zulip/zerver/tests/test_message_move_topic.py

from datetime import timedelta
from typing import Any, Dict, List
from unittest import mock

import orjson

from zerver.actions.message_edit import check_update_message, do_update_message
from zerver.actions.reactions import do_add_reaction
from zerver.actions.realm_settings import do_set_realm_property
from zerver.actions.user_topics import do_set_user_topic_visibility_policy
from zerver.lib.message import truncate_topic
from zerver.lib.test_classes import ZulipTestCase, get_topic_messages
from zerver.lib.topic import RESOLVED_TOPIC_PREFIX
from zerver.lib.user_topics import (
    get_users_with_user_topic_visibility_policy,
    set_topic_visibility_policy,
    topic_has_visibility_policy,
)
from zerver.lib.utils import assert_is_not_none
from zerver.models import Message, Realm, UserMessage, UserProfile, UserTopic
from zerver.models.constants import MAX_TOPIC_NAME_LENGTH


class MessageMoveTopicTest(ZulipTestCase):
    def check_topic(self, msg_id: int, topic_name: str) -> None:
        msg = Message.objects.get(id=msg_id)
        self.assertEqual(msg.topic_name(), topic_name)

    def test_private_message_edit_topic(self) -> None:
        hamlet = self.example_user("hamlet")
        self.login("hamlet")
        cordelia = self.example_user("cordelia")
        msg_id = self.send_personal_message(hamlet, cordelia)

        result = self.client_patch(
            "/json/messages/" + str(msg_id),
            {
                "topic": "Should not exist",
            },
        )

        self.assert_json_error(result, "Direct messages cannot have topics.")

    def test_propagate_invalid(self) -> None:
        self.login("hamlet")
        id1 = self.send_stream_message(self.example_user("hamlet"), "Denmark", topic_name="topic1")

        result = self.client_patch(
            "/json/messages/" + str(id1),
            {
                "topic": "edited",
                "propagate_mode": "invalid",
            },
        )
        self.assert_json_error(result, "Invalid propagate_mode")
        self.check_topic(id1, topic_name="topic1")

        result = self.client_patch(
            "/json/messages/" + str(id1),
            {
                "content": "edited",
                "propagate_mode": "change_all",
            },
        )
        self.assert_json_error(result, "Invalid propagate_mode without topic edit")
        self.check_topic(id1, topic_name="topic1")

    def test_edit_message_no_topic(self) -> None:
        self.login("hamlet")
        msg_id = self.send_stream_message(
            self.example_user("hamlet"), "Denmark", topic_name="editing", content="before edit"
        )
        result = self.client_patch(
            "/json/messages/" + str(msg_id),
            {
                "topic": " ",
            },
        )
        self.assert_json_error(result, "Topic can't be empty!")

    def test_edit_message_invalid_topic(self) -> None:
        self.login("hamlet")
        msg_id = self.send_stream_message(
            self.example_user("hamlet"), "Denmark", topic_name="editing", content="before edit"
        )
        result = self.client_patch(
            "/json/messages/" + str(msg_id),
            {
                "topic": "editing\nfun",
            },
        )
        self.assert_json_error(result, "Invalid character in topic, at position 8!")

    @mock.patch("zerver.actions.message_edit.send_event")
    def test_edit_topic_public_history_stream(self, mock_send_event: mock.MagicMock) -> None:
        stream_name = "Macbeth"
        hamlet = self.example_user("hamlet")
        cordelia = self.example_user("cordelia")
        self.make_stream(stream_name, history_public_to_subscribers=True)
        self.subscribe(hamlet, stream_name)
        self.login_user(hamlet)
        message_id = self.send_stream_message(hamlet, stream_name, "Where am I?")

        self.login_user(cordelia)
        self.subscribe(cordelia, stream_name)
        message = Message.objects.get(id=message_id)

        def do_update_message_topic_success(
            user_profile: UserProfile,
            message: Message,
            topic_name: str,
            users_to_be_notified: List[Dict[str, Any]],
        ) -> None:
            do_update_message(
                user_profile=user_profile,
                target_message=message,
                new_stream=None,
                topic_name=topic_name,
                propagate_mode="change_later",
                send_notification_to_old_thread=False,
                send_notification_to_new_thread=False,
                content=None,
                rendering_result=None,
                prior_mention_user_ids=set(),
                mention_data=None,
            )

            mock_send_event.assert_called_with(mock.ANY, mock.ANY, users_to_be_notified)

        # Returns the users that need to be notified when a message topic is changed
        def notify(user_id: int) -> Dict[str, Any]:
            um = UserMessage.objects.get(message=message_id)
            if um.user_profile_id == user_id:
                return {
                    "id": user_id,
                    "flags": um.flags_list(),
                }

            else:
                return {
                    "id": user_id,
                    "flags": ["read"],
                }

        users_to_be_notified = list(map(notify, [hamlet.id, cordelia.id]))
        # Edit topic of a message sent before Cordelia subscribed the stream
        do_update_message_topic_success(
            cordelia, message, "Othello eats apple", users_to_be_notified
        )

        # If Cordelia is long-term idle, she doesn't get a notification.
        cordelia.long_term_idle = True
        cordelia.save()
        users_to_be_notified = list(map(notify, [hamlet.id]))
        do_update_message_topic_success(
            cordelia, message, "Another topic idle", users_to_be_notified
        )
        cordelia.long_term_idle = False
        cordelia.save()

        # Even if Hamlet unsubscribes the stream, he should be notified when the topic is changed
        # because he has a UserMessage row.
        self.unsubscribe(hamlet, stream_name)
        users_to_be_notified = list(map(notify, [hamlet.id, cordelia.id]))
        do_update_message_topic_success(cordelia, message, "Another topic", users_to_be_notified)

        # Hamlet subscribes to the stream again and Cordelia unsubscribes, then Hamlet changes
        # the message topic. Cordelia won't receive any updates when a message on that stream is
        # changed because she is not a subscriber and doesn't have a UserMessage row.
        self.subscribe(hamlet, stream_name)
        self.unsubscribe(cordelia, stream_name)
        self.login_user(hamlet)
        users_to_be_notified = list(map(notify, [hamlet.id]))
        do_update_message_topic_success(hamlet, message, "Change again", users_to_be_notified)

    @mock.patch("zerver.actions.user_topics.send_event")
    def test_edit_muted_topic(self, mock_send_event: mock.MagicMock) -> None:
        stream_name = "Stream 123"
        stream = self.make_stream(stream_name)
        hamlet = self.example_user("hamlet")
        cordelia = self.example_user("cordelia")
        aaron = self.example_user("aaron")
        self.subscribe(hamlet, stream_name)
        self.login_user(hamlet)
        message_id = self.send_stream_message(
            hamlet, stream_name, topic_name="Topic1", content="Hello World"
        )

        self.subscribe(cordelia, stream_name)
        self.login_user(cordelia)
        self.subscribe(aaron, stream_name)
        self.login_user(aaron)

        def assert_is_topic_muted(
            user_profile: UserProfile,
            stream_id: int,
            topic_name: str,
            *,
            muted: bool,
        ) -> None:
            if muted:
                self.assertTrue(
                    topic_has_visibility_policy(
                        user_profile, stream_id, topic_name, UserTopic.VisibilityPolicy.MUTED
                    )
                )
            else:
                self.assertFalse(
                    topic_has_visibility_policy(
                        user_profile, stream_id, topic_name, UserTopic.VisibilityPolicy.MUTED
                    )
                )

        already_muted_topic_name = "Already muted topic"
        muted_topics = [
            [stream_name, "Topic1"],
            [stream_name, "Topic2"],
            [stream_name, already_muted_topic_name],
        ]
        set_topic_visibility_policy(hamlet, muted_topics, UserTopic.VisibilityPolicy.MUTED)
        set_topic_visibility_policy(cordelia, muted_topics, UserTopic.VisibilityPolicy.MUTED)

