synapse/synapse/module_api/__init__.py

# Copyright 2017 New Vector Ltd
# Copyright 2020 The Matrix.org Foundation C.I.C.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import email.utils
import logging
from typing import (
    TYPE_CHECKING,
    Any,
    Callable,
    Collection,
    Dict,
    Generator,
    Iterable,
    List,
    Mapping,
    Optional,
    Tuple,
    TypeVar,
    Union,
)

import attr
import jinja2
from typing_extensions import Concatenate, ParamSpec

from twisted.internet import defer
from twisted.internet.interfaces import IDelayedCall
from twisted.web.resource import Resource

from synapse.api import errors
from synapse.api.errors import SynapseError
from synapse.api.presence import UserPresenceState
from synapse.config import ConfigError
from synapse.events import EventBase
from synapse.events.presence_router import (
    GET_INTERESTED_USERS_CALLBACK,
    GET_USERS_FOR_STATES_CALLBACK,
    PresenceRouter,
)
from synapse.events.utils import ADD_EXTRA_FIELDS_TO_UNSIGNED_CLIENT_EVENT_CALLBACK
from synapse.handlers.account_data import ON_ACCOUNT_DATA_UPDATED_CALLBACK
from synapse.handlers.auth import (
    CHECK_3PID_AUTH_CALLBACK,
    CHECK_AUTH_CALLBACK,
    GET_DISPLAYNAME_FOR_REGISTRATION_CALLBACK,
    GET_USERNAME_FOR_REGISTRATION_CALLBACK,
    IS_3PID_ALLOWED_CALLBACK,
    ON_LOGGED_OUT_CALLBACK,
    AuthHandler,
)
from synapse.handlers.device import DeviceHandler
from synapse.handlers.push_rules import RuleSpec, check_actions
from synapse.http.client import SimpleHttpClient
from synapse.http.server import (
    DirectServeHtmlResource,
    DirectServeJsonResource,
    respond_with_html,
)
from synapse.http.servlet import parse_json_object_from_request
from synapse.http.site import SynapseRequest
from synapse.logging.context import (
    defer_to_thread,
    make_deferred_yieldable,
    run_in_background,
)
from synapse.metrics.background_process_metrics import run_as_background_process
from synapse.module_api.callbacks.account_validity_callbacks import (
    IS_USER_EXPIRED_CALLBACK,
    ON_LEGACY_ADMIN_REQUEST,
    ON_LEGACY_RENEW_CALLBACK,
    ON_LEGACY_SEND_MAIL_CALLBACK,
    ON_USER_REGISTRATION_CALLBACK,
)
from synapse.module_api.callbacks.spamchecker_callbacks import (
    CHECK_EVENT_FOR_SPAM_CALLBACK,
    CHECK_LOGIN_FOR_SPAM_CALLBACK,
    CHECK_MEDIA_FILE_FOR_SPAM_CALLBACK,
    CHECK_REGISTRATION_FOR_SPAM_CALLBACK,
    CHECK_USERNAME_FOR_SPAM_CALLBACK,
    SHOULD_DROP_FEDERATED_EVENT_CALLBACK,
    USER_MAY_CREATE_ROOM_ALIAS_CALLBACK,
    USER_MAY_CREATE_ROOM_CALLBACK,
    USER_MAY_INVITE_CALLBACK,
    USER_MAY_JOIN_ROOM_CALLBACK,
    USER_MAY_PUBLISH_ROOM_CALLBACK,
    USER_MAY_SEND_3PID_INVITE_CALLBACK,
    SpamCheckerModuleApiCallbacks,
)
from synapse.module_api.callbacks.third_party_event_rules_callbacks import (
    CHECK_CAN_DEACTIVATE_USER_CALLBACK,
    CHECK_CAN_SHUTDOWN_ROOM_CALLBACK,
    CHECK_EVENT_ALLOWED_CALLBACK,
    CHECK_THREEPID_CAN_BE_INVITED_CALLBACK,
    CHECK_VISIBILITY_CAN_BE_MODIFIED_CALLBACK,
    ON_ADD_USER_THIRD_PARTY_IDENTIFIER_CALLBACK,
    ON_CREATE_ROOM_CALLBACK,
    ON_NEW_EVENT_CALLBACK,
    ON_PROFILE_UPDATE_CALLBACK,
    ON_REMOVE_USER_THIRD_PARTY_IDENTIFIER_CALLBACK,
    ON_THREEPID_BIND_CALLBACK,
    ON_USER_DEACTIVATION_STATUS_CHANGED_CALLBACK,
)
from synapse.push.httppusher import HttpPusher
from synapse.rest.client.login import LoginResponse
from synapse.storage import DataStore
from synapse.storage.background_updates import (
    DEFAULT_BATCH_SIZE_CALLBACK,
    MIN_BATCH_SIZE_CALLBACK,
    ON_UPDATE_CALLBACK,
)
from synapse.storage.database import DatabasePool, LoggingTransaction
from synapse.storage.databases.main.roommember import ProfileInfo
from synapse.types import (
    DomainSpecificString,
    JsonDict,
    JsonMapping,
    Requester,
    RoomAlias,
    RoomID,
    StateMap,
    UserID,
    UserInfo,
    UserProfile,
    create_requester,
)
from synapse.types.state import StateFilter
from synapse.util import Clock
from synapse.util.async_helpers import maybe_awaitable
from synapse.util.caches.descriptors import CachedFunction, cached as _cached
from synapse.util.frozenutils import freeze

if TYPE_CHECKING:
    from synapse.app.generic_worker import GenericWorkerStore
    from synapse.server import HomeServer


T = TypeVar("T")
P = ParamSpec("P")
F = TypeVar("F", bound=Callable[..., Any])

"""
This package defines the 'stable' API which can be used by extension modules which
are loaded into Synapse.
"""

PRESENCE_ALL_USERS = PresenceRouter.ALL_USERS
NOT_SPAM = SpamCheckerModuleApiCallbacks.NOT_SPAM

__all__ = [
    "errors",
    "make_deferred_yieldable",
    "parse_json_object_from_request",
    "respond_with_html",
    "run_in_background",
    "run_as_background_process",
    "cached",
    "NOT_SPAM",
    "UserID",
    "DatabasePool",
    "LoggingTransaction",
    "DirectServeHtmlResource",
    "DirectServeJsonResource",
    "ModuleApi",
    "PRESENCE_ALL_USERS",
    "LoginResponse",
    "JsonDict",
    "JsonMapping",
    "EventBase",
    "StateMap",
    "ProfileInfo",
    "RoomAlias",
    "UserProfile",
]

logger = logging.getLogger(__name__)


@attr.s(auto_attribs=True)
class UserIpAndAgent:
    """
    An IP address and user agent used by a user to connect to this homeserver.
    """

    ip: str
    user_agent: str
    # The time at which this user agent/ip was last seen.
    last_seen: int


def cached(
    *,
    max_entries: int = 1000,
    num_args: Optional[int] = None,
    uncached_args: Optional[Collection[str]] = None,
) -> Callable[[F], CachedFunction[F]]:
    """Returns a decorator that applies a memoizing cache around the function. This
    decorator behaves similarly to functools.lru_cache.

    Example:

        @cached()
        def foo('a', 'b'):
            ...

    Added in Synapse v1.74.0.

    Args:
        max_entries: The maximum number of entries in the cache. If the cache is full
            and a new entry is added, the least recently accessed entry will be evicted
            from the cache.
        num_args: The number of positional arguments (excluding `self`) to use as cache
            keys. Defaults to all named args of the function.
        uncached_args: A list of argument names to not use as the cache key. (`self` is
            always ignored.) Cannot be used with num_args.

