Implement Headless JavaScript Playback

import { AudioTrack, HTMLMediaElement, TextTrack, VideoPlayer, VideoTrack } from '@amazon-devices/react-native-w3cmedia/dist/headless';
import {
  Event,
  EventListener,
  TrackEvent,
} from '@amazon-devices/react-native-w3cmedia/dist/headless';

import { ShakaPlayer } from './shakaplayer/ShakaPlayer';

import {
  IHttpHeader,
  IPlayerSessionId,
  IPlayerSessionLoadParams,
  IPlayerSessionMediaInfo,
  IPlayerSessionPosition,
  IPlayerSessionState,
  IPlayerSessionStatus,
  ITimeRange,
  ITrackType,
  IViewHandle,
} from '@amazon-devices/kepler-player-server';

import {
  IPlayerServer,
  IPlayerServerHandler,
  IPlayerServerFactory,
  PlayerServerFactory,
} from '@amazon-devices/kepler-player-server';

class PlayerServerHandler implements IPlayerServerHandler {
  #playerService: PlayerService;

  constructor(playerService: PlayerService) {
    console.log('[PlayerService] VegaPlayerServerHandler ctor');
    this.#playerService = playerService;
  }

  handleLoad(mediaInfo: IPlayerSessionMediaInfo, loadParams?: IPlayerSessionLoadParams, sessionId?: IPlayerSessionId): void {
    console.log('[PlayerService] handleLoad called with: ', {
      mediaInfo,
      loadParams,
      sessionId,
    });
    this.#playerService?.onLoad(mediaInfo, loadParams, sessionId);
  }

  handleUnload(sessionId?: IPlayerSessionId): void {
    console.log('[PlayerService] handleUnload called with: ', {
      sessionId
    });
    this.#playerService?.onUnload();
  }

  handleSetVideoView(handle: IViewHandle, sessionId?: IPlayerSessionId): void {
    console.log('[PlayerService] handleSetVideoView called with:', {
      handle,
      sessionId
    });
    this.#playerService?.onSurfaceViewCreated(handle.handle);
  }

  handleClearVideoView(sessionId?: IPlayerSessionId): void {
    console.log('[PlayerService] handleClearVideoView called with sessionId:', sessionId);
    this.#playerService?.onSurfaceViewDestroyed();
  }

  handleSetTextView(handle: IViewHandle, sessionId?: IPlayerSessionId): void {
    console.log('[PlayerService] handleSetVideoView called with:', {
      handle,
      sessionId
    });
    this.#playerService?.onCaptionViewCreated(handle.handle);
  }

  handleClearTextView(sessionId?: IPlayerSessionId): void {
    console.log('[PlayerService] handleClearTextView called with:', {
      sessionId
    });
    this.#playerService?.onCaptionViewDestroyed(handle.handle);
  }

  handlePlay(sessionId?: IPlayerSessionId): void {
    console.log('[PlayerService] handlePlay called with sessionId:', sessionId);
    this.#playerService?.handlePlay();
  }

  handlePause(sessionId?: IPlayerSessionId): void {
    console.log('[PlayerService] handlePause called with sessionId:', sessionId);
    this.#playerService?.handlePause();
  }

  handleSeek(position: number, isRelative?: boolean, sessionId?: IPlayerSessionId): void {
    console.log('[PlayerService] handleSeek called with:', {
      position,
      sessionId
    });
    this.#playerService?.handleSeek(position);
  }

  handleSetMute(isMuted: boolean, sessionId?: IPlayerSessionId): void {
    console.debug('[PlayerService] handleSetMute called with:', {
      sessionId
    });
    this.#playerService?.handleSetMute(isMuted);
  }

  handleSetPlaybackRate(playbackRate: number, sessionId?: IPlayerSessionId): void {
    console.log('[PlayerService] handleSetPlaybackRate called with:', {
      sessionId
    });
  }

  handleSetVolume(volume: number, sessionId?: IPlayerSessionId): void {
    console.log('[PlayerService] handleSetVolume called with:', {
      volume,
      sessionId
    });
    this.#playerService?.handleSetVolume(volume);
  }

  handleSetActiveTrack(trackType: ITrackType, trackId: string, sessionId?: IPlayerSessionId): void {
    console.log('[PlayerService] handleSetActiveTrack called with:', {
      trackType,
      trackId,
      sessionId
    });
    this.#playerService.handleSetActiveTrack(String(trackType), trackId);
  }

