/**
 * Copyright 2013 JogAmp Community. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification, are
 * permitted provided that the following conditions are met:
 *
 *    1. Redistributions of source code must retain the above copyright notice, this list of
 *       conditions and the following disclaimer.
 *
 *    2. Redistributions in binary form must reproduce the above copyright notice, this list
 *       of conditions and the following disclaimer in the documentation and/or other materials
 *       provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY JogAmp Community ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
 * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL JogAmp Community OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * The views and conclusions contained in the software and documentation are those of the
 * authors and should not be interpreted as representing official policies, either expressed
 * or implied, of JogAmp Community.
 */
package com.jogamp.opengl.util;

import java.nio.Buffer;
import java.nio.ByteBuffer;

import javax.media.nativewindow.util.PixelFormat;
import javax.media.opengl.GL;
import javax.media.opengl.GL2;
import javax.media.opengl.GL2ES2;
import javax.media.opengl.GL2ES3;
import javax.media.opengl.GL2GL3;
import javax.media.opengl.GLContext;
import javax.media.opengl.GLException;
import javax.media.opengl.GLProfile;

import com.jogamp.common.nio.Buffers;
import com.jogamp.opengl.util.texture.TextureData;

/**
 * OpenGL pixel data buffer, allowing user to provide buffers via their {@link GLPixelBufferProvider} implementation.
 * <p>
 * {@link GLPixelBufferProvider} produces a {@link GLPixelBuffer}.
 * </p>
 * <p>
 * You may use {@link #defaultProviderNoRowStride}.
 * </p>
 */
public class GLPixelBuffer {

    /** Allows user to interface with another toolkit to define {@link GLPixelAttributes} and memory buffer to produce {@link TextureData}. */
    public static interface GLPixelBufferProvider {
        /** Allow {@link GL2ES3#GL_PACK_ROW_LENGTH}, or {@link GL2ES2#GL_UNPACK_ROW_LENGTH}. */
        boolean getAllowRowStride();

        /** Called first to determine {@link GLPixelAttributes}. */
        GLPixelAttributes getAttributes(GL gl, int componentCount);

        /**
         * Allocates a new {@link GLPixelBuffer} object.
         * <p>
         * Being called to gather the initial {@link GLPixelBuffer},
         * or a new replacement {@link GLPixelBuffer} if {@link GLPixelBuffer#requiresNewBuffer(GL, int, int, int)}.
         * </p>
         * <p>
         * The minimum required {@link Buffer#remaining() remaining} byte size equals to <code>minByteSize</code>, if &gt; 0,
         * otherwise utilize {@link GLBuffers#sizeof(GL, int[], int, int, int, int, int, boolean)}
         * to calculate it.
         * </p>
         *
         * @param gl the corresponding current GL context object
         * @param pixelAttributes the desired {@link GLPixelAttributes}
         * @param width in pixels
         * @param height in pixels
         * @param depth in pixels
         * @param pack true for read mode GPU -> CPU, otherwise false for write mode CPU -> GPU
         * @param minByteSize if &gt; 0, the pre-calculated minimum byte-size for the resulting buffer, otherwise ignore.
         */
        GLPixelBuffer allocate(GL gl, GLPixelAttributes pixelAttributes, int width, int height, int depth, boolean pack, int minByteSize);
    }

    /** Single {@link GLPixelBuffer} provider. */
    public static interface SingletonGLPixelBufferProvider extends GLPixelBufferProvider {
        /** Return the last {@link #allocate(GL, GLPixelAttributes, int, int, int, boolean, int) allocated} {@link GLPixelBuffer} w/ {@link GLPixelAttributes#componentCount}. */
        GLPixelBuffer getSingleBuffer(GLPixelAttributes pixelAttributes);
        /**
         * Initializes the single {@link GLPixelBuffer} w/ a given size, if not yet {@link #allocate(GL, GLPixelAttributes, int, int, int, boolean, int) allocated}.
         * @return the newly initialized single {@link GLPixelBuffer}, or null if already allocated.
         */
        GLPixelBuffer initSingleton(int componentCount, int width, int height, int depth, boolean pack);
    }

    public static class DefaultGLPixelBufferProvider implements GLPixelBufferProvider {
        private final boolean allowRowStride;

