/*

 * Copyright (c) 2019, 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.java2d.metal;

import sun.awt.CGraphicsConfig;

import sun.awt.CGraphicsDevice;

import sun.awt.image.OffScreenImage;

import sun.awt.image.SunVolatileImage;

import sun.awt.image.SurfaceManager;

import sun.java2d.Disposer;

import sun.java2d.DisposerRecord;

import sun.java2d.Surface;

import sun.java2d.SurfaceData;

import sun.java2d.pipe.hw.AccelGraphicsConfig;

import sun.java2d.pipe.hw.AccelSurface;

import sun.java2d.pipe.hw.AccelTypedVolatileImage;

import sun.java2d.pipe.hw.ContextCapabilities;

import sun.lwawt.LWComponentPeer;

import sun.lwawt.macosx.CFRetainedResource;

import sun.lwawt.macosx.CPlatformView;

import java.awt.*;

import java.awt.color.ColorSpace;

import java.awt.image.*;

import java.io.File;

import java.security.AccessController;

import java.security.PrivilegedAction;

import java.util.HashMap;

import static sun.java2d.opengl.OGLSurfaceData.TEXTURE;

import static sun.java2d.pipe.hw.AccelSurface.RT_TEXTURE;

import static sun.java2d.pipe.hw.ContextCapabilities.*;

public final class MTLGraphicsConfig extends CGraphicsConfig

        implements AccelGraphicsConfig, SurfaceManager.ProxiedGraphicsConfig

{

    //private static final int kOpenGLSwapInterval =

    // RuntimeOptions.getCurrentOptions().OpenGLSwapInterval;

    private static final int kOpenGLSwapInterval = 0; // TODO

    private static boolean mtlAvailable;

    private static ImageCapabilities imageCaps = new MTLImageCaps();

    private static final String mtlShadersLib = AccessController.doPrivileged(

            (PrivilegedAction<String>) () ->

                    System.getProperty("java.home", "") + File.separator +

                            "lib" + File.separator + "shaders.metallib");

    private int pixfmt;

    private BufferCapabilities bufferCaps;

    private long pConfigInfo;

    private ContextCapabilities mtlCaps;

    private MTLContext context;

    private final Object disposerReferent = new Object();

    private final int maxTextureSize;

    private static native boolean initMTL();

    private static native long getMTLConfigInfo(int displayID, String mtlShadersLib);

    /**

     * Returns GL_MAX_TEXTURE_SIZE from the shared opengl context. Must be

     * called under OGLRQ lock, because this method change current context.

     *

     * @return GL_MAX_TEXTURE_SIZE

     */

    private static native int nativeGetMaxTextureSize();

    private static final HashMap<Long, Integer> pGCRefCounts = new HashMap<>();

    static {

        mtlAvailable = initMTL();

    }

    private MTLGraphicsConfig(CGraphicsDevice device, int pixfmt,

                              long configInfo, int maxTextureSize,

                              ContextCapabilities mtlCaps) {

        super(device);

        this.pixfmt = pixfmt;

        this.pConfigInfo = configInfo;

        this.mtlCaps = mtlCaps;

        this.maxTextureSize = maxTextureSize;

        context = new MTLContext(MTLRenderQueue.getInstance(), this);

        refPConfigInfo(pConfigInfo);

        // add a record to the Disposer so that we destroy the native

        // MTLGraphicsConfigInfo data when this object goes away

        Disposer.addRecord(disposerReferent,

                new MTLGCDisposerRecord(pConfigInfo));

    }

    @Override

    public Object getProxyKey() {

        return this;

    }

    public SurfaceData createManagedSurface(int w, int h, int transparency) {

        return MTLSurfaceData.createData(this, w, h,

                getColorModel(transparency),

                null,

                MTLSurfaceData.TEXTURE);

    }

    public static MTLGraphicsConfig getConfig(CGraphicsDevice device,

                                              int displayID, int pixfmt)

    {

        if (!mtlAvailable) {

            return null;

        }

        long cfginfo = 0;

        int textureSize = 0;

        final String[] ids = new String[1];

        MTLRenderQueue rq = MTLRenderQueue.getInstance();

        rq.lock();

        try {

            // getCGLConfigInfo() creates and destroys temporary

            // surfaces/contexts, so we should first invalidate the current

            // Java-level context and flush the queue...

            MTLContext.invalidateCurrentContext();

            cfginfo = getMTLConfigInfo(displayID, mtlShadersLib);

            if (cfginfo != 0L) {

                textureSize = nativeGetMaxTextureSize();

                // 7160609: GL still fails to create a square texture of this

                // size. Half should be safe enough.

