/*
 * Copyright (c) 2009-2010 jMonkeyEngine
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 * * Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * * 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.
 *
 * * Neither the name of 'jMonkeyEngine' nor the names of its contributors
 *   may be used to endorse or promote products derived from this software
 *   without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "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 THE COPYRIGHT OWNER 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.
 */

package com.jme3.texture.plugins;

import com.jme3.asset.AssetInfo;
import com.jme3.asset.AssetLoadException;
import com.jme3.asset.AssetLoader;
import com.jme3.asset.TextureKey;
import com.jme3.texture.Image;
import com.jme3.texture.Image.Format;
import com.jme3.util.BufferUtils;
import java.awt.Transparency;
import java.awt.color.ColorSpace;
import java.awt.image.*;
import java.io.IOException;
import java.io.InputStream;
import java.nio.ByteBuffer;
import javax.imageio.ImageIO;

public class AWTLoader implements AssetLoader {

    public static final ColorModel AWT_RGBA4444 = new DirectColorModel(16,
                                                                       0xf000,
                                                                       0x0f00,
                                                                       0x00f0,
                                                                       0x000f);

    public static final ColorModel AWT_RGBA5551
            = new ComponentColorModel(ColorSpace.getInstance(ColorSpace.CS_sRGB), 
                                      new int[]{5, 5, 5, 1},
                                      true,
                                      false,
                                      Transparency.BITMASK,
                                      DataBuffer.TYPE_BYTE);

    private Object extractImageData(BufferedImage img){
        DataBuffer buf = img.getRaster().getDataBuffer();
        switch (buf.getDataType()){
            case DataBuffer.TYPE_BYTE:
                DataBufferByte byteBuf = (DataBufferByte) buf;
                return byteBuf.getData();
            case DataBuffer.TYPE_USHORT:
                DataBufferUShort shortBuf = (DataBufferUShort) buf;
                return shortBuf.getData();
        }
        return null;
    }

    private void flipImage(byte[] img, int width, int height, int bpp){
        int scSz = (width * bpp) / 8;
        byte[] sln = new byte[scSz];
        int y2 = 0;
        for (int y1 = 0; y1 < height / 2; y1++){
            y2 = height - y1 - 1;
            System.arraycopy(img, y1 * scSz, sln, 0,         scSz);
            System.arraycopy(img, y2 * scSz, img, y1 * scSz, scSz);
            System.arraycopy(sln, 0,         img, y2 * scSz, scSz);
        }
    }
    
    private void flipImage(short[] img, int width, int height, int bpp){
        int scSz = (width * bpp) / 8;
        scSz /= 2; // Because shorts are 2 bytes
        short[] sln = new short[scSz];
        int y2 = 0;
        for (int y1 = 0; y1 < height / 2; y1++){
            y2 = height - y1 - 1;
            System.arraycopy(img, y1 * scSz, sln, 0,         scSz);
            System.arraycopy(img, y2 * scSz, img, y1 * scSz, scSz);
            System.arraycopy(sln, 0,         img, y2 * scSz, scSz);
        }
    }

    public Image load(BufferedImage img, boolean flipY){
        int width = img.getWidth();
        int height = img.getHeight();

        switch (img.getType()){
            case BufferedImage.TYPE_4BYTE_ABGR: // most common in PNG images w/ alpha
               byte[] dataBuf1 = (byte[]) extractImageData(img);
               if (flipY)
                   flipImage(dataBuf1, width, height, 32);
                
               ByteBuffer data1 = BufferUtils.createByteBuffer(img.getWidth()*img.getHeight()*4);
               data1.put(dataBuf1);
               return new Image(Format.ABGR8, width, height, data1);
            case BufferedImage.TYPE_3BYTE_BGR: // most common in JPEG images
               byte[] dataBuf2 = (byte[]) extractImageData(img);
               if (flipY)
                   flipImage(dataBuf2, width, height, 24);
               
               ByteBuffer data2 = BufferUtils.createByteBuffer(img.getWidth()*img.getHeight()*3);
               data2.put(dataBuf2);
               return new Image(Format.BGR8, width, height, data2);
            case BufferedImage.TYPE_BYTE_GRAY: // grayscale fonts
                byte[] dataBuf3 = (byte[]) extractImageData(img);
                if (flipY)
                    flipImage(dataBuf3, width, height, 8);
                ByteBuffer data3 = BufferUtils.createByteBuffer(img.getWidth()*img.getHeight());
                data3.put(dataBuf3);
                return new Image(Format.Luminance8, width, height, data3);
            case BufferedImage.TYPE_USHORT_GRAY: // grayscale heightmap
                short[] dataBuf4 = (short[]) extractImageData(img);
                if (flipY)
                    flipImage(dataBuf4, width, height, 16);
                
                ByteBuffer data4 = BufferUtils.createByteBuffer(img.getWidth()*img.getHeight()*2);
                data4.asShortBuffer().put(dataBuf4);
                return new Image(Format.Luminance16, width, height, data4);
            default:
                break;
        }

        if (img.getTransparency() == Transparency.OPAQUE){
            ByteBuffer data = BufferUtils.createByteBuffer(img.getWidth()*img.getHeight()*3);
            // no alpha
            for (int y = 0; y < height; y++){
                for (int x = 0; x < width; x++){
                    int ny = y;
                    if (flipY){
                        ny = height - y - 1;
                    }

                    int rgb = img.getRGB(x,ny);
                    byte r = (byte) ((rgb & 0x00FF0000) >> 16);
                    byte g = (byte) ((rgb & 0x0000FF00) >> 8);
                    byte b = (byte) ((rgb & 0x000000FF));
                    data.put(r).put(g).put(b);
                }
            }
            data.flip();
            return new Image(Format.RGB8, width, height, data);
        }else{
            ByteBuffer data = BufferUtils.createByteBuffer(img.getWidth()*img.getHeight()*4);
            // no alpha
            for (int y = 0; y < height; y++){
                for (int x = 0; x < width; x++){
                    int ny = y;
                    if (flipY){
                        ny = height - y - 1;
                    }

                    int rgb = img.getRGB(x,ny);
                    byte a = (byte) ((rgb & 0xFF000000) >> 24);
                    byte r = (byte) ((rgb & 0x00FF0000) >> 16);
                    byte g = (byte) ((rgb & 0x0000FF00) >> 8);
                    byte b = (byte) ((rgb & 0x000000FF));
                    data.put(r).put(g).put(b).put(a);
                }
            }
            data.flip();
            return new Image(Format.RGBA8, width, height, data);
        }
    }

    public Image load(InputStream in, boolean flipY) throws IOException{
        ImageIO.setUseCache(false);
        BufferedImage img = ImageIO.read(in);
        if (img == null){
            return null;
        }
        return load(img, flipY);
    }

    public Object load(AssetInfo info) throws IOException {
        if (ImageIO.getImageReadersBySuffix(info.getKey().getExtension()) != null){
            boolean flip = ((TextureKey) info.getKey()).isFlipY();
            InputStream in = null;
            try {
                in = info.openStream();
                Image img = load(in, flip);
                if (img == null){
                    throw new AssetLoadException("The given image cannot be loaded " + info.getKey());
                }
                return img;
            } finally {
                if (in != null){
                    in.close();
                }
            }
        }else{
            throw new AssetLoadException("The extension " + info.getKey().getExtension() + " is not supported");
        }
    }
}