/*

 * Copyright 2007 Sun Microsystems, Inc.  All Rights Reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code 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 General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 */

/**

 * @test

 * @bug     6198111

 * @summary Test verifies that PNG image reader correctly handles

 *          hIST chunk if length of image palette in not power of two.

 *

 * @run     main ShortHistogramTest 15

 */

import java.awt.Color;

import java.awt.Graphics2D;

import java.awt.image.BufferedImage;

import java.awt.image.DataBuffer;

import java.awt.image.IndexColorModel;

import java.awt.image.Raster;

import java.io.File;

import java.io.IOException;

import java.util.Arrays;

import java.util.Random;

import javax.imageio.IIOImage;

import javax.imageio.ImageIO;

import javax.imageio.ImageTypeSpecifier;

import javax.imageio.ImageWriteParam;

import javax.imageio.ImageWriter;

import javax.imageio.metadata.IIOInvalidTreeException;

import javax.imageio.metadata.IIOMetadata;

import javax.imageio.metadata.IIOMetadataNode;

import javax.imageio.stream.ImageOutputStream;

import org.w3c.dom.NamedNodeMap;

import org.w3c.dom.Node;

public class ShortHistogramTest {

    public static void main(String[] args) throws IOException {

        int numColors = 15;

        if (args.length > 0) {

            try {

                numColors = Integer.parseInt(args[0]);

            } catch (NumberFormatException e) {

                System.out.println("Invalid number of colors: " + args[0]);

            }

        }

        System.out.println("Test number of colors: " + numColors);

        ShortHistogramTest t = new ShortHistogramTest(numColors);

        t.doTest();

    }

    int numColors;

    public ShortHistogramTest(int numColors) {

        this.numColors = numColors;

    }

    public void doTest() throws IOException {

        BufferedImage bi = createTestImage(numColors);

        File f = writeImageWithHist(bi);

        System.out.println("Test file is " + f.getCanonicalPath());

        try {

            ImageIO.read(f);

        } catch (IOException e) {

            throw new RuntimeException("Test FAILED!", e);

        }

        System.out.println("Test PASSED!");

    }

    protected File writeImageWithHist(BufferedImage bi) throws IOException {

        File f = File.createTempFile("hist_", ".png", new File("."));

        ImageWriter writer = ImageIO.getImageWritersByFormatName("PNG").next();

        ImageOutputStream ios = ImageIO.createImageOutputStream(f);

        writer.setOutput(ios);

        ImageWriteParam param = writer.getDefaultWriteParam();

        ImageTypeSpecifier type = new ImageTypeSpecifier(bi);

        IIOMetadata imgMetadata = writer.getDefaultImageMetadata(type, param);

        /* add hIST node to image metadata */

        imgMetadata = upgradeMetadata(imgMetadata, bi);

        IIOImage iio_img = new IIOImage(bi,

                                        null, // no thumbnails

                                        imgMetadata);

        writer.write(iio_img);

        ios.flush();

        ios.close();

        return f;

    }

    private IIOMetadata upgradeMetadata(IIOMetadata src, BufferedImage bi) {

        String format = src.getNativeMetadataFormatName();

        System.out.println("Native format: " + format);

        Node root = src.getAsTree(format);

        // add hIST node

        Node n = lookupChildNode(root, "hIST");

        if (n == null) {

            System.out.println("Appending new hIST node...");

            Node hIST = gethISTNode(bi);

            root.appendChild(hIST);

        }

        System.out.println("Upgraded metadata tree:");

        dump(root, "");

        System.out.println("Merging metadata...");

        try {

            src.mergeTree(format, root);

        } catch (IIOInvalidTreeException e) {

            throw new RuntimeException("Test FAILED!", e);

        }

        return src;

    }

    private IIOMetadataNode gethISTNode(BufferedImage bi) {

        IndexColorModel icm = (IndexColorModel)bi.getColorModel();

        int mapSize = icm.getMapSize();

        int[] hist = new int[mapSize];

        Arrays.fill(hist, 0);

        Raster r = bi.getData();

        for (int y = 0; y < bi.getHeight(); y++) {

            for (int x = 0; x < bi.getWidth(); x++) {

                int s = r.getSample(x, y, 0);

                hist[s] ++;

            }

        }

        IIOMetadataNode hIST = new IIOMetadataNode("hIST");

        for (int i = 0; i < hist.length; i++) {

            IIOMetadataNode n = new IIOMetadataNode("hISTEntry");

            n.setAttribute("index", "" + i);

            n.setAttribute("value", "" + hist[i]);

            hIST.appendChild(n);

        }

        return hIST;

    }

    private static Node lookupChildNode(Node root, String name) {

        Node n = root.getFirstChild();

        while (n != null && !name.equals(n.getNodeName())) {

            n = n.getNextSibling();

        }

        return n;

    }

    private static void dump(Node node, String ident) {

        if (node == null) {

            return;

        }

        System.out.printf("%s%s\n", ident, node.getNodeName());

        // dump node attributes...

        NamedNodeMap attribs = node.getAttributes();

        if (attribs != null) {

            for (int i = 0; i < attribs.getLength(); i++) {

                Node a = attribs.item(i);

                System.out.printf("%s  %s: %s\n", ident,

                        a.getNodeName(), a.getNodeValue());

            }

        }

        // dump node children...

        dump(node.getFirstChild(), ident + "    ");

        dump(node.getNextSibling(), ident);

    }

    protected BufferedImage createTestImage(int numColors) {

        IndexColorModel icm = createTestICM(numColors);

        int w = numColors * 10;

        int h = 20;

        BufferedImage img = new BufferedImage(w, h,

                BufferedImage.TYPE_BYTE_INDEXED, icm);

        Graphics2D g = img.createGraphics();

        for (int i = 0; i < numColors; i++) {

            int rgb = icm.getRGB(i);

            //System.out.printf("pixel %d, rgb %x\n", i, rgb);

            g.setColor(new Color(rgb));

            g.fillRect(i * 10, 0, w - i * 10, h);

        }

        g.dispose();

       return img;

    }

    protected IndexColorModel createTestICM(int numColors) {

        int[] palette = createTestPalette(numColors);

        int numBits = getNumBits(numColors);

        IndexColorModel icm = new IndexColorModel(numBits, numColors,

                palette, 0, false, -1,

                DataBuffer.TYPE_BYTE);

        return icm;

    }

    protected static int getNumBits(int numColors) {

        if (numColors < 0 || 256 < numColors) {

            throw new RuntimeException("Unsupported number of colors: " +

                                       numColors);

        }

        int numBits = 1;

        int limit = 1 << numBits;

        while (numColors > limit) {

            numBits++;

            limit = 1 << numBits;

        }

        return numBits;

    }

    private static Random rnd = new Random();

    protected static int[] createTestPalette(int numColors) {

        int[] palette = new int[numColors];

        for (int i = 0; i < numColors; i++) {

            int r = rnd.nextInt(256);

            int g = rnd.nextInt(256);

            int b = rnd.nextInt(256);

            palette[i] = 0xff000000 | (r << 16) | (g << 8) | b;

        }

        return palette;

    }

}