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

from django.db.models import Model, QuerySet
from django.utils.timezone import now as timezone_now

from zerver.lib.create_user import create_user_profile, get_display_email_address
from zerver.lib.initial_password import initial_password
from zerver.lib.streams import render_stream_description
from zerver.models import (
    Realm,
    RealmAuditLog,
    RealmUserDefault,
    Recipient,
    Stream,
    Subscription,
    UserGroup,
    UserGroupMembership,
    UserProfile,
)
from zerver.models.groups import SystemGroups


def bulk_create_users(
    realm: Realm,
    users_raw: Set[Tuple[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)

    realm_user_default = RealmUserDefault.objects.get(realm=realm)
    if bot_type is None:
        email_address_visibility = realm_user_default.email_address_visibility
    else:
        # There is no privacy motivation for limiting access to bot email addresses,
        # so we hardcode them to EMAIL_ADDRESS_VISIBILITY_EVERYONE.
        email_address_visibility = UserProfile.EMAIL_ADDRESS_VISIBILITY_EVERYONE

    # Now create user_profiles
    profiles_to_create: List[UserProfile] = []
    for email, full_name, active in users:
        profile = create_user_profile(
            realm,
            email,
            initial_password(email),
            active,
            bot_type,
            full_name,
            bot_owner,
            False,
            tos_version,
            timezone,
            default_language=realm.default_language,
            tutorial_status=UserProfile.TUTORIAL_FINISHED,
            email_address_visibility=email_address_visibility,
        )

        if bot_type is None:
            # This block simulates copy_default_settings from
            # zerver/lib/create_user.py.
            #
            # We cannot use 'copy_default_settings' directly here
            # because it calls '.save' after copying the settings, and
            # we are bulk creating the objects here instead.
            for settings_name in RealmUserDefault.property_types:
                if settings_name in ["default_language", "enable_login_emails"]:
                    continue
                value = getattr(realm_user_default, settings_name)
                setattr(profile, settings_name, value)
        profiles_to_create.append(profile)

    if email_address_visibility == UserProfile.EMAIL_ADDRESS_VISIBILITY_EVERYONE:
        UserProfile.objects.bulk_create(profiles_to_create)
    else:
        for user_profile in profiles_to_create:
            user_profile.email = user_profile.delivery_email

        UserProfile.objects.bulk_create(profiles_to_create)

        for user_profile in profiles_to_create:
            user_profile.email = get_display_email_address(user_profile)
        UserProfile.objects.bulk_update(profiles_to_create, ["email"])

    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 = [
        Recipient(type_id=user_id, type=Recipient.PERSONAL) for user_id in user_ids
    ]

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

    subscriptions_to_create = [
        Subscription(
            user_profile_id=user_profile.id,
            recipient=recipients_by_user_id[user_profile.id],
            is_user_active=user_profile.is_active,
        )
        for user_profile in profiles_to_create
    ]

    Subscription.objects.bulk_create(subscriptions_to_create)

    full_members_system_group = UserGroup.objects.get(
        name=SystemGroups.FULL_MEMBERS, realm=realm, is_system_group=True
    )
    members_system_group = UserGroup.objects.get(
        name=SystemGroups.MEMBERS, realm=realm, is_system_group=True
    )
    group_memberships_to_create: List[UserGroupMembership] = []
    for user_profile in profiles_to_create:
        # All users are members since this function is only used to create bots
        # and test and development environment users.
        assert user_profile.role == UserProfile.ROLE_MEMBER
        group_memberships_to_create.append(
            UserGroupMembership(user_profile=user_profile, user_group=members_system_group)
        )
        if not user_profile.is_provisional_member:
            group_memberships_to_create.append(
                UserGroupMembership(user_profile=user_profile, user_group=full_members_system_group)
            )

    UserGroupMembership.objects.bulk_create(group_memberships_to_create)
    now = timezone_now()
    RealmAuditLog.objects.bulk_create(
        RealmAuditLog(
            realm=realm,
            modified_user=membership.user_profile,
            modified_user_group=membership.user_group,
            event_type=RealmAuditLog.USER_GROUP_DIRECT_USER_MEMBERSHIP_ADDED,
            event_time=now,
            acting_user=None,
        )
        for membership in group_memberships_to_create
    )


def bulk_set_users_or_streams_recipient_fields(
    model: Type[Model],
    objects: Union[
        Collection[UserProfile], QuerySet[UserProfile], Collection[Stream], QuerySet[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 = {obj.id: obj for obj in objects}

    objects_to_update = set()
    for recipient in recipients:
        assert recipient.type == recipient_type
        result = objects_dict.get(recipient.type_id)
        if result is not None:
            result.recipient = recipient
            objects_to_update.add(result)
    model._default_manager.bulk_update(objects_to_update, ["recipient"])


# This is only sed in populate_db, so doesn't really need tests
def bulk_create_streams(realm: Realm, stream_dict: Dict[str, Dict[str, Any]]) -> None:  # nocoverage
    existing_streams = {
        name.lower() for name in Stream.objects.filter(realm=realm).values_list("name", flat=True)
    }
    administrators_user_group = UserGroup.objects.get(
        name=SystemGroups.ADMINISTRATORS, is_system_group=True, realm=realm
    )
    streams_to_create: 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:
            streams_to_create.append(
                Stream(
                    realm=realm,
                    name=name,
                    description=options["description"],
                    rendered_description=render_stream_description(options["description"], realm),
                    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,
                    can_remove_subscribers_group=administrators_user_group,
                ),
            )
    # 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 = [
        Recipient(type_id=stream["id"], type=Recipient.STREAM)
        for stream in Stream.objects.filter(realm=realm).values("id", "name")
        if stream["name"].lower() not in existing_streams
    ]
    Recipient.objects.bulk_create(recipients_to_create)

    bulk_set_users_or_streams_recipient_fields(Stream, streams_to_create, recipients_to_create)


def create_users(
    realm: Realm, name_list: Iterable[Tuple[str, str]], bot_type: Optional[int] = None
) -> None:
    user_set = set()
    for full_name, email in name_list:
        user_set.add((email, full_name, True))
    bulk_create_users(realm, user_set, bot_type)