MetaCrate/crates/libremetaverse-voice-vivox/src/gateway.rs

//! Native Vivox gateway using the bounded TCP control protocol.

use crate::*;
use base64::Engine as _;
use libremetaverse_types::compat::{EventHandler, Subscription};
use libremetaverse_types::{UUID, Vector3d};
use roxmltree::{Document, Node};
use std::any::Any;
use std::collections::HashMap;
use std::sync::{
    Arc, Mutex, Weak,
    atomic::{AtomicBool, AtomicU64, Ordering},
};

const MAX_XML_BYTES: usize = 1024 * 1024;

fn lock<T>(mutex: &Mutex<T>) -> std::sync::MutexGuard<'_, T> {
    mutex
        .lock()
        .unwrap_or_else(std::sync::PoisonError::into_inner)
}

#[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
enum EventKey {
    AccountLoginResponse,
    AccountLoginState,
    AuxAudioProperties,
    CaptureDevices,
    RenderDevices,
    ConnectorCreate,
    DaemonConnected,
    DaemonCouldntConnect,
    DaemonCouldntRun,
    DaemonDisconnected,
    DaemonExited,
    DaemonRunning,
    SessionAdded,
    SessionCreate,
    SessionCreateResponse,
    SessionGroupAdded,
    SessionMedia,
    SessionNew,
    ParticipantAdded,
    ParticipantProperties,
    ParticipantRemoved,
    ParticipantState,
    ParticipantUpdated,
    SessionRemove,
    SessionRemoved,
    SessionState,
    SessionUpdated,
    VoiceConnection,
    VoiceMicTest,
    VoiceResponse,
    RawControlLine,
}

type ErasedHandler = Arc<dyn Fn(&dyn Any) + Send + Sync>;

#[derive(Default)]
struct EventBus {
    next_id: AtomicU64,
    handlers: Arc<Mutex<HashMap<EventKey, HashMap<u64, ErasedHandler>>>>,
}

impl EventBus {
    fn subscribe<T>(&self, key: EventKey, handler: Option<EventHandler<T>>) -> Subscription
    where
        T: Any + Clone + Send + Sync + 'static,
    {
        let Some(handler) = handler else {
            return Subscription::detached();
        };
        let id = self.next_id.fetch_add(1, Ordering::Relaxed);
        let erased: ErasedHandler = Arc::new(move |value| {
            if let Some(value) = value.downcast_ref::<T>() {
                handler(value.clone());
            }
        });
        lock(&self.handlers)
            .entry(key)
            .or_default()
            .insert(id, erased);
        let handlers = Arc::downgrade(&self.handlers);
        Subscription::new(move || remove_handler(&handlers, key, id))
    }

    fn emit<T>(&self, key: EventKey, value: T)
    where
        T: Any + Send + Sync + 'static,
    {
        let handlers: Vec<_> = lock(&self.handlers)
            .get(&key)
            .into_iter()
            .flat_map(|handlers| handlers.values().cloned())
            .collect();
        for handler in handlers {
            handler(&value);
        }
    }
}

fn remove_handler(
    handlers: &Weak<Mutex<HashMap<EventKey, HashMap<u64, ErasedHandler>>>>,
    key: EventKey,
    id: u64,
) {
    let Some(handlers) = handlers.upgrade() else {
        return;
    };
    let mut handlers = lock(&handlers);
    if let Some(event) = handlers.get_mut(&key) {
        event.remove(&id);
        if event.is_empty() {
            handlers.remove(&key);
        }
    }
}

#[derive(Default)]
struct GatewayState {
    active: bool,
    current_capture_device: String,
    current_playback_device: String,
    daemon_connected: bool,
    daemon_running: bool,
    request_id: i32,
    testing: bool,
    connector_handle: String,
    account_handle: String,
    session_handle: String,
    sip_server: String,
    sessions: HashMap<String, VoiceSession>,
}

struct GatewayInner {
    _client: libremetaverse::GridClient,
    pipe: TCPPipe,
    state: Mutex<GatewayState>,
    events: EventBus,
    pipe_subscriptions: Mutex<Vec<Subscription>>,
    disposed: AtomicBool,
}

#[derive(Clone)]
pub struct VoiceGateway {
    inner: Arc<GatewayInner>,
}

macro_rules! event_subscription {
    ($name:ident, $key:ident, $type:ty) => {
        #[must_use]
        pub fn $name(&self, handler: Option<EventHandler<$type>>) -> Subscription {
            self.inner.events.subscribe(EventKey::$key, handler)
        }
    };
}

macro_rules! zero_callback_subscription {
    ($name:ident, $key:ident, $type:ty) => {
        #[must_use]
        pub fn $name(&self, handler: Option<$type>) -> Subscription {
            let handler = handler.map(|handler| {
                Arc::new(move |()| {
                    let _ = handler.invoke();
                }) as EventHandler<()>
            });
            self.inner.events.subscribe(EventKey::$key, handler)
        }
    };
}

impl VoiceGateway {
    pub fn new(c: libremetaverse::GridClient) -> Result<Self, Error> {
        let inner = Arc::new(GatewayInner {
            _client: c,
            pipe: TCPPipe::new()?,
            state: Mutex::new(GatewayState::default()),
            events: EventBus::default(),
            pipe_subscriptions: Mutex::new(Vec::new()),
            disposed: AtomicBool::new(false),
        });
        let weak = Arc::downgrade(&inner);
        let received =
            inner
                .pipe
                .subscribe_on_receive_line(Some(TCPPipeOnReceiveLineCallback::from_handler(
                    move |line| {
                        weak.upgrade()
                            .ok_or(Error::InvalidOperation)
                            .and_then(|inner| inner.handle_line(&line))
                    },
                )));
        let weak = Arc::downgrade(&inner);
        let disconnected = inner.pipe.subscribe_on_disconnected(Some(
            TCPPipeOnDisconnectedCallback::from_handler(move |_| {
                let inner = weak.upgrade().ok_or(Error::InvalidOperation)?;
                let mut state = lock(&inner.state);
                state.daemon_connected = false;
                drop(state);
                inner.events.emit(EventKey::DaemonDisconnected, ());
                Ok(())
            }),
        ));
        *lock(&inner.pipe_subscriptions) = vec![received, disconnected];
        Ok(Self { inner })
    }