        /**
         * @param allowRowStride If <code>true</code>, allow row-stride, otherwise not.
         * See {@link #getAllowRowStride()} and {@link GLPixelBuffer#requiresNewBuffer(GL, int, int, int)}.
         */
        public DefaultGLPixelBufferProvider(boolean allowRowStride) {
            this.allowRowStride = allowRowStride;
        }

        @Override
        public boolean getAllowRowStride() { return allowRowStride; }

        @Override
        public GLPixelAttributes getAttributes(GL gl, int componentCount) {
            final GLContext ctx = gl.getContext();
            final int dFormat, dType;

            if( 1 == componentCount ) {
                if( gl.isGL3ES3() ) {
                    // RED is supported on ES3 and >= GL3 [core]; ALPHA is deprecated on core
                    dFormat = GL2ES2.GL_RED;
                } else {
                    // ALPHA is supported on ES2 and GL2, i.e. <= GL3 [core] or compatibility
                    dFormat = GL2ES2.GL_ALPHA;
                }
                dType   = GL.GL_UNSIGNED_BYTE;
            } else if( 3 == componentCount ) {
                dFormat = GL.GL_RGB;
                dType   = GL.GL_UNSIGNED_BYTE;
            } else if( 4 == componentCount ) {
                int _dFormat = ctx.getDefaultPixelDataFormat();
                final int dComps = GLBuffers.componentCount(_dFormat);
                if( dComps == componentCount ) {
                    dFormat = _dFormat;
                    dType   = ctx.getDefaultPixelDataType();
                } else {
                    dFormat = GL.GL_RGBA;
                    dType   = GL.GL_UNSIGNED_BYTE;
                }
            } else {
                throw new GLException("Unsupported componentCount "+componentCount+", contact maintainer to enhance");
            }
            return new GLPixelAttributes(componentCount, dFormat, dType);
        }

        /**
         * {@inheritDoc}
         * <p>
         * Returns an NIO {@link ByteBuffer}.
         * </p>
         */
        @Override
        public GLPixelBuffer allocate(GL gl, GLPixelAttributes pixelAttributes, int width, int height, int depth, boolean pack, int minByteSize) {
            if( minByteSize > 0 ) {
                return new GLPixelBuffer(pixelAttributes, width, height, depth, pack, Buffers.newDirectByteBuffer(minByteSize), getAllowRowStride());
            } else {
                int[] tmp = { 0 };
                final int byteSize = GLBuffers.sizeof(gl, tmp, pixelAttributes.bytesPerPixel, width, height, depth, pack);
                return new GLPixelBuffer(pixelAttributes, width, height, depth, pack, Buffers.newDirectByteBuffer(byteSize), getAllowRowStride());
            }
        }
    }

    /**
     * Default {@link GLPixelBufferProvider} with {@link GLPixelBufferProvider#getAllowRowStride()} == <code>false</code>,
     * utilizing best match for {@link GLPixelAttributes}
     * and {@link GLPixelBufferProvider#allocate(GL, GLPixelAttributes, int, int, int, boolean, int) allocating} a {@link ByteBuffer}.
     */
    public static GLPixelBufferProvider defaultProviderNoRowStride = new DefaultGLPixelBufferProvider(false);

    /**
     * Default {@link GLPixelBufferProvider} with {@link GLPixelBufferProvider#getAllowRowStride()} == <code>true</code>,
     * utilizing best match for {@link GLPixelAttributes}
     * and {@link GLPixelBufferProvider#allocate(GL, GLPixelAttributes, int, int, int, boolean, int) allocating} a {@link ByteBuffer}.
     */
    public static GLPixelBufferProvider defaultProviderWithRowStride = new DefaultGLPixelBufferProvider(true);

    /** Pixel attributes. */
    public static class GLPixelAttributes {
        /** Undefined instance of {@link GLPixelAttributes}, having componentCount:=0, format:=0 and type:= 0. */
        public static final GLPixelAttributes UNDEF = new GLPixelAttributes(0, 0, 0, false);

