syntax = "proto2";

package hudiy.app.api;

enum Constants {
    // option allow_alias = true;
    API_MAJOR_VERSION = 1;
    API_MINOR_VERSION = 3;
}

enum MessageType {
    MESSAGE_INVALID_ID = 0;
    MESSAGE_HELLO_REQUEST = 1;
    MESSAGE_HELLO_RESPONSE = 2;
    MESSAGE_SET_STATUS_SUBSCRIPTIONS = 3;
    MESSAGE_SET_REVERSE_CAMERA_STATUS = 4;
    MESSAGE_PROJECTION_STATUS = 5;
    MESSAGE_MEDIA_STATUS = 6;
    MESSAGE_MEDIA_METADATA = 7;
    MESSAGE_NAVIGATION_STATUS = 8;
    MESSAGE_NAVIGATION_MANEUVER_DETAILS = 9;
    MESSAGE_NAVIGATION_MANEUVER_DISTANCE = 10;
    MESSAGE_REGISTER_STATUS_ICON_REQUEST = 11;
    MESSAGE_REGISTER_STATUS_ICON_RESPONSE = 12;
    MESSAGE_UNREGISTER_STATUS_ICON = 13;
    MESSAGE_CHANGE_STATUS_ICON_STATE = 14;
    MESSAGE_REGISTER_NOTIFICATION_CHANNEL_REQUEST = 15;
    MESSAGE_REGISTER_NOTIFICATION_CHANNEL_RESPONSE = 16;
    MESSAGE_UNREGISTER_NOTIFICATION_CHANNEL = 17;
    MESSAGE_SHOW_NOTIFICATION = 18;
    MESSAGE_REGISTER_TOAST_CHANNEL_REQUEST = 19;
    MESSAGE_REGISTER_TOAST_CHANNEL_RESPONSE = 20;
    MESSAGE_UNREGISTER_TOAST_CHANNEL = 21;
    MESSAGE_SHOW_TOAST = 22;
    MESSAGE_OBD_CONNECTION_STATUS = 23;
    MESSAGE_QUERY_OBD_DEVICE_REQUEST = 24;
    MESSAGE_QUERY_OBD_DEVICE_RESPONSE = 25;
    MESSAGE_REGISTER_AUDIO_FOCUS_RECEIVER_REQUEST = 26;
    MESSAGE_REGISTER_AUDIO_FOCUS_RECEIVER_RESPONSE = 27;
    MESSAGE_UNREGISTER_AUDIO_FOCUS_RECEIVER = 28;
    MESSAGE_AUDIO_FOCUS_CHANGE_REQUEST = 29;
    MESSAGE_AUDIO_FOCUS_CHANGE_RESPONSE = 30;
    MESSAGE_AUDIO_FOCUS_ACTION = 31;
    MESSAGE_AUDIO_FOCUS_MEDIA_KEY = 32;
    MESSAGE_PHONE_CONNECTION_STATUS = 33;
    MESSAGE_PHONE_VOICE_CALL_STATUS = 34;
    MESSAGE_PHONE_LEVELS_STATUS = 35;
    MESSAGE_KEY_EVENT = 36;
    MESSAGE_SET_DARK_MODE = 37;
    MESSAGE_SET_CUSTOM_OVERLAY_VISIBILITY = 38;
    MESSAGE_SET_NAVIGATION_OVERLAY_VISIBILITY = 39;
    MESSAGE_SET_VOLUME_OVERLAY_VISIBILITY = 40;
    MESSAGE_REGISTER_ACTION_REQUEST = 41;
    MESSAGE_REGISTER_ACTION_RESPONSE = 42;
    MESSAGE_DISPATCH_ACTION = 43;
    MESSAGE_SET_EQUALIZER_PRESET  = 44;
    MESSAGE_COVERART_REQUEST = 45;
    MESSAGE_COVERART_RESPONSE = 46;
    MESSAGE_PING = 47;
    MESSAGE_PONG = 48;
    MESSAGE_BYEBYE = 49;
    MESSAGE_SET_ANDROID_AUTO_DAY_NIGHT_MODE = 50;
    MESSAGE_SET_AUTOBOX_DAY_NIGHT_MODE = 51;
    MESSAGE_CURRENT_MENU_ACTION = 52;
    MESSAGE_SET_BASS_TREBLE_BOOST = 53;
}

message Version {
    required int32 major = 1;
    required int32 minor = 2;
}

// Id: MESSAGE_HELLO_REQUEST
// Receiver: Hudiy
// Description: The Hello request/response pair is used for version negotiation.
message HelloRequest {
    // Name of the client used for identification
    required string name = 1;

