webamp/js/mediaMiddleware.js

import {
  IS_PLAYING,
  IS_STOPPED,
  LOAD_AUDIO_URL,
  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,
  SET_EQ_OFF,
  SET_EQ_ON
} 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, action.autoPlay);
        break;
      case SET_BAND_VALUE:
        if (action.band === "preamp") {
          media.setPreamp(action.value);
        } else {
          media.setEqBand(action.band, action.value);
        }
        break;
      case SET_EQ_OFF:
        media.disableEq();
        break;
      case SET_EQ_ON:
        media.enableEq();
        break;
    }
    return next(action);
  };
};