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

 * 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);

		}

	}

}