    Returns:
        A decorator that applies a memoizing cache around the function.
    """
    return _cached(
        max_entries=max_entries,
        num_args=num_args,
        uncached_args=uncached_args,
    )


class ModuleApi:
    """A proxy object that gets passed to various plugin modules so they
    can register new users etc if necessary.
    """

    def __init__(self, hs: "HomeServer", auth_handler: AuthHandler) -> None:
        self._hs = hs

        # TODO: Fix this type hint once the types for the data stores have been ironed
        #       out.
        self._store: Union[DataStore, "GenericWorkerStore"] = hs.get_datastores().main
        self._storage_controllers = hs.get_storage_controllers()
        self._auth = hs.get_auth()
        self._auth_handler = auth_handler
        self._server_name = hs.hostname
        self._presence_stream = hs.get_event_sources().sources.presence
        self._state = hs.get_state_handler()
        self._clock: Clock = hs.get_clock()
        self._registration_handler = hs.get_registration_handler()
        self._send_email_handler = hs.get_send_email_handler()
        self._push_rules_handler = hs.get_push_rules_handler()
        self._pusherpool = hs.get_pusherpool()
        self._device_handler = hs.get_device_handler()
        self.custom_template_dir = hs.config.server.custom_template_directory
        self._callbacks = hs.get_module_api_callbacks()
        self.msc3861_oauth_delegation_enabled = hs.config.experimental.msc3861.enabled
        self._event_serializer = hs.get_event_client_serializer()

        try:
            app_name = self._hs.config.email.email_app_name

            self._from_string = self._hs.config.email.email_notif_from % {
                "app": app_name
            }
        except (KeyError, TypeError):
            # If substitution failed (which can happen if the string contains
            # placeholders other than just "app", or if the type of the placeholder is
            # not a string), fall back to the bare strings.
            self._from_string = self._hs.config.email.email_notif_from

        self._raw_from = email.utils.parseaddr(self._from_string)[1]

        # We expose these as properties below in order to attach a helpful docstring.
        self._http_client: SimpleHttpClient = hs.get_simple_http_client()
        self._public_room_list_manager = PublicRoomListManager(hs)
        self._account_data_manager = AccountDataManager(hs)

        self._password_auth_provider = hs.get_password_auth_provider()
        self._presence_router = hs.get_presence_router()
        self._account_data_handler = hs.get_account_data_handler()

    #################################################################################
    # The following methods should only be called during the module's initialisation.

    def register_spam_checker_callbacks(
        self,
        *,
        check_event_for_spam: Optional[CHECK_EVENT_FOR_SPAM_CALLBACK] = None,
        should_drop_federated_event: Optional[
            SHOULD_DROP_FEDERATED_EVENT_CALLBACK
        ] = None,
        user_may_join_room: Optional[USER_MAY_JOIN_ROOM_CALLBACK] = None,
        user_may_invite: Optional[USER_MAY_INVITE_CALLBACK] = None,
        user_may_send_3pid_invite: Optional[USER_MAY_SEND_3PID_INVITE_CALLBACK] = None,
        user_may_create_room: Optional[USER_MAY_CREATE_ROOM_CALLBACK] = None,
        user_may_create_room_alias: Optional[
            USER_MAY_CREATE_ROOM_ALIAS_CALLBACK
        ] = None,
        user_may_publish_room: Optional[USER_MAY_PUBLISH_ROOM_CALLBACK] = None,
        check_username_for_spam: Optional[CHECK_USERNAME_FOR_SPAM_CALLBACK] = None,
        check_registration_for_spam: Optional[
            CHECK_REGISTRATION_FOR_SPAM_CALLBACK
        ] = None,
        check_media_file_for_spam: Optional[CHECK_MEDIA_FILE_FOR_SPAM_CALLBACK] = None,
        check_login_for_spam: Optional[CHECK_LOGIN_FOR_SPAM_CALLBACK] = None,
    ) -> None:
        """Registers callbacks for spam checking capabilities.

        Added in Synapse v1.37.0.
        """
        return self._callbacks.spam_checker.register_callbacks(
            check_event_for_spam=check_event_for_spam,
            should_drop_federated_event=should_drop_federated_event,
            user_may_join_room=user_may_join_room,
            user_may_invite=user_may_invite,
            user_may_send_3pid_invite=user_may_send_3pid_invite,
            user_may_create_room=user_may_create_room,
            user_may_create_room_alias=user_may_create_room_alias,
            user_may_publish_room=user_may_publish_room,
            check_username_for_spam=check_username_for_spam,
            check_registration_for_spam=check_registration_for_spam,
            check_media_file_for_spam=check_media_file_for_spam,
            check_login_for_spam=check_login_for_spam,
        )

    def register_account_validity_callbacks(
        self,
        *,
        is_user_expired: Optional[IS_USER_EXPIRED_CALLBACK] = None,
        on_user_registration: Optional[ON_USER_REGISTRATION_CALLBACK] = None,
        on_legacy_send_mail: Optional[ON_LEGACY_SEND_MAIL_CALLBACK] = None,
        on_legacy_renew: Optional[ON_LEGACY_RENEW_CALLBACK] = None,
        on_legacy_admin_request: Optional[ON_LEGACY_ADMIN_REQUEST] = None,
    ) -> None:
        """Registers callbacks for account validity capabilities.

        Added in Synapse v1.39.0.
        """
        return self._callbacks.account_validity.register_callbacks(
            is_user_expired=is_user_expired,
            on_user_registration=on_user_registration,
            on_legacy_send_mail=on_legacy_send_mail,
            on_legacy_renew=on_legacy_renew,
            on_legacy_admin_request=on_legacy_admin_request,
        )

    def register_third_party_rules_callbacks(
        self,
        *,
        check_event_allowed: Optional[CHECK_EVENT_ALLOWED_CALLBACK] = None,
        on_create_room: Optional[ON_CREATE_ROOM_CALLBACK] = None,
        check_threepid_can_be_invited: Optional[
            CHECK_THREEPID_CAN_BE_INVITED_CALLBACK
        ] = None,
        check_visibility_can_be_modified: Optional[
            CHECK_VISIBILITY_CAN_BE_MODIFIED_CALLBACK
        ] = None,
        on_new_event: Optional[ON_NEW_EVENT_CALLBACK] = None,
        check_can_shutdown_room: Optional[CHECK_CAN_SHUTDOWN_ROOM_CALLBACK] = None,
        check_can_deactivate_user: Optional[CHECK_CAN_DEACTIVATE_USER_CALLBACK] = None,
        on_profile_update: Optional[ON_PROFILE_UPDATE_CALLBACK] = None,
        on_user_deactivation_status_changed: Optional[
            ON_USER_DEACTIVATION_STATUS_CHANGED_CALLBACK
        ] = None,
        on_threepid_bind: Optional[ON_THREEPID_BIND_CALLBACK] = None,
        on_add_user_third_party_identifier: Optional[
            ON_ADD_USER_THIRD_PARTY_IDENTIFIER_CALLBACK
        ] = None,
        on_remove_user_third_party_identifier: Optional[
            ON_REMOVE_USER_THIRD_PARTY_IDENTIFIER_CALLBACK
        ] = None,
    ) -> None:
        """Registers callbacks for third party event rules capabilities.