    // Version of the protocol used by the client
    required Version api_version = 2;
}

// Id: MESSAGE_HELLO_RESPONSE
// Receiver: Client
// Description: The Hello request/response pair is used for version negotiation.
message HelloResponse {
    enum HelloResponseResult {
        HELLO_RESPONSE_RESULT_OK = 1;
        HELLO_RESPONSE_RESULT_VERSION_MISMATCH = 2;
        HELLO_RESPONSE_RESULT_UNKNOWN_ERROR = 3;
    }

    // Version of the application
    required Version app_version = 1;

    // Version of the api used by Hudiy
    required Version api_version = 2;

    // Result of the hello procedure
    required HelloResponseResult result = 3;
}

// Id: MESSAGE_SET_STATUS_SUBSCRIPTIONS
// Receiver: Hudiy
// Description:
//     Manages active subscriptions to update the status of related functionalities.
//     Each subscription has dedicated messages for updating statuses related to its topic.
//     Every time the client subscribes or unsubscribes, it must provide the full list of desired subscriptions.
message SetStatusSubscriptions {
    enum Subscription {
        PROJECTION = 1;
        MEDIA = 2;
        NAVIGATION = 3;
        OBD = 4;
        PHONE = 5;
        COVERARTS = 6;
        CURRENT_MENU_ACTION = 7;
    }

    // List of desired subscriptions
    repeated Subscription subscriptions = 1;
}

// Id: MESSAGE_SET_REVERSE_CAMERA_STATUS
// Receiver: Hudiy
// Description: Toggle reverse camera feed visibility
message SetReverseCameraStatus {
    // true – the camera feed is visible on the screen; false – the camera feed is not visible
    required bool visible = 1;
}

// Id: MESSAGE_PROJECTION_STATUS
// Receiver: Client
// Description:
//     Updates the status of Android Auto or CarPlay projection visibility.
//     The message will be sent only if Subscription::PROJECTION is present.
message ProjectionStatus {
    required bool active = 1;
}

enum MediaSource {
    MEDIA_SOURCE_NONE = 0;
    MEDIA_SOURCE_ANDROID_AUTO = 1;
    MEDIA_SOURCE_AUTOBOX = 2;
    MEDIA_SOURCE_A2DP = 3;
    MEDIA_SOURCE_STORAGE = 4;
    MEDIA_SOURCE_FM_RADIO = 5;
    MEDIA_SOURCE_WEB = 6;
}

// Id: MESSAGE_MEDIA_STATUS
// Receiver: Client
// Description:
//     Updates the playback status and source of the currently playing media.
//     The message will be sent only if Subscription::MEDIA is present.
message MediaStatus {
    // Current track position, e.g. 01:23
    required string position_label = 1;

    // Playback status
    required bool is_playing = 2;

    // Source of the media
    required MediaSource source = 3;
}

// Id: MESSAGE_MEDIA_METADATA
// Receiver: Client
// Description:
//     Updates the metadata of the currently playing media.
//     The message will be sent only if Subscription::MEDIA is present.
message MediaMetadata {
    required string album = 1;
    required string artist = 2;
    required string title = 3;

    // Media duration label, e.g. 04:56
    required string duration_label = 4;

    // Buffer containing the cover art image if available.
    // The image format depends on the cover art source.
    required bytes coverart = 5;
}


