def test_online_to_idle(self):
        wheel_timer = Mock()
        user_id = "@foo:bar"
        now = 5000000

        prev_state = UserPresenceState.default(user_id)
        prev_state = prev_state.copy_and_replace(
            state=PresenceState.ONLINE,
            last_active_ts=now,
            currently_active=True,
        )

        new_state = prev_state.copy_and_replace(
            state=PresenceState.UNAVAILABLE,
        )

        state, persist_and_notify, federation_ping = handle_update(
            prev_state, new_state, is_mine=True, wheel_timer=wheel_timer, now=now
        )

        self.assertTrue(persist_and_notify)
        self.assertEquals(new_state.state, state.state)
        self.assertEquals(state.last_federation_update_ts, now)
        self.assertEquals(new_state.state, state.state)
        self.assertEquals(new_state.status_msg, state.status_msg)

        self.assertEquals(wheel_timer.insert.call_count, 1)
        wheel_timer.insert.assert_has_calls([
            call(
                now=now,
                obj=user_id,
                then=new_state.last_user_sync_ts + SYNC_ONLINE_TIMEOUT
            )
        ], any_order=True)

    def test_remote_ping_timer(self):
        wheel_timer = Mock()
        user_id = "@foo:bar"
        now = 5000000

        prev_state = UserPresenceState.default(user_id)
        prev_state = prev_state.copy_and_replace(
            state=PresenceState.ONLINE,
            last_active_ts=now,
        )

        new_state = prev_state.copy_and_replace(
            state=PresenceState.ONLINE,
        )

        state, persist_and_notify, federation_ping = handle_update(
            prev_state, new_state, is_mine=False, wheel_timer=wheel_timer, now=now
        )

        self.assertFalse(persist_and_notify)
        self.assertFalse(federation_ping)
        self.assertFalse(state.currently_active)
        self.assertEquals(new_state.state, state.state)
        self.assertEquals(new_state.status_msg, state.status_msg)

        self.assertEquals(wheel_timer.insert.call_count, 1)
        wheel_timer.insert.assert_has_calls([
            call(
                now=now,
                obj=user_id,
                then=new_state.last_federation_update_ts + FEDERATION_TIMEOUT
            ),
        ], any_order=True)

    def test_online_to_offline(self):
        wheel_timer = Mock()
        user_id = "@foo:bar"
        now = 5000000

        prev_state = UserPresenceState.default(user_id)
        prev_state = prev_state.copy_and_replace(
            state=PresenceState.ONLINE,
            last_active_ts=now,
            currently_active=True,
        )

        new_state = prev_state.copy_and_replace(
            state=PresenceState.OFFLINE,
        )

        state, persist_and_notify, federation_ping = handle_update(
            prev_state, new_state, is_mine=True, wheel_timer=wheel_timer, now=now
        )

        self.assertTrue(persist_and_notify)
        self.assertEquals(new_state.state, state.state)
        self.assertEquals(state.last_federation_update_ts, now)

        self.assertEquals(wheel_timer.insert.call_count, 0)

    def current_state_for_users(self, user_ids):
        """Get the current presence state for multiple users.

        Returns:
            dict: `user_id` -> `UserPresenceState`
        """
        states = {
            user_id: self.user_to_current_state.get(user_id, None)
            for user_id in user_ids
        }

        missing = [user_id for user_id, state in states.items() if not state]
        if missing:
            # There are things not in our in memory cache. Lets pull them out of
            # the database.
            res = yield self.store.get_presence_for_users(missing)
            states.update({state.user_id: state for state in res})

            missing = [user_id for user_id, state in states.items() if not state]
            if missing:
                new = {
                    user_id: UserPresenceState.default(user_id)
                    for user_id in missing
                }
                states.update(new)
                self.user_to_current_state.update(new)

        defer.returnValue(states)

    def get_states(self, target_user_ids, as_event=False):
        """Get the presence state for users.

        Args:
            target_user_ids (list)
            as_event (bool): Whether to format it as a client event or not.

