import type { TrackReferenceOrPlaceholder } from '@livekit/components-core';
import { LocalTrackPublication, facingModeFromLocalTrack } from 'livekit-client';

/**
 * Try to determine the `facingMode` of a local participant video track.
 * @remarks
 * Works only on local video tracks.
 * @see {@link https://developer.mozilla.org/en-US/docs/Web/API/MediaTrackConstraints/facingMode | MDN docs on facingMode}
 * @alpha
 */
export function useFacingMode(
  trackReference: TrackReferenceOrPlaceholder,
): 'user' | 'environment' | 'left' | 'right' | 'undefined' {
  if (trackReference.publication instanceof LocalTrackPublication) {
    const localTrack = trackReference.publication.track;
    if (localTrack) {
      const { facingMode } = facingModeFromLocalTrack(localTrack);
      return facingMode;
    }
  }
  return 'undefined';
}