!7

import static x30_pkg.x30_util.VF1;

sclass AudioInput > DynPrintLog {
  int bufSize = 40960;
  transient AudioLoop loop;
  transient float volume; // in percent
  
  visualize {
    ret centerAndSouthWithMargins(super.visualize(),
      jCenteredLine(jLiveValueLabel(mapLiveValue(func(float volume) -> S { "Volume: " + iround(volume) + " %" }, S, dm_fieldLiveValue('volume)))));
  }

  void start {
    ownTimer(loop = new AudioLoop(bufSize));
    loop.start();
  }
  
  void addAudioListener(VF1<short[]> l) { loop.audioListeners.add(l); }
  void removeAudioListener(VF1<short[]> l) { loop.audioListeners.remove(l); }

  class AudioLoop extends Thread implements AutoCloseable {
    TargetDataLine line;
    new Flag stopFlag;
    byte[] buf;
    L<VF1<short[]>> audioListeners = synchroList();
  
    *(int bufSize) {
      line = javaSound_recordLine(javaSound_cdQuality(), bufSize);
      buf = new byte[bufSize];
    }
    
    public void start { line.start°; super.start°; }
    void stopRecording { // "stop()" was taken
      if (stopFlag.isUp()) ret;
      stopFlag.raise°; line.close°;
      print("Audio input loop stopped.");
    }
    public void close { stopRecording(); }
    
    public void run° {
      print("Audio input loop started. Buffer size=" + l(buf) + " (" + iround(l(buf)/44100.0/4*1000) + " ms)");
      
      while (licensed() && !stopFlag.isUp()) {
        int n = line.read(buf, 0, l(buf));
        if (n < l(buf)) print("Weird: Got less than a buffer: " + n + "/" + l(buf));
        handleData(subByteArray(buf, 0, n));
      }
    }
    
    void handleData(byte[] data) {
      //print("Got audio data " + l(data));
      int min = 32767, max = -32768, n = l(data);
      for (int i = 0; i < n; i += 2) {
        short sample = shortFromBytes_littleEndian(data, i);
        min = min(min, sample);
        max = max(max, sample);
      }
      setField(volume := (float) (100*min(1, max(0, max-min)/65534.0)));
      //print("Volume: " + formatDouble(volume, 1) + " %");
      
      for i over audioListeners: { // synchro-safe, garbage-free iteration
        VF1<short[]> l = syncGet(audioListeners, i);
        continue if l == null;
        callF(l, data);
      }
    }
  }
}