# Documented in https://zulip.readthedocs.io/en/latest/subsystems/sending-messages.html#soft-deactivation import logging from collections import defaultdict from typing import Any, DefaultDict, Dict, Iterable, List, Optional, Sequence, Set, TypedDict, Union from django.conf import settings from django.db import transaction from django.db.models import Exists, Max, OuterRef, QuerySet from django.utils.timezone import now as timezone_now from sentry_sdk import capture_exception from zerver.lib.logging_util import log_to_file from zerver.lib.queue import queue_json_publish from zerver.lib.utils import assert_is_not_none from zerver.models import ( Message, NotificationTriggers, Realm, RealmAuditLog, Recipient, Subscription, UserActivity, UserMessage, UserProfile, ) logger = logging.getLogger("zulip.soft_deactivation") log_to_file(logger, settings.SOFT_DEACTIVATION_LOG_PATH) BULK_CREATE_BATCH_SIZE = 10000 class MissingMessageDict(TypedDict): id: int recipient__type_id: int def filter_by_subscription_history( user_profile: UserProfile, all_stream_messages: DefaultDict[int, List[MissingMessageDict]], all_stream_subscription_logs: DefaultDict[int, List[RealmAuditLog]], ) -> List[UserMessage]: user_messages_to_insert: List[UserMessage] = [] seen_message_ids: Set[int] = set() def store_user_message_to_insert(message: MissingMessageDict) -> None: if message["id"] not in seen_message_ids: user_message = UserMessage(user_profile=user_profile, message_id=message["id"], flags=0) user_messages_to_insert.append(user_message) seen_message_ids.add(message["id"]) for stream_id, stream_messages_raw in all_stream_messages.items(): stream_subscription_logs = all_stream_subscription_logs[stream_id] # Make a copy of the original list of messages, which we will # mutate in the loop below. stream_messages = list(stream_messages_raw) for log_entry in stream_subscription_logs: # For each stream, we iterate through all of the changes # to the user's subscription to that stream, ordered by # event_last_message_id, to determine whether the user was # subscribed to the target stream at that time. # # For each message, we're looking for the first event for # the user's subscription to the target stream after the # message was sent. # * If it's an unsubscribe, we know the user was subscribed # when the message was sent, and create a UserMessage # * If it's a subscribe, we know the user was not, and we # skip the message by mutating the stream_messages list # to skip that message. if len(stream_messages) == 0: # Because stream_messages gets mutated below, this # check belongs in this inner loop, not the outer loop. break event_last_message_id = assert_is_not_none(log_entry.event_last_message_id) if log_entry.event_type == RealmAuditLog.SUBSCRIPTION_DEACTIVATED: # If the event shows the user was unsubscribed after # event_last_message_id, we know they must have been # subscribed immediately before the event. for stream_message in stream_messages: if stream_message["id"] <= event_last_message_id: store_user_message_to_insert(stream_message) else: break elif log_entry.event_type in ( RealmAuditLog.SUBSCRIPTION_ACTIVATED, RealmAuditLog.SUBSCRIPTION_CREATED, ): initial_msg_count = len(stream_messages) for i, stream_message in enumerate(stream_messages): if stream_message["id"] > event_last_message_id: stream_messages = stream_messages[i:] break final_msg_count = len(stream_messages) if ( initial_msg_count == final_msg_count and stream_messages[-1]["id"] <= event_last_message_id ): stream_messages = [] else: raise AssertionError(f"{log_entry.event_type} is not a subscription event.") # We do this check for last event since if the last subscription # event was a subscription_deactivated then we don't want to create # UserMessage rows for any of the remaining messages. if len(stream_messages) > 0 and stream_subscription_logs[-1].event_type in ( RealmAuditLog.SUBSCRIPTION_ACTIVATED, RealmAuditLog.SUBSCRIPTION_CREATED, ): for stream_message in stream_messages: store_user_message_to_insert(stream_message) return user_messages_to_insert def add_missing_messages(user_profile: UserProfile) -> None: """This function takes a soft-deactivated user, and computes and adds to the database any UserMessage rows that were not created while the user was soft-deactivated. The end result is that from the perspective of the message database, it should be impossible to tell that the user was soft-deactivated at all. At a high level, the algorithm is as follows: * Find all the streams that the user was at any time a subscriber of when or after they were soft-deactivated (`recipient_ids` below). * Find all the messages sent to those streams since the user was soft-deactivated. This will be a superset of the target UserMessages we need to create in two ways: (1) some UserMessage rows will have already been created in do_send_messages because the user had a nonzero set of flags (the fact that we do so in do_send_messages simplifies things considerably, since it means we don't need to inspect message