        Returns:
            list
        """

        updates = yield self.current_state_for_users(target_user_ids)
        updates = updates.values()

        for user_id in set(target_user_ids) - set(u.user_id for u in updates):
            updates.append(UserPresenceState.default(user_id))

        now = self.clock.time_msec()
        if as_event:
            defer.returnValue([
                {
                    "type": "m.presence",
                    "content": _format_user_presence_state(state, now),
                }
                for state in updates
            ])
        else:
            defer.returnValue([
                _format_user_presence_state(state, now) for state in updates
            ])

    def _handle_timeouts(self):
        """Checks the presence of users that have timed out and updates as
        appropriate.
        """
        now = self.clock.time_msec()

        with Measure(self.clock, "presence_handle_timeouts"):
            # Fetch the list of users that *may* have timed out. Things may have
            # changed since the timeout was set, so we won't necessarily have to
            # take any action.
            users_to_check = self.wheel_timer.fetch(now)

            states = [
                self.user_to_current_state.get(
                    user_id, UserPresenceState.default(user_id)
                )
                for user_id in set(users_to_check)
            ]

            timers_fired_counter.inc_by(len(states))

            changes = handle_timeouts(
                states,
                is_mine_fn=self.hs.is_mine_id,
                user_to_num_current_syncs=self.user_to_num_current_syncs,
                now=now,
            )

        preserve_fn(self._update_states)(changes)

    def test_no_timeout(self):
        user_id = "@foo:bar"
        now = 5000000

        state = UserPresenceState.default(user_id)
        state = state.copy_and_replace(
            state=PresenceState.ONLINE,
            last_active_ts=now,
            last_user_sync_ts=now,
            last_federation_update_ts=now,
        )

        new_state = handle_timeout(state, is_mine=True, syncing_user_ids=set(), now=now)

        self.assertIsNone(new_state)

    def test_sync_timeout(self):
        user_id = "@foo:bar"
        now = 5000000

        state = UserPresenceState.default(user_id)
        state = state.copy_and_replace(
            state=PresenceState.ONLINE,
            last_active_ts=0,
            last_user_sync_ts=now - SYNC_ONLINE_TIMEOUT - 1,
        )

        new_state = handle_timeout(state, is_mine=True, syncing_user_ids=set(), now=now)

        self.assertIsNotNone(new_state)
        self.assertEquals(new_state.state, PresenceState.OFFLINE)

    def _handle_timeouts(self):
        """Checks the presence of users that have timed out and updates as
        appropriate.
        """
        logger.info("Handling presence timeouts")
        now = self.clock.time_msec()

        try:
            with Measure(self.clock, "presence_handle_timeouts"):
                # Fetch the list of users that *may* have timed out. Things may have
                # changed since the timeout was set, so we won't necessarily have to
                # take any action.
                users_to_check = set(self.wheel_timer.fetch(now))

                # Check whether the lists of syncing processes from an external
                # process have expired.
                expired_process_ids = [
                    process_id for process_id, last_update
                    in self.external_process_last_updated_ms.items()
                    if now - last_update > EXTERNAL_PROCESS_EXPIRY
                ]
                for process_id in expired_process_ids:
                    users_to_check.update(
                        self.external_process_last_updated_ms.pop(process_id, ())
                    )
                    self.external_process_last_update.pop(process_id)

                states = [
                    self.user_to_current_state.get(
                        user_id, UserPresenceState.default(user_id)
                    )
                    for user_id in users_to_check
                ]

                timers_fired_counter.inc_by(len(states))

                changes = handle_timeouts(
                    states,
                    is_mine_fn=self.is_mine_id,
                    syncing_user_ids=self.get_currently_syncing_users(),
                    now=now,
                )

            preserve_fn(self._update_states)(changes)
        except:
            logger.exception("Exception in _handle_timeouts loop")

    def test_idle_timer(self):
        user_id = "@foo:bar"
        now = 5000000

        state = UserPresenceState.default(user_id)
        state = state.copy_and_replace(
            state=PresenceState.ONLINE,
            last_active_ts=now - IDLE_TIMER - 1,
            last_user_sync_ts=now,
        )

        new_state = handle_timeout(
            state, is_mine=True, user_to_num_current_syncs={}, now=now
        )

        self.assertIsNotNone(new_state)
        self.assertEquals(new_state.state, PresenceState.UNAVAILABLE)

    def test_last_active(self):
        user_id = "@foo:bar"
        now = 5000000

        state = UserPresenceState.default(user_id)
        state = state.copy_and_replace(
            state=PresenceState.ONLINE,
            last_active_ts=now - LAST_ACTIVE_GRANULARITY - 1,
            last_user_sync_ts=now,
            last_federation_update_ts=now,
        )

        new_state = handle_timeout(
            state, is_mine=True, user_to_num_current_syncs={}, now=now
        )

        self.assertIsNotNone(new_state)
        self.assertEquals(state, new_state)

