webamp/js/mediaMiddleware.js

import {
  IS_PLAYING,
  IS_STOPPED,
  LOAD_AUDIO_URL,
  LOAD_AUDIO_FILE,
  PAUSE,
  PLAY,
  SEEK_TO_PERCENT_COMPLETE,
  SET_BAND_VALUE,
  SET_BALANCE,
  SET_MEDIA,
  SET_VOLUME,
  START_WORKING,
  STOP,
  STOP_WORKING,
  TOGGLE_REPEAT,
  TOGGLE_SHUFFLE,
  UPDATE_TIME_ELAPSED
} from './actionTypes';

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});
    });

    media.addEventListener('fileLoaded', () => {
      store.dispatch({
        type: SET_MEDIA,
        kbps: '128',
        khz: Math.round(media.sampleRate() / 1000).toString(),
        channels: media.channels(),
        name: media.name,
        length: media.duration()
      });
    });

    return (next) => (action) => {
      switch (action.type) {
        case PLAY:
          media.play();
          break;
        case PAUSE:
          media.pause();
          break;
        case STOP:
          media.stop();
          break;
        case SET_VOLUME:
          media.setVolume(action.volume);
          break;
        case SET_BALANCE:
          media.setBalance(action.balance);
          break;
        case TOGGLE_REPEAT:
          media.toggleRepeat();
          break;
        case TOGGLE_SHUFFLE:
          media.toggleShuffle();
          break;
        case SEEK_TO_PERCENT_COMPLETE:
          media.seekToPercentComplete(action.percent);
          break;
        case LOAD_AUDIO_URL:
          media.loadFromUrl(action.url, action.name);
          break;
        case LOAD_AUDIO_FILE:
          media.loadFromFileReference(action.file.fileReference);
          break;
        case SET_BAND_VALUE:
          if (action.band === 'preamp') {
            media.setPreamp(action.value);
          } else {
            media.setEqBand(action.band, action.value);
          }
          break;
      }
      return next(action);
    };
  }
);