// Id: MESSAGE_NAVIGATION_STATUS
// Receiver: Client
// Description:
//     Updates the status of navigation.
//     The message will be sent only if Subscription::NAVIGATION is present.
message NavigationStatus {
    enum NavigationSource {
        NAVIGATION_SOURCE_NONE = 0;
        NAVIGATION_SOURCE_ANDROID_AUTO = 1;
        NAVIGATION_SOURCE_AUTOBOX = 2;
    }
   
    enum NavigationState {
        NAVIGATION_STATE_ACTIVE = 1;
        NAVIGATION_STATE_INACTIVE = 2;
    }

    // Source of the navigation data
    required NavigationSource source = 1;

    // Current state of the navigation
    required NavigationState state = 2;
}

// Id: MESSAGE_NAVIGATION_MANEUVER_DETAILS
// Receiver: Client
// Description:
//     Updates the details of the current navigation maneuver.
//     The message will be sent only if Subscription::NAVIGATION is present.
message NavigationManeuverDetails {
    enum NavigationManeuverType
    {
        UNKNOWN = 0;
        DEPART = 1;
        NAME_CHANGE = 2;
        SLIGHT_TURN = 3;
        TURN = 4;
        SHARP_TURN = 5;
        U_TURN = 6;
        ON_RAMP = 7;
        OFF_RAMP = 8;
        FORK = 9;
        MERGE = 10;
        ROUNDABOUT_ENTER = 11;
        ROUNDABOUT_EXIT = 12;
        ROUNDABOUT_ENTER_AND_EXIT = 13;
        STRAIGHT = 14;
        FERRY_BOAT = 16;
        FERRY_TRAIN = 17;
        DESTINATION = 19;
    }

    enum NavigationManeuverSide
    {
        LEFT = 1;
        RIGHT = 2;
        UNSPECIFIED = 3;
    }

    // description of the maneuver (e. g. Turn left into 2nd Ave)
    required string description = 1;

    // Buffer containing the maneuver icon.
    // The image format depends on the navigation source.
    required bytes icon = 2;
    optional NavigationManeuverSide maneuver_side = 3;
    optional NavigationManeuverType maneuver_type = 4;
    optional uint32 maneuver_angle = 5;
}

// Id: MESSAGE_NAVIGATION_MANEUVER_DISTANCE
// Receiver: Client
// Description:
//     Updates the distance of current menauver.
//     The message will be sent only if Subscription::NAVIGATION is present.
message NavigationManeuverDistance {

    // Label of the maneuver distance (e. g. 5 km)
    required string label = 1;
}

// Id: MESSAGE_REGISTER_STATUS_ICON_REQUEST
// Receiver: Hudiy
// Description: Request to register custom status icon
message RegisterStatusIconRequest {
    // Description of the status icon. When the icon is visible, this description will be shown in the status menu.
    required string description = 1;

    // Font family used for the status icon. The font must be registered in Hudiy by adding it to main_configuration.json
    required string icon_font_family = 2;

    // Identifier of the icon within the font.
    required string icon_name = 3;
}

// Id: MESSAGE_REGISTER_STATUS_ICON_RESPONSE
// Receiver: Client
// Description: Response for registering custom status icon
message RegisterStatusIconResponse {
    enum RegisterStatusIconResult {
        REGISTER_STATUS_ICON_RESULT_OK = 1;
        REGISTER_STATUS_ICON_RESULT_FAILED = 2;
    }

    required RegisterStatusIconResult result = 1;

    // Unique identifier of the icon. It will be used later to show or hide the icon, or to unregister it.
    optional int32 id = 2;
}

// Id: MESSAGE_UNREGISTER_STATUS_ICON
// Receiver: Hudiy
// Description: Unregister previously registered status icon
message UnregisterStatusIcon {
    // Unique identifier of the icon, provided in the MESSAGE_REGISTER_STATUS_ICON_RESPONSE message.
    required int32 id = 1;
}

// Id: MESSAGE_CHANGE_STATUS_ICON_STATE
// Receiver: Hudiy
// Description: Shows or hides a previously registered status icon.
message ChangeStatusIconState {
    // Unique identifier of the icon, provided in the MESSAGE_REGISTER_STATUS_ICON_RESPONSE message.
    required int32 id = 1;