    /// Feeds one already-framed control line through the same bounded parser
    /// used by the TCP reader. This is shared by the legacy manager facade.
    #[cfg(test)]
    pub(crate) fn process_control_line(&self, line: &str) -> Result<(), Error> {
        self.inner.handle_line(line)
    }

    pub(crate) fn subscribe_control_line(&self, handler: EventHandler<String>) -> Subscription {
        self.inner
            .events
            .subscribe(EventKey::RawControlLine, Some(handler))
    }

    event_subscription!(
        subscribe_on_account_login_response,
        AccountLoginResponse,
        VoiceGatewayVoiceAccountEventArgs
    );
    event_subscription!(
        subscribe_on_account_login_state_change_event,
        AccountLoginState,
        VoiceGatewayAccountLoginStateChangeEventArgs
    );
    event_subscription!(
        subscribe_on_aux_audio_properties_event,
        AuxAudioProperties,
        VoiceGatewayAudioPropertiesEventArgs
    );
    event_subscription!(
        subscribe_on_aux_get_capture_devices_response,
        CaptureDevices,
        VoiceGatewayVoiceDevicesEventArgs
    );
    event_subscription!(
        subscribe_on_aux_get_render_devices_response,
        RenderDevices,
        VoiceGatewayVoiceDevicesEventArgs
    );
    event_subscription!(
        subscribe_on_connector_create_response,
        ConnectorCreate,
        VoiceGatewayVoiceConnectorEventArgs
    );
    zero_callback_subscription!(
        subscribe_on_daemon_connected,
        DaemonConnected,
        VoiceGatewayDaemonConnectedCallback
    );
    zero_callback_subscription!(
        subscribe_on_daemon_couldnt_connect,
        DaemonCouldntConnect,
        VoiceGatewayDaemonCouldntConnectCallback
    );
    zero_callback_subscription!(
        subscribe_on_daemon_couldnt_run,
        DaemonCouldntRun,
        VoiceGatewayDaemonCouldntRunCallback
    );
    zero_callback_subscription!(
        subscribe_on_daemon_disconnected,
        DaemonDisconnected,
        VoiceGatewayDaemonDisconnectedCallback
    );
    zero_callback_subscription!(
        subscribe_on_daemon_exited,
        DaemonExited,
        VoiceGatewayDaemonExitedCallback
    );
    zero_callback_subscription!(
        subscribe_on_daemon_running,
        DaemonRunning,
        VoiceGatewayDaemonRunningCallback
    );
    event_subscription!(
        subscribe_on_session_added_event,
        SessionAdded,
        VoiceGatewaySessionAddedEventArgs
    );
    event_subscription!(subscribe_on_session_create, SessionCreate, ());
    event_subscription!(
        subscribe_on_session_create_response,
        SessionCreateResponse,
        VoiceGatewayVoiceSessionEventArgs
    );
    event_subscription!(
        subscribe_on_session_group_added_event,
        SessionGroupAdded,
        VoiceGatewaySessionGroupAddedEventArgs
    );
    event_subscription!(
        subscribe_on_session_media_event,
        SessionMedia,
        VoiceGatewaySessionMediaEventArgs
    );
    event_subscription!(
        subscribe_on_session_new_event,
        SessionNew,
        VoiceGatewayNewSessionEventArgs
    );
    event_subscription!(
        subscribe_on_session_participant_added_event,
        ParticipantAdded,
        VoiceGatewayParticipantAddedEventArgs
    );
    event_subscription!(
        subscribe_on_session_participant_properties_event,
        ParticipantProperties,
        VoiceGatewayParticipantPropertiesEventArgs
    );
    event_subscription!(
        subscribe_on_session_participant_removed_event,
        ParticipantRemoved,
        VoiceGatewayParticipantRemovedEventArgs
    );
    event_subscription!(
        subscribe_on_session_participant_state_change_event,
        ParticipantState,
        VoiceGatewayParticipantStateChangeEventArgs
    );
    event_subscription!(
        subscribe_on_session_participant_updated_event,
        ParticipantUpdated,
        VoiceGatewayParticipantUpdatedEventArgs
    );
    event_subscription!(subscribe_on_session_remove, SessionRemove, ());
    event_subscription!(
        subscribe_on_session_removed_event,
        SessionRemoved,
        VoiceGatewaySessionRemovedEventArgs
    );
    event_subscription!(
        subscribe_on_session_state_change_event,
        SessionState,
        VoiceGatewaySessionStateChangeEventArgs
    );
    event_subscription!(
        subscribe_on_session_updated_event,
        SessionUpdated,
        VoiceGatewaySessionUpdatedEventArgs
    );
    event_subscription!(
        subscribe_on_voice_response,
        VoiceResponse,
        VoiceGatewayVoiceResponseEventArgs
    );

    #[must_use]
    pub fn subscribe_on_voice_connection_change(
        &self,
        handler: Option<VoiceGatewayVoiceConnectionChangeCallback>,
    ) -> Subscription {
        let handler = handler.map(|handler| {
            Arc::new(move |state| {
                let _ = handler.invoke(state);
            }) as EventHandler<VoiceGatewayConnectionState>
        });
        self.inner
            .events
            .subscribe(EventKey::VoiceConnection, handler)
    }

    #[must_use]
    pub fn subscribe_on_voice_mic_test(
        &self,
        handler: Option<VoiceGatewayVoiceMicTestCallback>,
    ) -> Subscription {
        let handler = handler.map(|handler| {
            Arc::new(move |level| {
                let _ = handler.invoke(level);
            }) as EventHandler<f32>
        });
        self.inner.events.subscribe(EventKey::VoiceMicTest, handler)
    }

    pub fn connect_to_daemon(&self, address: String, port: i32) -> Result<bool, Error> {
        self.ensure_active_object()?;
        let connected = self.inner.pipe.connect(address, port)?.is_none();
        {
            let mut state = lock(&self.inner.state);
            state.daemon_connected = connected;
            state.daemon_running = connected;
        }
        if connected {
            self.inner.events.emit(EventKey::DaemonRunning, ());
            self.inner.events.emit(EventKey::DaemonConnected, ());
            self.inner.events.emit(
                EventKey::VoiceConnection,
                VoiceGatewayConnectionState::DaemonConnected,
            );
        } else {
            self.inner.events.emit(EventKey::DaemonCouldntConnect, ());
        }
        Ok(connected)
    }

    pub fn start(&self) -> Result<(), Error> {
        self.ensure_active_object()?;
        lock(&self.inner.state).active = true;
        Ok(())
    }