  handleGetCurrentPosition(sessionId?: IPlayerSessionId): number {
    console.log('[PlayerService] handleGetCurrentPosition called with:', {
      sessionId
    });
    return this.#playerService.getCurrentPlaybackPosition().position;
  }

  handleMessage(message: any, sessionId?: IPlayerSessionId): void {
    console.log('[PlayerService] handleMessage called with:', {
      sessionId
    });
  }

  handleStartBufferedRangesUpdates(sessionId?: IPlayerSessionId): void {
    console.log('[PlayerService] handleStartBufferedRangesUpdates called with:', {
      sessionId
    });
  }

  handleStopBufferedRangesUpdates(sessionId?: IPlayerSessionId): void {
    console.log('[PlayerService] handleStopBufferedRangesUpdates called with:', {
      sessionId
    });
  }

  handleStartStatusUpdates(sessionId?: IPlayerSessionId): void {
    console.log('[PlayerService] handleStartStatusUpdates called with:', {
      sessionId
    });
  }

  handleStopStatusUpdates(sessionId?: IPlayerSessionId): void {
    console.log('[PlayerService] handleStopStatusUpdates called with:', {
      sessionId
    });
  }

  handleStartTrackUpdates(sessionId?: IPlayerSessionId): void {
    console.log('[PlayerService] handleStartTrackUpdates called with:', {
      sessionId
    });
  }

  handleStopTrackUpdates(sessionId?: IPlayerSessionId): void {
    console.log('[PlayerService] handleStopTrackUpdates called with:', {
      sessionId
    });
  }

  handleStartMessageUpdates(sessionId?: IPlayerSessionId): void {
    console.log('[PlayerService] handleStartMessageUpdates called with:', {
      sessionId
    });
  }

  handleStopMessageUpdates(sessionId?: IPlayerSessionId): void {
    console.log('[PlayerService] handleStopMessageUpdates called with:', {
      sessionId
    });
  }

  handleStartErrorUpdates(sessionId?: IPlayerSessionId): void {
    console.log('[PlayerService] handleStartErrorUpdates called with:', {
      sessionId
    });
  }

  handleStopErrorUpdates(sessionId?: IPlayerSessionId): void {
    console.log('[PlayerService] handleStopErrorUpdates called with:', {
      sessionId
    });
  }
}

class PlayerService {
  #playerServerFactory: IPlayerServerFactory | undefined;
  #playerServer: IPlayerServer | undefined;
  #playerServerHandler: IPlayerServerHandler | undefined;
  #msePlayer: ShakaPlayer | undefined;
  #videoPlayer: VideoPlayer | undefined;
  #serviceComponentId: string = "com.yourcompany.kepler.headlessjsmediaplayer.service";
  #activeSurfaceHandle: string | undefined;
  #activeCaptionHandle: string | undefined;
  #activeSessionId: IPlayerSessionId | undefined;
  #hasError: boolean = false;

  #AUTOPLAY: boolean = true;

  #initializeVideoPlayer = async (): Promise<void> => {
    console.log('[PlayerService] initializeVideoPlayer');
    this.#videoPlayer = new VideoPlayer();
    // @ts-ignore
    global.gmedia = this.#videoPlayer;
    await this.#videoPlayer.initialize();
    this.#setUpEventListeners();
    this.#videoPlayer.autoplay = this.#AUTOPLAY;
    this.#initialiseMsePlayer();
  };

  #initialiseMsePlayer = () => {
    console.log('[PlayerService] initialiseMsePlayer');
    if (this.#videoPlayer !== undefined) {
      this.#msePlayer = new ShakaPlayer(this.#videoPlayer as HTMLMediaElement, {
          secure: false,                    // Playback goes through secure or non-secure mode
          abrEnabled: true,                 // Enables Adaptive Bit-Rate (ABR) switching
          abrMaxWidth: 3840,   // Maximum width allowed for ABR
          abrMaxHeight: 2160, // Maximum height allowed for ABR
          startPosition: 0
        });
    }
  };