    def test_federation_timeout(self):
        user_id = "@foo:bar"
        now = 5000000

        state = UserPresenceState.default(user_id)
        state = state.copy_and_replace(
            state=PresenceState.ONLINE,
            last_active_ts=now,
            last_user_sync_ts=now,
            last_federation_update_ts=now - FEDERATION_TIMEOUT - 1,
        )

        new_state = handle_timeout(
            state, is_mine=False, user_to_num_current_syncs={}, now=now
        )

        self.assertIsNotNone(new_state)
        self.assertEquals(new_state.state, PresenceState.OFFLINE)

    def test_online_to_online_last_active_noop(self):
        wheel_timer = Mock()
        user_id = "@foo:bar"
        now = 5000000

        prev_state = UserPresenceState.default(user_id)
        prev_state = prev_state.copy_and_replace(
            state=PresenceState.ONLINE,
            last_active_ts=now - LAST_ACTIVE_GRANULARITY - 10,
            currently_active=True,
        )

        new_state = prev_state.copy_and_replace(
            state=PresenceState.ONLINE, last_active_ts=now
        )

        state, persist_and_notify, federation_ping = handle_update(
            prev_state, new_state, is_mine=True, wheel_timer=wheel_timer, now=now
        )

        self.assertFalse(persist_and_notify)
        self.assertTrue(federation_ping)
        self.assertTrue(state.currently_active)
        self.assertEquals(new_state.state, state.state)
        self.assertEquals(new_state.status_msg, state.status_msg)
        self.assertEquals(state.last_federation_update_ts, now)

        self.assertEquals(wheel_timer.insert.call_count, 3)
        wheel_timer.insert.assert_has_calls(
            [
                call(now=now, obj=user_id, then=new_state.last_active_ts + IDLE_TIMER),
                call(
                    now=now,
                    obj=user_id,
                    then=new_state.last_user_sync_ts + SYNC_ONLINE_TIMEOUT,
                ),
                call(
                    now=now,
                    obj=user_id,
                    then=new_state.last_active_ts + LAST_ACTIVE_GRANULARITY,
                ),
            ],
            any_order=True,
        )

 def from_data(data):
     return PresenceRow(
         state=UserPresenceState.from_dict(data)
     )

    def _update_states(self, new_states):
        """Updates presence of users. Sets the appropriate timeouts. Pokes
        the notifier and federation if and only if the changed presence state
        should be sent to clients/servers.
        """
        now = self.clock.time_msec()

        with Measure(self.clock, "presence_update_states"):

            # NOTE: We purposefully don't yield between now and when we've
            # calculated what we want to do with the new states, to avoid races.

            to_notify = {}  # Changes we want to notify everyone about
            to_federation_ping = {}  # These need sending keep-alives

            for new_state in new_states:
                user_id = new_state.user_id

                # Its fine to not hit the database here, as the only thing not in
                # the current state cache are OFFLINE states, where the only field
                # of interest is last_active which is safe enough to assume is 0
                # here.
                prev_state = self.user_to_current_state.get(
                    user_id, UserPresenceState.default(user_id)
                )

                new_state, should_notify, should_ping = handle_update(
                    prev_state, new_state,
                    is_mine=self.hs.is_mine_id(user_id),
                    wheel_timer=self.wheel_timer,
                    now=now
                )

                self.user_to_current_state[user_id] = new_state

                if should_notify:
                    to_notify[user_id] = new_state
                elif should_ping:
                    to_federation_ping[user_id] = new_state

            # TODO: We should probably ensure there are no races hereafter

            presence_updates_counter.inc_by(len(new_states))

            if to_notify:
                notified_presence_counter.inc_by(len(to_notify))
                yield self._persist_and_notify(to_notify.values())

            self.unpersisted_users_changes |= set(s.user_id for s in new_states)
            self.unpersisted_users_changes -= set(to_notify.keys())

            to_federation_ping = {
                user_id: state for user_id, state in to_federation_ping.items()
                if user_id not in to_notify
            }
            if to_federation_ping:
                federation_presence_out_counter.inc_by(len(to_federation_ping))

                _, _, hosts_to_states = yield self._get_interested_parties(
                    to_federation_ping.values()
                )

                self._push_to_remotes(hosts_to_states)

 def from_data(data):
     return PresenceDestinationsRow(
         state=UserPresenceState.from_dict(data["state"]),
         destinations=data["dests"],
     )