    pub fn stop(&self) -> Result<(), Error> {
        if self.inner.disposed.load(Ordering::Acquire) {
            return Ok(());
        }
        let (session, account, connector, connected) = {
            let state = lock(&self.inner.state);
            (
                state.session_handle.clone(),
                state.account_handle.clone(),
                state.connector_handle.clone(),
                state.daemon_connected,
            )
        };
        if connected {
            if !session.is_empty() {
                let _ = self.session_terminate(session);
            }
            if !account.is_empty() {
                let _ = self.account_logout(account);
            }
            if !connector.is_empty() {
                let _ = self.connector_initiate_shutdown(connector);
            }
        }
        self.inner.pipe.disconnect()?;
        let mut state = lock(&self.inner.state);
        state.active = false;
        state.daemon_connected = false;
        state.daemon_running = false;
        state.connector_handle.clear();
        state.account_handle.clear();
        state.session_handle.clear();
        Ok(())
    }

    pub fn dispose(&self) -> Result<(), Error> {
        if self.inner.disposed.swap(true, Ordering::AcqRel) {
            return Ok(());
        }
        self.stop_after_dispose()
    }

    fn stop_after_dispose(&self) -> Result<(), Error> {
        self.inner.pipe.disconnect()?;
        let mut state = lock(&self.inner.state);
        state.active = false;
        state.daemon_connected = false;
        state.daemon_running = false;
        Ok(())
    }

    /// Native releases connect to an explicitly supplied service and never
    /// spawn a proprietary daemon or child process.
    pub fn start_daemon(&self, path: String, args: String) -> Result<(), Error> {
        if path.is_empty() || args.len() > 64 * 1024 {
            return Err(Error::Argument);
        }
        self.inner.events.emit(EventKey::DaemonCouldntRun, ());
        Err(Error::InvalidOperation)
    }

    pub fn stop_daemon(&self) -> Result<(), Error> {
        let was_running = lock(&self.inner.state).daemon_running;
        self.inner.pipe.disconnect()?;
        let mut state = lock(&self.inner.state);
        state.daemon_running = false;
        state.daemon_connected = false;
        drop(state);
        if was_running {
            self.inner.events.emit(EventKey::DaemonExited, ());
        }
        Ok(())
    }

    pub fn request_with_string(&self, action: String) -> Result<i32, Error> {
        self.request_with_string_string(action, None)
    }

    pub fn request_with_string_string(
        &self,
        action: String,
        request_xml: Option<String>,
    ) -> Result<i32, Error> {
        self.ensure_active_object()?;
        if !valid_xml_name(&action) {
            return Err(Error::Argument);
        }
        let connected = lock(&self.inner.state).daemon_connected;
        if !connected {
            return Ok(-1);
        }
        let body = request_xml.unwrap_or_default();
        validate_fragment(&body)?;
        let request_id = {
            let mut state = lock(&self.inner.state);
            let id = state.request_id;
            state.request_id = state
                .request_id
                .checked_add(1)
                .ok_or(Error::InvalidOperation)?;
            id
        };
        let request = if body.is_empty() {
            format!("<Request requestId=\"{request_id}\" action=\"{action}\" />\n\n\n")
        } else {
            format!(
                "<Request requestId=\"{request_id}\" action=\"{action}\">{body}</Request>\n\n\n"
            )
        };
        if request.len() > MAX_XML_BYTES {
            return Err(Error::Argument);
        }
        let bytes = request
            .chars()
            .map(|character| {
                if character.is_ascii() {
                    character as u8
                } else {
                    b'?'
                }
            })
            .collect();
        match self.inner.pipe.send_data(bytes) {
            Ok(()) => Ok(request_id),
            Err(Error::Socket | Error::InvalidOperation) => Ok(-1),
            Err(error) => Err(error),
        }
    }

    pub fn make_xml(name: String, text: String) -> Result<String, Error> {
        xml_element(&name, &text)
    }

    pub fn account_login(
        &self,
        connector_handle: String,
        account_name: String,
        account_password: String,
        audio_session_answer_mode: String,
        account_uri: String,
        participant_property_frequency: i32,
        enable_buddies_and_presence: bool,
    ) -> Result<i32, Error> {
        let body = xml_fields(&[
            ("ConnectorHandle", connector_handle),
            ("AccountName", account_name),
            ("AccountPassword", account_password),
            ("AudioSessionAnswerMode", audio_session_answer_mode),
            ("AccountURI", account_uri),
            (
                "ParticipantPropertyFrequency",
                participant_property_frequency.to_string(),
            ),
            (
                "EnableBuddiesAndPresence",
                enable_buddies_and_presence.to_string(),
            ),
            ("BuddyManagementMode", "Application".into()),
        ])?;
        self.request_with_string_string("Account.Login.1".into(), Some(body))
    }

    pub fn account_logout(&self, account_handle: String) -> Result<i32, Error> {
        self.request_field("Account.Logout.1", "AccountHandle", account_handle)
    }

    pub fn aux_get_capture_devices(&self) -> Result<i32, Error> {
        self.request_with_string("Aux.GetCaptureDevices.1".into())
    }

    pub fn aux_get_render_devices(&self) -> Result<i32, Error> {
        self.request_with_string("Aux.GetRenderDevices.1".into())
    }

    pub fn aux_set_render_device(&self, value: String) -> Result<i32, Error> {
        self.request_field("Aux.SetRenderDevice.1", "RenderDeviceSpecifier", value)
    }

    pub fn aux_set_capture_device(&self, value: String) -> Result<i32, Error> {
        self.request_field("Aux.SetCaptureDevice.1", "CaptureDeviceSpecifier", value)
    }

    pub fn aux_capture_audio_start(&self, duration: i32) -> Result<i32, Error> {
        self.request_field("Aux.CaptureAudioStart.1", "Duration", duration.to_string())
    }

    pub fn aux_capture_audio_stop(&self) -> Result<i32, Error> {
        self.request_with_string("Aux.CaptureAudioStop.1".into())
    }

    pub fn aux_set_mic_level(&self, level: i32) -> Result<i32, Error> {
        self.request_field("Aux.SetMicLevel.1", "Level", level.to_string())
    }

    pub fn aux_set_speaker_level(&self, level: i32) -> Result<i32, Error> {
        self.request_field("Aux.SetSpeakerLevel.1", "Level", level.to_string())
    }