        Added in Synapse v1.39.0.
        """
        return self._callbacks.third_party_event_rules.register_third_party_rules_callbacks(
            check_event_allowed=check_event_allowed,
            on_create_room=on_create_room,
            check_threepid_can_be_invited=check_threepid_can_be_invited,
            check_visibility_can_be_modified=check_visibility_can_be_modified,
            on_new_event=on_new_event,
            check_can_shutdown_room=check_can_shutdown_room,
            check_can_deactivate_user=check_can_deactivate_user,
            on_profile_update=on_profile_update,
            on_user_deactivation_status_changed=on_user_deactivation_status_changed,
            on_threepid_bind=on_threepid_bind,
            on_add_user_third_party_identifier=on_add_user_third_party_identifier,
            on_remove_user_third_party_identifier=on_remove_user_third_party_identifier,
        )

    def register_presence_router_callbacks(
        self,
        *,
        get_users_for_states: Optional[GET_USERS_FOR_STATES_CALLBACK] = None,
        get_interested_users: Optional[GET_INTERESTED_USERS_CALLBACK] = None,
    ) -> None:
        """Registers callbacks for presence router capabilities.

        Added in Synapse v1.42.0.
        """
        return self._presence_router.register_presence_router_callbacks(
            get_users_for_states=get_users_for_states,
            get_interested_users=get_interested_users,
        )

    def register_password_auth_provider_callbacks(
        self,
        *,
        check_3pid_auth: Optional[CHECK_3PID_AUTH_CALLBACK] = None,
        on_logged_out: Optional[ON_LOGGED_OUT_CALLBACK] = None,
        auth_checkers: Optional[
            Dict[Tuple[str, Tuple[str, ...]], CHECK_AUTH_CALLBACK]
        ] = None,
        is_3pid_allowed: Optional[IS_3PID_ALLOWED_CALLBACK] = None,
        get_username_for_registration: Optional[
            GET_USERNAME_FOR_REGISTRATION_CALLBACK
        ] = None,
        get_displayname_for_registration: Optional[
            GET_DISPLAYNAME_FOR_REGISTRATION_CALLBACK
        ] = None,
    ) -> None:
        """Registers callbacks for password auth provider capabilities.

        Added in Synapse v1.46.0.
        """
        if self.msc3861_oauth_delegation_enabled:
            raise ConfigError(
                "Cannot use password auth provider callbacks when OAuth delegation is enabled"
            )

        return self._password_auth_provider.register_password_auth_provider_callbacks(
            check_3pid_auth=check_3pid_auth,
            on_logged_out=on_logged_out,
            is_3pid_allowed=is_3pid_allowed,
            auth_checkers=auth_checkers,
            get_username_for_registration=get_username_for_registration,
            get_displayname_for_registration=get_displayname_for_registration,
        )

    def register_background_update_controller_callbacks(
        self,
        *,
        on_update: ON_UPDATE_CALLBACK,
        default_batch_size: Optional[DEFAULT_BATCH_SIZE_CALLBACK] = None,
        min_batch_size: Optional[MIN_BATCH_SIZE_CALLBACK] = None,
    ) -> None:
        """Registers background update controller callbacks.

        Added in Synapse v1.49.0.
        """

        for db in self._hs.get_datastores().databases:
            db.updates.register_update_controller_callbacks(
                on_update=on_update,
                default_batch_size=default_batch_size,
                min_batch_size=min_batch_size,
            )

    def register_account_data_callbacks(
        self,
        *,
        on_account_data_updated: Optional[ON_ACCOUNT_DATA_UPDATED_CALLBACK] = None,
    ) -> None:
        """Registers account data callbacks.

        Added in Synapse 1.57.0.
        """
        return self._account_data_handler.register_module_callbacks(
            on_account_data_updated=on_account_data_updated,
        )

    def register_web_resource(self, path: str, resource: Resource) -> None:
        """Registers a web resource to be served at the given path.

        This function should be called during initialisation of the module.

        If multiple modules register a resource for the same path, the module that
        appears the highest in the configuration file takes priority.

        Added in Synapse v1.37.0.

        Args:
            path: The path to register the resource for.
            resource: The resource to attach to this path.
        """
        self._hs.register_module_web_resource(path, resource)

    def register_add_extra_fields_to_unsigned_client_event_callbacks(
        self,
        *,
        add_field_to_unsigned_callback: Optional[
            ADD_EXTRA_FIELDS_TO_UNSIGNED_CLIENT_EVENT_CALLBACK
        ] = None,
    ) -> None:
        """Registers a callback that can be used to add fields to the unsigned
        section of events.

        The callback is called every time an event is sent down to a client.

        Added in Synapse 1.96.0
        """
        if add_field_to_unsigned_callback is not None:
            self._event_serializer.register_add_extra_fields_to_unsigned_client_event_callback(
                add_field_to_unsigned_callback
            )

    #########################################################################
    # The following methods can be called by the module at any point in time.

    @property
    def http_client(self) -> SimpleHttpClient:
        """Allows making outbound HTTP requests to remote resources.

        An instance of synapse.http.client.SimpleHttpClient

        Added in Synapse v1.22.0.
        """
        return self._http_client

    @property
    def public_room_list_manager(self) -> "PublicRoomListManager":
        """Allows adding to, removing from and checking the status of rooms in the
        public room list.

        An instance of synapse.module_api.PublicRoomListManager

        Added in Synapse v1.22.0.
        """
        return self._public_room_list_manager

    @property
    def account_data_manager(self) -> "AccountDataManager":
        """Allows reading and modifying users' account data.

        Added in Synapse v1.57.0.
        """
        return self._account_data_manager

    @property
    def public_baseurl(self) -> str:
        """The configured public base URL for this homeserver.

        Added in Synapse v1.39.0.
        """
        return self._hs.config.server.public_baseurl

    @property
    def email_app_name(self) -> str:
        """The application name configured in the homeserver's configuration.

        Added in Synapse v1.39.0.
        """
        return self._hs.config.email.email_app_name

    @property
    def server_name(self) -> str:
        """The server name for the local homeserver.

        Added in Synapse v1.53.0.
        """
        return self._server_name

    @property
    def worker_name(self) -> Optional[str]:
        """The name of the worker this specific instance is running as per the
        "worker_name" configuration setting, or None if it's the main process.

        Added in Synapse v1.53.0.
        """
        return self._hs.config.worker.worker_name

    @property
    def worker_app(self) -> Optional[str]:
        """The name of the worker app this specific instance is running as per the
        "worker_app" configuration setting, or None if it's the main process.

        Added in Synapse v1.53.0.
        """
        return self._hs.config.worker.worker_app

    async def get_userinfo_by_id(self, user_id: str) -> Optional[UserInfo]:
        """Get user info by user_id

        Added in Synapse v1.41.0.

        Args:
            user_id: Fully qualified user id.
        Returns:
            UserInfo object if a user was found, otherwise None
        """
        return await self._store.get_user_by_id(user_id)

    async def get_user_by_req(
        self,
        req: SynapseRequest,
        allow_guest: bool = False,
        allow_expired: bool = False,
    ) -> Requester:
        """Check the access_token provided for a request

        Added in Synapse v1.39.0.

        Args:
            req: Incoming HTTP request
            allow_guest: True if guest users should be allowed. If this
                is False, and the access token is for a guest user, an
                AuthError will be thrown
            allow_expired: True if expired users should be allowed. If this
                is False, and the access token is for an expired user, an
                AuthError will be thrown

        Returns:
            The requester for this request

        Raises:
            InvalidClientCredentialsError: if no user by that token exists,
                or the token is invalid.
        """
        return await self._auth.get_user_by_req(
            req,
            allow_guest,
            allow_expired=allow_expired,
        )

    async def is_user_admin(self, user_id: str) -> bool:
        """Checks if a user is a server admin.

        Added in Synapse v1.39.0.

        Args:
            user_id: The Matrix ID of the user to check.

