/* ================================================================

  * Cewolf : Chart enabling Web Objects Framework

  * ================================================================

  *

  * Project Info:  http://cewolf.sourceforge.net

  * Project Lead:  Guido Laures (guido@laures.de);

  *

  * (C) Copyright 2002, by Guido Laures

  *

  * This library is free software; you can redistribute it and/or modify it under the terms

  * of the GNU Lesser General Public License as published by the Free Software Foundation;

  * either version 2.1 of the License, or (at your option) any later version.

  *

  * This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;

  * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

  * See the GNU Lesser General Public License for more details.

  *

  * You should have received a copy of the GNU Lesser General Public License along with this

  * library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,

  * Boston, MA 02111-1307, USA.

  */

 package de.laures.cewolf.util;

 import java.awt.Color;

 import java.awt.Dimension;

 import java.awt.Graphics2D;

 import java.awt.Rectangle;

 import java.awt.geom.Rectangle2D;

 import java.awt.image.BufferedImage;

 import java.io.ByteArrayOutputStream;

 import java.io.IOException;

 import java.io.OutputStreamWriter;

 import java.util.Iterator;

 import java.util.List;

 import org.apache.batik.dom.GenericDOMImplementation;

 import org.apache.batik.svggen.SVGGeneratorContext;

 import org.apache.batik.svggen.SVGGraphics2D;

 import org.apache.commons.logging.Log;

 import org.apache.commons.logging.LogFactory;

 import org.jfree.chart.ChartRenderingInfo;

 import org.jfree.chart.ChartUtilities;

 import org.jfree.chart.JFreeChart;

 import org.jfree.chart.block.RectangleConstraint;

 import org.jfree.chart.entity.StandardEntityCollection;

 import org.jfree.chart.title.LegendTitle;

 import org.jfree.ui.RectangleEdge;

 import org.w3c.dom.DOMImplementation;

 import org.w3c.dom.Document;

 import com.sun.image.codec.jpeg.JPEGCodec;

 import com.sun.image.codec.jpeg.JPEGEncodeParam;

 import com.sun.image.codec.jpeg.JPEGImageEncoder;

 import de.laures.cewolf.CewolfException;

 import de.laures.cewolf.ChartImage;

 import de.laures.cewolf.ChartRenderingException;

 import de.laures.cewolf.ConfigurationException;

 import de.laures.cewolf.WebConstants;

 /**

  * Renderer for ChartImageDefinitions.

  *

  * @author glaures

  * @author tbardzil

  * @see    de.laures.cewolf.ChartImage

  */

 public class Renderer implements WebConstants {

 	private final static Log log = LogFactory.getLog(Renderer.class);

 	/** Creates a new instance of Renderer */

 	private Renderer() {

 	};

 	/**

 	 * Renders a chart image

 	 *

 	 * @param  cd                  the chart to render

 	 * @return                     the rendered image

 	 * @throws CewolfException

 	 */

 	public static RenderedImage render(ChartImage cd, Object chart) throws CewolfException {

 		log.debug("rendering " + cd);

 		switch (cd.getType()) {

 			case ChartImage.IMG_TYPE_CHART :

 				return renderChart(cd, chart);

 			case ChartImage.IMG_TYPE_LEGEND :

 				return renderLegend(cd, chart);

 			default :

 				throw new ConfigurationException(cd.getType() + " is not a supported image type");

 		}

 	}

 	/**

 	 * Renders a chart

 	 * @param cd the chart image to be rendered

 	 * @return the rendered image

 	 * @throws CewolfException

 	 */

 	private static RenderedImage renderChart(ChartImage cd, Object chart) throws CewolfException {

 		try {

 			final ByteArrayOutputStream baos = new ByteArrayOutputStream();

 			final ChartRenderingInfo info = new ChartRenderingInfo(new StandardEntityCollection());

 			final String mimeType = cd.getMimeType();

 			if (MIME_PNG.equals(mimeType)) {

 				handlePNG(baos, (JFreeChart)chart, cd.getWidth(), cd.getHeight(), info);

 			} else if (MIME_JPEG.equals(mimeType)) {

 			    handleJPEG(baos, (JFreeChart)chart, cd.getWidth(), cd.getHeight(), info);

 			} else if (MIME_SVG.equals(mimeType)) {

 				handleSVG(baos, (JFreeChart)chart, cd.getWidth(), cd.getHeight());

 			} else {

 				throw new RenderingException("Mime type " + mimeType + " is unsupported.");

 			}

 			baos.close();

 			return new RenderedImage(baos.toByteArray(), mimeType, info);

 		} catch (IOException ioe) {

 			log.error(ioe);

 			throw new ChartRenderingException(ioe.getMessage(),ioe);

 		}

 	}

 	/**

 	 * Handles rendering a chart as a PNG. Currently this method is synchronized

 	 * because of concurrency issues with JFreeChart.