    pub fn connector_create(
        &self,
        client_name: String,
        account_management_server: String,
        minimum_port: u16,
        maximum_port: u16,
        logging: VoiceGatewayVoiceLoggingSettings,
    ) -> Result<i32, Error> {
        if minimum_port > maximum_port {
            return Err(Error::Argument);
        }
        let logging_xml = xml_fields(&[
            ("Enabled", logging.enabled.to_string()),
            ("Folder", logging.folder),
            ("FileNamePrefix", logging.file_name_prefix),
            ("FileNameSuffix", logging.file_name_suffix),
            ("LogLevel", logging.log_level.to_string()),
        ])?;
        let body = format!(
            "{}<Logging>{logging_xml}</Logging>",
            xml_fields(&[
                ("ClientName", client_name),
                ("AccountManagementServer", account_management_server),
                ("MinimumPort", minimum_port.to_string()),
                ("MaximumPort", maximum_port.to_string()),
                ("Mode", "Normal".into()),
            ])?
        );
        self.request_with_string_string("Connector.Create.1".into(), Some(body))
    }

    pub fn connector_initiate_shutdown(&self, handle: String) -> Result<i32, Error> {
        self.request_field("Connector.InitiateShutdown.1", "ConnectorHandle", handle)
    }

    pub fn connector_mute_local_mic(&self, handle: String, mute: bool) -> Result<i32, Error> {
        self.connector_value_request("Connector.MuteLocalMic.1", handle, mute.to_string())
    }

    pub fn connector_mute_local_speaker(&self, handle: String, mute: bool) -> Result<i32, Error> {
        self.connector_value_request("Connector.MuteLocalSpeaker.1", handle, mute.to_string())
    }

    pub fn connector_set_local_mic_volume(&self, handle: String, value: i32) -> Result<i32, Error> {
        self.connector_value_request("Connector.SetLocalMicVolume.1", handle, value.to_string())
    }

    pub fn connector_set_local_speaker_volume(
        &self,
        handle: String,
        value: i32,
    ) -> Result<i32, Error> {
        self.connector_value_request(
            "Connector.SetLocalSpeakerVolume.1",
            handle,
            value.to_string(),
        )
    }

    pub fn session_connect(
        &self,
        session_handle: String,
        audio_media: String,
    ) -> Result<i32, Error> {
        self.request_fields_action(
            "Session.Connect.1",
            &[
                ("SessionHandle", session_handle),
                ("AudioMedia", audio_media),
            ],
        )
    }

    #[allow(clippy::too_many_arguments)]
    pub fn session_create(
        &self,
        account_handle: String,
        session_uri: String,
        name: String,
        password: String,
        join_audio: bool,
        join_text: bool,
        password_hash_algorithm: String,
    ) -> Result<i32, Error> {
        let mut fields = vec![
            ("AccountHandle", account_handle),
            ("URI", session_uri),
            ("Name", name),
        ];
        if !password.is_empty() {
            fields.push(("Password", password));
            fields.push(("PasswordHashAlgorithm", password_hash_algorithm));
        }
        fields.extend([
            ("ConnectAudio", join_audio.to_string()),
            ("ConnectText", join_text.to_string()),
            ("JoinAudio", join_audio.to_string()),
            ("JoinText", join_text.to_string()),
            ("VoiceFontID", "0".into()),
        ]);
        self.request_fields_action("Session.Create.1", &fields)
    }

    pub fn session_render_audio_start(
        &self,
        sound_file_path: String,
        loop_: bool,
    ) -> Result<i32, Error> {
        self.request_fields_action(
            "Session.RenderAudioStart.1",
            &[
                ("SoundFilePath", sound_file_path),
                ("Loop", if loop_ { "1" } else { "0" }.into()),
            ],
        )
    }

    pub fn session_render_audio_stop(&self, path: String) -> Result<i32, Error> {
        self.request_field("Session.RenderAudioStop.1", "SoundFilePath", path)
    }

    pub fn session_terminate(&self, handle: String) -> Result<i32, Error> {
        self.request_field("Session.Terminate.1", "SessionHandle", handle)
    }

    pub fn session_set_participant_volume_for_me(
        &self,
        session_handle: String,
        participant_uri: String,
        volume: i32,
    ) -> Result<i32, Error> {
        self.request_fields_action(
            "Session.SetParticipantVolumeForMe.1",
            &[
                ("SessionHandle", session_handle),
                ("ParticipantURI", participant_uri),
                ("Volume", volume.to_string()),
            ],
        )
    }

    pub(crate) fn session_set_participant_mute_for_me(
        &self,
        session_handle: String,
        participant_uri: String,
        mute: bool,
    ) -> Result<i32, Error> {
        self.request_fields_action(
            "Session.SetParticipantMuteForMe.1",
            &[
                ("SessionHandle", session_handle),
                ("ParticipantURI", participant_uri),
                ("Mute", if mute { "1" } else { "0" }.into()),
            ],
        )
    }

    pub fn session_set3_d_position(
        &self,
        session_handle: String,
        speaker_position: VoicePosition,
        listener_position: VoicePosition,
    ) -> Result<i32, Error> {
        let body = format!(
            "{}<SpeakerPosition>{}</SpeakerPosition><ListenerPosition>{}</ListenerPosition>",
            xml_element("SessionHandle", &session_handle)?,
            position_xml(&speaker_position)?,
            position_xml(&listener_position)?,
        );
        self.request_with_string_string("Session.Set3DPosition.1".into(), Some(body))
    }

    pub fn sip_from_uuid(&self, id: UUID) -> Result<String, Error> {
        if id == UUID::zero() {
            return Ok(format!("sip:@{}", lock(&self.inner.state).sip_server));
        }
        let encoded = base64::engine::general_purpose::STANDARD
            .encode(id.get_bytes()?)
            .replace('+', "-")
            .replace('/', "_");
        Ok(format!(
            "sip:x{encoded}@{}",
            lock(&self.inner.state).sip_server
        ))
    }

    #[must_use]
    pub fn current_capture_device(&self) -> String {
        lock(&self.inner.state).current_capture_device.clone()
    }

    pub fn set_current_capture_device(&mut self, value: String) {
        lock(&self.inner.state).current_capture_device = value.clone();
        let _ = self.aux_set_capture_device(value);
    }

    #[must_use]
    pub fn playback_device(&self) -> String {
        lock(&self.inner.state).current_playback_device.clone()
    }

    pub fn set_playback_device(&mut self, value: String) {
        lock(&self.inner.state).current_playback_device = value.clone();
        let _ = self.aux_set_render_device(value);
    }