        Returns:
            True if the user is a server admin, False otherwise.
        """
        return await self._store.is_server_admin(UserID.from_string(user_id))

    async def set_user_admin(self, user_id: str, admin: bool) -> None:
        """Sets if a user is a server admin.

        Added in Synapse v1.56.0.

        Args:
            user_id: The Matrix ID of the user to set admin status for.
            admin: True iff the user is to be a server admin, false otherwise.
        """
        await self._store.set_server_admin(UserID.from_string(user_id), admin)

    def get_qualified_user_id(self, username: str) -> str:
        """Qualify a user id, if necessary

        Takes a user id provided by the user and adds the @ and :domain to
        qualify it, if necessary

        Added in Synapse v0.25.0.

        Args:
            username: provided user id

        Returns:
            qualified @user:id
        """
        if username.startswith("@"):
            return username
        return UserID(username, self._hs.hostname).to_string()

    async def get_profile_for_user(self, localpart: str) -> ProfileInfo:
        """Look up the profile info for the user with the given localpart.

        Added in Synapse v1.39.0.

        Args:
            localpart: The localpart to look up profile information for.

        Returns:
            The profile information (i.e. display name and avatar URL).
        """
        server_name = self._hs.hostname
        user_id = UserID.from_string(f"@{localpart}:{server_name}")
        return await self._store.get_profileinfo(user_id)

    async def get_threepids_for_user(self, user_id: str) -> List[Dict[str, str]]:
        """Look up the threepids (email addresses and phone numbers) associated with the
        given Matrix user ID.

        Added in Synapse v1.39.0.

        Args:
            user_id: The Matrix user ID to look up threepids for.

        Returns:
            A list of threepids, each threepid being represented by a dictionary
            containing a "medium" key which value is "email" for email addresses and
            "msisdn" for phone numbers, and an "address" key which value is the
            threepid's address.
        """
        return [attr.asdict(t) for t in await self._store.user_get_threepids(user_id)]

    def check_user_exists(self, user_id: str) -> "defer.Deferred[Optional[str]]":
        """Check if user exists.

        Added in Synapse v0.25.0.

        Args:
            user_id: Complete @user:id

        Returns:
            Canonical (case-corrected) user_id, or None
               if the user is not registered.
        """
        return defer.ensureDeferred(self._auth_handler.check_user_exists(user_id))

    @defer.inlineCallbacks
    def register(
        self,
        localpart: str,
        displayname: Optional[str] = None,
        emails: Optional[List[str]] = None,
    ) -> Generator["defer.Deferred[Any]", Any, Tuple[str, str]]:
        """Registers a new user with given localpart and optional displayname, emails.

        Also returns an access token for the new user.

        Deprecated: avoid this, as it generates a new device with no way to
        return that device to the user. Prefer separate calls to register_user and
        register_device.

        Added in Synapse v0.25.0.

        Args:
            localpart: The localpart of the new user.
            displayname: The displayname of the new user.
            emails: Emails to bind to the new user.

        Returns:
            a 2-tuple of (user_id, access_token)
        """
        logger.warning(
            "Using deprecated ModuleApi.register which creates a dummy user device."
        )
        user_id = yield self.register_user(localpart, displayname, emails or [])
        _, access_token, _, _ = yield self.register_device(user_id)
        return user_id, access_token

    def register_user(
        self,
        localpart: str,
        displayname: Optional[str] = None,
        emails: Optional[List[str]] = None,
        admin: bool = False,
    ) -> "defer.Deferred[str]":
        """Registers a new user with given localpart and optional displayname, emails.

        Added in Synapse v1.2.0.
        Changed in Synapse v1.56.0: add 'admin' argument to register the user as admin.

        Args:
            localpart: The localpart of the new user.
            displayname: The displayname of the new user.
            emails: Emails to bind to the new user.
            admin: True if the user should be registered as a server admin.

        Raises:
            SynapseError if there is an error performing the registration. Check the
                'errcode' property for more information on the reason for failure

        Returns:
            user_id
        """
        return defer.ensureDeferred(
            self._hs.get_registration_handler().register_user(
                localpart=localpart,
                default_display_name=displayname,
                bind_emails=emails or [],
                admin=admin,
            )
        )

    def register_device(
        self,
        user_id: str,
        device_id: Optional[str] = None,
        initial_display_name: Optional[str] = None,
    ) -> "defer.Deferred[Tuple[str, str, Optional[int], Optional[str]]]":
        """Register a device for a user and generate an access token.

        Added in Synapse v1.2.0.

        Args:
            user_id: full canonical @user:id
            device_id: The device ID to check, or None to generate
                a new one.
            initial_display_name: An optional display name for the
                device.

        Returns:
            Tuple of device ID, access token, access token expiration time and refresh token
        """
        return defer.ensureDeferred(
            self._hs.get_registration_handler().register_device(
                user_id=user_id,
                device_id=device_id,
                initial_display_name=initial_display_name,
            )
        )

    def record_user_external_id(
        self, auth_provider_id: str, remote_user_id: str, registered_user_id: str
    ) -> defer.Deferred:
        """Record a mapping between an external user id from a single sign-on provider
        and a mxid.

        Added in Synapse v1.9.0.

        Args:
            auth_provider: identifier for the remote auth provider, see `sso` and
                `oidc_providers` in the homeserver configuration.

                Note that no error is raised if the provided value is not in the
                homeserver configuration.
            external_id: id on that system
            user_id: complete mxid that it is mapped to
        """
        return defer.ensureDeferred(
            self._store.record_user_external_id(
                auth_provider_id, remote_user_id, registered_user_id
            )
        )

    async def create_login_token(
        self,
        user_id: str,
        duration_in_ms: int = (2 * 60 * 1000),
        auth_provider_id: Optional[str] = None,
        auth_provider_session_id: Optional[str] = None,
    ) -> str:
        """Create a login token suitable for m.login.token authentication

        Added in Synapse v1.69.0.

        Args:
            user_id: gives the ID of the user that the token is for

            duration_in_ms: the time that the token will be valid for

            auth_provider_id: the ID of the SSO IdP that the user used to authenticate
                to get this token, if any. This is encoded in the token so that
                /login can report stats on number of successful logins by IdP.

            auth_provider_session_id: The session ID got during login from the SSO IdP,
                if any.
        """
        return await self._hs.get_auth_handler().create_login_token_for_user_id(
            user_id,
            duration_in_ms,
            auth_provider_id,
            auth_provider_session_id,
        )

    @defer.inlineCallbacks
    def invalidate_access_token(
        self, access_token: str
    ) -> Generator["defer.Deferred[Any]", Any, None]:
        """Invalidate an access token for a user

        Can only be called from the main process.

        Added in Synapse v0.25.0.

        Args:
            access_token: access token

        Returns:
            twisted.internet.defer.Deferred - resolves once the access token
               has been removed.

        Raises:
            synapse.api.errors.AuthError: the access token is invalid
        """
        assert isinstance(
            self._device_handler, DeviceHandler
        ), "invalidate_access_token can only be called on the main process"

        # see if the access token corresponds to a device
        user_info = yield defer.ensureDeferred(
            self._auth.get_user_by_access_token(access_token)
        )
        device_id = user_info.get("device_id")
        user_id = user_info["user"].to_string()
        if device_id:
            # delete the device, which will also delete its access tokens
            yield defer.ensureDeferred(
                self._device_handler.delete_devices(user_id, [device_id])
            )
        else:
            # no associated device. Just delete the access token.
            yield defer.ensureDeferred(
                self._auth_handler.delete_access_token(access_token)
            )

    def run_db_interaction(
        self,
        desc: str,
        func: Callable[Concatenate[LoggingTransaction, P], T],
        *args: P.args,
        **kwargs: P.kwargs,
    ) -> "defer.Deferred[T]":
        """Run a function with a database connection

        Added in Synapse v0.25.0.