        # users that need to be notified by send_event in the case of change-topic-name operation.
        users_to_be_notified_via_muted_topics_event: List[int] = []
        users_to_be_notified_via_user_topic_event: List[int] = []
        for user_topic in get_users_with_user_topic_visibility_policy(stream.id, "Topic1"):
            # We are appending the same data twice because 'user_topic' event notifies
            # the user during delete and create operation.
            users_to_be_notified_via_user_topic_event.append(user_topic.user_profile_id)
            users_to_be_notified_via_user_topic_event.append(user_topic.user_profile_id)
            # 'muted_topics' event notifies the user of muted topics during create
            # operation only.
            users_to_be_notified_via_muted_topics_event.append(user_topic.user_profile_id)

        change_all_topic_name = "Topic 1 edited"
        # Verify how many total database queries are required. We
        # expect 6 queries (4/visibility_policy to update the muted
        # state + 1/user with a UserTopic row for the events data)
        # beyond what is typical were there not UserTopic records to
        # update. Ideally, we'd eliminate the per-user component.
        with self.assert_database_query_count(25):
            check_update_message(
                user_profile=hamlet,
                message_id=message_id,
                stream_id=None,
                topic_name=change_all_topic_name,
                propagate_mode="change_all",
                send_notification_to_old_thread=False,
                send_notification_to_new_thread=False,
                content=None,
            )

        # Extract the send_event call where event type is 'user_topic' or 'muted_topics.
        # Here we assert that the expected users are notified properly.
        users_notified_via_muted_topics_event: List[int] = []
        users_notified_via_user_topic_event: List[int] = []
        for call_args in mock_send_event.call_args_list:
            (arg_realm, arg_event, arg_notified_users) = call_args[0]
            if arg_event["type"] == "user_topic":
                users_notified_via_user_topic_event.append(*arg_notified_users)
            elif arg_event["type"] == "muted_topics":
                users_notified_via_muted_topics_event.append(*arg_notified_users)
        self.assertEqual(
            sorted(users_notified_via_muted_topics_event),
            sorted(users_to_be_notified_via_muted_topics_event),
        )
        self.assertEqual(
            sorted(users_notified_via_user_topic_event),
            sorted(users_to_be_notified_via_user_topic_event),
        )

        assert_is_topic_muted(hamlet, stream.id, "Topic1", muted=False)
        assert_is_topic_muted(cordelia, stream.id, "Topic1", muted=False)
        assert_is_topic_muted(aaron, stream.id, "Topic1", muted=False)
        assert_is_topic_muted(hamlet, stream.id, "Topic2", muted=True)
        assert_is_topic_muted(cordelia, stream.id, "Topic2", muted=True)
        assert_is_topic_muted(aaron, stream.id, "Topic2", muted=False)
        assert_is_topic_muted(hamlet, stream.id, change_all_topic_name, muted=True)
        assert_is_topic_muted(cordelia, stream.id, change_all_topic_name, muted=True)
        assert_is_topic_muted(aaron, stream.id, change_all_topic_name, muted=False)

        change_later_topic_name = "Topic 1 edited again"
        check_update_message(
            user_profile=hamlet,
            message_id=message_id,
            stream_id=None,
            topic_name=change_later_topic_name,
            propagate_mode="change_later",
            send_notification_to_old_thread=False,
            send_notification_to_new_thread=False,
            content=None,
        )
        assert_is_topic_muted(hamlet, stream.id, change_all_topic_name, muted=False)
        assert_is_topic_muted(hamlet, stream.id, change_later_topic_name, muted=True)

        # Make sure we safely handle the case of the new topic being already muted.
        check_update_message(
            user_profile=hamlet,
            message_id=message_id,
            stream_id=None,
            topic_name=already_muted_topic_name,
            propagate_mode="change_all",
            send_notification_to_old_thread=False,
            send_notification_to_new_thread=False,
            content=None,
        )
        assert_is_topic_muted(hamlet, stream.id, change_later_topic_name, muted=False)
        assert_is_topic_muted(hamlet, stream.id, already_muted_topic_name, muted=True)

        change_one_topic_name = "Topic 1 edited change_one"
        check_update_message(
            user_profile=hamlet,
            message_id=message_id,
            stream_id=None,
            topic_name=change_one_topic_name,
            propagate_mode="change_one",
            send_notification_to_old_thread=False,
            send_notification_to_new_thread=False,
            content=None,
        )
        assert_is_topic_muted(hamlet, stream.id, change_one_topic_name, muted=True)
        assert_is_topic_muted(hamlet, stream.id, change_later_topic_name, muted=False)

        # Move topic between two public streams.
        desdemona = self.example_user("desdemona")
        message_id = self.send_stream_message(
            hamlet, stream_name, topic_name="New topic", content="Hello World"
        )
        new_public_stream = self.make_stream("New public stream")
        self.subscribe(desdemona, new_public_stream.name)
        self.login_user(desdemona)
        muted_topics = [
            [stream_name, "New topic"],
        ]
        set_topic_visibility_policy(desdemona, muted_topics, UserTopic.VisibilityPolicy.MUTED)
        set_topic_visibility_policy(cordelia, muted_topics, UserTopic.VisibilityPolicy.MUTED)

        with self.assert_database_query_count(27):
            check_update_message(
                user_profile=desdemona,
                message_id=message_id,
                stream_id=new_public_stream.id,
                propagate_mode="change_all",
                send_notification_to_old_thread=False,
                send_notification_to_new_thread=False,
                content=None,
            )

        assert_is_topic_muted(desdemona, stream.id, "New topic", muted=False)
        assert_is_topic_muted(cordelia, stream.id, "New topic", muted=False)
        assert_is_topic_muted(aaron, stream.id, "New topic", muted=False)
        assert_is_topic_muted(desdemona, new_public_stream.id, "New topic", muted=True)
        assert_is_topic_muted(cordelia, new_public_stream.id, "New topic", muted=True)
        assert_is_topic_muted(aaron, new_public_stream.id, "New topic", muted=False)

        # Move topic to a private stream.
        message_id = self.send_stream_message(
            hamlet, stream_name, topic_name="New topic", content="Hello World"
        )
        new_private_stream = self.make_stream("New private stream", invite_only=True)
        self.subscribe(desdemona, new_private_stream.name)
        self.login_user(desdemona)
        muted_topics = [
            [stream_name, "New topic"],
        ]
        set_topic_visibility_policy(desdemona, muted_topics, UserTopic.VisibilityPolicy.MUTED)
        set_topic_visibility_policy(cordelia, muted_topics, UserTopic.VisibilityPolicy.MUTED)
        with self.assert_database_query_count(33):
            check_update_message(
                user_profile=desdemona,
                message_id=message_id,
                stream_id=new_private_stream.id,
                propagate_mode="change_all",
                send_notification_to_old_thread=False,
                send_notification_to_new_thread=False,
                content=None,
            )

        # Cordelia is not subscribed to the private stream, so
        # Cordelia should have had the topic unmuted, while Desdemona
        # should have had her muted topic record moved.
        assert_is_topic_muted(desdemona, stream.id, "New topic", muted=False)
        assert_is_topic_muted(cordelia, stream.id, "New topic", muted=False)
        assert_is_topic_muted(aaron, stream.id, "New topic", muted=False)
        assert_is_topic_muted(desdemona, new_private_stream.id, "New topic", muted=True)
        assert_is_topic_muted(cordelia, new_private_stream.id, "New topic", muted=False)
        assert_is_topic_muted(aaron, new_private_stream.id, "New topic", muted=False)