                // Explicitly not support a texture more than 2^14, see 8010999.

                textureSize = textureSize <= 16384 ? textureSize / 2 : 8192;

                MTLContext.setScratchSurface(cfginfo);

                rq.flushAndInvokeNow(() -> {

                    ids[0] = MTLContext.getMTLIdString();

                });

            }

        } finally {

            rq.unlock();

        }

        if (cfginfo == 0) {

            return null;

        }

        ContextCapabilities caps = new MTLContext.MTLContextCaps(

                CAPS_PS30 | CAPS_PS20 | CAPS_RT_PLAIN_ALPHA |

                        CAPS_RT_TEXTURE_ALPHA | CAPS_RT_TEXTURE_OPAQUE |

                        CAPS_MULTITEXTURE | CAPS_TEXNONPOW2 | CAPS_TEXNONSQUARE,

                ids[0]);

        return new MTLGraphicsConfig(device, pixfmt, cfginfo, textureSize, caps);

    }

    static void refPConfigInfo(long pConfigInfo) {

        synchronized (pGCRefCounts) {

            Integer count = pGCRefCounts.get(pConfigInfo);

            if (count == null) {

                count = 1;

            }

            else {

                count++;

            }

            pGCRefCounts.put(pConfigInfo, count);

        }

    }

    static void deRefPConfigInfo(long pConfigInfo) {

        synchronized (pGCRefCounts) {

            Integer count = pGCRefCounts.get(pConfigInfo);

            if (count != null) {

                count--;

                pGCRefCounts.put(pConfigInfo, count);

                if (count == 0) {

                    MTLRenderQueue.disposeGraphicsConfig(pConfigInfo);

                    pGCRefCounts.remove(pConfigInfo);

                }

            }

        }

    }

    /**

     * Returns true if the provided capability bit is present for this config.

     * See MTLContext.java for a list of supported capabilities.

     */

    public boolean isCapPresent(int cap) {

        return ((mtlCaps.getCaps() & cap) != 0);

    }

    public long getNativeConfigInfo() {

        return pConfigInfo;

    }

    /**

     * {@inheritDoc}

     *

     * @see sun.java2d.pipe.hw.BufferedContextProvider#getContext

     */

    @Override

    public MTLContext getContext() {

        return context;

    }

    @Override

    public BufferedImage createCompatibleImage(int width, int height) {

        ColorModel model = new DirectColorModel(24, 0xff0000, 0xff00, 0xff);

        WritableRaster

                raster = model.createCompatibleWritableRaster(width, height);

        return new BufferedImage(model, raster, model.isAlphaPremultiplied(),

                null);

    }

    @Override

    public ColorModel getColorModel(int transparency) {

        switch (transparency) {

            case Transparency.OPAQUE:

                // REMIND: once the ColorModel spec is changed, this should be

                //         an opaque premultiplied DCM...

                return new DirectColorModel(24, 0xff0000, 0xff00, 0xff);

            case Transparency.BITMASK:

                return new DirectColorModel(25, 0xff0000, 0xff00, 0xff, 0x1000000);

            case Transparency.TRANSLUCENT:

                ColorSpace cs = ColorSpace.getInstance(ColorSpace.CS_sRGB);

                return new DirectColorModel(cs, 32,

                        0xff0000, 0xff00, 0xff, 0xff000000,

                        true, DataBuffer.TYPE_INT);

            default:

                return null;

        }

    }

    public boolean isDoubleBuffered() {

        return true;

    }

    private static class MTLGCDisposerRecord implements DisposerRecord {

        private long pCfgInfo;

        public MTLGCDisposerRecord(long pCfgInfo) {

            this.pCfgInfo = pCfgInfo;

        }

        public void dispose() {

            if (pCfgInfo != 0) {

                deRefPConfigInfo(pCfgInfo);

                pCfgInfo = 0;

            }

        }

    }

    // TODO: CGraphicsConfig doesn't implement displayChanged() yet

    //@Override

    public synchronized void displayChanged() {

        //super.displayChanged();

        // the context could hold a reference to a MTLSurfaceData, which in

        // turn has a reference back to this MTLGraphicsConfig, so in order

        // for this instance to be disposed we need to break the connection

        MTLRenderQueue rq = MTLRenderQueue.getInstance();

        rq.lock();

        try {

            MTLContext.invalidateCurrentContext();

        } finally {

            rq.unlock();

        }

    }

    @Override

    public String toString() {

        return ("MTLGraphicsConfig[" + getDevice().getIDstring() +

                ",pixfmt="+pixfmt+"]");

    }

    @Override

    public SurfaceData createSurfaceData(CPlatformView pView) {

        return MTLSurfaceData.createData(pView);