  #setUpEventListeners = (): void => {
    console.log('[PlayerService] setUpEventListeners');
    this.#videoPlayer?.addEventListener('play', this.#onPlay);
    this.#videoPlayer?.addEventListener('pause', this.#onPause);
    this.#videoPlayer?.addEventListener('seeked', this.#onSeeked);
    this.#videoPlayer?.addEventListener('ended', this.#onEnded);
    this.#videoPlayer?.addEventListener('error', this.#onError);

    this.#videoPlayer?.audioTracks.addEventListener('addtrack', this.#onAudioTrackAdded);
    this.#videoPlayer?.videoTracks.addEventListener('addtrack', this.#onVideoTrackAdded);
    this.#videoPlayer?.textTracks.addEventListener('addtrack', this.#onTextTrackAdded);
    this.#videoPlayer?.audioTracks.addEventListener('removetrack', this.#onAudioTrackRemoved);
    this.#videoPlayer?.videoTracks.addEventListener('removetrack', this.#onVideoTrackRemoved);
    this.#videoPlayer?.textTracks.addEventListener('removetrack', this.#onTextTrackRemoved);

    (this.#videoPlayer as HTMLMediaElement)?.addEventListener('waiting', this.#updateBufferedRanges);
    (this.#videoPlayer as HTMLMediaElement)?.addEventListener('canplay', this.#updateBufferedRanges);
  };

  #removeEventListeners = (): void => {
    console.log('[PlayerService] removeEventListeners');
    this.#videoPlayer?.removeEventListener('play', this.#onPlay);
    this.#videoPlayer?.removeEventListener('pause', this.#onPause);
    this.#videoPlayer?.removeEventListener('seeked', this.#onSeeked);
    this.#videoPlayer?.removeEventListener('ended', this.#onEnded);
    this.#videoPlayer?.removeEventListener('error', this.#onError);

    this.#videoPlayer?.audioTracks.removeEventListener('addtrack', this.#onAudioTrackAdded);
    this.#videoPlayer?.videoTracks.removeEventListener('addtrack', this.#onVideoTrackAdded);
    this.#videoPlayer?.textTracks.removeEventListener('addtrack', this.#onTextTrackAdded);
    this.#videoPlayer?.audioTracks.removeEventListener('removetrack', this.#onAudioTrackRemoved);
    this.#videoPlayer?.videoTracks.removeEventListener('removetrack', this.#onVideoTrackRemoved);
    this.#videoPlayer?.textTracks.removeEventListener('removetrack', this.#onTextTrackRemoved);

    (this.#videoPlayer as HTMLMediaElement)?.removeEventListener('waiting', this.#updateBufferedRanges);
    (this.#videoPlayer as HTMLMediaElement)?.removeEventListener('canplay', this.#updateBufferedRanges);
  };

  #onPlay: EventListener = (event?: Event) => {
    console.log(`[PlayerService] onPlay ${event?.type}`);
    this.updateStatus(this.#activeSessionId);
  }

  #onPause: EventListener = (event?: Event) => {
    console.log('[PlayerService] onPause');
    this.updateStatus(this.#activeSessionId);
  }

  #onSeeked: EventListener = (event?: Event) => {
    console.log('[PlayerService] onSeeked');
  }

  #onEnded: EventListener = (event?: Event) => {
    console.log('[PlayerService] onEnded');
    this.updateStatus(this.#activeSessionId);
    this.onUnload();
  }

  #onError: EventListener = (event?: Event) => {
    console.log(`[PlayerService] onError with code: {}, message: {}`,
      this.#videoPlayer?.error.code, this.#videoPlayer?.error.message);
    this.#hasError = true;
  };

  #onAudioTrackAdded: EventListener = (event?: Event) => {
    if (event instanceof TrackEvent) {
      let track = (event as TrackEvent).track;
      if (track !== undefined) {
        this.#playerServer?.addTrack({
          id: track.id,
          type: "AUDIO",
          kind: track.kind,
          label: track.label,
          language: track.language,
          enabled: (track as AudioTrack).enabled
        }, this.#activeSessionId);
        // Do other operations if needed.
      } else {
        console.error("Undefined audio track.");
      }
    }
  }

  #onVideoTrackAdded: EventListener = (event?: Event) => {
    if (event instanceof TrackEvent) {
      let track = (event as TrackEvent).track;
      if (track !== undefined) {
        this.#playerServer?.addTrack({
          id: track.id,
          type: "VIDEO",
          kind: track.kind,
          label: track.label,
          language: track.language,
          enabled: (track as VideoTrack).selected
        }, this.#activeSessionId);
        // Do other operations if needed.
      } else {
        console.error("Undefined video track.");
      }
    }
  }