        Args:
            desc: description for the transaction, for metrics etc
            func: function to be run. Passed a database cursor object
                as well as *args and **kwargs
            *args: positional args to be passed to func
            **kwargs: named args to be passed to func

        Returns:
            Result of func
        """
        # type-ignore: See https://github.com/python/mypy/issues/8862
        return defer.ensureDeferred(
            self._store.db_pool.runInteraction(desc, func, *args, **kwargs)  # type: ignore[arg-type]
        )

    def register_cached_function(self, cached_func: CachedFunction) -> None:
        """Register a cached function that should be invalidated across workers.
        Invalidation local to a worker can be done directly using `cached_func.invalidate`,
        however invalidation that needs to go to other workers needs to call `invalidate_cache`
        on the module API instead.

        Added in Synapse v1.69.0.

        Args:
            cached_function: The cached function that will be registered to receive invalidation
            locally and from other workers.
        """
        self._store.register_external_cached_function(
            f"{cached_func.__module__}.{cached_func.__name__}", cached_func
        )

    async def invalidate_cache(
        self, cached_func: CachedFunction, keys: Tuple[Any, ...]
    ) -> None:
        """Invalidate a cache entry of a cached function across workers. The cached function
        needs to be registered on all workers first with `register_cached_function`.

        Added in Synapse v1.69.0.

        Args:
            cached_function: The cached function that needs an invalidation
            keys: keys of the entry to invalidate, usually matching the arguments of the
            cached function.
        """
        cached_func.invalidate(keys)
        await self._store.send_invalidation_to_replication(
            f"{cached_func.__module__}.{cached_func.__name__}",
            keys,
        )

    async def complete_sso_login_async(
        self,
        registered_user_id: str,
        request: SynapseRequest,
        client_redirect_url: str,
        new_user: bool = False,
        auth_provider_id: str = "<unknown>",
    ) -> None:
        """Complete a SSO login by redirecting the user to a page to confirm whether they
        want their access token sent to `client_redirect_url`, or redirect them to that
        URL with a token directly if the URL matches with one of the whitelisted clients.

        Added in Synapse v1.13.0.

        Args:
            registered_user_id: The MXID that has been registered as a previous step of
                of this SSO login.
            request: The request to respond to.
            client_redirect_url: The URL to which to offer to redirect the user (or to
                redirect them directly if whitelisted).
            new_user: set to true to use wording for the consent appropriate to a user
                who has just registered.
            auth_provider_id: the ID of the SSO IdP which was used to log in. This
                is used to track counts of sucessful logins by IdP.
        """
        await self._auth_handler.complete_sso_login(
            registered_user_id,
            auth_provider_id,
            request,
            client_redirect_url,
            new_user=new_user,
        )

    @defer.inlineCallbacks
    def get_state_events_in_room(
        self, room_id: str, types: Iterable[Tuple[str, Optional[str]]]
    ) -> Generator[defer.Deferred, Any, Iterable[EventBase]]:
        """Gets current state events for the given room.

        (This is exposed for compatibility with the old SpamCheckerApi. We should
        probably deprecate it and replace it with an async method in a subclass.)

        Added in Synapse v1.22.0.

        Args:
            room_id: The room ID to get state events in.
            types: The event type and state key (using None
                to represent 'any') of the room state to acquire.

        Returns:
            The filtered state events in the room.
        """
        state_ids = yield defer.ensureDeferred(
            self._storage_controllers.state.get_current_state_ids(
                room_id=room_id, state_filter=StateFilter.from_types(types)
            )
        )
        state = yield defer.ensureDeferred(self._store.get_events(state_ids.values()))
        return state.values()

    async def update_room_membership(
        self,
        sender: str,
        target: str,
        room_id: str,
        new_membership: str,
        content: Optional[JsonDict] = None,
        remote_room_hosts: Optional[List[str]] = None,
    ) -> EventBase:
        """Updates the membership of a user to the given value.

        Added in Synapse v1.46.0.
        Changed in Synapse v1.65.0: Added the 'remote_room_hosts' parameter.

        Args:
            sender: The user performing the membership change. Must be a user local to
                this homeserver.
            target: The user whose membership is changing. This is often the same value
                as `sender`, but it might differ in some cases (e.g. when kicking a user,
                the `sender` is the user performing the kick and the `target` is the user
                being kicked).
            room_id: The room in which to change the membership.
            new_membership: The new membership state of `target` after this operation. See
                https://spec.matrix.org/unstable/client-server-api/#mroommember for the
                list of allowed values.
            content: Additional values to include in the resulting event's content.
            remote_room_hosts: Remote servers to use for remote joins/knocks/etc.

        Returns:
            The newly created membership event.

        Raises:
            RuntimeError if the `sender` isn't a local user.
            ShadowBanError if a shadow-banned requester attempts to send an invite.
            SynapseError if the module attempts to send a membership event that isn't
                allowed, either by the server's configuration (e.g. trying to set a
                per-room display name that's too long) or by the validation rules around
                membership updates (e.g. the `membership` value is invalid).
        """
        if not self.is_mine(sender):
            raise RuntimeError(
                "Tried to send an event as a user that isn't local to this homeserver",
            )

        requester = create_requester(sender)
        target_user_id = UserID.from_string(target)

        if content is None:
            content = {}

        # Set the profile if not already done by the module.
        if "avatar_url" not in content or "displayname" not in content:
            try:
                # Try to fetch the user's profile.
                profile = await self._hs.get_profile_handler().get_profile(
                    target_user_id.to_string(),
                )
            except SynapseError as e:
                # If the profile couldn't be found, use default values.
                profile = {
                    "displayname": target_user_id.localpart,
                    "avatar_url": None,
                }

                if e.code != 404:
                    # If the error isn't 404, it means we tried to fetch the profile over
                    # federation but the remote server responded with a non-standard
                    # status code.
                    logger.error(
                        "Got non-404 error status when fetching profile for %s",
                        target_user_id.to_string(),
                    )

            # Set the profile where it needs to be set.
            if "avatar_url" not in content:
                content["avatar_url"] = profile["avatar_url"]

            if "displayname" not in content:
                content["displayname"] = profile["displayname"]

        event_id, _ = await self._hs.get_room_member_handler().update_membership(
            requester=requester,
            target=target_user_id,
            room_id=room_id,
            action=new_membership,
            content=content,
            remote_room_hosts=remote_room_hosts,
        )

        # Try to retrieve the resulting event.
        event = await self._hs.get_datastores().main.get_event(event_id)

        return event

    async def create_and_send_event_into_room(self, event_dict: JsonDict) -> EventBase:
        """Create and send an event into a room.

        Membership events are not supported by this method. To update a user's membership
        in a room, please use the `update_room_membership` method instead.

        Added in Synapse v1.22.0.

        Args:
            event_dict: A dictionary representing the event to send.
                Required keys are `type`, `room_id`, `sender` and `content`.

        Returns:
            The event that was sent. If state event deduplication happened, then
                the previous, duplicate event instead.

        Raises:
            SynapseError if the event was not allowed.
        """
        # Create a requester object
        requester = create_requester(
            event_dict["sender"], authenticated_entity=self._server_name
        )

        # Create and send the event
        (
            event,
            _,
        ) = await self._hs.get_event_creation_handler().create_and_send_nonmember_event(
            requester,
            event_dict,
            ratelimit=False,
            ignore_shadow_ban=True,
        )

        return event

    async def send_local_online_presence_to(self, users: Iterable[str]) -> None:
        """
        Forces the equivalent of a presence initial_sync for a set of local or remote
        users. The users will receive presence for all currently online users that they
        are considered interested in.