    // Visibility state of the icon.
    required bool visible = 2;
}

// Id: MESSAGE_REGISTER_NOTIFICATION_CHANNEL_REQUEST
// Receiver: Hudiy
// Description: Registers a new channel for notifications.
message RegisterNotificationChannelRequest {
    // Name of the channel
    required string name = 1;

    // Description of the channel
    required string description = 2;
}

// Id: MESSAGE_REGISTER_NOTIFICATION_CHANNEL_RESPONSE
// Receiver: Client
// Description: Response for registering notification channel
message RegisterNotificationChannelResponse {
    enum RegisterNotificationChannelResult {
        REGISTER_NOTIFICATION_CHANNEL_RESULT_OK = 1;
        REGISTER_NOTIFICATION_CHANNEL_RESULT_FAILED = 2;
    }

    required RegisterNotificationChannelResult result = 1;

    // Unique identifier of the channel. It will be used later to show notifications or to deregister the channel.
    optional int32 id = 2;
}

// Id: MESSAGE_UNREGISTER_NOTIFICATION_CHANNEL
// Receiver: Hudiy
// Description: Deregisters a previously registered notification channel.
message UnregisterNotificationChannel {
    // Unique identifier of the channel, provided in the MESSAGE_REGISTER_NOTIFICATION_CHANNEL_RESPONSE message.
    required int32 id = 1;
}

// Id: MESSAGE_SHOW_NOTIFICATION
// Receiver: Hudiy
// Description: Displays a notification in a previously registered channel.
message ShowNotification {
    // Unique identifier of the channel, provided in the MESSAGE_REGISTER_NOTIFICATION_CHANNEL_RESPONSE message.
    required int32 channel_id = 1;
    required string title = 2;
    required string description = 3;

    // Font family used for the notification icon. The font must be registered in Hudiy by adding it to main_configuration.json
    required string icon_font_family = 4;

    // Identifier of the icon within the font.
    required string icon_name = 5;

    // The action to dispatch when the notification is clicked.
    required string action = 6;

    // Whether to play the configured sound when the notification is displayed.
    required bool play_sound = 7;
}

// Id: MESSAGE_REGISTER_TOAST_CHANNEL_REQUEST
// Receiver: Hudiy
// Description: Registers a new channel for toast messages.
message RegisterToastChannelRequest {
    // Name of the channel
    required string name = 1;

    // Description of the channel
    required string description = 2;
}

// Id: MESSAGE_REGISTER_TOAST_CHANNEL_RESPONSE
// Receiver: Client
// Description: Response for registering toast channel
message RegisterToastChannelResponse {
    enum RegisterToastChannelResult {
        REGISTER_TOAST_CHANNEL_RESULT_OK = 1;
        REGISTER_TOAST_CHANNEL_RESULT_FAILED = 2;
    }

    required RegisterToastChannelResult result = 1;

    // Unique identifier of the channel. It will be used later to show toasts or to deregister the channel.
    optional int32 id = 2;
}

// Id: MESSAGE_UNREGISTER_TOAST_CHANNEL
// Receiver: Hudiy
// Description: Deregisters a previously registered toast channel.
message UnregisterToastChannel {
    // Unique identifier of the channel, provided in the MESSAGE_REGISTER_TOAST_CHANNEL_RESPONSE message.
    required int32 id = 1;
}

// Id: MESSAGE_SHOW_TOAST
// Receiver: Hudiy
// Description: Displays a toast message in a previously registered channel.
message ShowToast {
    // Unique identifier of the channel, provided in the MESSAGE_REGISTER_TOAST_CHANNEL_RESPONSE message.
    required int32 channel_id = 1;
    required string message = 2;

    // Font family used for the toast message icon. The font must be registered in Hudiy by adding it to main_configuration.json
    required string icon_font_family = 3;