content to look for things like mentions here), and (2) the user might not have been subscribed to all of the streams in recipient_ids for the entire time window. * Correct the list from the previous state by excluding those with existing UserMessage rows. * Correct the list from the previous state by excluding those where the user wasn't subscribed at the time, using the RealmAuditLog data to determine exactly when the user was subscribed/unsubscribed. * Create the UserMessage rows. For further documentation, see: https://zulip.readthedocs.io/en/latest/subsystems/sending-messages.html#soft-deactivation """ assert user_profile.last_active_message_id is not None all_stream_subs = list( Subscription.objects.filter( user_profile=user_profile, recipient__type=Recipient.STREAM ).values("recipient_id", "recipient__type_id") ) # For stream messages we need to check messages against data from # RealmAuditLog for visibility to user. So we fetch the subscription logs. stream_ids = [sub["recipient__type_id"] for sub in all_stream_subs] # We have a partial index on RealmAuditLog for these rows -- if # this set changes, the partial index must be updated as well, to # keep this query performant events = [ RealmAuditLog.SUBSCRIPTION_CREATED, RealmAuditLog.SUBSCRIPTION_DEACTIVATED, RealmAuditLog.SUBSCRIPTION_ACTIVATED, ] # Important: We order first by event_last_message_id, which is the # official ordering, and then tiebreak by RealmAuditLog event ID. # That second tiebreak is important in case a user is subscribed # and then unsubscribed without any messages being sent in the # meantime. Without that tiebreak, we could end up incorrectly # processing the ordering of those two subscription changes. Note # that this means we cannot backfill events unless there are no # pre-existing events for this stream/user pair! subscription_logs = list( RealmAuditLog.objects.filter( modified_user=user_profile, modified_stream_id__in=stream_ids, event_type__in=events ) .order_by("event_last_message_id", "id") .only("id", "event_type", "modified_stream_id", "event_last_message_id") ) all_stream_subscription_logs: DefaultDict[int, List[RealmAuditLog]] = defaultdict(list) for log in subscription_logs: all_stream_subscription_logs[assert_is_not_none(log.modified_stream_id)].append(log) recipient_ids = [] for sub in all_stream_subs: stream_subscription_logs = all_stream_subscription_logs[sub["recipient__type_id"]] if stream_subscription_logs[-1].event_type == RealmAuditLog.SUBSCRIPTION_DEACTIVATED: assert stream_subscription_logs[-1].event_last_message_id is not None if ( stream_subscription_logs[-1].event_last_message_id <= user_profile.last_active_message_id ): # We are going to short circuit this iteration as its no use # iterating since user unsubscribed before soft-deactivation continue recipient_ids.append(sub["recipient_id"]) new_stream_msgs = ( Message.objects.annotate( has_user_message=Exists( UserMessage.objects.filter( user_profile_id=user_profile, message_id=OuterRef("id"), ) ) ) .filter( # Uses index: zerver_message_realm_recipient_id has_user_message=0, realm_id=user_profile.realm_id, recipient_id__in=recipient_ids, id__gt=user_profile.last_active_message_id, ) .order_by("id") .values("id", "recipient__type_id") ) stream_messages: DefaultDict[int, List[MissingMessageDict]] = defaultdict(list) for msg in new_stream_msgs: stream_messages[msg["recipient__type_id"]].append( MissingMessageDict(id=msg["id"], recipient__type_id=msg["recipient__type_id"]) ) # Calling this function to filter out stream messages based upon # subscription logs and then store all UserMessage objects for bulk insert # This function does not perform any SQL related task and gets all the data # required for its operation in its params. user_messages_to_insert = filter_by_subscription_history( user_profile, stream_messages, all_stream_subscription_logs ) # Doing a bulk create for all the UserMessage objects stored for creation. while len(user_messages_to_insert) > 0: messages, user_messages_to_insert = ( user_messages_to_insert[0:BULK_CREATE_BATCH_SIZE], user_messages_to_insert[BULK_CREATE_BATCH_SIZE:], ) UserMessage.objects.bulk_create(messages) user_profile.last_active_message_id = messages[-1].message_id user_profile.save(update_fields=["last_active_message_id"]) def do_soft_deactivate_user(user_profile: UserProfile) -> None: try: user_profile.last_active_message_id = ( UserMessage.objects.filter(user_profile=user_profile) .order_by("-message_id")[0] .message_id ) except IndexError: # nocoverage # In the unlikely event that a user somehow has never received # a message, we just use the overall max message ID. last_message = Message.objects.last() assert last_message is not None user_profile.last_active_message_id = last_message.id user_profile.long_term_idle = True user_profile.save(update_fields=["long_term_idle", "last_active_message_id"]) logger.info("Soft deactivated user %s", user_profile.id) def do_soft_deactivate_users( users: Union[Sequence[UserProfile], QuerySet[UserProfile]] ) -> List[UserProfile]: BATCH_SIZE = 100 users_soft_deactivated = [] while True: (user_batch, users) = (users[0:BATCH_SIZE], users[BATCH_SIZE:]) if len(user_batch) == 0: break with transaction.atomic(): realm_logs = [] for user in user_batch: do_soft_deactivate_user(user) event_time = timezone_now() log = RealmAuditLog( realm=user.realm, modified_user=user, event_type=RealmAuditLog.USER_SOFT_DEACTIVATED, event_time=event_time, ) realm_logs.append(log) users_soft_deactivated.append(user) RealmAuditLog.objects.bulk_create(realm_logs) logger.info( "Soft-deactivated batch of %s users; %s remain to process", len(user_batch), len(users) ) return users_soft_deactivated def do_auto_soft_deactivate_users( inactive_for_days: int, realm: Optional[Realm] ) -> List[UserProfile]: filter_kwargs: Dict[str, Realm] = {} if realm is not None: filter_kwargs = dict(user_profile__realm=realm) users_to_deactivate = get_users_for_soft_deactivation(inactive_for_days, filter_kwargs) users_deactivated = do_soft_deactivate_users(users_to_deactivate) if not settings.AUTO_CATCH_UP_SOFT_DEACTIVATED_USERS: logger.info("Not catching up users since AUTO_CATCH_UP_SOFT_DEACTIVATED_USERS is off") return users_deactivated if realm is not None: filter_kwargs = dict(realm=realm) users_to_catch_up = get_soft_deactivated_users_for_catch_up(filter_kwargs) do_catch_up_soft_deactivated_users(users_to_catch_up) return users_deactivated def reactivate_user_if_soft_deactivated(user_profile: UserProfile) -> Union[UserProfile, None]: if user_profile.long_term_idle: add_missing_messages(user_profile) user_profile.long_term_idle = False user_profile.save(update_fields=["long_term_idle"]) RealmAuditLog.objects.create( realm=user_profile.realm, modified_user=user_profile, event_type=RealmAuditLog.USER_SOFT_ACTIVATED, event_time=timezone_now(), ) logger.info("Soft reactivated user %s", user_profile.id) return user_profile return None def get_users_for_soft_deactivation( inactive_for_days: int, filter_kwargs: Any ) -> List[UserProfile]: users_activity = list( UserActivity.objects.filter( user_profile__is_active=True, user_profile__is_bot=False, user_profile__long_term_idle=False, **filter_kwargs, ) .values("user_profile_id") .annotate(last_visit=Max("last_visit")) ) today = timezone_now() user_ids_to_deactivate = [ user_activity["user_profile_id"] for user_activity in users_activity if (today - user_activity["last_visit"]).days > inactive_for_days ] users_to_deactivate = list(UserProfile.objects.filter(id__in=user_ids_to_deactivate)) return users_to_deactivate def do_soft_activate_users(users: List[UserProfile]) -> List[UserProfile]: return [ user_activated for user_profile in users if (user_activated := reactivate_user_if_soft_deactivated(user_profile)) is not None ] def do_catch_up_soft_deactivated_users(users: Iterable[UserProfile]) -> List[UserProfile]: users_caught_up = [] failures = [] for user_profile in users: if user_profile.long_term_idle: try: add_missing_messages(user_profile) users_caught_up.append(user_profile) except Exception: # nocoverage capture_exception() # nocoverage failures.append(user_profile) # nocoverage logger.info("Caught up %d soft-deactivated users", len(users_caught_up)) if failures: logger.error("Failed to catch up %d soft-deactivated users", len(failures)) # nocoverage return users_caught_up def get_soft_deactivated_users_for_catch_up(filter_kwargs: Any) -> QuerySet[UserProfile]: users_to_catch_up = UserProfile.objects.filter( long_term_idle=True, is_active=True, is_bot=False, **filter_kwargs, ) return users_to_catch_up def queue_soft_reactivation(user_profile_id: int) -> None: event = { "type": "soft_reactivate", "user_profile_id": user_profile_id, } queue_json_publish("deferred_work", event) def soft_reactivate_if_personal_notification( user_profile: UserProfile, unique_triggers: Set[str], mentioned_user_group_name: Optional[str] ) -> None: """When we're about to send an email/push notification to a long_term_idle user, it's very likely that the user will try to return to Zulip. As a result, it makes sense to optimistically soft-reactivate that user, to give them a good return experience. It's important that we do nothing for stream wildcard or group mentions, because soft-reactivating an entire realm would be very expensive (and we can't easily check the group's size). The caller is responsible for passing a mentioned_user_group_name that is None for messages that contain both a personal mention and a group mention. """ if not user_profile.long_term_idle: return direct_message = NotificationTriggers.DIRECT_MESSAGE in unique_triggers personal_mention = ( NotificationTriggers.MENTION in unique_triggers and mentioned_user_group_name is None ) topic_wildcard_mention = any( trigger in unique_triggers for trigger in [ NotificationTriggers.TOPIC_WILDCARD_MENTION, NotificationTriggers.TOPIC_WILDCARD_MENTION_IN_FOLLOWED_TOPIC, ] ) if not direct_message and not personal_mention and not topic_wildcard_mention: return queue_soft_reactivation(user_profile.id)