    #[must_use]
    pub fn daemon_is_connected(&self) -> bool {
        lock(&self.inner.state).daemon_connected
    }

    pub fn set_daemon_is_connected(&mut self, value: bool) {
        lock(&self.inner.state).daemon_connected = value;
    }

    #[must_use]
    pub fn daemon_is_running(&self) -> bool {
        lock(&self.inner.state).daemon_running
    }

    pub fn set_daemon_is_running(&mut self, value: bool) {
        lock(&self.inner.state).daemon_running = value;
    }

    #[must_use]
    pub fn request_id(&self) -> i32 {
        lock(&self.inner.state).request_id
    }

    pub fn set_request_id(&mut self, value: i32) {
        lock(&self.inner.state).request_id = value;
    }

    pub fn set_mic_level(&mut self, value: i32) {
        let handle = lock(&self.inner.state).connector_handle.clone();
        let _ = self.connector_set_local_mic_volume(handle, value);
    }

    pub fn set_spkr_level(&mut self, value: i32) {
        let handle = lock(&self.inner.state).connector_handle.clone();
        let _ = self.connector_set_local_speaker_volume(handle, value);
    }

    pub fn set_mic_mute(&mut self, value: bool) {
        let handle = lock(&self.inner.state).connector_handle.clone();
        let _ = self.connector_mute_local_mic(handle, value);
    }

    pub fn set_spkr_mute(&mut self, value: bool) {
        let handle = lock(&self.inner.state).connector_handle.clone();
        let _ = self.connector_mute_local_speaker(handle, value);
    }

    #[must_use]
    pub fn test_mode(&self) -> bool {
        lock(&self.inner.state).testing
    }

    pub fn set_test_mode(&mut self, value: bool) {
        lock(&self.inner.state).testing = value;
        if value {
            let _ = self.aux_capture_audio_start(0);
        } else {
            let _ = self.aux_capture_audio_stop();
        }
    }

    fn ensure_active_object(&self) -> Result<(), Error> {
        if self.inner.disposed.load(Ordering::Acquire) {
            Err(Error::InvalidOperation)
        } else {
            Ok(())
        }
    }

    fn request_field(&self, action: &str, name: &str, value: String) -> Result<i32, Error> {
        self.request_fields_action(action, &[(name, value)])
    }

    fn request_fields_action(&self, action: &str, fields: &[(&str, String)]) -> Result<i32, Error> {
        self.request_with_string_string(action.into(), Some(xml_fields(fields)?))
    }

    fn connector_value_request(
        &self,
        action: &str,
        handle: String,
        value: String,
    ) -> Result<i32, Error> {
        self.request_fields_action(action, &[("ConnectorHandle", handle), ("Value", value)])
    }
}

impl GatewayInner {
    fn handle_line(self: &Arc<Self>, line: &str) -> Result<(), Error> {
        if line.len() > MAX_XML_BYTES || line.contains("<!DOCTYPE") || line.contains("<!ENTITY") {
            return Err(Error::Argument);
        }
        let document = Document::parse(line).map_err(|_| Error::Argument)?;
        self.events.emit(EventKey::RawControlLine, line.to_owned());
        let root = document.root_element();
        match root.tag_name().name() {
            "Response" => self.handle_response(root),
            "Event" => self.handle_event(root),
            _ => Err(Error::Argument),
        }
    }

    fn handle_response(self: &Arc<Self>, root: Node<'_, '_>) -> Result<(), Error> {
        let action = root.attribute("action").ok_or(Error::Argument)?;
        let return_code = field_i32(root, "ReturnCode");
        let status_code = field_i32(root, "StatusCode");
        let status = field(root, "StatusString");
        match action {
            "Connector.Create.1" => {
                let version = field(root, "VersionID");
                let handle = field(root, "ConnectorHandle");
                lock(&self.state).connector_handle = handle.clone();
                self.events.emit(
                    EventKey::ConnectorCreate,
                    VoiceGatewayVoiceConnectorEventArgs::new(
                        return_code,
                        status_code,
                        status,
                        version,
                        handle,
                    )?,
                );
            }
            "Aux.GetCaptureDevices.1" | "Aux.GetRenderDevices.1" => {
                let capture = action.contains("Capture");
                let item = if capture {
                    "CaptureDevice"
                } else {
                    "RenderDevice"
                };
                let current_item = if capture {
                    "CurrentCaptureDevice"
                } else {
                    "CurrentRenderDevice"
                };
                let devices = device_values(root, item);
                let current = nested_device(root, current_item);
                let type_ = if capture {
                    VoiceGatewayResponseType::GetCaptureDevices
                } else {
                    VoiceGatewayResponseType::GetRenderDevices
                };
                let key = if capture {
                    lock(&self.state).current_capture_device = current.clone();
                    EventKey::CaptureDevices
                } else {
                    lock(&self.state).current_playback_device = current.clone();
                    EventKey::RenderDevices
                };
                self.events.emit(
                    key,
                    VoiceGatewayVoiceDevicesEventArgs::new(
                        type_,
                        return_code,
                        status_code,
                        status,
                        current,
                        devices,
                    )?,
                );
            }
            "Account.Login.1" => {
                let handle = field(root, "AccountHandle");
                lock(&self.state).account_handle = handle.clone();
                self.events.emit(
                    EventKey::AccountLoginResponse,
                    VoiceGatewayVoiceAccountEventArgs::new(
                        return_code,
                        status_code,
                        status,
                        handle,
                    )?,
                );
            }
            "Session.Create.1" => {
                let handle = field(root, "SessionHandle");
                let mut state = lock(&self.state);
                state.session_handle = handle.clone();
                if !handle.is_empty() && return_code == 0 && status_code == 0 {
                    let gateway = VoiceGateway {
                        inner: Arc::clone(self),
                    };
                    state
                        .sessions
                        .insert(handle.clone(), VoiceSession::new(gateway, handle.clone())?);
                }
                drop(state);
                self.events.emit(
                    EventKey::SessionCreateResponse,
                    VoiceGatewayVoiceSessionEventArgs::new(
                        return_code,
                        status_code,
                        status,
                        handle,
                    )?,
                );
                self.events.emit(EventKey::SessionCreate, ());
            }
            _ => {
                if let Some(type_) = response_type(action) {
                    self.events.emit(
                        EventKey::VoiceResponse,
                        VoiceGatewayVoiceResponseEventArgs::new(
                            type_,
                            return_code,
                            status_code,
                            status,
                        )?,
                    );
                }
            }
        }
        Ok(())
    }

