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 * Copyright (c) 2013, 2014, 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.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * 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
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package sun.awt.image;

import java.awt.Image;
import java.awt.image.ImageConsumer;
import java.awt.image.ImageObserver;
import java.awt.image.ImageProducer;
import java.awt.image.MultiResolutionImage;
import java.awt.image.ResolutionVariantItem;
import java.util.List;
import java.util.stream.Collectors;
import sun.misc.SoftCache;

public class MultiResolutionToolkitImage extends ToolkitImage implements MultiResolutionImage {

    List<ResolutionVariantItem<Image>> resolutionVariants;

    public MultiResolutionToolkitImage(ImageProducer mriProducer) {
        super(mriProducer);
        this.resolutionVariants = mriProducer.getResolutionVariantItems().stream()
                .map((item) -> new ResolutionVariantItem<Image>(
                        new ToolkitImage(item.getValue()),
                        item.getScaleX(),
                        item.getScaleY()))
                .collect(Collectors.toList());
    }

    public MultiResolutionToolkitImage(
            List<ResolutionVariantItem<Image>> resolutionVariants) {
        super(resolutionVariants.get(0).getValue().getSource());
        this.resolutionVariants = resolutionVariants;
    }


    @Override
    public Image getResolutionVariant(double destWidth, double destHeight) {
        return getResolutionVariantItem(destWidth, destHeight).getValue();
    }

    public ResolutionVariantItem<Image> getResolutionVariantItem(
            double destWidth, double destHeight) {
        checkSize(destWidth, destHeight);
        int baseWidth = getWidth();
        int baseHeight = getHeight();

        for (ResolutionVariantItem<Image> rvItem : resolutionVariants) {
            double sx = rvItem.getScaleX();
            double sy = rvItem.getScaleY();
            if (destWidth <= baseWidth * sx && destHeight <= baseHeight * sy) {
                return rvItem;
            }
        }

        return resolutionVariants.get(resolutionVariants.size() - 1);
    }


    private static void checkSize(double width, double height) {
        if (width <= 0 || height <= 0) {
            throw new IllegalArgumentException(String.format(
                    "Width (%s) or height (%s) cannot be <= 0", width, height));
        }

        if (!Double.isFinite(width) || !Double.isFinite(height)) {
            throw new IllegalArgumentException(String.format(
                    "Width (%s) or height (%s) is not finite", width, height));
        }
    }

    @Override
    public List<Image> getResolutionVariants() {
        return resolutionVariants.stream()
                .map(rvItem -> rvItem.getValue())
                .collect(Collectors.toList());
    }

    public List<ResolutionVariantItem<Image>> getResolutionVariantItems() {
        return resolutionVariants;
    }

    @Override
    public ImageProducer getSource() {
        return new MultiResolutionImageProducer(resolutionVariants.stream()
                .map(rvItem -> new ResolutionVariantItem<>(
                        rvItem.getValue().getSource(),
                        rvItem.getScaleX(),
                        rvItem.getScaleY()))
                .collect(Collectors.toList()));
    }

    private static final int BITS_INFO = ImageObserver.SOMEBITS
            | ImageObserver.FRAMEBITS | ImageObserver.ALLBITS;

    private static class ObserverCache {

        @SuppressWarnings("deprecation")
        static final SoftCache INSTANCE = new SoftCache();
    }

    public static ImageObserver getResolutionVariantObserver(
            final Image image, final ImageObserver observer,
            final double scaleX, final double scaleY,
            boolean concatenateInfo) {

        if (observer == null) {
            return null;
        }

        synchronized (ObserverCache.INSTANCE) {

            Object key = new ResolutionVariantItem<>(observer, scaleX, scaleY);
            ImageObserver o = (ImageObserver) ObserverCache.INSTANCE.get(key);

            if (o == null) {

                o = (Image resolutionVariant, int flags,
                        int x, int y, int width, int height) -> {

                            if ((flags & (ImageObserver.WIDTH | BITS_INFO)) != 0) {
                                width = (int) Math.floor(width / scaleX);
                            }

                            if ((flags & (ImageObserver.HEIGHT | BITS_INFO)) != 0) {
                                height = (int) Math.floor(height / scaleY);
                            }

                            if ((flags & BITS_INFO) != 0) {
                                x = (int) Math.ceil(x / scaleX);
                                y = (int) Math.ceil(y / scaleY);
                            }

                            if(concatenateInfo){
                                flags &= ((ToolkitImage) image).
                                        getImageRep().check(null);
                            }

                            return observer.imageUpdate(
                                    image, flags, x, y, width, height);
                        };

                ObserverCache.INSTANCE.put(key, o);
            }
            return o;
        }
    }

    public static class MultiResolutionImageProducer implements ImageProducer {

        private final ImageProducer baseImageProducer;
        private final List<ResolutionVariantItem<ImageProducer>> rvProducers;

        public MultiResolutionImageProducer(
                List<ResolutionVariantItem<ImageProducer>> rvProducers)
        {
            this.baseImageProducer = rvProducers.get(0).getValue();
            this.rvProducers = rvProducers;
        }

        @Override
        public void addConsumer(ImageConsumer ic) {
            getBaseImageProducer().addConsumer(ic);
        }

        @Override
        public boolean isConsumer(ImageConsumer ic) {
            return getBaseImageProducer().isConsumer(ic);
        }

        @Override
        public void removeConsumer(ImageConsumer ic) {
            getBaseImageProducer().removeConsumer(ic);
        }

        @Override
        public void startProduction(ImageConsumer ic) {
            getBaseImageProducer().startProduction(ic);
        }

        @Override
        public void requestTopDownLeftRightResend(ImageConsumer ic) {
            getBaseImageProducer().requestTopDownLeftRightResend(ic);
        }

        private ImageProducer getBaseImageProducer() {
            return baseImageProducer;
        }

        @Override
        public boolean isMultiResolutionImageProducer() {
            return true;
        }

        @Override
        public List<ResolutionVariantItem<ImageProducer>> getResolutionVariantItems() {
            return rvProducers;
        }
    }
}