        Updates to remote users will be sent immediately, whereas local users will receive
        them on their next sync attempt.

        Note that this method can only be run on the process that is configured to write to the
        presence stream. By default this is the main process.

        Added in Synapse v1.32.0.
        """
        if self._hs._instance_name not in self._hs.config.worker.writers.presence:
            raise Exception(
                "send_local_online_presence_to can only be run "
                "on the process that is configured to write to the "
                "presence stream (by default this is the main process)",
            )

        local_users = set()
        remote_users = set()
        for user in users:
            if self._hs.is_mine_id(user):
                local_users.add(user)
            else:
                remote_users.add(user)

        # We pull out the presence handler here to break a cyclic
        # dependency between the presence router and module API.
        presence_handler = self._hs.get_presence_handler()

        if local_users:
            # Force a presence initial_sync for these users next time they sync.
            await presence_handler.send_full_presence_to_users(local_users)

        for user in remote_users:
            # Retrieve presence state for currently online users that this user
            # is considered interested in.
            presence_events, _ = await self._presence_stream.get_new_events(
                UserID.from_string(user), from_key=None, include_offline=False
            )

            # Send to remote destinations.
            destination = UserID.from_string(user).domain
            await presence_handler.get_federation_queue().send_presence_to_destinations(
                presence_events, [destination]
            )

    async def set_presence_for_users(
        self, users: Mapping[str, Tuple[str, Optional[str]]]
    ) -> None:
        """
        Update the internal presence state of users.

        This can be used for either local or remote users.

        Note that this method can only be run on the process that is configured to write to the
        presence stream. By default, this is the main process.

        Added in Synapse v1.96.0.
        """

        # We pull out the presence handler here to break a cyclic
        # dependency between the presence router and module API.
        presence_handler = self._hs.get_presence_handler()

        from synapse.handlers.presence import PresenceHandler

        assert isinstance(presence_handler, PresenceHandler)

        states = await presence_handler.current_state_for_users(users.keys())
        for user_id, (state, status_msg) in users.items():
            prev_state = states.setdefault(user_id, UserPresenceState.default(user_id))
            states[user_id] = prev_state.copy_and_replace(
                state=state, status_msg=status_msg
            )

        await presence_handler._update_states(states.values(), force_notify=True)

    def looping_background_call(
        self,
        f: Callable,
        msec: float,
        *args: object,
        desc: Optional[str] = None,
        run_on_all_instances: bool = False,
        **kwargs: object,
    ) -> None:
        """Wraps a function as a background process and calls it repeatedly.

        NOTE: Will only run on the instance that is configured to run
        background processes (which is the main process by default), unless
        `run_on_all_workers` is set.

        Waits `msec` initially before calling `f` for the first time.

        Added in Synapse v1.39.0.

        Args:
            f: The function to call repeatedly. f can be either synchronous or
                asynchronous, and must follow Synapse's logcontext rules.
                More info about logcontexts is available at
                https://matrix-org.github.io/synapse/latest/log_contexts.html
            msec: How long to wait between calls in milliseconds.
            *args: Positional arguments to pass to function.
            desc: The background task's description. Default to the function's name.
            run_on_all_instances: Whether to run this on all instances, rather
                than just the instance configured to run background tasks.
            **kwargs: Key arguments to pass to function.
        """
        if desc is None:
            desc = f.__name__

        if self._hs.config.worker.run_background_tasks or run_on_all_instances:
            self._clock.looping_call(
                run_as_background_process,
                msec,
                desc,
                lambda: maybe_awaitable(f(*args, **kwargs)),
            )
        else:
            logger.warning(
                "Not running looping call %s as the configuration forbids it",
                f,
            )

    def should_run_background_tasks(self) -> bool:
        """
        Return true if and only if the current worker is configured to run
        background tasks.
        There should only be one worker configured to run background tasks, so
        this is helpful when you need to only run a task on one worker but don't
        have any other good way to choose which one.

        Added in Synapse v1.89.0.
        """
        return self._hs.config.worker.run_background_tasks

    def delayed_background_call(
        self,
        msec: float,
        f: Callable,
        *args: object,
        desc: Optional[str] = None,
        **kwargs: object,
    ) -> IDelayedCall:
        """Wraps a function as a background process and calls it in a given number of milliseconds.

        The scheduled call is not persistent: if the current Synapse instance is
        restarted before the call is made, the call will not be made.

        Added in Synapse v1.90.0.

        Args:
            msec: How long to wait before calling, in milliseconds.
            f: The function to call once. f can be either synchronous or
                asynchronous, and must follow Synapse's logcontext rules.
                More info about logcontexts is available at
                https://matrix-org.github.io/synapse/latest/log_contexts.html
            *args: Positional arguments to pass to function.
            desc: The background task's description. Default to the function's name.
            **kwargs: Keyword arguments to pass to function.

        Returns:
            IDelayedCall handle from twisted, which allows to cancel the delayed call if desired.
        """

        if desc is None:
            desc = f.__name__

        return self._clock.call_later(
            # convert ms to seconds as needed by call_later.
            msec * 0.001,
            run_as_background_process,
            desc,
            lambda: maybe_awaitable(f(*args, **kwargs)),
        )

    async def sleep(self, seconds: float) -> None:
        """Sleeps for the given number of seconds.

        Added in Synapse v1.49.0.
        """

        await self._clock.sleep(seconds)

    async def send_http_push_notification(
        self,
        user_id: str,
        device_id: Optional[str],
        content: JsonDict,
        tweaks: Optional[JsonMapping] = None,
        default_payload: Optional[JsonMapping] = None,
    ) -> Dict[str, bool]:
        """Send an HTTP push notification that is forwarded to the registered push gateway
        for the specified user/device.

        Added in Synapse v1.82.0.

        Args:
            user_id: The user ID to send the push notification to.
            device_id: The device ID of the device where to send the push notification. If `None`,
            the notification will be sent to all registered HTTP pushers of the user.
            content: A dict of values that will be put in the `notification` field of the push
            (cf Push Gateway spec). `devices` field will be overrided if included.
            tweaks: A dict of `tweaks` that will be inserted in the `devices` section, cf spec.
            default_payload: default payload to add in `devices[0].data.default_payload`.
            This will be merged (and override if some matching values already exist there)
            with existing `default_payload`.

        Returns:
            a dict reprensenting the status of the push per device ID
        """
        status = {}
        if user_id in self._pusherpool.pushers:
            for p in self._pusherpool.pushers[user_id].values():
                if isinstance(p, HttpPusher) and (
                    not device_id or p.device_id == device_id
                ):
                    res = await p.dispatch_push(content, tweaks, default_payload)
                    # Check if the push was successful and no pushers were rejected.
                    sent = res is not False and not res

                    # This is mainly to accomodate mypy
                    # device_id should never be empty after the `set_device_id_for_pushers`
                    # background job has been properly run.
                    if p.device_id:
                        status[p.device_id] = sent
        return status

    async def send_mail(
        self,
        recipient: str,
        subject: str,
        html: str,
        text: str,
    ) -> None:
        """Send an email on behalf of the homeserver.

        Added in Synapse v1.39.0.

        Args:
            recipient: The email address for the recipient.
            subject: The email's subject.
            html: The email's HTML content.
            text: The email's text content.
        """
        await self._send_email_handler.send_email(
            email_address=recipient,
            subject=subject,
            app_name=self.email_app_name,
            html=html,
            text=text,
        )

    def read_templates(
        self,
        filenames: List[str],
        custom_template_directory: Optional[str] = None,
    ) -> List[jinja2.Template]:
        """Read and load the content of the template files at the given location.
        By default, Synapse will look for these templates in its configured template
        directory, but another directory to search in can be provided.

