package org.jaudiotagger.tag;

 import org.jaudiotagger.tag.datatype.Artwork;

 import org.jaudiotagger.tag.id3.valuepair.ImageFormats;

 import javax.imageio.ImageIO;

 import javax.imageio.ImageWriter;

 import java.awt.*;

 import java.awt.geom.AffineTransform;

 import java.awt.image.BufferedImage;

 import java.io.ByteArrayOutputStream;

 import java.io.IOException;

 import java.util.Iterator;

 /**

  * User: paul

  * Date: 11-Dec-2008

  */

 public class ImageHandling

 {

     /**

      * Resize the image until the total size require to store the image is less than maxsize

      * @param artwork

      * @param maxSize

      * @throws IOException

      */

     public static void reduceQuality(Artwork artwork, int maxSize) throws IOException

     {

         while(artwork.getBinaryData().length > maxSize)

         {

             Image srcImage = artwork.getImage();

             int w = srcImage.getWidth(null);

             int newSize = w /2;

             makeSmaller(artwork,newSize);

         }

     }

      /**

      * Resize image using Java 2D

       * @param artwork

       * @param size

       * @throws java.io.IOException

       */

     private static void makeSmaller(Artwork artwork,int size) throws IOException

     {

         Image srcImage = artwork.getImage();

         int w = srcImage.getWidth(null);

         int h = srcImage.getHeight(null);

         // Determine the scaling required to get desired result.

         float scaleW = (float) size / (float) w;

         float scaleH = (float) size / (float) h;

         //Create an image buffer in which to paint on, create as an opaque Rgb type image, it doesnt matter what type

         //the original image is we want to convert to the best type for displaying on screen regardless

         BufferedImage bi = new BufferedImage(size, size, BufferedImage.TYPE_INT_RGB);

         // Set the scale.

         AffineTransform tx = new AffineTransform();

         tx.scale(scaleW, scaleH);

         // Paint image.

         Graphics2D g2d = bi.createGraphics();

         g2d.drawImage(srcImage, tx, null);

         g2d.dispose();

         if(artwork.getMimeType()!=null && isMimeTypeWritable(artwork.getMimeType()))

         {

             artwork.setBinaryData(writeImage(bi,artwork.getMimeType()));

         }

         else

         {

             artwork.setBinaryData(writeImageAsPng(bi));

         }

     }

     public static boolean isMimeTypeWritable(String mimeType)

     {

         Iterator<ImageWriter> writers =  ImageIO.getImageWritersByMIMEType(mimeType);

         return writers.hasNext();

     }

     /**

      *  Write buffered image as required format

      *

      * @param bi

      * @param mimeType

      * @return

      * @throws IOException

      */

     public static byte[] writeImage(BufferedImage bi,String mimeType) throws IOException

     {

         Iterator<ImageWriter> writers =  ImageIO.getImageWritersByMIMEType(mimeType);

         if(writers.hasNext())

         {

             ImageWriter writer = writers.next();

             ByteArrayOutputStream baos = new ByteArrayOutputStream();

             writer.setOutput(ImageIO.createImageOutputStream(baos));

             writer.write(bi);

             return baos.toByteArray();

         }

         throw new IOException("Cannot write to this mimetype");

     }

     /**

      *

      * @param bi

      * @return

      * @throws IOException

      */

     public static byte[] writeImageAsPng(BufferedImage bi) throws IOException

     {

         ByteArrayOutputStream baos = new ByteArrayOutputStream();

         ImageIO.write(bi, ImageFormats.MIME_TYPE_PNG,baos);

         return baos.toByteArray();

     }

     /**

      * Show read formats

      *

      * On Windows supports png/jpeg/bmp/gif

      */

     public static void showReadFormats()

     {

          String[] formats = ImageIO.getReaderMIMETypes();

         for(String f:formats)

         {

             System.out.println("r"+f);

         }

     }

     /**

      * Show write formats

      *

      * On Windows supports png/jpeg/bmp

      */

     public static void showWriteFormats()

     {

          String[] formats = ImageIO.getWriterMIMETypes();

         for(String f:formats)

         {

             System.out.println(f);

         }

     }

 }