        # Move topic between two public streams with change in topic name.
        desdemona = self.example_user("desdemona")
        message_id = self.send_stream_message(
            hamlet, stream_name, topic_name="New topic 2", content="Hello World"
        )
        self.login_user(desdemona)
        muted_topics = [
            [stream_name, "New topic 2"],
        ]
        set_topic_visibility_policy(desdemona, muted_topics, UserTopic.VisibilityPolicy.MUTED)
        set_topic_visibility_policy(cordelia, muted_topics, UserTopic.VisibilityPolicy.MUTED)

        with self.assert_database_query_count(27):
            check_update_message(
                user_profile=desdemona,
                message_id=message_id,
                stream_id=new_public_stream.id,
                topic_name="changed topic name",
                propagate_mode="change_all",
                send_notification_to_old_thread=False,
                send_notification_to_new_thread=False,
                content=None,
            )

        assert_is_topic_muted(desdemona, stream.id, "New topic 2", muted=False)
        assert_is_topic_muted(cordelia, stream.id, "New topic 2", muted=False)
        assert_is_topic_muted(aaron, stream.id, "New topic 2", muted=False)
        assert_is_topic_muted(desdemona, new_public_stream.id, "changed topic name", muted=True)
        assert_is_topic_muted(cordelia, new_public_stream.id, "changed topic name", muted=True)
        assert_is_topic_muted(aaron, new_public_stream.id, "changed topic name", muted=False)

        # Moving only half the messages doesn't move UserTopic records.
        second_message_id = self.send_stream_message(
            hamlet, stream_name, topic_name="changed topic name", content="Second message"
        )
        with self.assert_database_query_count(22):
            check_update_message(
                user_profile=desdemona,
                message_id=second_message_id,
                stream_id=new_public_stream.id,
                topic_name="final topic name",
                propagate_mode="change_later",
                send_notification_to_old_thread=False,
                send_notification_to_new_thread=False,
                content=None,
            )

        assert_is_topic_muted(desdemona, new_public_stream.id, "changed topic name", muted=True)
        assert_is_topic_muted(cordelia, new_public_stream.id, "changed topic name", muted=True)
        assert_is_topic_muted(aaron, new_public_stream.id, "changed topic name", muted=False)
        assert_is_topic_muted(desdemona, new_public_stream.id, "final topic name", muted=False)
        assert_is_topic_muted(cordelia, new_public_stream.id, "final topic name", muted=False)
        assert_is_topic_muted(aaron, new_public_stream.id, "final topic name", muted=False)

    @mock.patch("zerver.actions.user_topics.send_event")
    def test_edit_unmuted_topic(self, mock_send_event: mock.MagicMock) -> None:
        stream_name = "Stream 123"
        stream = self.make_stream(stream_name)

        hamlet = self.example_user("hamlet")
        cordelia = self.example_user("cordelia")
        aaron = self.example_user("aaron")
        othello = self.example_user("othello")

        def assert_has_visibility_policy(
            user_profile: UserProfile,
            topic_name: str,
            visibility_policy: int,
            *,
            expected: bool,
        ) -> None:
            if expected:
                self.assertTrue(
                    topic_has_visibility_policy(
                        user_profile, stream.id, topic_name, visibility_policy
                    )
                )
            else:
                self.assertFalse(
                    topic_has_visibility_policy(
                        user_profile, stream.id, topic_name, visibility_policy
                    )
                )

        self.subscribe(hamlet, stream_name)
        self.login_user(hamlet)
        message_id = self.send_stream_message(
            hamlet, stream_name, topic_name="Topic1", content="Hello World"
        )

        self.subscribe(cordelia, stream_name)
        self.login_user(cordelia)
        self.subscribe(aaron, stream_name)
        self.login_user(aaron)
        self.subscribe(othello, stream_name)
        self.login_user(othello)

        # Initially, hamlet and othello set visibility_policy as UNMUTED for 'Topic1' and 'Topic2',
        # cordelia sets visibility_policy as MUTED for 'Topic1' and 'Topic2', while
        # aaron doesn't have a visibility_policy set for 'Topic1' or 'Topic2'.
        #
        # After moving messages from 'Topic1' to 'Topic 1 edited', the expected behaviour is:
        # hamlet and othello have UNMUTED 'Topic 1 edited' and no visibility_policy set for 'Topic1'
        # cordelia has MUTED 'Topic 1 edited' and no visibility_policy set for 'Topic1'
        #
        # There is no change in visibility_policy configurations for 'Topic2', i.e.
        # hamlet and othello have UNMUTED 'Topic2' + cordelia has MUTED 'Topic2'
        # aaron still doesn't have visibility_policy set for any topic.
        #
        # Note: We have used two users with UNMUTED 'Topic1' to verify that the query count
        # doesn't increase (in order to update UserTopic records) with an increase in users.
        # (We are using bulk database operations.)
        # 1 query/user is added in order to send muted_topics event.(which will be deprecated)
        topics = [
            [stream_name, "Topic1"],
            [stream_name, "Topic2"],
        ]
        set_topic_visibility_policy(hamlet, topics, UserTopic.VisibilityPolicy.UNMUTED)
        set_topic_visibility_policy(cordelia, topics, UserTopic.VisibilityPolicy.MUTED)
        set_topic_visibility_policy(othello, topics, UserTopic.VisibilityPolicy.UNMUTED)

        # users that need to be notified by send_event in the case of change-topic-name operation.
        users_to_be_notified_via_muted_topics_event: List[int] = []
        users_to_be_notified_via_user_topic_event: List[int] = []
        for user_topic in get_users_with_user_topic_visibility_policy(stream.id, "Topic1"):
            # We are appending the same data twice because 'user_topic' event notifies
            # the user during delete and create operation.
            users_to_be_notified_via_user_topic_event.append(user_topic.user_profile_id)
            users_to_be_notified_via_user_topic_event.append(user_topic.user_profile_id)
            # 'muted_topics' event notifies the user of muted topics during create
            # operation only.
            users_to_be_notified_via_muted_topics_event.append(user_topic.user_profile_id)

        change_all_topic_name = "Topic 1 edited"
        with self.assert_database_query_count(30):
            check_update_message(
                user_profile=hamlet,
                message_id=message_id,
                stream_id=None,
                topic_name=change_all_topic_name,
                propagate_mode="change_all",
                send_notification_to_old_thread=False,
                send_notification_to_new_thread=False,
                content=None,
            )

        # Extract the send_event call where event type is 'user_topic' or 'muted_topics.
        # Here we assert that the expected users are notified properly.
        users_notified_via_muted_topics_event: List[int] = []
        users_notified_via_user_topic_event: List[int] = []
        for call_args in mock_send_event.call_args_list:
            (arg_realm, arg_event, arg_notified_users) = call_args[0]
            if arg_event["type"] == "user_topic":
                users_notified_via_user_topic_event.append(*arg_notified_users)
            elif arg_event["type"] == "muted_topics":
                users_notified_via_muted_topics_event.append(*arg_notified_users)
        self.assertEqual(
            sorted(users_notified_via_muted_topics_event),
            sorted(users_to_be_notified_via_muted_topics_event),
        )
        self.assertEqual(
            sorted(users_notified_via_user_topic_event),
            sorted(users_to_be_notified_via_user_topic_event),
        )

