!7

module RecognizeScreen > DynPrintLogAndEnabled {
  switchable int x1;
  switchable int y1;
  switchable int w = screenWidth();
  switchable int h = screenHeight();
  switchable double maxFPS = 10;
  switchable int previewWidth = 200;

  PersistableThrowable lastProcessingError;
  transient WithTimestamp<OKOrError<BufferedImage>> lastScreen;
  transient new Average screenShotTime;
  transient new Average iiTime;
  transient Timestamp loopStarted;
  transient new RestartableCountdown screenShotCountdown;
  transient BWIntegralImage ii;
  transient ImageSurface imageSurface;
  transient Throwable currentProcessingError;
  transient BufferedImage previewImage;

  Rect area() { ret rect(x1, y1, w, h); }
  
  start-thread {
    dm_doEvery(10.0, 60.0, r { if (enabled) printStats(); });

    loopStarted = tsNow();
    shoot();
  }

  void shoot enter {
    if (!enabled) ret;
    
    long targetTime = sysNow()+iround(1000/maxFPS);
    long time = nanoTime();

    try {
      lastScreen = withTimestamp(okOrError(-> screenshot(area())));
      screenShotTime.add(nanosToSeconds(nanoTime()-time));
      if (lastScreen->isOK()) {
        time = nanoTime();
        ii = BWIntegralImage(lastScreen!!);
        iiTime.add(nanosToSeconds(nanoTime()-time));
  
        previewImage = scaledBufferedImageFromBWIntegralImage(ii, previewWidth);
        imageSurface?.setImage(previewImage);
      }

      currentProcessingError = null;
    } catch print e {
      setField(lastProcessingError := currentProcessingError = e);
      sleepSeconds(60); // errors in processing are no good
    }
    
    screenShotCountdown.setTargetTime(targetTime, r shoot);
  }

  void printStats() { print(stats()); }

  S stats() {
    var screen = lastScreen?!;
    ret formatColonProperties_noNulls(
      "Monitored area", area(),
      "Error", screen?.getError(),
      "Last screenshot taken", lastScreen?.timeStamp(),
      "Average time to take a screenshot", screenShotTime,
      "Average time to make integral image", iiTime,
      "Capacity left in first core", percentRatioStrOneDigit(
        toSeconds(screenShotCountdown.totalSleepTime),
        elapsedSeconds(loopStarted))
     );
  }

  visual hsplit(super, imageSurface = doubleBufferedImageSurface_noAlpha());
}