/*
 * Copyright (c) 2018, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

/*
 * @test
 * @bug     6574555
 * @summary Test verifies that PNGImageWriter encodes the R, G, B
 *          values of bKGD chunk properly.
 * @run     main VerifyRGBValuesFromBKGDChunk
 */

import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.Iterator;
import javax.imageio.ImageTypeSpecifier;
import javax.imageio.ImageWriter;
import javax.imageio.ImageReader;
import javax.imageio.ImageIO;
import javax.imageio.ImageWriteParam;
import javax.imageio.metadata.IIOMetadata;
import javax.imageio.metadata.IIOMetadataNode;
import javax.imageio.IIOImage;
import javax.imageio.stream.ImageInputStream;
import javax.imageio.stream.ImageOutputStream;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.InputStream;

public class VerifyRGBValuesFromBKGDChunk {

    public static void main(String[] args) throws IOException {
        int width = 1;
        int height = 1;
        BufferedImage img = new
            BufferedImage(width, height, BufferedImage.TYPE_INT_BGR);
        Iterator<ImageWriter> iterWriter =
            ImageIO.getImageWritersBySuffix("png");
        ImageWriter writer = iterWriter.next();

        ImageWriteParam param = writer.getDefaultWriteParam();
        ImageTypeSpecifier specifier =
            ImageTypeSpecifier.
                createFromBufferedImageType(BufferedImage.TYPE_INT_BGR);
        IIOMetadata encodeMetadata =
            writer.getDefaultImageMetadata(specifier, param);

        // Write png image with bKGD chunk
        IIOMetadataNode bKGD_rgb = new IIOMetadataNode("bKGD_RGB");
        String red = "100";
        String green = "150";
        String blue = "200";
        bKGD_rgb.setAttribute("red", red);
        bKGD_rgb.setAttribute("green", green);
        bKGD_rgb.setAttribute("blue", blue);

        IIOMetadataNode bKGD = new IIOMetadataNode("bKGD");
        bKGD.appendChild(bKGD_rgb);
        IIOMetadataNode encodeRoot =
            new IIOMetadataNode("javax_imageio_png_1.0");
        encodeRoot.appendChild(bKGD);

        encodeMetadata.mergeTree("javax_imageio_png_1.0", encodeRoot);

        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        ImageOutputStream ios = ImageIO.createImageOutputStream(baos);
        writer.setOutput(ios);

        writer.write(encodeMetadata,
                     new IIOImage(img, null, encodeMetadata), param);
        writer.dispose();

        baos.flush();
        byte[] imageByteArray = baos.toByteArray();
        baos.close();

        // Get bKGD chunk from image and verify the values
        InputStream input= new ByteArrayInputStream(imageByteArray);
        ImageInputStream iis = ImageIO.createImageInputStream(input);
        Iterator<ImageReader> iterReader =
            ImageIO.getImageReadersBySuffix("png");
        ImageReader reader = iterReader.next();
        reader.setInput(iis, false, false);

        IIOMetadata decodeMetadata = reader.getImageMetadata(0);
        IIOMetadataNode decodeRoot =
            (IIOMetadataNode) decodeMetadata.
                getAsTree("javax_imageio_png_1.0");
        bKGD_rgb = (IIOMetadataNode)
            decodeRoot.getElementsByTagName("bKGD_RGB").item(0);

        if (!(red.equals(bKGD_rgb.getAttribute("red")) &&
              green.equals(bKGD_rgb.getAttribute("green")) &&
              blue.equals(bKGD_rgb.getAttribute("blue")))) {
            throw new RuntimeException("bKGD RGB values are not stored" +
            " properly");
        }
    }
}