        # No visibility_policy set for 'Topic1'
        assert_has_visibility_policy(
            hamlet, "Topic1", UserTopic.VisibilityPolicy.UNMUTED, expected=False
        )
        assert_has_visibility_policy(
            cordelia, "Topic1", UserTopic.VisibilityPolicy.MUTED, expected=False
        )
        assert_has_visibility_policy(
            othello, "Topic1", UserTopic.VisibilityPolicy.UNMUTED, expected=False
        )
        assert_has_visibility_policy(
            aaron, "Topic1", UserTopic.VisibilityPolicy.UNMUTED, expected=False
        )
        # No change in visibility_policy configurations for 'Topic2'
        assert_has_visibility_policy(
            hamlet, "Topic2", UserTopic.VisibilityPolicy.UNMUTED, expected=True
        )
        assert_has_visibility_policy(
            cordelia, "Topic2", UserTopic.VisibilityPolicy.MUTED, expected=True
        )
        assert_has_visibility_policy(
            othello, "Topic2", UserTopic.VisibilityPolicy.UNMUTED, expected=True
        )
        assert_has_visibility_policy(
            aaron, "Topic2", UserTopic.VisibilityPolicy.UNMUTED, expected=False
        )
        # UserTopic records moved to 'Topic 1 edited' after move-topic operation.
        assert_has_visibility_policy(
            hamlet, change_all_topic_name, UserTopic.VisibilityPolicy.UNMUTED, expected=True
        )
        assert_has_visibility_policy(
            cordelia, change_all_topic_name, UserTopic.VisibilityPolicy.MUTED, expected=True
        )
        assert_has_visibility_policy(
            othello, change_all_topic_name, UserTopic.VisibilityPolicy.UNMUTED, expected=True
        )
        assert_has_visibility_policy(
            aaron, change_all_topic_name, UserTopic.VisibilityPolicy.MUTED, expected=False
        )

    def test_merge_user_topic_states_on_move_messages(self) -> None:
        stream_name = "Stream 123"
        stream = self.make_stream(stream_name)

        hamlet = self.example_user("hamlet")
        cordelia = self.example_user("cordelia")
        aaron = self.example_user("aaron")

        def assert_has_visibility_policy(
            user_profile: UserProfile,
            topic_name: str,
            visibility_policy: int,
        ) -> None:
            self.assertTrue(
                topic_has_visibility_policy(user_profile, stream.id, topic_name, visibility_policy)
            )

        self.subscribe(hamlet, stream_name)
        self.login_user(hamlet)
        self.subscribe(cordelia, stream_name)
        self.login_user(cordelia)
        self.subscribe(aaron, stream_name)
        self.login_user(aaron)

        # Test the following cases:
        #
        #  orig_topic | target_topic | final behaviour
        #   INHERIT       INHERIT       INHERIT
        #   INHERIT        MUTED        INHERIT
        #   INHERIT       UNMUTED       UNMUTED
        orig_topic = "Topic1"
        target_topic = "Topic1 edited"
        orig_message_id = self.send_stream_message(
            hamlet, stream_name, topic_name=orig_topic, content="Hello World"
        )
        self.send_stream_message(
            hamlet, stream_name, topic_name=target_topic, content="Hello World 2"
        )

        # By default:
        # visibility_policy of 'hamlet', 'cordelia', 'aaron' for 'orig_topic': INHERIT
        # visibility_policy of 'hamlet' for 'target_topic': INHERIT
        #
        # So we don't need to manually set visibility_policy to INHERIT whenever required,
        # here and later in this test.
        do_set_user_topic_visibility_policy(
            cordelia, stream, target_topic, visibility_policy=UserTopic.VisibilityPolicy.MUTED
        )
        do_set_user_topic_visibility_policy(
            aaron, stream, target_topic, visibility_policy=UserTopic.VisibilityPolicy.UNMUTED
        )

        check_update_message(
            user_profile=hamlet,
            message_id=orig_message_id,
            stream_id=None,
            topic_name=target_topic,
            propagate_mode="change_all",
            send_notification_to_old_thread=False,
            send_notification_to_new_thread=False,
            content=None,
        )

        assert_has_visibility_policy(hamlet, orig_topic, UserTopic.VisibilityPolicy.INHERIT)
        assert_has_visibility_policy(cordelia, orig_topic, UserTopic.VisibilityPolicy.INHERIT)
        assert_has_visibility_policy(aaron, orig_topic, UserTopic.VisibilityPolicy.INHERIT)
        assert_has_visibility_policy(hamlet, target_topic, UserTopic.VisibilityPolicy.INHERIT)
        assert_has_visibility_policy(cordelia, target_topic, UserTopic.VisibilityPolicy.INHERIT)
        assert_has_visibility_policy(aaron, target_topic, UserTopic.VisibilityPolicy.UNMUTED)

        # Test the following cases:
        #
        #  orig_topic | target_topic | final behaviour
        #     MUTED       INHERIT        INHERIT
        #     MUTED        MUTED          MUTED
        #     MUTED       UNMUTED        UNMUTED
        orig_topic = "Topic2"
        target_topic = "Topic2 edited"
        orig_message_id = self.send_stream_message(
            hamlet, stream_name, topic_name=orig_topic, content="Hello World"
        )
        self.send_stream_message(
            hamlet, stream_name, topic_name=target_topic, content="Hello World 2"
        )

        do_set_user_topic_visibility_policy(
            hamlet, stream, orig_topic, visibility_policy=UserTopic.VisibilityPolicy.MUTED
        )
        do_set_user_topic_visibility_policy(
            cordelia, stream, orig_topic, visibility_policy=UserTopic.VisibilityPolicy.MUTED
        )
        do_set_user_topic_visibility_policy(
            aaron, stream, orig_topic, visibility_policy=UserTopic.VisibilityPolicy.MUTED
        )
        do_set_user_topic_visibility_policy(
            cordelia, stream, target_topic, visibility_policy=UserTopic.VisibilityPolicy.MUTED
        )
        do_set_user_topic_visibility_policy(
            aaron, stream, target_topic, visibility_policy=UserTopic.VisibilityPolicy.UNMUTED
        )

        check_update_message(
            user_profile=hamlet,
            message_id=orig_message_id,
            stream_id=None,
            topic_name=target_topic,
            propagate_mode="change_all",
            send_notification_to_old_thread=False,
            send_notification_to_new_thread=False,
            content=None,
        )

        assert_has_visibility_policy(hamlet, orig_topic, UserTopic.VisibilityPolicy.INHERIT)
        assert_has_visibility_policy(cordelia, orig_topic, UserTopic.VisibilityPolicy.INHERIT)
        assert_has_visibility_policy(aaron, orig_topic, UserTopic.VisibilityPolicy.INHERIT)
        assert_has_visibility_policy(hamlet, target_topic, UserTopic.VisibilityPolicy.INHERIT)
        assert_has_visibility_policy(cordelia, target_topic, UserTopic.VisibilityPolicy.MUTED)
        assert_has_visibility_policy(aaron, target_topic, UserTopic.VisibilityPolicy.UNMUTED)

        # Test the following cases:
        #
        #  orig_topic | target_topic | final behaviour
        #    UNMUTED       INHERIT        UNMUTED
        #    UNMUTED        MUTED         UNMUTED
        #    UNMUTED       UNMUTED        UNMUTED
        orig_topic = "Topic3"
        target_topic = "Topic3 edited"
        orig_message_id = self.send_stream_message(
            hamlet, stream_name, topic_name=orig_topic, content="Hello World"
        )
        self.send_stream_message(
            hamlet, stream_name, topic_name=target_topic, content="Hello World 2"
        )

        do_set_user_topic_visibility_policy(
            hamlet, stream, orig_topic, visibility_policy=UserTopic.VisibilityPolicy.UNMUTED
        )
        do_set_user_topic_visibility_policy(
            cordelia, stream, orig_topic, visibility_policy=UserTopic.VisibilityPolicy.UNMUTED
        )
        do_set_user_topic_visibility_policy(
            aaron, stream, orig_topic, visibility_policy=UserTopic.VisibilityPolicy.UNMUTED
        )
        do_set_user_topic_visibility_policy(
            cordelia, stream, target_topic, visibility_policy=UserTopic.VisibilityPolicy.MUTED
        )
        do_set_user_topic_visibility_policy(
            aaron, stream, target_topic, visibility_policy=UserTopic.VisibilityPolicy.UNMUTED
        )

