package webraveler.plugin;

import java.util.*;
import java.io.*;

import webraveler.http.HTTPResponse;
import webraveler.ravel.PluginCallbackException;

import com.sun.image.codec.jpeg.*;
import java.awt.*;
import java.awt.image.*;


/**
 *
 */
public class ImageDegradationPlugin extends webraveler.ravel.RavelerPlugin {
	/* variables */
	private HTTPResponse response;
	private boolean DEBUG = false;
	
	/*constructors*/
	public ImageDegradationPlugin () throws Exception{		
		name = "ImageDegradationPlugin";
		mimeTypes.add("image/gif");
		mimeTypes.add("image/jpeg");
		mimeTypes.add("image/png");
	}
	
	/*methods*/
	
	public void setDefaultAttributes () {
		attributes = new Hashtable();
		name = "ImageDegradationPlugin";
	} 
	
	public boolean initialize () {
		return true;
	}//initialize()
	
	public HTTPResponse execute (HTTPResponse response, Hashtable attributes) throws PluginCallbackException {
		if (DEBUG) System.out.println("ImageDegradationPlugin: executing on response...");
		
		byte[] imageBytes = response.entityBytes;
		try {
			Image image = Toolkit.getDefaultToolkit().createImage(imageBytes);
			MediaTracker mediaTracker = new MediaTracker(new Container());
		    mediaTracker.addImage(image, 0);
		    mediaTracker.waitForID(0);
		    
		    BufferedImage thumbImage = new BufferedImage(image.getWidth(null),
		    											 image.getHeight(null),
														 BufferedImage.TYPE_INT_RGB);
		    Graphics2D graphics2D = thumbImage.createGraphics();
		    graphics2D.setRenderingHint(RenderingHints.KEY_INTERPOLATION,
		    				RenderingHints.VALUE_INTERPOLATION_BILINEAR);
		    graphics2D.drawImage(image, 0, 0, image.getWidth(null), image.getHeight(null), null);
		    
		    ByteArrayOutputStream out = new ByteArrayOutputStream();
		    JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
		    JPEGEncodeParam param = encoder.
		      getDefaultJPEGEncodeParam(thumbImage);
		    int quality = 10;
		    quality = Math.max(0, Math.min(quality, 100));
		    param.setQuality((float)quality / 100.0f, false);
		    encoder.setJPEGEncodeParam(param);
		    encoder.encode(thumbImage);
		    
		    imageBytes = out.toByteArray();
			
			response.entityBytes = imageBytes;	
		} catch ( Exception e ) {
			if( DEBUG ) System.out.println("ImageDegradationPlugin: Failed to degrade this image!");
			return response;
		}
		
		response.deleteHeader("content-length");
		response.setHeader("content-length", new String(""+response.entityBytes.length));
		
		response.deleteHeader("content-type");
		response.setHeader("content-type", "image/jpeg");
		
		response.protocolVersion = "HTTP/1.0";
		response.status = 200;
		response.reasonPhrase = "OK";
		
		response.htmlPage = null;
		
		response.deleteHeader("connection");
		response.setHeader("connection", new String("close"));
		
		throw new PluginCallbackException(response);
	} //execute(HTTPResponse)
	
	
	public  void terminate() {
		
	} // terminate()
	
	
}//InsertAtTop