package e4s.tutorial;

import java.awt.Color;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Iterator;

import javax.imageio.ImageIO;
import javax.imageio.ImageWriter;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;

import e4s.html.E4CgiParams;
import e4s.html.E4DocumentBase;
import e4s.html.E4Method;
import e4s.html.E4MethodSilent;
import e4s.html.HTML;
import e4s.servlet.E4ModuleImplementation;
import e4s.servlet.E4ServletImplementation_Servlet;


/**
 * Generate graphic's on the fly by your servlet.
 * 
 * This example lines out how images can be produces by a servlet and how these images can be integrated dynamically
 * into your HTML output. It is based on HttpServletResponse. There is another example showing this together with 
 * an Ajax refresh mechanism in the tutorial.
 *
 * {@tutorial Example_Grafic_Generation}
 *
 */
public class Example_Grafic_Generation extends E4ModuleImplementation
{
   public static E4Method start = null;
   public static E4MethodSilent cross = null;
   public static E4MethodSilent circle = null;

   public void start( HTML html )
   {
      html.IMG(cross.constructUrl(getServlet()),E4DocumentBase.EMPTY);
      html.IMG(circle.constructUrl(getServlet()),E4DocumentBase.EMPTY);
   }

   public void cross( HTML html, E4CgiParams params )
   {
//      try
//      {
//         BufferedImage bufferedImage = new BufferedImage(50,50,BufferedImage.TYPE_BYTE_INDEXED);
//         
//         Graphics g = bufferedImage.getGraphics();
//         g.setColor(Color.white);
//         g.fillRect(0,0,50,50);
//         g.setColor(Color.blue);
//         for( int i = -3; i <= +3; i++ )
//         {
//            g.drawLine(i,0,50 + i,50);
//            g.drawLine(i,50,50 + i,0);
//         }
//         
//         g.dispose();
//         
//         E4ServletImplementation_Servlet servlet = (E4ServletImplementation_Servlet)getServlet();
//         servlet.writePng(bufferedImage);
//      }
//      catch( IOException ioe )
//      {
//         TRACE(ioe);
//          html.SystemError(ioe);
//      }
   }
   
   public void circle( HTML html, E4CgiParams params )
   {
      circle2(html,params);
      circle1(html,params);
   }
   
   public void circle1( HTML html, E4CgiParams params )
   {

      try
      {
         BufferedImage bufferedImage = new BufferedImage(50,50,BufferedImage.TYPE_INT_RGB);
         
         Graphics g = bufferedImage.getGraphics();
         g.setColor(Color.white);
         g.fillRect(0,0,50,50);
         g.setColor(Color.red);
         g.fillOval(0,0,50,50);
         g.setColor(Color.white);
         g.fillOval(5,5,40,40);
         
         g.dispose();
         
         File f = new File("e:/temp");
         ImageIO.setCacheDirectory(f);
         
         E4ServletImplementation_Servlet servlet = (E4ServletImplementation_Servlet)getServlet();
         HttpServletResponse response = servlet.getResponse();
   
TRACE(ImageIO.getCacheDirectory());
TRACE(ImageIO.getUseCache());

x("jpg");
x("png");
x("jpeg");
x("gif");

         ServletOutputStream stream = servlet.getOutputStream();
TRACE(stream);
         //ImageIO.write(bufferedImage,"jpg",stream);
         X_ImageIO.write(bufferedImage,"jpg",stream);

         response.setContentType("image/jpg");
      }
      catch( IOException ioe )
      {
         TRACE(ioe);
         html.SystemError(ioe);
      }
   }

   public void circle2( HTML html, E4CgiParams params )
   {

      try
      {
         BufferedImage bufferedImage = new BufferedImage(50,50,BufferedImage.TYPE_INT_RGB);
         
         Graphics g = bufferedImage.getGraphics();
         g.setColor(Color.white);
         g.fillRect(0,0,50,50);
         g.setColor(Color.red);
         g.fillOval(0,0,50,50);
         g.setColor(Color.white);
         g.fillOval(5,5,40,40);
         
         g.dispose();
         
         FileOutputStream fstream = new FileOutputStream("e:/temp/circle.jpg");
         X_ImageIO.write(bufferedImage,"jpg",fstream);
TRACE("*** done ***");         
         fstream.close();
      }
      catch( IOException ioe )
      {
         TRACE(ioe);
         html.SystemError(ioe);
      }
   }

   private void x(String string)
   {
      TRACE(string);
      
      try
      {
         Iterator<ImageWriter> it = ImageIO.getImageWritersByFormatName(string);
         if (it != null)
         {
            while(it.hasNext())
            {
               ImageWriter x = it.next();
               if (x == null)
                  break;
               TRACE(x);
            }
         }
      }
      catch(Throwable t)
      {
         TRACE(t);
      }
   }

}