        check_update_message(
            user_profile=hamlet,
            message_id=orig_message_id,
            stream_id=None,
            topic_name=target_topic,
            propagate_mode="change_all",
            send_notification_to_old_thread=False,
            send_notification_to_new_thread=False,
            content=None,
        )

        assert_has_visibility_policy(hamlet, orig_topic, UserTopic.VisibilityPolicy.INHERIT)
        assert_has_visibility_policy(cordelia, orig_topic, UserTopic.VisibilityPolicy.INHERIT)
        assert_has_visibility_policy(aaron, orig_topic, UserTopic.VisibilityPolicy.INHERIT)
        assert_has_visibility_policy(hamlet, target_topic, UserTopic.VisibilityPolicy.UNMUTED)
        assert_has_visibility_policy(cordelia, target_topic, UserTopic.VisibilityPolicy.UNMUTED)
        assert_has_visibility_policy(aaron, target_topic, UserTopic.VisibilityPolicy.UNMUTED)

    def test_user_topic_states_on_moving_to_topic_with_no_messages(self) -> None:
        stream_name = "Stream 123"
        stream = self.make_stream(stream_name)

        hamlet = self.example_user("hamlet")
        cordelia = self.example_user("cordelia")
        aaron = self.example_user("aaron")

        self.subscribe(hamlet, stream_name)
        self.subscribe(cordelia, stream_name)
        self.subscribe(aaron, stream_name)

        def assert_has_visibility_policy(
            user_profile: UserProfile,
            topic_name: str,
            visibility_policy: int,
        ) -> None:
            self.assertTrue(
                topic_has_visibility_policy(user_profile, stream.id, topic_name, visibility_policy)
            )

        # Test the case where target topic has no messages:
        #
        #  orig_topic | final behaviour
        #    INHERIT       INHERIT
        #    UNMUTED       UNMUTED
        #    MUTED         MUTED

        orig_topic = "Topic1"
        target_topic = "Topic1 edited"
        orig_message_id = self.send_stream_message(
            hamlet, stream_name, topic_name=orig_topic, content="Hello World"
        )

        do_set_user_topic_visibility_policy(
            hamlet, stream, orig_topic, visibility_policy=UserTopic.VisibilityPolicy.UNMUTED
        )
        do_set_user_topic_visibility_policy(
            cordelia, stream, orig_topic, visibility_policy=UserTopic.VisibilityPolicy.MUTED
        )

        check_update_message(
            user_profile=hamlet,
            message_id=orig_message_id,
            stream_id=None,
            topic_name=target_topic,
            propagate_mode="change_all",
            send_notification_to_old_thread=False,
            send_notification_to_new_thread=False,
            content=None,
        )

        assert_has_visibility_policy(hamlet, orig_topic, UserTopic.VisibilityPolicy.INHERIT)
        assert_has_visibility_policy(cordelia, orig_topic, UserTopic.VisibilityPolicy.INHERIT)
        assert_has_visibility_policy(aaron, orig_topic, UserTopic.VisibilityPolicy.INHERIT)
        assert_has_visibility_policy(hamlet, target_topic, UserTopic.VisibilityPolicy.UNMUTED)
        assert_has_visibility_policy(cordelia, target_topic, UserTopic.VisibilityPolicy.MUTED)
        assert_has_visibility_policy(aaron, target_topic, UserTopic.VisibilityPolicy.INHERIT)

        def test_user_topic_state_for_messages_deleted_from_target_topic(
            orig_topic: str, target_topic: str, original_topic_state: int
        ) -> None:
            # Test the case where target topic has no messages but has UserTopic row
            # due to messages being deleted from the target topic.
            orig_message_id = self.send_stream_message(
                hamlet, stream_name, topic_name=orig_topic, content="Hello World"
            )
            target_message_id = self.send_stream_message(
                hamlet, stream_name, topic_name=target_topic, content="Hello World"
            )

            if original_topic_state != UserTopic.VisibilityPolicy.INHERIT:
                users = [hamlet, cordelia, aaron]
                for user in users:
                    do_set_user_topic_visibility_policy(
                        user, stream, orig_topic, visibility_policy=original_topic_state
                    )

            do_set_user_topic_visibility_policy(
                hamlet, stream, target_topic, visibility_policy=UserTopic.VisibilityPolicy.UNMUTED
            )
            do_set_user_topic_visibility_policy(
                cordelia, stream, target_topic, visibility_policy=UserTopic.VisibilityPolicy.MUTED
            )

            # Delete the message in target topic to make it empty.
            self.login("hamlet")
            do_set_realm_property(
                hamlet.realm,
                "delete_own_message_policy",
                Realm.POLICY_MEMBERS_ONLY,
                acting_user=None,
            )
            self.client_delete(f"/json/messages/{target_message_id}")

            check_update_message(
                user_profile=hamlet,
                message_id=orig_message_id,
                stream_id=None,
                topic_name=target_topic,
                propagate_mode="change_all",
                send_notification_to_old_thread=False,
                send_notification_to_new_thread=False,
                content=None,
            )

            assert_has_visibility_policy(hamlet, orig_topic, UserTopic.VisibilityPolicy.INHERIT)
            assert_has_visibility_policy(cordelia, orig_topic, UserTopic.VisibilityPolicy.INHERIT)
            assert_has_visibility_policy(aaron, orig_topic, UserTopic.VisibilityPolicy.INHERIT)
            assert_has_visibility_policy(hamlet, target_topic, original_topic_state)
            assert_has_visibility_policy(cordelia, target_topic, original_topic_state)
            assert_has_visibility_policy(aaron, target_topic, original_topic_state)

        # orig_topic | target_topic | final behaviour
        #   INHERIT      INHERIT         INHERIT
        #   INHERIT      UNMUTED         INHERIT
        #   INHERIT      MUTED           INHERIT
        test_user_topic_state_for_messages_deleted_from_target_topic(
            orig_topic="Topic2",
            target_topic="Topic2 edited",
            original_topic_state=UserTopic.VisibilityPolicy.INHERIT,
        )

        # orig_topic | target_topic | final behaviour
        #   MUTED      INHERIT         MUTED
        #   MUTED      UNMUTED         MUTED
        #   MUTED      MUTED           MUTED
        test_user_topic_state_for_messages_deleted_from_target_topic(
            orig_topic="Topic3",
            target_topic="Topic3 edited",
            original_topic_state=UserTopic.VisibilityPolicy.MUTED,
        )

        # orig_topic | target_topic | final behaviour
        #   UNMUTED     INHERIT         UNMUTED
        #   UNMUTED     UNMUTED         UNMUTED
        #   UNMUTED     MUTED           UNMUTED
        test_user_topic_state_for_messages_deleted_from_target_topic(
            orig_topic="Topic4",
            target_topic="Topic4 edited",
            original_topic_state=UserTopic.VisibilityPolicy.UNMUTED,
        )

    def test_topic_edit_history_saved_in_all_message(self) -> None:
        self.login("hamlet")
        id1 = self.send_stream_message(self.example_user("hamlet"), "Denmark", topic_name="topic1")
        id2 = self.send_stream_message(self.example_user("iago"), "Denmark", topic_name="topic1")
        id3 = self.send_stream_message(self.example_user("iago"), "Verona", topic_name="topic1")
        id4 = self.send_stream_message(self.example_user("hamlet"), "Denmark", topic_name="topic2")
        id5 = self.send_stream_message(self.example_user("iago"), "Denmark", topic_name="topic1")

        def verify_edit_history(new_topic_name: str, len_edit_history: int) -> None:
            for msg_id in [id1, id2, id5]:
                msg = Message.objects.get(id=msg_id)