 	 *

 	 * @param  baos

 	 * @param  chart

 	 * @param  width

 	 * @param  height

 	 * @param  info

 	 * @throws IOException

 	 */

 	private static synchronized void handlePNG(

 		ByteArrayOutputStream baos,

 		JFreeChart chart,

 		int width,

 		int height,

 		ChartRenderingInfo info)

 		throws IOException {

 		ChartUtilities.writeChartAsPNG(baos, chart, width, height, info);

 	}

 	/**

 	 * Handles rendering a chart as a JPEG. Currently this method is synchronized

 	 * because of concurrency issues with JFreeChart.

 	 *

 	 * @param  baos

 	 * @param  chart

 	 * @param  width

 	 * @param  height

 	 * @param  info

 	 * @throws IOException

 	 */

 	private static synchronized void handleJPEG(

 		ByteArrayOutputStream baos,

 		JFreeChart chart,

 		int width,

 		int height,

 		ChartRenderingInfo info)

 		throws IOException {

 		ChartUtilities.writeChartAsJPEG(baos, chart, width, height, info);

 	}			

 	/**

 	 * Handles rendering a chart as a SVG. Currently this method is synchronized

 	 * because of concurrency issues with JFreeChart.

 	 *

 	 * @param  baos

 	 * @param  chart

 	 * @param  width

 	 * @param  height

 	 * @throws IOException

 	 */

 	private static synchronized void handleSVG(ByteArrayOutputStream baos, JFreeChart chart, int width, int height)

 		throws IOException {

 		OutputStreamWriter writer = new OutputStreamWriter(baos, "UTF-8");

 		DOMImplementation domImpl = GenericDOMImplementation.getDOMImplementation();

 		Document document = domImpl.createDocument("cewolf-svg", "svg", null);

 		SVGGeneratorContext ctx = SVGGeneratorContext.createDefault(document);

 		ctx.setComment("Generated by Cewolf using JFreeChart and Apache Batik SVG Generator");

 		SVGGraphics2D svgGenerator = new SVGGraphics2D(ctx, false);

 		svgGenerator.setSVGCanvasSize(new Dimension(width, height));

 		chart.draw(svgGenerator, new Rectangle2D.Double(0, 0, width, height), null);

 		svgGenerator.stream(writer, false);

 		writer.close();

 	}

   //gets first legend in the list

   public static LegendTitle getLegend(JFreeChart chart)

   {

     //i need to find the legend now.

     LegendTitle legend = null;

     List subTitles = chart.getSubtitles();

     Iterator iter = subTitles.iterator();

     while (iter.hasNext())

     {

       Object o = iter.next();

       if (o instanceof LegendTitle)

       {

         legend = (LegendTitle) o;

         break;

       }

     }

     return legend;

   }

   //removes first legend in the list

   public static void removeLegend(JFreeChart chart)

   {

     List subTitles = chart.getSubtitles();

     Iterator iter = subTitles.iterator();

     while (iter.hasNext())

     {

       Object o = iter.next();

       if (o instanceof LegendTitle)

       {

         iter.remove();

         break;

       }

     }

   }

 	/**

 	 * Renders a legend

 	 * @param cd the chart iamge to be rendred

 	 * @return the rendered image

 	 * @throws CewolfException

 	 */

 	private static RenderedImage renderLegend(ChartImage cd, Object c) throws CewolfException {

 		try {

 		    JFreeChart chart = (JFreeChart) c;

 			final int width = cd.getWidth();

 			final int height = cd.getHeight();

 			LegendTitle legend = getLegend(chart);

 			boolean haslegend = true;

 			// with JFreeChart v0.9.20, the only way to get a valid legend,

 			// is either to retrieve it from the chart or to assign a new

 			// one to the chart. In the case where the chart has no legend,

 			// a new one must be assigned, but just for rendering. After, we

 			// have to reset the legend to null in the chart.

 			if (null == legend) {

 				haslegend = false;

 				legend = new LegendTitle(chart.getPlot());   

 			}

 			legend.setPosition(RectangleEdge.BOTTOM);

 			BufferedImage bimage = ImageHelper.createImage(width, height);

 			Graphics2D g = bimage.createGraphics();

 			g.setColor(Color.white);

 			g.fillRect(0, 0, width, height);

 			legend.arrange(g,new RectangleConstraint(width,height));

  			legend.draw(g, new Rectangle(width, height));

 			ByteArrayOutputStream out = new ByteArrayOutputStream();

 			JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);

 			JPEGEncodeParam param = encoder.getDefaultJPEGEncodeParam(bimage);

 			param.setQuality(1.0f, true);

 			encoder.encode(bimage, param);

 			out.close();

 			// if the chart had no legend, reset it to null in order to give back the

 			// chart in the state we received it.

 			if (!haslegend) {

 				removeLegend(chart);

 			}

 			return new RenderedImage(

 				out.toByteArray(),

 				"image/jpeg",

 				new ChartRenderingInfo(new StandardEntityCollection()));

 		} catch (IOException ioex) {

 			log.error(ioex);

 			throw new ChartRenderingException(ioex.getMessage(), ioex);

 		}

 	}

 }