  #onTextTrackAdded: EventListener = (event?: Event) => {
    if (event instanceof TrackEvent) {
      let track = (event as TrackEvent).track;
      if (track !== undefined) {
        this.#playerServer?.addTrack({
          id: track.id,
          type: "TEXT",
          kind: track.kind,
          label: track.label,
          language: track.language,
          mode: (track as TextTrack).mode
        }, this.#activeSessionId);
        // Do other operations if needed.
      } else {
        console.error("Undefined text track.");
      }
    }
  }

  #onAudioTrackRemoved: EventListener = (event?: Event) => {
    if (event instanceof TrackEvent) {
      let track = (event as TrackEvent).track;
      if (track !== undefined) {
        this.#playerServer?.removeTrack({
          id: track.id,
          type: "AUDIO",
          kind: track.kind,
          label: track.label,
          language: track.language,
          enabled: (track as AudioTrack).enabled
        }, this.#activeSessionId);
        // Do other operations if needed.
      } else {
        console.error("Undefined audio track.");
      }
    }
  }

  #onVideoTrackRemoved: EventListener = (event?: Event) => {
    if (event instanceof TrackEvent) {
      let track = (event as TrackEvent).track;
      if (track !== undefined) {
        this.#playerServer?.removeTrack({
          id: track.id,
          type: "VIDEO",
          kind: track.kind,
          label: track.label,
          language: track.language,
          enabled: (track as VideoTrack).selected
        }, this.#activeSessionId);
        // Do other operations if needed.
      } else {
        console.error("Undefined video track.");
      }
    }
  }

  #onTextTrackRemoved: EventListener = (event?: Event) => {
    if (event instanceof TrackEvent) {
      let track = (event as TrackEvent).track;
      if (track !== undefined) {
        this.#playerServer?.removeTrack({
          id: track.id,
          type: "TEXT",
          kind: track.kind,
          label: track.label,
          language: track.language,
          mode: (track as TextTrack).mode
        }, this.#activeSessionId);
        // Do other operations if needed.
      } else {
        console.error("Undefined text track.");
      }
    }
  }

  #updateBufferedRanges: EventListener = (event?: Event) => {
    const result: Array<ITimeRange> = [];
    const bufferedTimeRanges = this.#videoPlayer?.buffered;
    if (bufferedTimeRanges === undefined) {
      return;
    }
    for (let i = 0; i < bufferedTimeRanges.length; ++i) {
      result.push({
        start: bufferedTimeRanges.start(i),
        end: bufferedTimeRanges.end(i)
      });
    }

    this.#playerServer?.updateBufferedRanges(result, this.#activeSessionId);
  }

  #getPlaybackState = () : IPlayerSessionState => {
    if (!this.#videoPlayer) return IPlayerSessionState.ENDED;

    if (this.#hasError) return IPlayerSessionState.ERROR;
    if (this.#videoPlayer.ended) return IPlayerSessionState.ENDED;
    if (this.#videoPlayer.seeking) return IPlayerSessionState.SEEKING;
    if (this.#videoPlayer.paused) {
      return IPlayerSessionState.PAUSED;
    }
    return IPlayerSessionState.PLAYING;
  }

  updateStatus = (sessionId?: IPlayerSessionId) => {
    console.debug(`[PlayerService] updateStatus with sessionId: ${sessionId !== undefined ? sessionId?.id: "undefined"}`);
    const playerSessionStatus: IPlayerSessionStatus = {
      sessionId: sessionId,
      playbackState: this.#getPlaybackState(),
      playbackRate: this.#videoPlayer?.playbackRate || 1,
      isMuted: this.#videoPlayer?.muted || false,
      volume: this.#videoPlayer?.volume || 0,
      seekable: (this.#videoPlayer?.seekable.length || 0) > 0,
      duration: this.#videoPlayer?.duration
    }
    this.#playerServer?.updateStatus([playerSessionStatus]);
  }

  getCurrentPlaybackPosition = () : IPlayerSessionPosition => {
    return {
      sessionId: this.#activeSessionId,
      position: this.#videoPlayer?.currentTime ?? 0 as number,
    } as IPlayerSessionPosition;
  }

  onSurfaceViewCreated = (surfaceHandle: string): void => {
    console.log('[PlayerService] onSurfaceViewCreated called with surfaceHandle: ', surfaceHandle);
    this.#activeSurfaceHandle = surfaceHandle;
    this.#videoPlayer?.setSurfaceHandle(surfaceHandle);
  };