    // Identifier of the icon within the font.
    required string icon_name = 4;
}

// Id: MESSAGE_OBD_CONNECTION_STATUS
// Receiver: Client
// Description:
//     Updates the status of ELM327 device connection to the car.
//     The message will be sent only if Subscription::OBD is present.
message ObdConnectionStatus {
    enum ObdConnectionState {
        OBD_CONNECTION_STATE_CONNECTED = 1;
        OBD_CONNECTION_STATE_DISCONNECTED = 2;
    }

    required ObdConnectionState state = 1;
}

// Id: MESSAGE_REGISTER_AUDIO_FOCUS_RECEIVER_REQUEST
// Receiver: Hudiy
// Description: Registers a receiver for controlling audio focus.
message RegisterAudioFocusReceiverRequest {
    // Name of the audio focus receiver
    required string name = 1;

    enum AudioStreamCategory {
        AUDIO_STREAM_CATEGORY_ENTERTAINMENT = 1;
        AUDIO_STREAM_CATEGORY_COMMUNICATION = 2;
    }
    
    // Category of the audio stream
    required AudioStreamCategory category = 2;

    // Priority of the stream when audio focus is in ducking mode.
    // Duck mode is a state where audio from other sources is not fully muted but temporarily lowered in volume ("ducked").
    // Navigation instructions use priority 100 by default.
    // If the stream is less important, set its priority below 100.
    // If the priority is higher than that of the current stream, audio focus will be taken over, otherwise request will be rejected.
    required int32 duck_priority = 3;
}

// Id: MESSAGE_REGISTER_AUDIO_FOCUS_RECEIVER_RESPONSE
// Receiver: Client
// Description: Response to the registration of a receiver for controlling audio focus.
message RegisterAudioFocusReceiverResponse {
    enum RegisterAudioFocusReceiverResult {
        REGISTER_AUDIO_FOCUS_RECEIVER_RESULT_OK = 1;
        REGISTER_AUDIO_FOCUS_RECEIVER_RESULT_FAILED = 2;
    }

    required RegisterAudioFocusReceiverResult result = 1;

    // Unique identifier of the receiver. It will be used later to request audio focus or to deregister the receiver.
    optional int32 id = 2;
}


// Id: MESSAGE_UNREGISTER_AUDIO_FOCUS_RECEIVER
// Receiver: Hudiy
// Description: Deregisters a previously registered audio focus receiver.
message UnregisterAudioFocusReceiver {
    // Unique identifier of the receiver, provided in the MESSAGE_REGISTER_AUDIO_FOCUS_RECEIVER_RESPONSE message.
    required int32 id = 1;
}

// Id: MESSAGE_AUDIO_FOCUS_CHANGE_REQUEST
// Receiver: Hudiy
// Description: Request audio focus change.
message AudioFocusChangeRequest {
    enum AudioFocusType {
        // Type of audio focus, e.g., for playing a media file.
        AUDIO_FOCUS_TYPE_GAIN = 1;

        // Type of audio focus, e.g., for a voice call.
        AUDIO_FOCUS_TYPE_TRANSIENT = 2;

        // Type of audio focus, e.g., for notifications or navigation instructions.
        AUDIO_FOCUS_TYPE_DUCK = 3;

        // Type used to release the currently granted audio focus.
        AUDIO_FOCUS_TYPE_RELEASE = 4;
    }

    // Unique identifier of the receiver, provided in the MESSAGE_REGISTER_AUDIO_FOCUS_RECEIVER_RESPONSE message.
    required int32 id = 1;

    // Type of audio focus the receiver wants to gain.
    required AudioFocusType type = 2;
}

// Id: MESSAGE_AUDIO_FOCUS_CHANGE_RESPONSE
// Receiver: Client
// Description: Response for the audio focus change.
message AudioFocusChangeResponse {
    // Unique identifier of the receiver, provided in the MESSAGE_REGISTER_AUDIO_FOCUS_RECEIVER_RESPONSE message.
    required int32 id = 1;