        Added in Synapse v1.39.0.

        Args:
            filenames: The name of the template files to look for.
            custom_template_directory: An additional directory to look for the files in.

        Returns:
            A list containing the loaded templates, with the orders matching the one of
            the filenames parameter.
        """
        return self._hs.config.server.read_templates(
            filenames,
            (td for td in (self.custom_template_dir, custom_template_directory) if td),
        )

    def is_mine(self, id: Union[str, DomainSpecificString]) -> bool:
        """
        Checks whether an ID (user id, room, ...) comes from this homeserver.

        Added in Synapse v1.44.0.

        Args:
            id: any Matrix id (e.g. user id, room id, ...), either as a raw id,
                e.g. string "@user:example.com" or as a parsed UserID, RoomID, ...
        Returns:
            True if id comes from this homeserver, False otherwise.
        """
        if isinstance(id, DomainSpecificString):
            return self._hs.is_mine(id)
        else:
            return self._hs.is_mine_id(id)

    async def get_user_ip_and_agents(
        self, user_id: str, since_ts: int = 0
    ) -> List[UserIpAndAgent]:
        """
        Return the list of user IPs and agents for a user.

        Added in Synapse v1.44.0.

        Args:
            user_id: the id of a user, local or remote
            since_ts: a timestamp in seconds since the epoch,
                or the epoch itself if not specified.
        Returns:
            The list of all UserIpAndAgent that the user has
            used to connect to this homeserver since `since_ts`.
            If the user is remote, this list is empty.
        """
        # Don't hit the db if this is not a local user.
        is_mine = False
        try:
            # Let's be defensive against ill-formed strings.
            if self.is_mine(user_id):
                is_mine = True
        except Exception:
            pass

        if is_mine:
            raw_data = await self._store.get_user_ip_and_agents(
                UserID.from_string(user_id), since_ts
            )
            # Sanitize some of the data. We don't want to return tokens.
            return [
                UserIpAndAgent(
                    ip=data["ip"],
                    user_agent=data["user_agent"],
                    last_seen=data["last_seen"],
                )
                for data in raw_data
            ]
        else:
            return []

    async def get_room_state(
        self,
        room_id: str,
        event_filter: Optional[Iterable[Tuple[str, Optional[str]]]] = None,
    ) -> StateMap[EventBase]:
        """Returns the current state of the given room.

        The events are returned as a mapping, in which the key for each event is a tuple
        which first element is the event's type and the second one is its state key.

        Added in Synapse v1.47.0

        Args:
            room_id: The ID of the room to get state from.
            event_filter: A filter to apply when retrieving events. None if no filter
                should be applied. If provided, must be an iterable of tuples. A tuple's
                first element is the event type and the second is the state key, or is
                None if the state key should not be filtered on.
                An example of a filter is:
                    [
                        ("m.room.member", "@alice:example.com"),  # Member event for @alice:example.com
                        ("org.matrix.some_event", ""),  # State event of type "org.matrix.some_event"
                                                        # with an empty string as its state key
                        ("org.matrix.some_other_event", None),  # State events of type "org.matrix.some_other_event"
                                                                # regardless of their state key
                    ]
        """
        state_filter = None
        if event_filter:
            # If a filter was provided, turn it into a StateFilter and retrieve a filtered
            # view of the state.
            state_filter = StateFilter.from_types(event_filter)

        state_ids = await self._storage_controllers.state.get_current_state_ids(
            room_id,
            state_filter,
        )

        state_events = await self._store.get_events(state_ids.values())

        return {key: state_events[event_id] for key, event_id in state_ids.items()}

    async def defer_to_thread(
        self,
        f: Callable[P, T],
        *args: P.args,
        **kwargs: P.kwargs,
    ) -> T:
        """Runs the given function in a separate thread from Synapse's thread pool.

        Added in Synapse v1.49.0.

        Args:
            f: The function to run.
            args: The function's arguments.
            kwargs: The function's keyword arguments.

        Returns:
            The return value of the function once ran in a thread.
        """
        return await defer_to_thread(self._hs.get_reactor(), f, *args, **kwargs)

    async def check_username(self, username: str) -> None:
        """Checks if the provided username uses the grammar defined in the Matrix
        specification, and is already being used by an existing user.

        Added in Synapse v1.52.0.

        Args:
            username: The username to check. This is the local part of the user's full
                Matrix user ID, i.e. it's "alice" if the full user ID is "@alice:foo.com".

        Raises:
            SynapseError with the errcode "M_USER_IN_USE" if the username is already in
            use.
        """
        await self._registration_handler.check_username(username)

    async def store_remote_3pid_association(
        self, user_id: str, medium: str, address: str, id_server: str
    ) -> None:
        """Stores an existing association between a user ID and a third-party identifier.

        The association must already exist on the remote identity server.

        Added in Synapse v1.56.0.

        Args:
            user_id: The user ID that's been associated with the 3PID.
            medium: The medium of the 3PID (current supported values are "msisdn" and
                "email").
            address: The address of the 3PID.
            id_server: The identity server the 3PID association has been registered on.
                This should only be the domain (or IP address, optionally with the port
                number) for the identity server. This will be used to reach out to the
                identity server using HTTPS (unless specified otherwise by Synapse's
                configuration) when attempting to unbind the third-party identifier.


        """
        await self._store.add_user_bound_threepid(user_id, medium, address, id_server)

    def check_push_rule_actions(
        self, actions: List[Union[str, Dict[str, str]]]
    ) -> None:
        """Checks if the given push rule actions are valid according to the Matrix
        specification.

        See https://spec.matrix.org/v1.2/client-server-api/#actions for the list of valid
        actions.

        Added in Synapse v1.58.0.

        Args:
            actions: the actions to check.

        Raises:
            synapse.module_api.errors.InvalidRuleException if the actions are invalid.
        """
        check_actions(actions)

    async def set_push_rule_action(
        self,
        user_id: str,
        scope: str,
        kind: str,
        rule_id: str,
        actions: List[Union[str, Dict[str, str]]],
    ) -> None:
        """Changes the actions of an existing push rule for the given user.

        See https://spec.matrix.org/v1.2/client-server-api/#push-rules for more
        information about push rules and their syntax.

        Can only be called on the main process.

        Added in Synapse v1.58.0.

        Args:
            user_id: the user for which to change the push rule's actions.
            scope: the push rule's scope, currently only "global" is allowed.
            kind: the push rule's kind.
            rule_id: the push rule's identifier.
            actions: the actions to run when the rule's conditions match.

        Raises:
            RuntimeError if this method is called on a worker or `scope` is invalid.
            synapse.module_api.errors.RuleNotFoundException if the rule being modified
                can't be found.
            synapse.module_api.errors.InvalidRuleException if the actions are invalid.
        """
        if self.worker_app is not None:
            raise RuntimeError("module tried to change push rule actions on a worker")

        if scope != "global":
            raise RuntimeError(
                "invalid scope %s, only 'global' is currently allowed" % scope
            )

        spec = RuleSpec(scope, kind, rule_id, "actions")
        await self._push_rules_handler.set_rule_attr(
            user_id, spec, {"actions": actions}
        )

    async def get_monthly_active_users_by_service(
        self, start_timestamp: Optional[int] = None, end_timestamp: Optional[int] = None
    ) -> List[Tuple[str, str]]:
        """Generates list of monthly active users and their services.
        Please see corresponding storage docstring for more details.

        Added in Synapse v1.61.0.