  onSurfaceViewDestroyed = (): void => {
    console.log('[PlayerService] onSurfaceViewDestroyed called');
    if (this.#activeSurfaceHandle !== undefined) {
      this.#videoPlayer?.clearSurfaceHandle(this.#activeSurfaceHandle);
    }
  }

  onCaptionViewCreated = (surfaceHandle: string): void => {
    console.log('[PlayerService] onCaptionViewCreated called with surfaceHandle: ', surfaceHandle);
    this.#activeCaptionHandle = surfaceHandle;
    this.#videoPlayer?.setCaptionViewHandle(surfaceHandle);
  };

  onCaptionViewDestroyed = (): void => {
    console.log('[PlayerService] onCaptionViewDestroyed called');
    if (this.#activeCaptionHandle !== undefined) {
      this.#videoPlayer?.clearCaptionViewHandle(this.#activeCaptionHandle);
    }
  }

  #findValueByKey = (httpHeaders: Array<IHttpHeader> | undefined, key: string) : string | undefined => {
    if (httpHeaders !== undefined) {
      for (let i : number = 0; i < httpHeaders.length; ++i) {
        if (httpHeaders[i].name === key) {
            return httpHeaders[i].value;
        }
      }
    }

    return undefined;
  }

  onLoad = async (urlInfo: IPlayerSessionMediaInfo,
      loadParams?: IPlayerSessionLoadParams,
      sessionId? : IPlayerSessionId): Promise<void> => {
    console.log(`[PlayerService] onLoad with urlInfo: {}`, JSON.stringify(urlInfo));
    if (loadParams !== undefined) {
      console.log(`[PlayerService] onLoad with loadParams: {}`, JSON.stringify(loadParams));
    }
    this.#hasError = false;
    const content = {
      "uri" : urlInfo.mediaUrl.url,
      "container": this.#findValueByKey(urlInfo.mediaUrl.httpHeaders, 'container') || 'FMP4'
    };
    this.onUnload();
    this.#activeSessionId = sessionId;
    await this.#initializeVideoPlayer();
    this.#msePlayer?.load(content, this.#AUTOPLAY);
  }

  onUnload = () => {
    console.log('[PlayerService] onUnload');
    this.#removeEventListeners();
    this.#msePlayer?.unload();
    this.#msePlayer = undefined;
    this.#videoPlayer?.deinitialize();
    this.#videoPlayer = undefined;
    this.#hasError = false;
    // @ts-ignore
    global.gmedia = null;
  };

  handlePlay = () => {
    console.log('[PlayerService] handlePlay');
    if (this.#videoPlayer) {
      this.#videoPlayer.play();
    } else {
      console.log('[PlayerService] handlePlay this.#videoPlayer is undefined');
    }
  };

  handlePause = () => {
    console.log('[PlayerService] handlePause');
    if (this.#videoPlayer) {
      this.#videoPlayer.pause();
    } else {
      console.log('[PlayerService] handlePause this.#videoPlayer is undefined');
    }
  };

  handleSeek = (seekTimeSeconds: number) => {
    console.log(`[PlayerService] handleSeek with seekTimeSeconds: ${seekTimeSeconds}`);
    if (this.#videoPlayer) {
      const currentTime = this.#videoPlayer.currentTime;
      this.#videoPlayer.currentTime = currentTime + seekTimeSeconds;
    } else {
      console.log('[PlayerService] handleSeek this.#videoPlayer is undefined');
    }
  }

  handleSetMute = (isMuted: boolean) => {
    console.debug('[PlayerService] handleSetMute');
    if (this.#videoPlayer) {
      this.#videoPlayer.muted = isMuted;
      this.updateStatus(this.#activeSessionId);
    } else {
      console.log('[PlayerService] handleSetMute this.#videoPlayer is undefined');
    }
  };

  handleSetVolume = (volume: number) => {
    console.debug('[PlayerService] handleSetVolume');
    if (this.#videoPlayer) {
      this.#videoPlayer.volume = volume;
      this.updateStatus(this.#activeSessionId);
    }
  }

  handleSetActiveTrack = (trackType: string, trackId: string) => {
    console.debug(`[PlayerService] handleSetActiveTrack ${trackType} ${trackId}`);
    if (trackType === 'AUDIO') {
      if (this.#msePlayer) {
        const audioTrackList = this.#msePlayer.getAudioLanguages();
        if (audioTrackList !== undefined && audioTrackList.length > 0) {
          let trackLang: string = audioTrackList[parseInt(trackId)];
          this.#msePlayer.selectAudioLanguage(trackLang);
        } else {
          console.error('[PlayerService] handleSetActiveTrack - audio track list is empty.');
        }
      } else {
        console.error('[PlayerService]: handleSetActiveTrack msePlayer not initialised');
      }
    } else {
      console.debug('[PlayerService] handleSetActiveTrack - only audio track handling is implemented.');
    }
  }

