package com.atlassian.core.util.thumbnail.loader;
   
   import com.atlassian.core.util.ImageInfo;
   import com.google.common.base.Optional;
   import com.google.common.base.Throwables;
   
   import javax.imageio.ImageIO;
   import javax.imageio.ImageReadParam;
   import javax.imageio.ImageReader;
  import javax.imageio.ImageTypeSpecifier;
  import javax.imageio.stream.ImageInputStream;
  import java.awt.image.BufferedImage;
  import java.io.IOException;
  import java.io.InputStream;
  import java.util.Iterator;
  
  /**
   * This is a workaround for JDK bug:
   * http://bugs.sun.com/view_bug.do?bug_id=4884308
   * "IllegalArgExptn thrown when reading image using TYPE_BYTE_GRAY after TYPE_CUSTOM"
   * <p/>
   * Such image will be loaded Black-and-white instead of not being loaded at all.
   */
  class FixedImageLoader implements ImageLoader
  {
  
      @Override
      public Optional<BufferedImage> loadImage(final InputStream inputStream, ImageInfo imageInfo) throws IOException
      {
          ImageInputStream imageInputStream = null;
          BufferedImage bufferedImage = null;
          Exception lastException = null;
          try
          {
              inputStream.reset();
              imageInputStream = ImageIO.createImageInputStream(inputStream);
              final Iterator<ImageReader> imageReaders = ImageIO.getImageReadersByFormatName("JPEG");
  
              while (imageReaders.hasNext())
              {
                  ImageReader reader = null;
                  try
                  {
                      reader = imageReaders.next();
                      reader.setInput(imageInputStream);
  
                      bufferedImage = reader.read(0, getFixedReadParam(reader));
                      if (null != bufferedImage) break;
                  }
                  catch (Exception e)
                  {
                      lastException = e;
                  }
                  finally
                  {
                      if (null != reader)
                          reader.dispose();
                  }
              }
          }
          finally
          {
              if (imageInputStream != null)
                  imageInputStream.close();
          }
          if(bufferedImage == null)
          {
              Throwables.propagateIfInstanceOf(lastException, IOException.class);
              throw new IOException(lastException);
          }
          return Optional.of(bufferedImage);
      }
  
      private ImageReadParam getFixedReadParam(final ImageReader reader) throws IOException
      {
          ImageReadParam param = reader.getDefaultReadParam();
          Iterator<ImageTypeSpecifier> imageTypes = reader.getImageTypes(0);
          while (imageTypes.hasNext())
          {
              ImageTypeSpecifier imageTypeSpecifier = imageTypes.next();
              int bufferedImageType = imageTypeSpecifier.getBufferedImageType();
              if (bufferedImageType == BufferedImage.TYPE_BYTE_GRAY)
              {
                  param.setDestinationType(imageTypeSpecifier);
                  break;
              }
          }
          return param;
      }
  }