        /** Pixel <i>source</i> component count, i.e. number of meaningful components. */
        public final int componentCount;
        /** The OpenGL pixel data format */
        public final int format;
        /** The OpenGL pixel data type  */
        public final int type;
        /** The OpenGL pixel size in bytes  */
        public final int bytesPerPixel;

        /**
         * Deriving {@link #componentCount} via GL <code>dataFormat</code>, i.e. {@link GLBuffers#componentCount(int)} if &gt; 0.
         * @param dataFormat GL data format
         * @param dataType GL data type
         */
        public GLPixelAttributes(int dataFormat, int dataType) {
            this(0 < dataFormat ? GLBuffers.componentCount(dataFormat) : 0, dataFormat, dataType);
        }
        /**
         * Using user specified source {@link #componentCount}.
         * @param componentCount source component count
         * @param dataFormat GL data format
         * @param dataType GL data type
         */
        public GLPixelAttributes(int componentCount, int dataFormat, int dataType) {
            this(componentCount, dataFormat, dataType, true);
        }

        /**
         * Returns the matching {@link GLPixelAttributes} for the given {@link PixelFormat} and {@link GLProfile} if exists,
         * otherwise returns <code>null</code>.
         */
        public static final GLPixelAttributes convert(PixelFormat pixFmt, GLProfile glp) {
            int df = 0; // format
            int dt = GL.GL_UNSIGNED_BYTE; // data type
            switch(pixFmt) {
                case LUMINANCE:
                    if( glp.isGL3ES3() ) {
                        // RED is supported on ES3 and >= GL3 [core]; ALPHA/LUMINANCE is deprecated on core
                        df = GL2ES2.GL_RED;
                    } else {
                        // ALPHA/LUMINANCE is supported on ES2 and GL2, i.e. <= GL3 [core] or compatibility
                        df = GL2ES2.GL_LUMINANCE;
                    }
                    break;
                case BGR888:
                    if( glp.isGL2GL3() ) {
                        df = GL2GL3.GL_BGR;
                    }
                    break;
                case RGB888:
                    df = GL.GL_RGB;
                    break;
                case RGBA8888:
                    df = GL.GL_RGBA;
                    break;
                case ABGR8888:
                    if( glp.isGL2GL3() ) {
                        df = GL.GL_RGBA; dt = GL2GL3.GL_UNSIGNED_INT_8_8_8_8;
                    }
                    break;
                case BGRA8888:
                    df = GL.GL_BGRA;
                    break;
                case ARGB8888:
                    if( glp.isGL2GL3() ) {
                        df = GL.GL_BGRA; dt = GL2GL3.GL_UNSIGNED_INT_8_8_8_8;
                    }
                    break;
                default:
                    break;
            }
            if( 0 != df ) {
                return new GLPixelAttributes(pixFmt.componentCount, df, dt, true);
            }
            return null;
        }
        private GLPixelAttributes(int componentCount, int dataFormat, int dataType, boolean checkArgs) {
            this.componentCount = componentCount;
            this.format = dataFormat;
            this.type = dataType;
            this.bytesPerPixel = ( 0 < dataFormat && 0 < dataType ) ? GLBuffers.bytesPerPixel(dataFormat, dataType) : 0;
            if( checkArgs ) {
                if( 0 == componentCount || 0 == format || 0 == type ) {
                    throw new GLException("Zero components, format and/or type: "+this);
                }
                if( 0 == bytesPerPixel ) {
                    throw new GLException("Zero bytesPerPixel: "+this);
                }
            }
        }