    // Indicates whether audio focus was granted.
    required bool result = 2;
}

// Id: MESSAGE_AUDIO_FOCUS_ACTION
// Receiver: Client
// Description: Notifications about changes in audio focus within the system.
message AudioFocusAction {
    enum AudioFocusActionType {
        // Audio played by the receiver should be suspended.
        AUDIO_FOCUS_ACTION_TYPE_SUSPEND = 1;

        // Audio played by the receiver can be restored.
        AUDIO_FOCUS_ACTION_TYPE_RESTORE = 2;

        // Audio focus was granted to another receiver.
        AUDIO_FOCUS_ACTION_TYPE_LOSS = 3;

        // The receiver should lower the volume of the currently playing audio.
        AUDIO_FOCUS_ACTION_TYPE_DUCK_START = 4;

        // The receiver can restore volume level of the currently playing audio.
        AUDIO_FOCUS_ACTION_TYPE_DUCK_END = 5;
    }

    enum LostAudioFocusType {
        LOST_AUDIO_FOCUS_TYPE_GAIN = 1;
        LOST_AUDIO_FOCUS_TYPE_TRANSIENT = 2;
        LOST_AUDIO_FOCUS_TYPE_DUCK = 3;
    }

    // Unique identifier of the receiver, provided in the MESSAGE_REGISTER_AUDIO_FOCUS_RECEIVER_RESPONSE message.
    required int32 id = 1;
    required AudioFocusActionType action = 2;

    // Type of audio focus previously granted to the receiver that has now been lost.
    optional LostAudioFocusType lost_type = 3;
}

// Id: MESSAGE_AUDIO_FOCUS_MEDIA_KEY
// Receiver: Client
// Description: Notifications about media key events.
message AudioFocusMediaKey {
    enum AudioFocusMediaKeyEventType
    {
        AUDIO_FOCUS_MEDIA_KEY_EVENT_TYPE_NONE = 0;
        AUDIO_FOCUS_MEDIA_KEY_EVENT_TYPE_PRESS = 1;
        AUDIO_FOCUS_MEDIA_KEY_EVENT_TYPE_RELEASE = 2;
    }

    enum AudioFocusMediaKeyType {
        AUDIO_FOCUS_MEDIA_KEY_TYPE_NONE = 0;
        AUDIO_FOCUS_MEDIA_KEY_TYPE_PLAY = 1;
        AUDIO_FOCUS_MEDIA_KEY_TYPE_PAUSE = 2;
        AUDIO_FOCUS_MEDIA_KEY_TYPE_PREVIOUS = 3;
        AUDIO_FOCUS_MEDIA_KEY_TYPE_NEXT = 4;
        AUDIO_FOCUS_MEDIA_KEY_TYPE_TOGGLE_PLAY = 5;
    }

    // Unique identifier of the receiver, provided in the MESSAGE_REGISTER_AUDIO_FOCUS_RECEIVER_RESPONSE message.
    required int32 id = 1;
    required AudioFocusMediaKeyEventType event_type = 2;
    required AudioFocusMediaKeyType key_type = 3;
}

// Id: MESSAGE_PHONE_CONNECTION_STATUS
// Receiver: Client
// Description:
//     Current status of the phone connection.
//     The message will be sent only if Subscription::PHONE is present.
message PhoneConnectionStatus {
    enum PhoneConnectionState {
        PHONE_CONNECTION_STATE_CONNECTED = 1;
        PHONE_CONNECTION_STATE_DISCONNECTED = 2;
    }

    required PhoneConnectionState state = 1;
    // Bluetooth name of the phone.
    required string name = 2;
}

// Id: MESSAGE_PHONE_VOICE_CALL_STATUS
// Receiver: Client
// Description:
//     Current status of the voice call.
//     The message will be sent only if Subscription::PHONE is present.
message PhoneVoiceCallStatus {
    enum PhoneVoiceCallState {
        PHONE_VOICE_CALL_STATE_NONE = 0;
        PHONE_VOICE_CALL_STATE_INCOMING = 1;
        PHONE_VOICE_CALL_STATE_ALERTING = 2;
        PHONE_VOICE_CALL_STATE_ACTIVE = 3;
    }

    required PhoneVoiceCallState state = 1;

