import BaseCommand, CommandError
from django.conf import settings
from zerver.forms import PasswordResetForm
from zerver.models import UserProfile, get_user_profile_by_email, get_realm
from django.template import loader
from django.utils.http import urlsafe_base64_encode
from django.utils.encoding import force_bytes

from django.contrib.auth.tokens import default_token_generator, PasswordResetTokenGenerator

from zerver.lib.send_email import send_email

class Command(BaseCommand):
    help = """Send email to specified email address."""

    def add_arguments(self, parser):
        # type: (ArgumentParser) -> None
        parser.add_argument('--to', metavar='<to>', type=str,
                            help="email of user to send the email")
        parser.add_argument('--realm', metavar='<realm>', type=str,
                            help="realm to send the email to all users in")
        parser.add_argument('--server', metavar='<server>', type=str,
                            help="If you specify 'YES' will send to everyone on server")

    def handle(self, *args, **options):
        # type: (*Any, **str) -> None
        if options["to"]:
            users = [get_user_profile_by_email(options["to"])]
        elif options["realm"]:
            realm = get_realm(options["realm"])
            users = UserProfile.objects.filter(realm=realm, is_active=True, is_bot=False,
                                               is_mirror_dummy=False)
        elif options["server"] == "YES":
            users = UserProfile.objects.filter(is_active=True, is_bot=False,
                                               is_mirror_dummy=False)
        else:
            raise RuntimeError("Missing arguments")
        self.send(users)

    def send(self, users, subject_template_name='', email_template_name='',
             use_https=True, token_generator=default_token_generator,
             from_email=None, html_email_template_name=None):
        # type: (List[UserProfile], str, str, bool, PasswordResetTokenGenerator, Optional[Text], Optional[str]) -> None
        """Sends one-use only links for resetting password to target users

        """
        for user_profile in users:
            context = {
                'email': user_profile.email,
                'domain': user_profile.realm.host,
                'site_name': "zulipo",
                'uid': urlsafe_base64_encode(force_bytes(user_profile.pk)),
                'user': user_profile,
                'token': token_generator.make_token(user_profile),
                'protocol': 'https' if use_https else 'http',
            }

            logging.warning("Sending %s email to %s" % (email_template_name, user_profile.email,))
            send_email('zerver/emails/password_reset', user_profile.email, context=context)