package de.intevation.gnv.exports;

import com.lowagie.text.Document;
import com.lowagie.text.DocumentException;
import com.lowagie.text.PageSize;
import com.lowagie.text.Rectangle;

import com.lowagie.text.pdf.PdfContentByte;
import com.lowagie.text.pdf.PdfTemplate;
import com.lowagie.text.pdf.PdfWriter;

import de.intevation.artifactdatabase.XMLUtils;

import de.intevation.gnv.chart.Chart;

import java.awt.Graphics2D;
import java.awt.Transparency;

import java.awt.geom.Rectangle2D.Double;

import java.awt.geom.Rectangle2D;

import java.awt.image.BufferedImage;

import java.io.IOException;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.UnsupportedEncodingException;

import javax.imageio.ImageIO;

import org.apache.batik.svggen.SVGGraphics2D;
import org.apache.batik.svggen.SVGGraphics2DIOException;

import org.apache.log4j.Logger;

import org.jfree.chart.JFreeChart;

/**
 * This class is a helper class which supports some methods to export charts
 * into specific formats.
 *
 * @author <a href="mailto:ingo.weinzierl@intevation.de">Ingo Weinzierl</a>
 */
public class ChartExportHelper {

    /**
     * Constant field to define A4 as default page size.
     */
    private static final String  DEFAULT_PAGE_SIZE = "A4";

    /**
     * Constant field to define UTF-8 as default encoding.
     */
    private static final String  DEFAULT_ENCODING  = "UTF-8";

    /**
     * Logger used for logging with log4j.
     */
    private static Logger log = Logger.getLogger(ChartExportHelper.class);


    /**
     * A method to export a <code>JFreeChart</code> as image to an
     * <code>OutputStream</code> with a given format, width and height.
     *
     * @param out OutputStream
     * @param chart JFreeChart object to be exported.
     * @param format Format (e.g. png, gif, jpg)
     * @param width Width, the image used to be
     * @param height Height, the image used to be
     *
     * @throws IOException if writing image to OutputStream failed.
     */
    public static void exportImage(
        OutputStream out,
        JFreeChart chart,
        String format,
        int width,
        int height
    )
    throws IOException
    {
        log.info("export chart as png");

        ImageIO.write(
            chart.createBufferedImage(
                width, height, Transparency.BITMASK, null
            ),
            format,
            out
        );
    }


    /**
     * A method to export a <code>JFreeChart</code> histogram as image to an
     * <code>OutputStream</code> with a  given format, width and height.
     *
     * @param out OutputStream
     * @param histograms Array of {@link de.intevation.gnv.chart.Chart} objects
     * @param format A format (e.g. png, gif, jpg)
     * @param width Width the image used to be
     * @param height Height the image used to be
     *
     * @throws IOException if writing image to OutputStream failed.
     */
    public static void exportHistograms(
        OutputStream out,
        Chart[]      histograms,
        String       format,
        int          width,
        int          height)
    throws IOException
    {
        log.info("export histograms");

        int size            = histograms.length;
        BufferedImage image = new BufferedImage(
            width, height*size, BufferedImage.TYPE_INT_RGB);
        Graphics2D g        = image.createGraphics();

        for (int i = 0; i < size; i++) {
            JFreeChart chart = histograms[i].generateChart();
            chart.draw(g, new Rectangle2D.Double(0.0D, i*height, width, height));
        }
        g.finalize();

        ImageIO.write(image, format, out);
    }


    /**
     * A method to export a <code>JFreeChart</code> histogram as SVG to an
     * <code>OutputStream</code>.
     *
     * @param out OutputStream
     * @param histograms Array of {@link de.intevation.gnv.chart.Chart}
     * @param encoding Encoding, defaults to {@link DEFAULT_ENCODING} if null
     * @param width Width the svg used to be
     * @param height Height the svg used to be
     */
    public static void exportHistogramsAsSVG(
        OutputStream out,
        Chart[]      histograms,
        String       encoding,
        int          width,
        int          height
    ) {
        log.info("export histograms as svg");

        if (encoding == null)
            encoding = DEFAULT_ENCODING;

        org.w3c.dom.Document document = XMLUtils.newDocument();
        SVGGraphics2D        graphics = new SVGGraphics2D(document);

        int size = histograms.length;
        for (int i = 0; i < size; i++) {
            JFreeChart chart = histograms[i].generateChart();
            chart.draw(graphics, new Rectangle2D.Double(
                0.0D, i*height,width,height));
        }
        graphics.finalize();

        try {
            graphics.stream(new OutputStreamWriter(out, encoding));
        }
        catch (SVGGraphics2DIOException svge) {
            log.error("Error while writing svg export to output stream.", svge);
        }
        catch (UnsupportedEncodingException uee) {
            log.error("Unsupported encoding: " + encoding, uee);
        }
    }