    #[allow(clippy::too_many_lines)]
    fn handle_event(self: &Arc<Self>, root: Node<'_, '_>) -> Result<(), Error> {
        match root.attribute("type").ok_or(Error::Argument)? {
            "LoginStateChangeEvent" | "AccountLoginStateChangeEvent" => self.events.emit(
                EventKey::AccountLoginState,
                VoiceGatewayAccountLoginStateChangeEventArgs::new(
                    field(root, "AccountHandle"),
                    field_i32(root, "StatusCode"),
                    field(root, "StatusString"),
                    login_state(field_i32(root, "State")),
                )?,
            ),
            "SessionNewEvent" => self.events.emit(
                EventKey::SessionNew,
                VoiceGatewayNewSessionEventArgs::new(
                    field(root, "AccountHandle"),
                    field(root, "SessionHandle"),
                    field(root, "URI"),
                    field_bool(root, "IsChannel"),
                    field(root, "Name"),
                    field(root, "AudioMedia"),
                )?,
            ),
            "SessionStateChangeEvent" => self.events.emit(
                EventKey::SessionState,
                VoiceGatewaySessionStateChangeEventArgs::new(
                    field(root, "SessionHandle"),
                    field_i32(root, "StatusCode"),
                    field(root, "StatusString"),
                    session_state(field_i32(root, "State")),
                    field(root, "URI"),
                    field_bool(root, "IsChannel"),
                    field(root, "ChannelName"),
                )?,
            ),
            "ParticipantAddedEvent" => {
                let session_handle = field(root, "SessionHandle");
                let participant_uri = field(root, "ParticipantUri");
                if let Some(session) = lock(&self.state).sessions.get(&session_handle).cloned() {
                    session.add_participant(participant_uri.clone())?;
                }
                self.events.emit(
                    EventKey::ParticipantAdded,
                    VoiceGatewayParticipantAddedEventArgs::new(
                        field(root, "SessionGroupHandle"),
                        session_handle,
                        participant_uri,
                        field(root, "AccountName"),
                        field(root, "DisplayName"),
                        participant_type(field_i32(root, "ParticipantType")),
                        field(root, "Application"),
                    )?,
                );
            }
            "ParticipantRemovedEvent" => {
                let session_handle = field(root, "SessionHandle");
                let participant_uri = field(root, "ParticipantUri");
                if let Some(session) = lock(&self.state).sessions.get(&session_handle).cloned() {
                    session.remove_participant(&participant_uri);
                }
                self.events.emit(
                    EventKey::ParticipantRemoved,
                    VoiceGatewayParticipantRemovedEventArgs::new(
                        field(root, "SessionGroupHandle"),
                        session_handle,
                        participant_uri,
                        field(root, "AccountName"),
                        field(root, "Reason"),
                    )?,
                );
            }
            "ParticipantStateChangeEvent" => self.events.emit(
                EventKey::ParticipantState,
                VoiceGatewayParticipantStateChangeEventArgs::new(
                    field(root, "SessionHandle"),
                    field_i32(root, "StatusCode"),
                    field(root, "StatusString"),
                    participant_state(field_i32(root, "State")),
                    field(root, "ParticipantUri"),
                    field(root, "AccountName"),
                    field(root, "DisplayName"),
                    participant_type(field_i32(root, "ParticipantType")),
                )?,
            ),
            "ParticipantPropertiesEvent" => {
                let session_handle = field(root, "SessionHandle");
                let participant_uri = field(root, "ParticipantUri");
                let locally_muted = field_bool(root, "IsLocallyMuted");
                let moderator_muted = field_bool(root, "IsModeratorMuted");
                let speaking = field_bool(root, "IsSpeaking");
                let volume = field_i32(root, "Volume");
                let energy = field_f32(root, "Energy");
                if let Some(session) = lock(&self.state).sessions.get(&session_handle).cloned() {
                    session.update_participant(
                        &participant_uri,
                        locally_muted || moderator_muted,
                        speaking,
                        volume,
                        energy,
                    );
                }
                self.events.emit(
                    EventKey::ParticipantProperties,
                    VoiceGatewayParticipantPropertiesEventArgs::new(
                        session_handle,
                        participant_uri,
                        locally_muted,
                        moderator_muted,
                        speaking,
                        volume,
                        energy,
                    )?,
                );
            }
            "ParticipantUpdatedEvent" => {
                let session_handle = field(root, "SessionHandle");
                let participant_uri = field(root, "ParticipantUri");
                let moderator_muted = field_bool(root, "IsModeratorMuted");
                let speaking = field_bool(root, "IsSpeaking");
                let volume = field_i32(root, "Volume");
                let energy = field_f32(root, "Energy");
                if let Some(session) = lock(&self.state).sessions.get(&session_handle).cloned() {
                    session.update_participant(
                        &participant_uri,
                        moderator_muted,
                        speaking,
                        volume,
                        energy,
                    );
                }
                self.events.emit(
                    EventKey::ParticipantUpdated,
                    VoiceGatewayParticipantUpdatedEventArgs::new(
                        session_handle,
                        participant_uri,
                        moderator_muted,
                        speaking,
                        volume,
                        energy,
                    )?,
                );
            }
            "SessionGroupAddedEvent" => self.events.emit(
                EventKey::SessionGroupAdded,
                VoiceGatewaySessionGroupAddedEventArgs::new(
                    field(root, "AccountHandle"),
                    field(root, "SessionGroupHandle"),
                    field(root, "Type"),
                )?,
            ),
            "SessionAddedEvent" => self.events.emit(
                EventKey::SessionAdded,
                VoiceGatewaySessionAddedEventArgs::new(
                    field(root, "SessionGroupHandle"),
                    field(root, "SessionHandle"),
                    field(root, "Uri"),
                    field_bool(root, "IsChannel"),
                    field_bool(root, "Incoming"),
                )?,
            ),
            "SessionRemovedEvent" => {
                let session_handle = field(root, "SessionHandle");
                if let Some(session) = lock(&self.state).sessions.remove(&session_handle) {
                    session.close();
                }
                self.events.emit(
                    EventKey::SessionRemoved,
                    VoiceGatewaySessionRemovedEventArgs::new(
                        field(root, "SessionGroupHandle"),
                        session_handle,
                        field(root, "Uri"),
                    )?,
                );
                self.events.emit(EventKey::SessionRemove, ());
            }
            "SessionUpdatedEvent" => self.events.emit(
                EventKey::SessionUpdated,
                VoiceGatewaySessionUpdatedEventArgs::new(
                    field(root, "SessionGroupHandle"),
                    field(root, "SessionHandle"),
                    field(root, "Uri"),
                    field_i32(root, "IsMuted") != 0,
                    field_i32(root, "Volume"),
                    field_i32(root, "TransmitEnabled") != 0,
                    field_i32(root, "IsFocused") != 0,
                )?,
            ),
            "AuxAudioPropertiesEvent" => {
                let energy = field_f32(root, "MicEnergy");
                self.events.emit(
                    EventKey::AuxAudioProperties,
                    VoiceGatewayAudioPropertiesEventArgs::new(
                        field_bool(root, "MicIsActive"),
                        energy,
                        field_i32(root, "MicVolume"),
                        field_i32(root, "SpeakerVolume"),
                    )?,
                );
                self.events.emit(EventKey::VoiceMicTest, energy);
            }
            "SessionMediaEvent" => self.events.emit(
                EventKey::SessionMedia,
                VoiceGatewaySessionMediaEventArgs::new(
                    field(root, "SessionHandle"),
                    field_bool(root, "HasText"),
                    field_bool(root, "HasAudio"),
                    field_bool(root, "HasVideo"),
                    field_bool(root, "Terminated"),
                )?,
            ),
            _ => {}
        }
        Ok(())
    }
}