                self.assertEqual(
                    new_topic_name,
                    msg.topic_name(),
                )
                # Since edit history is being generated by do_update_message,
                # it's contents can vary over time; So, to keep this test
                # future proof, we only verify it's length.
                self.assert_length(
                    orjson.loads(assert_is_not_none(msg.edit_history)), len_edit_history
                )

            for msg_id in [id3, id4]:
                msg = Message.objects.get(id=msg_id)
                self.assertEqual(msg.edit_history, None)

        new_topic_name = "edited"
        result = self.client_patch(
            f"/json/messages/{id1}",
            {
                "topic": new_topic_name,
                "propagate_mode": "change_later",
            },
        )

        self.assert_json_success(result)
        verify_edit_history(new_topic_name, 1)

        new_topic_name = "edited2"
        result = self.client_patch(
            f"/json/messages/{id1}",
            {
                "topic": new_topic_name,
                "propagate_mode": "change_later",
            },
        )

        self.assert_json_success(result)
        verify_edit_history(new_topic_name, 2)

    def test_topic_and_content_edit(self) -> None:
        self.login("hamlet")
        id1 = self.send_stream_message(self.example_user("hamlet"), "Denmark", "message 1", "topic")
        id2 = self.send_stream_message(self.example_user("iago"), "Denmark", "message 2", "topic")
        id3 = self.send_stream_message(self.example_user("hamlet"), "Denmark", "message 3", "topic")

        new_topic_name = "edited"
        result = self.client_patch(
            "/json/messages/" + str(id1),
            {
                "topic": new_topic_name,
                "propagate_mode": "change_later",
                "content": "edited message",
            },
        )

        self.assert_json_success(result)

        # Content change of only id1 should come in edit history
        # and topic change should be present in all the messages.
        msg1 = Message.objects.get(id=id1)
        msg2 = Message.objects.get(id=id2)
        msg3 = Message.objects.get(id=id3)

        msg1_edit_history = orjson.loads(assert_is_not_none(msg1.edit_history))
        self.assertTrue("prev_content" in msg1_edit_history[0])

        for msg in [msg2, msg3]:
            self.assertFalse(
                "prev_content" in orjson.loads(assert_is_not_none(msg.edit_history))[0]
            )

        for msg in [msg1, msg2, msg3]:
            self.assertEqual(
                new_topic_name,
                msg.topic_name(),
            )
            self.assert_length(orjson.loads(assert_is_not_none(msg.edit_history)), 1)

    def test_propagate_topic_forward(self) -> None:
        self.login("hamlet")
        id1 = self.send_stream_message(self.example_user("hamlet"), "Denmark", topic_name="topic1")
        id2 = self.send_stream_message(self.example_user("iago"), "Denmark", topic_name="topic1")
        id3 = self.send_stream_message(self.example_user("iago"), "Verona", topic_name="topic1")
        id4 = self.send_stream_message(self.example_user("hamlet"), "Denmark", topic_name="topic2")
        id5 = self.send_stream_message(self.example_user("iago"), "Denmark", topic_name="topic1")

        result = self.client_patch(
            f"/json/messages/{id1}",
            {
                "topic": "edited",
                "propagate_mode": "change_later",
            },
        )
        self.assert_json_success(result)

        self.check_topic(id1, topic_name="edited")
        self.check_topic(id2, topic_name="edited")
        self.check_topic(id3, topic_name="topic1")
        self.check_topic(id4, topic_name="topic2")
        self.check_topic(id5, topic_name="edited")

    def test_propagate_all_topics(self) -> None:
        self.login("hamlet")
        id1 = self.send_stream_message(self.example_user("hamlet"), "Denmark", topic_name="topic1")
        id2 = self.send_stream_message(self.example_user("hamlet"), "Denmark", topic_name="topic1")
        id3 = self.send_stream_message(self.example_user("iago"), "Verona", topic_name="topic1")
        id4 = self.send_stream_message(self.example_user("hamlet"), "Denmark", topic_name="topic2")
        id5 = self.send_stream_message(self.example_user("iago"), "Denmark", topic_name="topic1")
        id6 = self.send_stream_message(self.example_user("iago"), "Denmark", topic_name="topic3")

        result = self.client_patch(
            f"/json/messages/{id2}",
            {
                "topic": "edited",
                "propagate_mode": "change_all",
            },
        )
        self.assert_json_success(result)

        self.check_topic(id1, topic_name="edited")
        self.check_topic(id2, topic_name="edited")
        self.check_topic(id3, topic_name="topic1")
        self.check_topic(id4, topic_name="topic2")
        self.check_topic(id5, topic_name="edited")
        self.check_topic(id6, topic_name="topic3")

    def test_propagate_all_topics_with_different_uppercase_letters(self) -> None:
        self.login("hamlet")
        id1 = self.send_stream_message(self.example_user("hamlet"), "Denmark", topic_name="topic1")
        id2 = self.send_stream_message(self.example_user("hamlet"), "Denmark", topic_name="Topic1")
        id3 = self.send_stream_message(self.example_user("iago"), "Verona", topic_name="topiC1")
        id4 = self.send_stream_message(self.example_user("iago"), "Denmark", topic_name="toPic1")

        result = self.client_patch(
            f"/json/messages/{id2}",
            {
                "topic": "edited",
                "propagate_mode": "change_all",
            },
        )
        self.assert_json_success(result)

        self.check_topic(id1, topic_name="edited")
        self.check_topic(id2, topic_name="edited")
        self.check_topic(id3, topic_name="topiC1")
        self.check_topic(id4, topic_name="edited")

    def test_change_all_propagate_mode_for_moving_from_stream_with_restricted_history(self) -> None:
        self.make_stream("privatestream", invite_only=True, history_public_to_subscribers=False)
        iago = self.example_user("iago")
        cordelia = self.example_user("cordelia")
        self.subscribe(iago, "privatestream")
        self.subscribe(cordelia, "privatestream")
        id1 = self.send_stream_message(iago, "privatestream", topic_name="topic1")
        id2 = self.send_stream_message(iago, "privatestream", topic_name="topic1")

        hamlet = self.example_user("hamlet")
        self.subscribe(hamlet, "privatestream")
        id3 = self.send_stream_message(iago, "privatestream", topic_name="topic1")
        id4 = self.send_stream_message(hamlet, "privatestream", topic_name="topic1")
        self.send_stream_message(hamlet, "privatestream", topic_name="topic1")

        message = Message.objects.get(id=id1)
        message.date_sent = message.date_sent - timedelta(days=10)
        message.save()

        message = Message.objects.get(id=id2)
        message.date_sent = message.date_sent - timedelta(days=9)
        message.save()

        message = Message.objects.get(id=id3)
        message.date_sent = message.date_sent - timedelta(days=8)
        message.save()

        message = Message.objects.get(id=id4)
        message.date_sent = message.date_sent - timedelta(days=6)
        message.save()

        self.login("hamlet")
        result = self.client_patch(
            f"/json/messages/{id4}",
            {
                "topic": "edited",
                "propagate_mode": "change_all",
                "send_notification_to_new_thread": "false",
            },
        )
        self.assert_json_error(
            result,
            "You only have permission to move the 2/3 most recent messages in this topic.",
        )

        self.login("cordelia")
        result = self.client_patch(
            f"/json/messages/{id4}",
            {
                "topic": "edited",
                "propagate_mode": "change_all",
                "send_notification_to_new_thread": "false",
            },
        )
        self.assert_json_error(
            result,
            "You only have permission to move the 2/5 most recent messages in this topic.",
        )