    // Id (phone number) of the caller.
    required string caller_id = 2;

    // Name of the caller from contacts (if available).
    required string caller_name = 3;
}

// Id: MESSAGE_PHONE_LEVELS_STATUS
// Receiver: Client
// Description:
//     Current status of the battery and signal.
//     The message will be sent only if Subscription::PHONE is present.
message PhoneLevelsStatus {
    // Battery level from 0 (almost empty) to 5 (full or nearly full).
    required int32 bettery_level = 1;

    // Signal strength as a percentage (0–100%).
    required int32 signal_level = 2;
}

// Id: MESSAGE_KEY_EVENT
// Receiver: Hudiy
// Description: Inject key event.
message KeyEvent {
    enum KeyType {
        KEY_TYPE_UP = 1;
        KEY_TYPE_DOWN = 2;
        KEY_TYPE_LEFT = 3;
        KEY_TYPE_RIGHT = 4;        
        KEY_TYPE_SCROLL_LEFT = 5;
        KEY_TYPE_SCROLL_RIGHT = 6;
        KEY_TYPE_ENTER = 7;
        KEY_TYPE_BACK = 8;
        KEY_TYPE_HOME = 9;
        KEY_TYPE_ANSWER_CALL = 10;
        KEY_TYPE_PHONE_MENU = 11;
        KEY_TYPE_HANGUP_CALL = 12;
        KEY_TYPE_PLAY = 13;
        KEY_TYPE_TOGGLE_PLAY = 14;
        KEY_TYPE_PAUSE = 15;
        KEY_TYPE_STOP = 16;
        KEY_TYPE_PREVIOUS_TRACK = 17;
        KEY_TYPE_NEXT_TRACK = 18;
        KEY_TYPE_MEDIA_MENU = 19;
        KEY_TYPE_NAVIGATION_MENU = 20;
        KEY_TYPE_VOICE_COMMAND = 21;
        KEY_TYPE_TOGGLE_INPUT_FOCUS = 23;
    }

    enum EventType {
        EVENT_TYPE_PRESS = 1;
        EVENT_TYPE_RELEASE = 2;
    }

    required KeyType key_type = 1;
    required EventType event_type = 2;
}

// Id: MESSAGE_QUERY_OBD_DEVICE_REQUEST
// Receiver: Hudiy
// Description: Executes the given commands on ELM327 devices.
message QueryObdDeviceRequest {
    // List of commands to execute, e.g., querying a PID.
    repeated string commands = 1;

    // Client-provided unique ID used to match the request with its response.
    required int32 request_code = 2;
}

// Id: MESSAGE_QUERY_OBD_DEVICE_RESPONSE
// Receiver: Client
// Description: Result of executed commands on ELM327 devices.
message QueryObdDeviceResponse {
    required bool result = 1;

    // Response data for each command, in the same order as in the request.
    repeated string data = 2;

    // unique ID provided in the request.
    required int32 request_code = 3;
}

// Id: MESSAGE_SET_DARK_MODE
// Receiver: Hudiy
// Description: Controls dark and light themes.
message SetDarkMode {
    required bool enabled = 1;
}

enum OverlayVisibility {
    OVERLAY_VISIBILITY_NONE = 0;
    OVERLAY_VISIBILITY_ALWAYS = 1;
    OVERLAY_VISIBILITY_NATIVE_UI_ONLY = 2;
    OVERLAY_VISIBILITY_PROJECTION_ONLY = 3;
}

// Id: MESSAGE_SET_CUSTOM_OVERLAY_VISIBILITY
// Receiver: Hudiy
// Description: Controls visibility of a custom overlay.
message SetCustomOverlayVisibility {
    // Identifier from config file.
    required string identifier = 1;
    required OverlayVisibility visibility = 2;
}

// Id: MESSAGE_SET_NAVIGATION_OVERLAY_VISIBILITY
// Receiver: Hudiy
// Description: Controls visibility of the built-in navigation overlay.
message SetNavigationOverlayVisibility {
    required OverlayVisibility visibility = 2;
}