    /**
     * A method to export a <code>JFreeChart</code> as SVG to an
     * <code>OutputStream</code>.
     *
     * @param out OutputStream
     * @param chart JFreeChart to be exported
     * @param encoding Encoding, defaults to {@link DEFAULT_ENCODING} if null
     * @param width Width the svg used to be
     * @param height Height the svg used to be
     */
    public static void exportSVG(
        OutputStream out,
        JFreeChart   chart,
        String       encoding,
        int          width,
        int          height
    ) {
        log.info("export chart as svg");

        if (encoding == null)
            encoding = DEFAULT_ENCODING;

        org.w3c.dom.Document document = XMLUtils.newDocument();
        SVGGraphics2D        graphics = new SVGGraphics2D(document);

        chart.draw(graphics, new Rectangle2D.Double(0.0D, 0.0D,width,height));

        try {
            graphics.stream(new OutputStreamWriter(out, encoding));
        }
        catch (SVGGraphics2DIOException svge) {
            log.error("Error while writing svg export to output stream.", svge);
        }
        catch (UnsupportedEncodingException uee) {
            log.error("Unsupported encoding: " + encoding, uee);
        }
    }


    /**
     * A method to export a <code>JFreeChart</code> as PDF to an
     * <code>OutputStream</code>.
     *
     * @param out OutputStream
     * @param chart JFreeChart
     * @param pageFormat String to specify a page format, {@link
     * DEFAULT_PAGE_SIZE} is used if no pageFormat is given
     * @param landscape If this is true, the pdf is delivered in landscape
     * format
     * @param marginLeft Space to left border
     * @param marginRight Space to right border
     * @param marginTop Space to upper border
     * @param marginBottom Space to lower border
     */
    public static void exportPDF(
        OutputStream out,
        JFreeChart   chart,
        String       pageFormat,
        boolean      landscape,
        float        marginLeft,
        float        marginRight,
        float        marginTop,
        float        marginBottom
    ) {
        log.info("export chart as pdf.");

        if (pageFormat == null)
            pageFormat = DEFAULT_PAGE_SIZE;

        Rectangle page = PageSize.getRectangle(pageFormat);
        int pageWidth  = (int) (page.getRight(marginRight) - page.getLeft(marginLeft));
        int pageHeight = (int) (page.getTop(marginTop) - page.getBottom(marginBottom));

        Document document = null;
        if (landscape) {
            document = new Document(page.rotate());
            log.debug("Create landscape pdf.");
        }
        else
            document = new Document(page);

        try {
            PdfWriter writer = PdfWriter.getInstance(document, out);

            document.addSubject(chart.getTitle().getText());
            document.addCreationDate();
            document.open();

            PdfContentByte content  = writer.getDirectContent();

            int width  = 0;
            int height = 0;
            if (landscape) {
                width  = pageHeight;
                height = pageWidth;
            }
            else {
                width  = pageWidth;
                height = pageHeight;
            }

            PdfTemplate template = content.createTemplate(width, height);
            Graphics2D  graphics = template.createGraphics(width, height);
            Rectangle2D area = new Rectangle2D.Double(0.0D, 0.0D,width,height);

            chart.draw(graphics, area);
            graphics.dispose();
            content.addTemplate(template, marginLeft, marginBottom);
        }
        catch (DocumentException de) {
            log.error("Error while exporting chart to pdf.", de);
        }
        finally {
            document.close();
        }
    }


    /**
     * A method to export <code>JFreeChart</code> histograms as PDF to an
     * <code>OutputStream</code>. Each histogram contained in histograms is
     * drawn to an own page in the resulting pdf.
     *
     * @param out OutputStream
     * @param histograms JFreeChart histograms
     * @param pageFormat String to specify a page format, {@link
     * DEFAULT_PAGE_SIZE} is used if no pageFormat is given
     * @param landscape If this is true, the pdf is delivered in landscape
     * format
     * @param marginLeft Space to left border
     * @param marginRight Space to right border
     * @param marginTop Space to upper border
     * @param marginBottom Space to lower border
     */
    public static void exportHistogramsAsPDF(
        OutputStream out,
        Chart[]      histograms,
        String       pageFormat,
        boolean      landscape,
        float        marginLeft,
        float        marginRight,
        float        marginTop,
        float        marginBottom
    ) {
        log.info("export histogram as pdf.");

        if (pageFormat == null)
            pageFormat = DEFAULT_PAGE_SIZE;

        Rectangle page = PageSize.getRectangle(pageFormat);
        int pageWidth  =
            (int) (page.getRight(marginRight) - page.getLeft(marginLeft));
        int pageHeight =
            (int) (page.getTop(marginTop) - page.getBottom(marginBottom));

        Document document = null;
        if (landscape) {
            document = new Document(page.rotate());
            log.debug("Create landscape pdf.");
        }
        else
            document = new Document(page);

        try {
            PdfWriter writer = PdfWriter.getInstance(document, out);

            document.addCreationDate();
            document.open();

            PdfContentByte content  = writer.getDirectContent();

            int width  = 0;
            int height = 0;
            if (landscape) {
                width  = pageHeight;
                height = pageWidth;
            }
            else {
                width  = pageWidth;
                height = pageHeight;
            }

            int size = histograms.length;
            for (int i = 0; i < size; i++) {
                if (i > 0) {
                    document.newPage();
                }

                JFreeChart chart     = histograms[i].generateChart();
                PdfTemplate template = content.createTemplate(width, height);
                Graphics2D  graphics = template.createGraphics(width, height);
                Rectangle2D area     = new Rectangle2D.Double(
                    0.0D, 0.0D,width,height);

                chart.draw(graphics, area);
                graphics.dispose();
                content.addTemplate(template, marginLeft, marginBottom);
            }
        }
        catch (DocumentException de) {
            log.error("Error while exporting chart to pdf.", de);
        }
        finally {
            document.close();
        }
    }
}
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