    }

    @Override

    public SurfaceData createSurfaceData(CFRetainedResource layer) {

        return MTLSurfaceData.createData((MTLLayer) layer);

    }

    @Override

    public Image createAcceleratedImage(Component target,

                                        int width, int height)

    {

        ColorModel model = getColorModel(Transparency.OPAQUE);

        WritableRaster wr = model.createCompatibleWritableRaster(width, height);

        return new OffScreenImage(target, model, wr,

                model.isAlphaPremultiplied());

    }

    @Override

    public void assertOperationSupported(final int numBuffers,

                                         final BufferCapabilities caps)

            throws AWTException {

        // Assume this method is never called with numBuffers != 2, as 0 is

        // unsupported, and 1 corresponds to a SingleBufferStrategy which

        // doesn't depend on the peer. Screen is considered as a separate

        // "buffer".

        if (numBuffers != 2) {

            throw new AWTException("Only double buffering is supported");

        }

        final BufferCapabilities configCaps = getBufferCapabilities();

        if (!configCaps.isPageFlipping()) {

            throw new AWTException("Page flipping is not supported");

        }

        if (caps.getFlipContents() == BufferCapabilities.FlipContents.PRIOR) {

            throw new AWTException("FlipContents.PRIOR is not supported");

        }

    }

    @Override

    public Image createBackBuffer(final LWComponentPeer<?, ?> peer) {

        final Rectangle r = peer.getBounds();

        // It is possible for the component to have size 0x0, adjust it to

        // be at least 1x1 to avoid IAE

        final int w = Math.max(1, r.width);

        final int h = Math.max(1, r.height);

        final int transparency = peer.isTranslucent() ? Transparency.TRANSLUCENT

                : Transparency.OPAQUE;

        return new SunVolatileImage(this, w, h, transparency, null);

    }

    @Override

    public void destroyBackBuffer(final Image backBuffer) {

        if (backBuffer != null) {

            backBuffer.flush();

        }

    }

    @Override

    public void flip(final LWComponentPeer<?, ?> peer, final Image backBuffer,

                     final int x1, final int y1, final int x2, final int y2,

                     final BufferCapabilities.FlipContents flipAction) {

        final Graphics g = peer.getGraphics();

        try {

            g.drawImage(backBuffer, x1, y1, x2, y2, x1, y1, x2, y2, null);

        } finally {

            g.dispose();

        }

        if (flipAction == BufferCapabilities.FlipContents.BACKGROUND) {

            final Graphics2D bg = (Graphics2D) backBuffer.getGraphics();

            try {

                bg.setBackground(peer.getBackground());

                bg.clearRect(0, 0, backBuffer.getWidth(null),

                        backBuffer.getHeight(null));

            } finally {

                bg.dispose();

            }

        }

    }

    private static class MTLBufferCaps extends BufferCapabilities {

        public MTLBufferCaps(boolean dblBuf) {

            super(imageCaps, imageCaps,

                    dblBuf ? FlipContents.UNDEFINED : null);

        }

    }

    @Override

    public BufferCapabilities getBufferCapabilities() {

        if (bufferCaps == null) {

            bufferCaps = new MTLBufferCaps(isDoubleBuffered());

        }

        return bufferCaps;

    }

    private static class MTLImageCaps extends ImageCapabilities {

        private MTLImageCaps() {

            super(true);

        }

        public boolean isTrueVolatile() {

            return true;

        }

    }

    @Override

    public ImageCapabilities getImageCapabilities() {

        return imageCaps;

    }

    @Override

    public VolatileImage createCompatibleVolatileImage(int width, int height,

                                                       int transparency,

                                                       int type) {

        if (type != RT_TEXTURE && type != TEXTURE) {

            return null;

        }

        SunVolatileImage vi = new AccelTypedVolatileImage(this, width, height,

                transparency, type);

        Surface sd = vi.getDestSurface();

        if (!(sd instanceof AccelSurface) ||

                ((AccelSurface)sd).getType() != type)

        {

            vi.flush();

            vi = null;

        }

        return vi;

    }

    /**

     * {@inheritDoc}

     *

     * @see sun.java2d.pipe.hw.AccelGraphicsConfig#getContextCapabilities

     */

    @Override

    public ContextCapabilities getContextCapabilities() {

        return mtlCaps;

    }

    @Override

    public int getMaxTextureWidth() {

        return Math.max(maxTextureSize / getDevice().getScaleFactor(),

                getBounds().width);

    }

    @Override

    public int getMaxTextureHeight() {

        return Math.max(maxTextureSize / getDevice().getScaleFactor(),

                getBounds().height);

    }

}