    def test_notify_new_topic(self) -> None:
        user_profile = self.example_user("iago")
        self.login("iago")
        stream = self.make_stream("public stream")
        self.subscribe(user_profile, stream.name)
        msg_id = self.send_stream_message(
            user_profile, stream.name, topic_name="test", content="First"
        )
        self.send_stream_message(user_profile, stream.name, topic_name="test", content="Second")
        self.send_stream_message(user_profile, stream.name, topic_name="test", content="third")

        result = self.client_patch(
            "/json/messages/" + str(msg_id),
            {
                "topic": "edited",
                "propagate_mode": "change_all",
                "send_notification_to_old_thread": "false",
                "send_notification_to_new_thread": "true",
            },
        )

        self.assert_json_success(result)

        messages = get_topic_messages(user_profile, stream, "test")
        self.assert_length(messages, 0)

        messages = get_topic_messages(user_profile, stream, "edited")
        self.assert_length(messages, 4)
        self.assertEqual(
            messages[3].content,
            f"This topic was moved here from #**public stream>test** by @_**Iago|{user_profile.id}**.",
        )

    def test_notify_old_topic(self) -> None:
        user_profile = self.example_user("iago")
        self.login("iago")
        stream = self.make_stream("public stream")
        self.subscribe(user_profile, stream.name)
        msg_id = self.send_stream_message(
            user_profile, stream.name, topic_name="test", content="First"
        )
        self.send_stream_message(user_profile, stream.name, topic_name="test", content="Second")
        self.send_stream_message(user_profile, stream.name, topic_name="test", content="third")

        result = self.client_patch(
            "/json/messages/" + str(msg_id),
            {
                "topic": "edited",
                "propagate_mode": "change_all",
                "send_notification_to_old_thread": "true",
                "send_notification_to_new_thread": "false",
            },
        )

        self.assert_json_success(result)

        messages = get_topic_messages(user_profile, stream, "test")
        self.assert_length(messages, 1)
        self.assertEqual(
            messages[0].content,
            f"This topic was moved to #**public stream>edited** by @_**Iago|{user_profile.id}**.",
        )

        messages = get_topic_messages(user_profile, stream, "edited")
        self.assert_length(messages, 3)

    def test_notify_both_topics(self) -> None:
        user_profile = self.example_user("iago")
        self.login("iago")
        stream = self.make_stream("public stream")
        self.subscribe(user_profile, stream.name)
        msg_id = self.send_stream_message(
            user_profile, stream.name, topic_name="test", content="First"
        )
        self.send_stream_message(user_profile, stream.name, topic_name="test", content="Second")
        self.send_stream_message(user_profile, stream.name, topic_name="test", content="third")

        result = self.client_patch(
            "/json/messages/" + str(msg_id),
            {
                "topic": "edited",
                "propagate_mode": "change_all",
                "send_notification_to_old_thread": "true",
                "send_notification_to_new_thread": "true",
            },
        )

        self.assert_json_success(result)

        messages = get_topic_messages(user_profile, stream, "test")
        self.assert_length(messages, 1)
        self.assertEqual(
            messages[0].content,
            f"This topic was moved to #**public stream>edited** by @_**Iago|{user_profile.id}**.",
        )

        messages = get_topic_messages(user_profile, stream, "edited")
        self.assert_length(messages, 4)
        self.assertEqual(
            messages[3].content,
            f"This topic was moved here from #**public stream>test** by @_**Iago|{user_profile.id}**.",
        )

    def test_notify_no_topic(self) -> None:
        user_profile = self.example_user("iago")
        self.login("iago")
        stream = self.make_stream("public stream")
        self.subscribe(user_profile, stream.name)
        msg_id = self.send_stream_message(
            user_profile, stream.name, topic_name="test", content="First"
        )
        self.send_stream_message(user_profile, stream.name, topic_name="test", content="Second")
        self.send_stream_message(user_profile, stream.name, topic_name="test", content="third")

        result = self.client_patch(
            "/json/messages/" + str(msg_id),
            {
                "topic": "edited",
                "propagate_mode": "change_all",
                "send_notification_to_old_thread": "false",
                "send_notification_to_new_thread": "false",
            },
        )

        self.assert_json_success(result)

        messages = get_topic_messages(user_profile, stream, "test")
        self.assert_length(messages, 0)

        messages = get_topic_messages(user_profile, stream, "edited")
        self.assert_length(messages, 3)

    def test_notify_old_topics_after_message_move(self) -> None:
        user_profile = self.example_user("iago")
        self.login("iago")
        stream = self.make_stream("public stream")
        self.subscribe(user_profile, stream.name)
        msg_id = self.send_stream_message(
            user_profile, stream.name, topic_name="test", content="First"
        )
        self.send_stream_message(user_profile, stream.name, topic_name="test", content="Second")
        self.send_stream_message(user_profile, stream.name, topic_name="test", content="Third")

        result = self.client_patch(
            "/json/messages/" + str(msg_id),
            {
                "topic": "edited",
                "propagate_mode": "change_one",
                "send_notification_to_old_thread": "true",
                "send_notification_to_new_thread": "false",
            },
        )

        self.assert_json_success(result)

        messages = get_topic_messages(user_profile, stream, "test")
        self.assert_length(messages, 3)
        self.assertEqual(messages[0].content, "Second")
        self.assertEqual(messages[1].content, "Third")
        self.assertEqual(
            messages[2].content,
            f"A message was moved from this topic to #**public stream>edited** by @_**Iago|{user_profile.id}**.",
        )

        messages = get_topic_messages(user_profile, stream, "edited")
        self.assert_length(messages, 1)
        self.assertEqual(messages[0].content, "First")

    def test_notify_no_topic_after_message_move(self) -> None:
        user_profile = self.example_user("iago")
        self.login("iago")
        stream = self.make_stream("public stream")
        self.subscribe(user_profile, stream.name)
        msg_id = self.send_stream_message(
            user_profile, stream.name, topic_name="test", content="First"
        )
        self.send_stream_message(user_profile, stream.name, topic_name="test", content="Second")
        self.send_stream_message(user_profile, stream.name, topic_name="test", content="Third")

        result = self.client_patch(
            "/json/messages/" + str(msg_id),
            {
                "topic": "edited",
                "propagate_mode": "change_one",
                "send_notification_to_old_thread": "false",
                "send_notification_to_new_thread": "false",
            },
        )

        self.assert_json_success(result)

        messages = get_topic_messages(user_profile, stream, "test")
        self.assert_length(messages, 2)
        self.assertEqual(messages[0].content, "Second")
        self.assertEqual(messages[1].content, "Third")

        messages = get_topic_messages(user_profile, stream, "edited")
        self.assert_length(messages, 1)
        self.assertEqual(messages[0].content, "First")

    def test_notify_resolve_topic_long_name(self) -> None:
        user_profile = self.example_user("hamlet")
        self.login("hamlet")
        stream = self.make_stream("public stream")
        self.subscribe(user_profile, stream.name)
        # Marking topics with a long name as resolved causes the new topic name to be truncated.
        # We want to avoid having code paths believing that the topic is "moved" instead of
        # "resolved" in this edge case.
        topic_name = "a" * MAX_TOPIC_NAME_LENGTH
        msg_id = self.send_stream_message(
            user_profile, stream.name, topic_name=topic_name, content="First"
        )

        resolved_topic = RESOLVED_TOPIC_PREFIX + topic_name
        result = self.client_patch(
            "/json/messages/" + str(msg_id),
            {
                "topic": resolved_topic,
                "propagate_mode": "change_all",
            },
        )
        self.assert_json_success(result)

        new_topic_name = truncate_topic(resolved_topic)
        messages = get_topic_messages(user_profile, stream, new_topic_name)
        self.assert_length(messages, 2)
        self.assertEqual(messages[0].content, "First")
        self.assertEqual(
            messages[1].content,
            f"@_**{user_profile.full_name}|{user_profile.id}** has marked this topic as resolved.",
        )