fn valid_xml_name(value: &str) -> bool {
    !value.is_empty()
        && value.len() <= 128
        && value
            .bytes()
            .all(|byte| byte.is_ascii_alphanumeric() || matches!(byte, b'.' | b'_' | b'-'))
}

fn validate_fragment(fragment: &str) -> Result<(), Error> {
    if fragment.len() > MAX_XML_BYTES
        || fragment.contains("<!DOCTYPE")
        || fragment.contains("<!ENTITY")
    {
        return Err(Error::Argument);
    }
    if !fragment.is_empty() {
        Document::parse(&format!("<Root>{fragment}</Root>")).map_err(|_| Error::Argument)?;
    }
    Ok(())
}

fn xml_element(name: &str, text: &str) -> Result<String, Error> {
    if !valid_xml_name(name) || text.len() > 64 * 1024 {
        return Err(Error::Argument);
    }
    if text.is_empty() {
        return Ok(format!("<{name} />"));
    }
    let mut escaped = String::with_capacity(text.len());
    for character in text.chars() {
        match character {
            '&' => escaped.push_str("&amp;"),
            '<' => escaped.push_str("&lt;"),
            '>' => escaped.push_str("&gt;"),
            '\'' => escaped.push_str("&apos;"),
            '"' => escaped.push_str("&quot;"),
            '\0'..='\x08' | '\x0b' | '\x0c' | '\x0e'..='\x1f' => {
                return Err(Error::Argument);
            }
            _ => escaped.push(character),
        }
    }
    Ok(format!("<{name}>{escaped}</{name}>"))
}

fn xml_fields(fields: &[(&str, String)]) -> Result<String, Error> {
    let mut output = String::new();
    for (name, value) in fields {
        output.push_str(&xml_element(name, value)?);
    }
    Ok(output)
}

fn position_xml(position: &VoicePosition) -> Result<String, Error> {
    fn vector(name: &str, value: Vector3d) -> Result<String, Error> {
        Ok(format!(
            "<{name}>{}</{name}>",
            xml_fields(&[
                ("X", value.x.to_string()),
                ("Y", value.y.to_string()),
                ("Z", value.z.to_string()),
            ])?
        ))
    }
    Ok([
        vector("Position", position.position)?,
        vector("Velocity", position.velocity)?,
        vector("AtOrientation", position.at_orientation)?,
        vector("UpOrientation", position.up_orientation)?,
        vector("LeftOrientation", position.left_orientation)?,
    ]
    .concat())
}

fn field(root: Node<'_, '_>, name: &str) -> String {
    root.descendants()
        .find(|node| node.has_tag_name(name))
        .and_then(|node| node.text())
        .unwrap_or_default()
        .to_owned()
}

fn field_i32(root: Node<'_, '_>, name: &str) -> i32 {
    field(root, name).parse().unwrap_or_default()
}

fn field_f32(root: Node<'_, '_>, name: &str) -> f32 {
    field(root, name).parse().unwrap_or_default()
}

fn field_bool(root: Node<'_, '_>, name: &str) -> bool {
    matches!(
        field(root, name).to_ascii_lowercase().as_str(),
        "true" | "1"
    )
}

fn nested_device(root: Node<'_, '_>, name: &str) -> String {
    root.descendants()
        .find(|node| node.has_tag_name(name))
        .map(|node| field(node, "Device"))
        .unwrap_or_default()
}

fn device_values(root: Node<'_, '_>, name: &str) -> Vec<String> {
    root.descendants()
        .filter(|node| node.has_tag_name(name))
        .map(|node| field(node, "Device"))
        .filter(|value| !value.is_empty())
        .collect()
}

fn response_type(action: &str) -> Option<VoiceGatewayResponseType> {
    Some(match action {
        "Connector.InitiateShutdown.1" => VoiceGatewayResponseType::ConnectorInitiateShutdown,
        "Aux.SetRenderDevice.1" => VoiceGatewayResponseType::SetRenderDevice,
        "Connector.MuteLocalMic.1" => VoiceGatewayResponseType::MuteLocalMic,
        "Connector.MuteLocalSpeaker.1" => VoiceGatewayResponseType::MuteLocalSpeaker,
        "Connector.SetLocalMicVolume.1" => VoiceGatewayResponseType::SetLocalMicVolume,
        "Connector.SetLocalSpeakerVolume.1" => VoiceGatewayResponseType::SetLocalSpeakerVolume,
        "Aux.SetCaptureDevice.1" => VoiceGatewayResponseType::SetCaptureDevice,
        "Session.RenderAudioStart.1" => VoiceGatewayResponseType::RenderAudioStart,
        "Session.RenderAudioStop.1" => VoiceGatewayResponseType::RenderAudioStop,
        "Aux.CaptureAudioStart.1" => VoiceGatewayResponseType::CaptureAudioStart,
        "Aux.CaptureAudioStop.1" => VoiceGatewayResponseType::CaptureAudioStop,
        "Aux.SetMicLevel.1" => VoiceGatewayResponseType::SetMicLevel,
        "Aux.SetSpeakerLevel.1" => VoiceGatewayResponseType::SetSpeakerLevel,
        "Account.Logout.1" => VoiceGatewayResponseType::AccountLogout,
        "Session.Connect.1" => VoiceGatewayResponseType::SessionConnect,
        "Session.Terminate.1" => VoiceGatewayResponseType::SessionTerminate,
        "Session.SetParticipantVolumeForMe.1" => {
            VoiceGatewayResponseType::SetParticipantVolumeForMe
        }
        "Session.SetParticipantMuteForMe.1" => VoiceGatewayResponseType::SetParticipantMuteForMe,
        "Session.Set3DPosition.1" => VoiceGatewayResponseType::Set3DPosition,
        _ => return None,
    })
}