  async start(): Promise<void> {
    console.log('[PlayerService] start');
    this.#playerServerFactory = new PlayerServerFactory();
    this.#playerServer = this.#playerServerFactory.getOrMakeServer();
    this.#playerServerHandler = new PlayerServerHandler(this);
    if (this.#playerServerHandler !== undefined) {
      console.log('[PlayerService] Calling setHandler');
      this.#playerServer?.setHandler(
        this.#playerServerHandler,
        this.#serviceComponentId);
    }
    await this.#initializeVideoPlayer();
    console.log('[PlayerService] Service started');
  }

  async stop(): Promise<void> {
    this.onUnload();
  }

}

const playerService: PlayerService = new PlayerService();

// Lifecycle methods
export async function onStartService(): Promise<void> {
  console.log('[PlayerService] Called onStartService()');

  // set global.navigator and globa.window needed by @amazon-devices/react-native-w3cmedia
  // This is a temporary workaround till either @amazon-devices/react-native-w3cmedia or headless runtime
  // do this on behalf of the app developer
  // @ts-ignore
  let navigator = global.navigator;
  if (navigator === undefined) {
    // @ts-ignore
    global.navigator = navigator = {};
  }
  /**
   * Sets up global variables for React Native.
   * You can use this module directly, or just require InitializeCore.
   */
  // @ts-ignore
  if (global.window === undefined) {
    // $FlowExpectedError[cannot-write] The global isn't writable anywhere but here, where we define it.
    // @ts-ignore
    global.window = global;
  }
  // @ts-ignore
  if (global.self === undefined) {
    // $FlowExpectedError[cannot-write] The global isn't writable anywhere but here, where we define it.
    // @ts-ignore
    global.self = global;
  }
  await playerService.start();
  console.log('[PlayerService] Service started');
}

export async function onStopService(): Promise<void> {
  console.log('[PlayerService] Called onStopService()');
  await playerService.stop();
  console.log('[PlayerService] Service stopped');
}

import React from 'react';
import { View, Text, StyleSheet } from 'react-native';

import { IPlayerClientFactory, IPlayerClient } from '@amazon-devices/kepler-player-client';
import { IPlayerSessionId } from '@amazon-devices/kepler-player-server';

import AppStack from './components/AppStack'

const App = () => {

  const playerClientFactory = useRef<IPlayerClientFactory | undefined>(undefined);
  const playerClient = useRef<IPlayerClient | undefined>(undefined);
  const playerSessionId = useRef<IPlayerSessionId | undefined>(undefined);
  const playerServiceComponentId = "com.yourcompany.kepler.headlessjsmediaplayer.service";

  // async function to initializePlayer
  const initializePlayer = async () => {
    console.log('[PlayerUI] start');
    console.log('[PlayerUI] Creating PlayerClientFactory');
    playerClientFactory.current = new PlayerClientFactory();
    console.log('[PlayerUI] Creating PlayerClient');
    playerClient.current
      = playerClientFactory.current.getOrMakeClient(playerServiceComponentId);
    if (!playerClient.current) {
      console.log('[PlayerUI] Error creating PlayerClient');
      throw new Error('Failed to initialize VegaPlayerClient');
    }
    playerSessionId.current = { id: Math.floor(Math.random() * 1000) };
  }

  React.useEffect(() => {
    // call player initialization
    initializePlayer();
  }, [])

  return (
    <Provider store={store}>
      <ThemeProvider theme={theme}>
        <NavigationContainer>
          {/* pass IPlayerClient */}
          <AppStack playerClient={playerClient} />
        </NavigationContainer>
      </ThemeProvider>
    </Provider>
  );
};

export default App;

const styles = StyleSheet.create({
  container: {
    flex: 1
  }
});

