from django.db.models import Model

from typing import Any, Dict, Iterable, List, Optional, Set, Tuple, Union

from zerver.lib.initial_password import initial_password
from zerver.models import Realm, Stream, UserProfile, \
    Subscription, Recipient, RealmAuditLog
from zerver.lib.create_user import create_user_profile

def bulk_create_users(realm: Realm,
                      users_raw: Set[Tuple[str, str, str, bool]],
                      bot_type: Optional[int]=None,
                      bot_owner: Optional[UserProfile]=None,
                      tos_version: Optional[str]=None,
                      timezone: str="") -> None:
    """
    Creates and saves a UserProfile with the given email.
    Has some code based off of UserManage.create_user, but doesn't .save()
    """
    existing_users = frozenset(UserProfile.objects.filter(
        realm=realm).values_list('email', flat=True))
    users = sorted([user_raw for user_raw in users_raw if user_raw[0] not in existing_users])

    # If we have a different email_address_visibility mode, the code
    # below doesn't have the logic to set user_profile.email properly.
    assert realm.email_address_visibility == Realm.EMAIL_ADDRESS_VISIBILITY_EVERYONE

    # Now create user_profiles
    profiles_to_create = []  # type: List[UserProfile]
    for (email, full_name, short_name, active) in users:
        profile = create_user_profile(realm, email,
                                      initial_password(email), active, bot_type,
                                      full_name, short_name, bot_owner, False, tos_version,
                                      timezone, tutorial_status=UserProfile.TUTORIAL_FINISHED,
                                      enter_sends=True)
        profiles_to_create.append(profile)
    UserProfile.objects.bulk_create(profiles_to_create)
    user_ids = {user.id for user in profiles_to_create}

    RealmAuditLog.objects.bulk_create(
        [RealmAuditLog(realm=realm, modified_user=profile_,
                       event_type=RealmAuditLog.USER_CREATED, event_time=profile_.date_joined)
         for profile_ in profiles_to_create])

    recipients_to_create = []  # type: List[Recipient]
    for user_id in user_ids:
        recipient = Recipient(type_id=user_id, type=Recipient.PERSONAL)
        recipients_to_create.append(recipient)

    Recipient.objects.bulk_create(recipients_to_create)

    bulk_set_users_or_streams_recipient_fields(UserProfile, profiles_to_create, recipients_to_create)

    recipients_by_user_id = {}  # type: Dict[int, Recipient]
    for recipient in recipients_to_create:
        recipients_by_user_id[recipient.type_id] = recipient

    subscriptions_to_create = []  # type: List[Subscription]
    for user_id in user_ids:
        recipient = recipients_by_user_id[user_id]
        subscription = Subscription(user_profile_id=user_id, recipient=recipient)
        subscriptions_to_create.append(subscription)

    Subscription.objects.bulk_create(subscriptions_to_create)

def bulk_set_users_or_streams_recipient_fields(model: Model,
                                               objects: Union[Iterable[UserProfile], Iterable[Stream]],
                                               recipients: Optional[Iterable[Recipient]]=None) -> None:
    assert model in [UserProfile, Stream]
    for obj in objects:
        assert isinstance(obj, model)

    if model == UserProfile:
        recipient_type = Recipient.PERSONAL
    elif model == Stream:
        recipient_type = Recipient.STREAM

    if recipients is None:
        object_ids = [obj.id for obj in objects]
        recipients = Recipient.objects.filter(type=recipient_type, type_id__in=object_ids)

    objects_dict = dict((obj.id, obj) for obj in objects)

    for recipient in recipients:
        assert recipient.type == recipient_type
        result = objects_dict.get(recipient.type_id)
        if result is not None:
            result.recipient = recipient
            # TODO: Django 2.2 has a bulk_update method, so once we manage to migrate to that version,
            # we take adventage of this, instead of calling save individually.
            result.save(update_fields=['recipient'])

# This is only sed in populate_db, so doesn't realy need tests
def bulk_create_streams(realm: Realm,
                        stream_dict: Dict[str, Dict[str, Any]]) -> None:  # nocoverage
    existing_streams = frozenset([name.lower() for name in
                                  Stream.objects.filter(realm=realm)
                                  .values_list('name', flat=True)])
    streams_to_create = []  # type: List[Stream]
    for name, options in stream_dict.items():
        if 'history_public_to_subscribers' not in options:
            options['history_public_to_subscribers'] = (
                not options.get("invite_only", False) and not realm.is_zephyr_mirror_realm)
        if name.lower() not in existing_streams:
            from zerver.lib.actions import render_stream_description
            streams_to_create.append(
                Stream(
                    realm=realm,
                    name=name,
                    description=options["description"],
                    rendered_description=render_stream_description(options["description"]),
                    invite_only=options.get("invite_only", False),
                    stream_post_policy=options.get("stream_post_policy",
                                                   Stream.STREAM_POST_POLICY_EVERYONE),
                    history_public_to_subscribers=options["history_public_to_subscribers"],
                    is_web_public=options.get("is_web_public", False),
                    is_in_zephyr_realm=realm.is_zephyr_mirror_realm,
                )
            )
    # Sort streams by name before creating them so that we can have a
    # reliable ordering of `stream_id` across different python versions.
    # This is required for test fixtures which contain `stream_id`. Prior
    # to python 3.3 hashes were not randomized but after a security fix
    # hash randomization was enabled in python 3.3 which made iteration
    # of dictionaries and sets completely unpredictable. Here the order
    # of elements while iterating `stream_dict` will be completely random
    # for python 3.3 and later versions.
    streams_to_create.sort(key=lambda x: x.name)
    Stream.objects.bulk_create(streams_to_create)

    recipients_to_create = []  # type: List[Recipient]
    for stream in Stream.objects.filter(realm=realm).values('id', 'name'):
        if stream['name'].lower() not in existing_streams:
            recipients_to_create.append(Recipient(type_id=stream['id'],
                                                  type=Recipient.STREAM))
    Recipient.objects.bulk_create(recipients_to_create)

    bulk_set_users_or_streams_recipient_fields(Stream, streams_to_create, recipients_to_create)