fn login_state(value: i32) -> VoiceGatewayLoginState {
    match value {
        1 => VoiceGatewayLoginState::LoggedIn,
        4 => VoiceGatewayLoginState::Error,
        _ => VoiceGatewayLoginState::LoggedOut,
    }
}

fn session_state(value: i32) -> VoiceGatewaySessionState {
    match value {
        2 => VoiceGatewaySessionState::Answering,
        3 => VoiceGatewaySessionState::InProgress,
        4 => VoiceGatewaySessionState::Connected,
        5 => VoiceGatewaySessionState::Disconnected,
        6 => VoiceGatewaySessionState::Hold,
        7 => VoiceGatewaySessionState::Refer,
        8 => VoiceGatewaySessionState::Ringing,
        _ => VoiceGatewaySessionState::Idle,
    }
}

fn participant_state(value: i32) -> VoiceGatewayParticipantState {
    match value {
        2 => VoiceGatewayParticipantState::Pending,
        3 => VoiceGatewayParticipantState::Incoming,
        4 => VoiceGatewayParticipantState::Answering,
        5 => VoiceGatewayParticipantState::InProgress,
        6 => VoiceGatewayParticipantState::Ringing,
        7 => VoiceGatewayParticipantState::Connected,
        8 => VoiceGatewayParticipantState::Disconnecting,
        9 => VoiceGatewayParticipantState::Disconnected,
        _ => VoiceGatewayParticipantState::Idle,
    }
}

fn participant_type(value: i32) -> VoiceGatewayParticipantType {
    match value {
        1 => VoiceGatewayParticipantType::Moderator,
        2 => VoiceGatewayParticipantType::Focus,
        _ => VoiceGatewayParticipantType::User,
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use std::sync::mpsc;

    #[test]
    fn xml_builder_escapes_values_and_rejects_active_xml() {
        assert_eq!(
            VoiceGateway::make_xml("Name".into(), "<&>\"'".into()).unwrap(),
            "<Name>&lt;&amp;&gt;&quot;&apos;</Name>"
        );
        assert!(validate_fragment("<!ENTITY x 'bad'>").is_err());
        assert!(VoiceGateway::make_xml("bad name".into(), "x".into()).is_err());
    }

    #[test]
    fn response_and_event_dispatch_retain_typed_payloads() {
        let client = libremetaverse::GridClient::new().unwrap();
        let gateway = VoiceGateway::new(client).unwrap();
        let (sender, receiver) = mpsc::channel();
        let _subscription =
            gateway.subscribe_on_session_participant_updated_event(Some(Arc::new(move |event| {
                sender.send(event).unwrap();
            })));
        gateway.inner.handle_line("<Event type=\"ParticipantUpdatedEvent\"><SessionHandle>s</SessionHandle><ParticipantUri>sip:p@example.test</ParticipantUri><IsModeratorMuted>true</IsModeratorMuted><IsSpeaking>1</IsSpeaking><Volume>42</Volume><Energy>0.75</Energy></Event>").unwrap();
        let event = receiver.recv().unwrap();
        assert_eq!(event.session_handle, "s");
        assert!(event.is_muted);
        assert!(event.is_speaking);
        assert_eq!(event.volume, 42);
        assert_eq!(event.energy, 0.75);
    }

    #[test]
    fn protocol_events_drive_the_session_participant_lifecycle() {
        let gateway = VoiceGateway::new(libremetaverse::GridClient::new().unwrap()).unwrap();
        gateway.inner.handle_line("<Response requestId=\"3\" action=\"Session.Create.1\"><ReturnCode>0</ReturnCode><Results><StatusCode>0</StatusCode><StatusString>OK</StatusString><SessionHandle>session-3</SessionHandle></Results></Response>").unwrap();
        let session = lock(&gateway.inner.state)
            .sessions
            .get("session-3")
            .cloned()
            .unwrap();
        let (sender, receiver) = mpsc::channel();
        let added = sender.clone();
        let _added = session.subscribe_on_participant_added(Some(Arc::new(move |()| {
            added.send("added").unwrap();
        })));
        let updated = sender.clone();
        let _updated = session.subscribe_on_participant_update(Some(Arc::new(move |()| {
            updated.send("updated").unwrap();
        })));
        let _removed = session.subscribe_on_participant_removed(Some(Arc::new(move |()| {
            sender.send("removed").unwrap();
        })));

        gateway.inner.handle_line("<Event type=\"ParticipantAddedEvent\"><SessionHandle>session-3</SessionHandle><ParticipantUri>sip:p@example.test</ParticipantUri></Event>").unwrap();
        gateway.inner.handle_line("<Event type=\"ParticipantUpdatedEvent\"><SessionHandle>session-3</SessionHandle><ParticipantUri>sip:p@example.test</ParticipantUri><IsSpeaking>1</IsSpeaking><Volume>42</Volume><Energy>0.75</Energy></Event>").unwrap();
        gateway.inner.handle_line("<Event type=\"ParticipantRemovedEvent\"><SessionHandle>session-3</SessionHandle><ParticipantUri>sip:p@example.test</ParticipantUri></Event>").unwrap();
        assert_eq!(receiver.recv().unwrap(), "added");
        assert_eq!(receiver.recv().unwrap(), "updated");
        assert_eq!(receiver.recv().unwrap(), "removed");

        gateway.inner.handle_line("<Event type=\"SessionRemovedEvent\"><SessionHandle>session-3</SessionHandle></Event>").unwrap();
        assert!(
            !lock(&gateway.inner.state)
                .sessions
                .contains_key("session-3")
        );
    }
}