// Id: MESSAGE_SET_VOLUME_OVERLAY_VISIBILITY
// Receiver: Hudiy
// Description: Controls visibility of the built-in volume overlay.
message SetVolumeOverlayVisibility {
    required OverlayVisibility visibility = 2;
}

// Id: MESSAGE_DISPATCH_ACTION
// Receiver: Hudiy/Client
// Description:
//     Triggers an action when sent to Hudiy.
//     When received by the client, it indicates that a previously registered action was requested to be dispatched.
message DispatchAction {
    required string action = 1;
}

// Id: MESSAGE_REGISTER_ACTION_REQUEST
// Receiver: Hudiy
// Description: Registers an action with the given name.
message RegisterActionRequest {
    // Name of the action to register.
    // Name must be unique across the entire application.
    required string action = 1;
}

// Id: MESSAGE_REGISTER_ACTION_RESPONSE
// Receiver: Client
// Description: Response to an action registration request.
message RegisterActionResponse {
    // Name of the action that was requested for registration.
    required string action = 1;
    required bool result = 2;
}

// Id: MESSAGE_COVERART_REQUEST
// Receiver: Client
// Description:
//     Requests cover art when it is not available from any other source.
//     The message will be sent only if Subscription::COVERARTS is present.
//     Best practice is to register only one Subscription::COVERARTS for the entire application
//     to avoid race conditions between multiple Subscription::COVERARTS.
message CoverartRequest {
    // Id of the request. It must be used in response.
    required int32 request_code = 1;
    required string artist = 2;
    required string album = 3;
    required string title = 4;

    // Source that requested the cover art.
    required MediaSource source = 5;
}

// Id: MESSAGE_COVERART_RESPONSE
// Receiver: Hudiy
// Description: Response for previously requested cover art.
message CoverartResponse {
    // Id from the request.
    required int32 request_code = 1;

    // Buffer containing the cover art image if available, otherwise empty.
    required bytes coverart = 2;
}

// Id: MESSAGE_SET_EQUALIZER_PRESET
// Receiver: Hudiy
// Description: Sets preset of the equalizer.
message SetEqualizerPreset {
    // Name of the preset from config file.
    required string name = 1;
}

// Id: MESSAGE_SET_ANDROID_AUTO_DAY_NIGHT_MODE
// Receiver: Hudiy
// Description: Sets day/night mode for Android Auto projection.
message SetAndroidAutoDayNightMode {
    enum DayNightMode {
        // Sync with dark theme settings of Native UI
        COMMON = 1;

        // Force day mode
        DAY = 2;

        // Force night mode
        NIGHT = 3;
    }

    // Desired mode
    required DayNightMode mode = 1;
}

// Id: MESSAGE_SET_AUTOBOX_DAY_NIGHT_MODE
// Receiver: Hudiy
// Description: Sets day/night mode for Autobox projection.
message SetAutoboxDayNightMode {
    enum DayNightMode {
        // Sync with dark theme settings of Native UI
        COMMON = 1;

        // Force day mode
        DAY = 2;

        // Force night mode
        NIGHT = 3;
    }

    // Desired mode
    required DayNightMode mode = 1;
}

// Id: MESSAGE_CURRENT_MENU_ACTION
// Receiver: Client
// Description:
//     Updates the name of the last dispatched menu action.
//     The message will be sent only if Subscription::CURRENT_MENU_ACTION is present.
message CurrentMenuAction {
    required string action_name = 1;
}

// Id: MESSAGE_SET_BASS_TREBLE_BOOST
// Receiver: Hudiy
// Description: Sets the value [dB] and frequency [Hz] of the bass and treble boost effects.
message SetBassTrebleBoost {
    // value of bass gain [dB]
    optional int32 bass_gain = 1;

    // value of bass shelf frequency [Hz]
    optional int32 bass_frequency = 2;

    // value of treble gain [dB]
    optional int32 treble_gain = 3;

    // value of treble shelf frequency [Hz]
    optional int32 treble_frequency = 4;
}