import DeviceChangeObserver from '../devicechangeobserver/DeviceChangeObserver';
import Device from './Device';
import DevicePermission from './DevicePermission';
/**
 * [[DeviceController]] keeps track of the devices being used for audio input
 * (e.g. microphone), video input (e.g. camera), audio output (e.g. speakers).
 * The list functions return MediaDeviceInfo objects. Once any list function is
 * called, changes in device availability are broadcast to any registered
 * [[DeviceChangeObserver]].
 *
 * Calling a choose function will request permission for the device indicated
 * by the device id or track constraint. Supply null to get the default device.
 * Make sure to choose the audio device before joining the session (even if
 * it is the default device) so that you can offer the user options if the
 * device cannot be selected before a connection is made.
 *
 * Note that in certain situations such as private tabs, the browser may
 * initially decline to provide device labels for when enumerating devices. If
 * this is the case, the internal device label trigger function is called to
 * try to coax the browser in to providing the labels. The default behavior of
 * the function is to make a microphone and camera access request which, if
 * successful, will unlock the labels. You may want to override this behavior to
 * provide a custom UX such as a prompt explaining why microphone and camera
 * access is being asked for by supplying your own function to
 * setDeviceLabelTrigger(). To disable the device label trigger, supply a
 * function that returns a rejected promise instead. For reference, the default
 * implementation calls getUserMedia for audio and video and returns the promise
 * to the stream so that the stream can be cleaned up once the labels are
 * detected.
 *
 * ```
 * (): Promise<MediaStream> => {
 *   return navigator.mediaDevices.getUserMedia({ audio: true, video: true });
 * }
 * ```
 */
export default interface DeviceController {
    /**
     * Lists currently available audio input devices.
     */
    listAudioInputDevices(): Promise<MediaDeviceInfo[]>;
    /**
     * Lists currently available video input devices.
     */
    listVideoInputDevices(): Promise<MediaDeviceInfo[]>;
    /**
     * Lists currently available audio output devices.
     */
    listAudioOutputDevices(): Promise<MediaDeviceInfo[]>;
    /**
     * Selects an audio input device to use. The constraint may be a device id,
     * MediaTrackConstraint, MediaStream (containing audio track), or null to
     * indicate no device. The promise always resolves with a DevicePermission
     * result indicating whether access was granted or denied.
     */
    chooseAudioInputDevice(device: Device): Promise<DevicePermission>;
    /**
     * Selects an video input device to use. The constraint may be a device id,
     * MediaTrackConstraint, MediaStream (containing video track), or null to
     * indicate no device. The promise always resolves with a DevicePermission
     * result indicating whether access was granted or denied.
     */
    chooseVideoInputDevice(device: Device): Promise<DevicePermission>;
    /**
     * Selects an audio output device for use. Null specifies the default device.
     */
    chooseAudioOutputDevice(deviceId: string | null): Promise<void>;
    /**
     * Adds an observer to receive callbacks about device changes.
     */
    addDeviceChangeObserver(observer: DeviceChangeObserver): void;
    /**
     * Removes an observer to stop receiving callbacks about device changes.
     */
    removeDeviceChangeObserver(observer: DeviceChangeObserver): void;
    /**
     * Gets an AnalyserNode from the current audio input. This node can be used to
     * generate the display for a mic indicator. Null is returned if no audio
     * input has been selected.
     */
    createAnalyserNodeForAudioInput(): AnalyserNode | null;
    /**
     * Starts a video preview of the currently selected video and binds it a video
     * element to be displayed before a meeting begins. Make sure to call
     * [[stopVideoPreviewForVideoInput]] when the preview is no longer necessary
     * so that the stream can be released and turn off the camera if it is not
     * being used anymore.
     */
    startVideoPreviewForVideoInput(element: HTMLVideoElement): void;
    /**
     * Stops the stream for a previously bound video preview and unbinds it from
     * the video element.
     */
    stopVideoPreviewForVideoInput(element: HTMLVideoElement): void;
    /**
     * Sets the device label trigger to use in the case where media device labels
     * are not present due to privacy restrictions in the browser. See above
     * for an explanation of how this works.
     */
    setDeviceLabelTrigger(trigger: () => Promise<MediaStream>): void;
    /**
     * Mixes the audio from the given media stream into the main audio input stream.
     */
    mixIntoAudioInput(stream: MediaStream): MediaStreamAudioSourceNode;
    /**
     * Sets the video input quality parameters to request when enabling video. These settings
     * take effect the next time a video input device is chosen. The default is 1280x720 @ 15 fps
     * with a max bandwidth of 1400 kbps.
     */
    chooseVideoInputQuality(width: number, height: number, frameRate: number, maxBandwidthKbps: number): void;
    /**
     * Sets the flag in [[DeviceController]] on whether to enable WebAudio-based device management.
     */
    enableWebAudio(flag: boolean): void;
}