        # Note that we are removing the prefix from the already truncated topic,
        # so unresolved_topic_name will not be the same as the original topic_name
        unresolved_topic_name = new_topic_name.replace(RESOLVED_TOPIC_PREFIX, "")
        result = self.client_patch(
            "/json/messages/" + str(msg_id),
            {
                "topic": unresolved_topic_name,
                "propagate_mode": "change_all",
            },
        )
        self.assert_json_success(result)

        messages = get_topic_messages(user_profile, stream, unresolved_topic_name)
        self.assert_length(messages, 3)
        self.assertEqual(
            messages[2].content,
            f"@_**{user_profile.full_name}|{user_profile.id}** has marked this topic as unresolved.",
        )

    def test_notify_resolve_and_move_topic(self) -> None:
        user_profile = self.example_user("hamlet")
        self.login("hamlet")
        stream = self.make_stream("public stream")
        topic_name = "test"
        self.subscribe(user_profile, stream.name)

        # Resolve a topic normally first
        msg_id = self.send_stream_message(user_profile, stream.name, "foo", topic_name=topic_name)
        resolved_topic_name = RESOLVED_TOPIC_PREFIX + topic_name
        result = self.client_patch(
            "/json/messages/" + str(msg_id),
            {
                "topic": resolved_topic_name,
                "propagate_mode": "change_all",
            },
        )
        self.assert_json_success(result)

        messages = get_topic_messages(user_profile, stream, resolved_topic_name)
        self.assert_length(messages, 2)
        self.assertEqual(
            messages[1].content,
            f"@_**{user_profile.full_name}|{user_profile.id}** has marked this topic as resolved.",
        )

        # Test unresolving a topic while moving it (✔ test -> bar)
        new_topic_name = "bar"
        result = self.client_patch(
            "/json/messages/" + str(msg_id),
            {
                "topic": new_topic_name,
                "propagate_mode": "change_all",
            },
        )
        self.assert_json_success(result)
        messages = get_topic_messages(user_profile, stream, new_topic_name)
        self.assert_length(messages, 4)
        self.assertEqual(
            messages[2].content,
            f"@_**{user_profile.full_name}|{user_profile.id}** has marked this topic as unresolved.",
        )
        self.assertEqual(
            messages[3].content,
            f"This topic was moved here from #**public stream>✔ test** by @_**{user_profile.full_name}|{user_profile.id}**.",
        )

        # Now test moving the topic while also resolving it (bar -> ✔ baz)
        new_resolved_topic_name = RESOLVED_TOPIC_PREFIX + "baz"
        result = self.client_patch(
            "/json/messages/" + str(msg_id),
            {
                "topic": new_resolved_topic_name,
                "propagate_mode": "change_all",
            },
        )
        self.assert_json_success(result)
        messages = get_topic_messages(user_profile, stream, new_resolved_topic_name)
        self.assert_length(messages, 6)
        self.assertEqual(
            messages[4].content,
            f"@_**{user_profile.full_name}|{user_profile.id}** has marked this topic as resolved.",
        )
        self.assertEqual(
            messages[5].content,
            f"This topic was moved here from #**public stream>{new_topic_name}** by @_**{user_profile.full_name}|{user_profile.id}**.",
        )

    def test_mark_topic_as_resolved(self) -> None:
        self.login("iago")
        admin_user = self.example_user("iago")
        hamlet = self.example_user("hamlet")
        cordelia = self.example_user("cordelia")
        aaron = self.example_user("aaron")

        # Set the user's translation language to German to test that
        # it is overridden by the realm's default language.
        admin_user.default_language = "de"
        admin_user.save()
        stream = self.make_stream("new")
        self.subscribe(admin_user, stream.name)
        self.subscribe(hamlet, stream.name)
        self.subscribe(cordelia, stream.name)
        self.subscribe(aaron, stream.name)

        original_topic_name = "topic 1"
        id1 = self.send_stream_message(hamlet, "new", topic_name=original_topic_name)
        id2 = self.send_stream_message(admin_user, "new", topic_name=original_topic_name)

        msg1 = Message.objects.get(id=id1)
        do_add_reaction(aaron, msg1, "tada", "1f389", "unicode_emoji")

        # Check that we don't incorrectly send "unresolve topic"
        # notifications when asking the preserve the current topic.
        result = self.client_patch(
            "/json/messages/" + str(id1),
            {
                "topic": original_topic_name,
                "propagate_mode": "change_all",
            },
        )
        self.assert_json_error(result, "Nothing to change")

        resolved_topic_name = RESOLVED_TOPIC_PREFIX + original_topic_name
        result = self.resolve_topic_containing_message(
            admin_user,
            id1,
            HTTP_ACCEPT_LANGUAGE="de",
        )

        self.assert_json_success(result)
        for msg_id in [id1, id2]:
            msg = Message.objects.get(id=msg_id)
            self.assertEqual(
                resolved_topic_name,
                msg.topic_name(),
            )

        messages = get_topic_messages(admin_user, stream, resolved_topic_name)
        self.assert_length(messages, 3)
        self.assertEqual(
            messages[2].content,
            f"@_**Iago|{admin_user.id}** has marked this topic as resolved.",
        )

        # Check topic resolved notification message is only unread for participants.
        assert (
            UserMessage.objects.filter(
                user_profile__in=[admin_user, hamlet, aaron], message__id=messages[2].id
            )
            .extra(where=[UserMessage.where_unread()])
            .count()
            == 3
        )

        assert (
            not UserMessage.objects.filter(user_profile=cordelia, message__id=messages[2].id)
            .extra(where=[UserMessage.where_unread()])
            .exists()
        )

        # Now move to a weird state and confirm we get the normal topic moved message.
        weird_topic_name = "✔ ✔✔" + original_topic_name
        result = self.client_patch(
            "/json/messages/" + str(id1),
            {
                "topic": weird_topic_name,
                "propagate_mode": "change_all",
            },
        )

        self.assert_json_success(result)
        for msg_id in [id1, id2]:
            msg = Message.objects.get(id=msg_id)
            self.assertEqual(
                weird_topic_name,
                msg.topic_name(),
            )

        messages = get_topic_messages(admin_user, stream, weird_topic_name)
        self.assert_length(messages, 4)
        self.assertEqual(
            messages[2].content,
            f"@_**Iago|{admin_user.id}** has marked this topic as resolved.",
        )
        self.assertEqual(
            messages[3].content,
            f"This topic was moved here from #**new>✔ topic 1** by @_**Iago|{admin_user.id}**.",
        )

        unresolved_topic_name = original_topic_name
        result = self.client_patch(
            "/json/messages/" + str(id1),
            {
                "topic": unresolved_topic_name,
                "propagate_mode": "change_all",
            },
        )

        self.assert_json_success(result)
        for msg_id in [id1, id2]:
            msg = Message.objects.get(id=msg_id)
            self.assertEqual(
                unresolved_topic_name,
                msg.topic_name(),
            )

        messages = get_topic_messages(admin_user, stream, unresolved_topic_name)
        self.assert_length(messages, 5)
        self.assertEqual(
            messages[2].content, f"@_**Iago|{admin_user.id}** has marked this topic as resolved."
        )
        self.assertEqual(
            messages[4].content,
            f"@_**Iago|{admin_user.id}** has marked this topic as unresolved.",
        )

        # Check topic unresolved notification message is only unread for participants.
        assert (
            UserMessage.objects.filter(
                user_profile__in=[admin_user, hamlet, aaron], message__id=messages[4].id
            )
            .extra(where=[UserMessage.where_unread()])
            .count()
            == 3
        )

        assert (
            not UserMessage.objects.filter(user_profile=cordelia, message__id=messages[4].id)
            .extra(where=[UserMessage.where_unread()])
            .exists()
        )