        /**
         * Returns the matching {@link PixelFormat} of this {@link GLPixelAttributes} if exists,
         * otherwise returns <code>null</code>.
         */
        public final PixelFormat getPixelFormat() {
            final PixelFormat pixFmt;
            // FIXME: Take 'type' into consideration and complete mapping!
            switch(format) {
                case GL.GL_ALPHA:
                case GL.GL_LUMINANCE:
                case GL2ES2.GL_RED:
                    pixFmt = PixelFormat.LUMINANCE;
                    break;
                case GL.GL_RGB:
                    pixFmt = PixelFormat.RGB888;
                    break;
                case GL.GL_RGBA:
                    pixFmt = PixelFormat.RGBA8888;
                    break;
                case GL2.GL_BGR:
                    pixFmt = PixelFormat.BGR888;
                    break;
                case GL.GL_BGRA:
                    pixFmt = PixelFormat.BGRA8888;
                    break;
                default:
                    switch( bytesPerPixel ) {
                        case 1:
                            pixFmt = PixelFormat.LUMINANCE;
                            break;
                        case 3:
                            pixFmt = PixelFormat.RGB888;
                            break;
                        case 4:
                            pixFmt = PixelFormat.RGBA8888;
                            break;
                        default:
                            pixFmt = null;
                            break;
                    }
                    break;
            }
            return pixFmt;
        }

        @Override
        public String toString() {
            return "PixelAttributes[comp "+componentCount+", fmt 0x"+Integer.toHexString(format)+", type 0x"+Integer.toHexString(type)+", bytesPerPixel "+bytesPerPixel+"]";
        }
    }

    /** The {@link GLPixelAttributes}. */
    public final GLPixelAttributes pixelAttributes;
    /**
     * Width in pixels, representing {@link #buffer}'s {@link #byteSize}.
     * <p>
     * May not represent actual image width as user may re-use buffer for different dimensions, see {@link #requiresNewBuffer(GL, int, int, int)}.
     * </p>
     */
    public final int width;
    /**
     * Height in pixels, representing {@link #buffer}'s {@link #byteSize}.
     * <p>
     * May not represent actual image height as user may re-use buffer for different dimensions, see {@link #requiresNewBuffer(GL, int, int, int)}.
     * </p>
     */
    public final int height;
    /** Depth in pixels. */
    public final int depth;
    /** Data packing direction. If <code>true</code> for read mode GPU -> CPU, <code>false</code> for write mode CPU -> GPU. */
    public final boolean pack;
    /** Byte size of the buffer. Actually the number of {@link Buffer#remaining()} bytes when passed in ctor. */
    public final int byteSize;
    /**
     * Buffer holding the pixel data. If {@link #rewind()}, it holds <code>byteSize</code> {@link Buffer#remaining()} bytes.
     * <p>
     * By default the {@link Buffer} is a {@link ByteBuffer}, due to {@link DefProvider#allocate(GL, GLPixelAttributes, int, int, int, boolean, int)}.
     * However, other {@link GLPixelBufferProvider} may utilize different {@link Buffer} types.
     * </p>
     */
    public final Buffer buffer;
    /** Buffer element size in bytes. */
    public final int bufferElemSize;

    /** Allow {@link GL2ES3#GL_PACK_ROW_LENGTH}, or {@link GL2ES2#GL_UNPACK_ROW_LENGTH}. See {@link #requiresNewBuffer(GL, int, int, int)}. */
    public final boolean allowRowStride;

    private boolean disposed = false;

    public StringBuilder toString(StringBuilder sb) {
        if(null == sb) {
            sb = new StringBuilder();
        }
        sb.append(pixelAttributes).append(", dim ").append(width).append("x").append(height).append("x").append(depth).append(", pack ").append(pack)
        .append(", disposed ").append(disposed).append(", valid ").append(isValid())
        .append(", buffer[bytes ").append(byteSize).append(", elemSize ").append(bufferElemSize).append(", ").append(buffer).append("]");
        return sb;
    }
    @Override
    public String toString() {
        return "GLPixelBuffer["+toString(null).toString()+"]";
    }

    /**
     * @param pixelAttributes the desired {@link GLPixelAttributes}
     * @param width in pixels
     * @param height in pixels
     * @param depth in pixels
     * @param pack true for read mode GPU -> CPU, otherwise false for write mode CPU -> GPU
     * @param buffer the backing array
     * @param allowRowStride If <code>true</code>, allow row-stride, otherwise not. See {@link #requiresNewBuffer(GL, int, int, int)}.
     */
    public GLPixelBuffer(GLPixelAttributes pixelAttributes, int width, int height, int depth, boolean pack, Buffer buffer, boolean allowRowStride) {
        this.pixelAttributes = pixelAttributes;
        this.width = width;
        this.height = height;
        this.depth = depth;
        this.pack = pack;
        this.buffer = buffer;
        this.byteSize = Buffers.remainingBytes(buffer);
        this.bufferElemSize = Buffers.sizeOfBufferElem(buffer);
        this.allowRowStride = allowRowStride;
    }

