srecord noeq G22ChallengePanel(G22Challenge challenge) extends HasChangeListeners is Swingable {
  settableWithChange long randomSeed = 1; //randomUnsignedInt();
  
  //transient JPanel imagesPanel = jline();
  transient DynamicHStack imagesPanel;
  transient L<Entry> entries = syncL();
  transient JComponent imagesSection;
  transient GazelleV_LeftArrowScript.Script parsedScript;
  settableWithChange Set<Class> solutionTypes = syncSet();

  transient settable new G22Utils g22utils;
  settable double timeoutPerImage = 10.0;
  settable int imagesToPaint = 3;
  settable int interval = 100;
  settable int imageDisplaySize = 100;
  settable Color imageBorderColor1 = Color.green;
  settable Color imageBorderColor2 = Color.red;
  settable int imageBorderSize = 1;
  
  visualize {
    imagesPanel = (DynamicHStack) dynamicHStack().spacing(20);
    awtCalcEvery(imagesPanel, interval, r _paintAnImage);
    
    ret withCenteredBoldTitle(str(challenge),
      withTopMargin(jvsplit(
        northAndCenterWithMargin(
          centerAndEastWithMargin(
            centeredLiveValueLabel(
              liveValue_hasChangeListeners(this,
                -> "Looking for: " + solutionTypeDesc())),
            swing(-> JPopDownButton(menu ->
              menu.add(jMenuItem("Random seed: " + n2(randomSeed)))))
          ),
          imagesSection = jCenteredRaisedSection("Images", jBorderlessHigherScrollPane(jfullcenter(imagesPanel))),
          /*jRightAlignedLine(
            withLabel("Random seed:",
              liveValueLabel(liveValue_hasChangeListeners(this, -> randomSeed)))),*/
        ),
        jCenteredSection("Analysis",
          jTodo()
        )
      )));
  }
  
  void _paintAnImage {
    if (l(entries) >= imagesToPaint) ret;
    
    int index = l(entries)+1;
    Entry entry = new(index, (int) (randomSeed+index-1));
    entries.add(entry);
      
    try {
      if (parsedScript == null) {
        var parser = g22utils.leftArrowParser();
        parsedScript = parser.parse(challenge.code);
      }
      
      new VarContext ctx;
      var result = evalWithTimeout(timeoutPerImage, -> {
        temp tempSetRandomSeed((int) entry.seed);
        ret parsedScript.get(ctx);
      });
      
      if (result.isA()) {
        var returnedObject = result.a();
        if (returnedObject instanceof MakesBufferedImage
          || returnedObject instanceof Image)
          returnedObject = toBufferedImage(returnedObject);
        if (returnedObject cast BufferedImage) {
          entry.solution(ctx.get("solution"));
          updateSolutionType(entry.solution);
          addImage(entry, returnedObject);
        } else {
          addImage(entry, null, jcenteredlabel("Script did not return an image but instead " + aOrAn(className(returnedObject))));
        }
      } else {
        addImage(entry, null, jcenteredlabel("Script timed out after " + nSeconds(iceil(timeoutPerImage))));
      }
    } catch print e {
      entry.error(e);
      addImage(entry, null, jError(e));
    } finally {
      entry.calculating(false);
    }
  }
  
  void addImage(Entry entry, BufferedImage image, JComponent component) {
    entry.image(image).component(component);
    addAndRevalidate(imagesPanel, component);
    setSectionTitle(imagesSection, firstToUpper(nImages(entries)) + " calculated");
  }
  
  void addImage(Entry entry, BufferedImage image) {
    entry.image(image);
    addImage(entry, image, imageToComponent(entry));
  }
  
  JComponent imageToComponent(Entry entry) {
    var image = entry.image;
    
    // var is = g22utils.stdImageSurface(image);
    // jFixedSize(image.getWidth(), image.getHeight(), is);
    // ret is;
        
    double scale = calcFitScale(image, imageDisplaySize);
    var image2 = scaleImageWithOp(image, scale,
      AffineTransformOp.TYPE_NEAREST_NEIGHBOR);
    for (color : ll(imageBorderColor1, imageBorderColor2))
      image2 = addBorderToImage(image2, color, imageBorderSize);
    S toolTip = "Image " + n2(entry.index) + " of " + challenge + " (seed " + n2(entry.seed) + ", " + image.getWidth() + "*" + image.getHeight() + " px)";
    JButton b = withToolTip(toolTip, jimageButton(image2));
    setMargin(10, b);
    ret b;
  }
  
  class Entry {
    int index; // index in sequence starting with 1
    long seed; // seed for randomizer
    settable BufferedImage image;
    settable Throwable error;
    settable O solution;
    settable bool calculating = true;
    settable JComponent component;
    
    *(int *index, long *seed) {}
  }
  
  void updateSolutionType(O solution) {
    Class c = _getClass(solution);
    if (solutionTypes.add(c)) change();
  }
  
  S solutionTypeDesc() {
    LS types = map solutionTypeDesc(solutionTypes);
    ret textOut_or(types, "Calculating...");
  }
  
  S solutionTypeDesc(Class c) {
    if (c == null)
      ret "no solution given";
    if (c == Rect)
      ret "a rectangular area in the image";
    ret aOrAn(shortClassName(c));
  }
}