// Use keplerPlayerClient where you load content in your player component

export const VideoTile = ({playerClient}) => {
  const positionListener = useRef<IPlayerSessionPositionListener>({
    onPositionUpdated: (updatedPosition: Array<IPlayerSessionPosition>) => {
      console.debug('[PlayerUI] onPositionUpdated', JSON.stringify(updatedPosition));
      const currentSessionId = playerSessionId.current;
      console.debug(`[PlayerUI] onPositionUpdated currentSessionId: ${currentSessionId?.id}`);
      const updatePositionForSession = updatedPosition.find(
          position => position.sessionId?.id === currentSessionId?.id
      ) ?? null;
      setPlaybackPosition(updatePositionForSession?.position + 's');
    }
  });

  const registerPlayerSessionPositionListener = async() => {
    if (positionListenerSubscription.current === undefined) {
      positionListenerSubscription.current = await playerClient.current?.registerPositionListener(positionListener.current, 1, playerSessionId.current); // receive new status update every 1s
      console.debug('[PlayerUI] IPlayerSessionPositionListener registered');
    } else {
      console.debug('[PlayerUI] IPlayerSessionPositionListener already registered');
    }
  }

  const unregisterPlayerSessionPositionListener = () : void => {
    if (positionListenerSubscription.current !== undefined) {
      positionListenerSubscription.current.unsubscribe();
      positionListenerSubscription.current = undefined;
      console.debug('[PlayerUI] IPlayerSessionPositionListener deregistered');
    } else {
      console.debug('[PlayerUI] IPlayerSessionPositionListener already deregistered');
    }
  }

  // let the values in content object are:
  // {
  //   title: 'Video 1',
  //   secure: 'false', // true : Use Secure Video Buffers. false: Use Unsecure Video Buffers.
  //   uri: 'https://storage.googleapis.com/shaka-demo-assets/angel-one-hls/hls.m3u8',
  //   drm_scheme: '', // com.microsoft.playready, com.widevine.alpha
  //   drm_license_uri: '', // DRM License acquisition server URL : needed only if the content is DRM protected
  //   container: 'FMP4',
  // }
  const handleVideoSelection = async(content) => {
    console.log('[PlayerUI] Video selected: ', content.title);
    console.log(`[PlayerUI] Calling IPlayerClient load with: `, {
      url: content.uri,
      sessionId: playerSessionId.current,
    });
    try {
      await playerClient.current?.load(
        {
          mediaUrl: {
            url: content.uri,
            httpHeaders: [
              {
                name: 'container',
                value: content.container
              }
            ]
          }
        } as IPlayerSessionMediaInfo,
        { startPosition: 0, autoPlay: true} as IPlayerSessionLoadParams,
        playerSessionId.current
      );
    } catch (error) {
      console.error('Error while calling load: ', error);
      // Perform error handling.
    }

    if (autoPlay.current) {
      registerPlayerSessionPositionListener();
    }
    await setActiveSurfaceHandle();
    await setActiveCaptionsViewHandle();
  }

  return (
    <View>
     {/* non exhaustive example, but assuming you have many video tiles */}
     {/* ... */ }
      <YourVideoCard>
        <TouchableOpacity
          key={index}
          style={styles.playlistItem}
          onPress={() => handleVideoSelection(item)}
        >
          <Text style={styles.playlistText}>{item.title}</Text>
        </TouchableOpacity>
      <YourVideoCard>
    </View>
  )
}

try {
  await playerClient.current?.load(
      {
        mediaUrl: {
          url: content.uri,
          httpHeaders: [
            {
              name: 'container',
              value: content.container
            }
          ]
        }
      } as IPlayerSessionMediaInfo,
      { startPosition: 0, autoPlay: true} as IPlayerSessionLoadParams,
      playerSessionId.current
  );
} catch (error) {
  console.error('Error while calling load: ', error);
  // Perform error handling.
}

// Use keplerPlayerClient to handle play/pause events where your playerUI is located

export const Player = ({playerClient}) {

  const handlePlay = async (): Promise<void> => {
    console.log('[PlayerUI] Play button pressed');
    registerPlayerSessionPositionListener();
    try {
      await playerClient.current?.play(playerSessionId.current);
    } catch (error) {
      console.error('Error while calling play: ', error);
      // Perform error handling.
    }
  };

  const handlePause = async (): Promise<void> => {
    console.log('[PlayerUI] Pause button pressed');
    unregisterPlayerSessionPositionListener();
    try {
      await playerClient.current?.pause(playerSessionId.current);
    } catch (error) {
      console.error('Error while calling pause: ', error);
      // Perform error handling.
    }
  };

  return (
    <YourPlayer>{...}</YourPlayer>
  )