        Arguments:
            start_timestamp: If specified, only include users that were first active
                at or after this point
            end_timestamp: If specified, only include users that were first active
                at or before this point

        Returns:
            A list of tuples (appservice_id, user_id)

        """
        return await self._store.get_monthly_active_users_by_service(
            start_timestamp, end_timestamp
        )

    async def get_canonical_room_alias(self, room_id: RoomID) -> Optional[RoomAlias]:
        """
        Retrieve the given room's current canonical alias.

        A room may declare an alias as "canonical", meaning that it is the
        preferred alias to use when referring to the room. This function
        retrieves that alias from the room's state.

        Added in Synapse v1.86.0.

        Args:
            room_id: The Room ID to find the alias of.

        Returns:
            None if the room ID does not exist, or if the room exists but has no canonical alias.
            Otherwise, the parsed room alias.
        """
        room_alias_str = (
            await self._storage_controllers.state.get_canonical_alias_for_room(
                room_id.to_string()
            )
        )
        if room_alias_str:
            return RoomAlias.from_string(room_alias_str)
        return None

    async def lookup_room_alias(self, room_alias: str) -> Tuple[str, List[str]]:
        """
        Get the room ID associated with a room alias.

        Added in Synapse v1.65.0.

        Args:
            room_alias: The alias to look up.

        Returns:
            A tuple of:
                The room ID (str).
                Hosts likely to be participating in the room ([str]).

        Raises:
            SynapseError if room alias is invalid or could not be found.
        """
        alias = RoomAlias.from_string(room_alias)
        (room_id, hosts) = await self._hs.get_room_member_handler().lookup_room_alias(
            alias
        )

        return room_id.to_string(), hosts

    async def create_room(
        self,
        user_id: str,
        config: JsonDict,
        ratelimit: bool = True,
        creator_join_profile: Optional[JsonDict] = None,
    ) -> Tuple[str, Optional[str]]:
        """Creates a new room.

        Added in Synapse v1.65.0.

        Args:
            user_id:
                The user who requested the room creation.
            config : A dict of configuration options. See "Request body" of:
                https://spec.matrix.org/latest/client-server-api/#post_matrixclientv3createroom
            ratelimit: set to False to disable the rate limiter for this specific operation.

            creator_join_profile:
                Set to override the displayname and avatar for the creating
                user in this room. If unset, displayname and avatar will be
                derived from the user's profile. If set, should contain the
                values to go in the body of the 'join' event (typically
                `avatar_url` and/or `displayname`.

        Returns:
                A tuple containing: 1) the room ID (str), 2) if an alias was requested,
                the room alias (str), otherwise None if no alias was requested.

        Raises:
            ResourceLimitError if server is blocked to some resource being
            exceeded.
            RuntimeError if the user_id does not refer to a local user.
            SynapseError if the user_id is invalid, room ID couldn't be stored, or
            something went horribly wrong.
        """
        if not self.is_mine(user_id):
            raise RuntimeError(
                "Tried to create a room as a user that isn't local to this homeserver",
            )

        requester = create_requester(user_id)
        room_id, room_alias, _ = await self._hs.get_room_creation_handler().create_room(
            requester=requester,
            config=config,
            ratelimit=ratelimit,
            creator_join_profile=creator_join_profile,
        )
        room_alias_str = room_alias.to_string() if room_alias else None
        return room_id, room_alias_str

    async def delete_room(self, room_id: str) -> None:
        """
        Schedules the deletion of a room from Synapse's database.

        If the room is already being deleted, this method does nothing.
        This method does not wait for the room to be deleted.

        Added in Synapse v1.89.0.
        """
        # Future extensions to this method might want to e.g. allow use of `force_purge`.
        # TODO In the future we should make sure this is persistent.
        await self._hs.get_pagination_handler().start_shutdown_and_purge_room(
            room_id,
            {
                "new_room_user_id": None,
                "new_room_name": None,
                "message": None,
                "requester_user_id": None,
                "block": False,
                "purge": True,
                "force_purge": False,
            },
        )

    async def set_displayname(
        self,
        user_id: UserID,
        new_displayname: str,
        deactivation: bool = False,
    ) -> None:
        """Sets a user's display name.

        Added in Synapse v1.76.0.

        Args:
            user_id:
                The user whose display name is to be changed.
            new_displayname:
                The new display name to give the user.
            deactivation:
                Whether this change was made while deactivating the user.
        """
        requester = create_requester(user_id)
        await self._hs.get_profile_handler().set_displayname(
            target_user=user_id,
            requester=requester,
            new_displayname=new_displayname,
            by_admin=True,
            deactivation=deactivation,
        )


class PublicRoomListManager:
    """Contains methods for adding to, removing from and querying whether a room
    is in the public room list.
    """

    def __init__(self, hs: "HomeServer"):
        self._store = hs.get_datastores().main

    async def room_is_in_public_room_list(self, room_id: str) -> bool:
        """Checks whether a room is in the public room list.

        Added in Synapse v1.22.0.

        Args:
            room_id: The ID of the room.

        Returns:
            Whether the room is in the public room list. Returns False if the room does
            not exist.
        """
        room = await self._store.get_room(room_id)
        if not room:
            return False

        return room.get("is_public", False)

    async def add_room_to_public_room_list(self, room_id: str) -> None:
        """Publishes a room to the public room list.

        Added in Synapse v1.22.0.

        Args:
            room_id: The ID of the room.
        """
        await self._store.set_room_is_public(room_id, True)

    async def remove_room_from_public_room_list(self, room_id: str) -> None:
        """Removes a room from the public room list.

        Added in Synapse v1.22.0.

        Args:
            room_id: The ID of the room.
        """
        await self._store.set_room_is_public(room_id, False)


class AccountDataManager:
    """
    Allows modules to manage account data.
    """

    def __init__(self, hs: "HomeServer") -> None:
        self._hs = hs
        self._store = hs.get_datastores().main
        self._handler = hs.get_account_data_handler()

    def _validate_user_id(self, user_id: str) -> None:
        """
        Validates a user ID is valid and local.
        Private method to be used in other account data methods.
        """
        user = UserID.from_string(user_id)
        if not self._hs.is_mine(user):
            raise ValueError(
                f"{user_id} is not local to this homeserver; can't access account data for remote users."
            )

    async def get_global(self, user_id: str, data_type: str) -> Optional[JsonMapping]:
        """
        Gets some global account data, of a specified type, for the specified user.

        The provided user ID must be a valid user ID of a local user.

        Added in Synapse v1.57.0.
        """
        self._validate_user_id(user_id)

        data = await self._store.get_global_account_data_by_type_for_user(
            user_id, data_type
        )
        # We clone and freeze to prevent the module accidentally mutating the
        # dict that lives in the cache, as that could introduce nasty bugs.
        return freeze(data)

    async def put_global(
        self, user_id: str, data_type: str, new_data: JsonDict
    ) -> None:
        """
        Puts some global account data, of a specified type, for the specified user.

        The provided user ID must be a valid user ID of a local user.

        Please note that this will overwrite existing the account data of that type
        for that user!

        Added in Synapse v1.57.0.
        """
        self._validate_user_id(user_id)

        if not isinstance(data_type, str):
            raise TypeError(f"data_type must be a str; got {type(data_type).__name__}")

        if not isinstance(new_data, dict):
            raise TypeError(f"new_data must be a dict; got {type(new_data).__name__}")

        # Ensure the user exists, so we don't just write to users that aren't there.
        if await self._store.get_user_by_id(user_id) is None:
            raise ValueError(f"User {user_id} does not exist on this server.")

        await self._handler.add_account_data_for_user(user_id, data_type, new_data)