    /** Allow {@link GL2ES3#GL_PACK_ROW_LENGTH}, or {@link GL2ES2#GL_UNPACK_ROW_LENGTH}. */
    public final boolean getAllowRowStride() { return allowRowStride; }

    /** Is not {@link #dispose() disposed} and has {@link #byteSize} &gt; 0. */
    public boolean isValid() {
        return !disposed && 0 < byteSize;
    }

    /** See {@link Buffer#rewind()}. */
    public Buffer rewind() {
        return buffer.rewind();
    }

    /** Returns the byte position of the {@link #buffer}. */
    public int position() {
        return buffer.position() * bufferElemSize;
    }

    /** Sets the byte position of the {@link #buffer}. */
    public Buffer position(int bytePos) {
        return buffer.position( bytePos / bufferElemSize );
    }

    /** Returns the byte capacity of the {@link #buffer}. */
    public int capacity() {
        return buffer.capacity() * bufferElemSize;
    }

    /** Returns the byte limit of the {@link #buffer}. */
    public int limit() {
        return buffer.limit() * bufferElemSize;
    }

    /** See {@link Buffer#flip()}. */
    public Buffer flip() {
        return buffer.flip();
    }

    /** See {@link Buffer#clear()}. */
    public Buffer clear() {
        return buffer.clear();
    }

    /**
     * Returns true, if {@link #isValid() invalid} or implementation requires a new buffer based on the new size
     * due to pixel alignment or byte size, otherwise false.
     * <p>
     * It is assumed that <code>pixelAttributes</code>, <code>depth</code> and <code>pack</code> stays the same!
     * </p>
     * <p>
     * The minimum required byte size equals to <code>minByteSize</code>, if &gt; 0,
     * otherwise {@link GLBuffers#sizeof(GL, int[], int, int, int, int, int, boolean) GLBuffers.sizeof(..)}
     * is being used to calculate it. This value is referred to <i>newByteSize</i>.
     * </p>
     * <p>
     * If <code>{@link #allowRowStride} = false</code>,
     * method returns <code>true</code> if the <i>newByteSize</i> &gt; <i>currentByteSize</i>
     * or the <code>newWidth</code> != <code>currentWidth</code>.
     * </p>
     * <p>
     * If <code>{@link #allowRowStride} = true</code>, see {@link GLPixelBufferProvider#getAllowRowStride()},
     * method returns <code>true</code> only if the <i>newByteSize</i> &gt; <i>currentByteSize</i>.
     * Assuming user utilizes the row-stride when dealing w/ the data, i.e. {@link GL2ES3#GL_PACK_ROW_LENGTH}.
     * </p>
     * @param gl the corresponding current GL context object
     * @param newWidth new width in pixels
     * @param newHeight new height in pixels
     * @param newByteSize if &gt; 0, the pre-calculated minimum byte-size for the resulting buffer, otherwise ignore.
     * @see GLPixelBufferProvider#allocate(GL, GLPixelAttributes, int, int, int, boolean, int)
     */
    public boolean requiresNewBuffer(GL gl, int newWidth, int newHeight, int newByteSize) {
        if( !isValid() ) {
            return true;
        }
        if( 0 >= newByteSize ) {
            final int[] tmp = { 0 };
            newByteSize = GLBuffers.sizeof(gl, tmp, pixelAttributes.bytesPerPixel, newWidth, newHeight, 1, true);
        }
        if( allowRowStride ) {
            return byteSize < newByteSize;
        }
        return byteSize < newByteSize || width != newWidth;
    }

    /** Dispose resources. See {@link #isValid()}. */
    public void dispose() {
        disposed = true;
        buffer.clear();
    }
}