package org.springbyexample.util.image;
   
   import java.awt.Graphics2D;
   import java.awt.geom.AffineTransform;
   import java.awt.image.BufferedImage;
   import java.io.File;
   import java.io.IOException;
   import java.io.InputStream;
   import java.io.OutputStream;
  
  import javax.imageio.ImageIO;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  import org.springframework.util.Assert;
  
  /**
   * Image processor.
   * 
   * @author David Winterfeldt
   */
  public class ImageProcessorImpl implements ImageProcessor{
  
  	final Logger logger = LoggerFactory.getLogger(ImageProcessorImpl.class);
  	
  	protected int imageScaleWidth = 200;
  
  	/**
       * Gets image width for scaling.
       */
      public int getImageScaleWidth() {
          return imageScaleWidth;
      }
      
  	/**
       * Sets image width for scaling.
       */
      public void setImageScaleWidth(int imageScaleWidth) {
          this.imageScaleWidth = imageScaleWidth;
      }
  
      /**
       * Creates a scaled new file.
       */
  	public void scaleImage(File imageFile, File newImageFile) 
  			throws IOException {
          Assert.notNull(imageFile, "Image file can not be null.");
          Assert.notNull(newImageFile, "New image file can not be null.");
  
  	    String imageFileName = imageFile.getName();
          String formatName = imageFileName.substring(imageFileName.lastIndexOf("."));
  
  	    BufferedImage image = ImageIO.read(imageFile);
  	    
  	    BufferedImage destImage = processImageScaling(image);
  
  	    ImageIO.write(destImage, formatName, newImageFile);
  
          logger.debug("Created '{}' from orginal file '{}'.", newImageFile.getAbsolutePath(), imageFile.getAbsolutePath());
  	}
  
      /**
       * Creates a scaled new file.
       */
      public void scaleImage(InputStream in, OutputStream out, String formatName) 
              throws IOException {
          Assert.notNull(in, "InputStream can not be null.");
          Assert.notNull(out, "OutStream can not be null.");
          Assert.hasText(formatName, "Format name can not be blank.");
          
          BufferedImage image = ImageIO.read(in);
          
          BufferedImage destImage = processImageScaling(image);
  
          ImageIO.write(destImage, formatName, out);
          
          logger.debug("Created scaled from orginal file.");
      }
      
      /**
       * Creates a scaled new file.
       */
      protected BufferedImage processImageScaling(BufferedImage image) 
              throws IOException {
  		double d = (double) imageScaleWidth / (double) image.getHeight(null);
  		
  		if (image.getWidth(null) > image.getHeight(null)) {
  			d = (double) imageScaleWidth / (double) image.getWidth(null);
  		}
  		
  		int j = (int) (d * (double) image.getWidth(null));
  		int k = (int) (d * (double) image.getHeight(null));
  		
  		BufferedImage destImage = new BufferedImage(j, k, 1);
  
  		AffineTransform at = new AffineTransform();
  		
  		if (d < 1.0D) {
  			at.scale(d, d);
 		}
 			
 		Graphics2D graphics2d = destImage.createGraphics();
 		graphics2d.drawImage(image, at, null);
 		graphics2d.dispose();
 		
 		return destImage;
 	}
 	   
 }