webamp/js/mediaMiddleware.js

export default (media) => (
  (store) => {
    media.addEventListener('timeupdate', () => {
      store.dispatch({type: 'UPDATE_TIME_ELAPSED', elapsed: media.timeElapsed()});
    });

    media.addEventListener('ended', () => {
      store.dispatch({type: 'IS_STOPPED'});
    });

    media.addEventListener('playing', () => {
      store.dispatch({type: 'IS_PLAYING'});
    });

    media.addEventListener('waiting', () => {
      store.dispatch({type: 'START_WORKING'});
    });

    media.addEventListener('stopWaiting', () => {
      store.dispatch({type: 'STOP_WORKING'});
    });

    return (next) => (action) => {
      switch (action.type) {
        case 'PLAY':
          media.play();
          break;
        case 'PAUSE':
          media.pause();
          break;
        case 'STOP':
          media.stop();
      }
      return next(action);
    };
  }
);