/*
 * Copyright (c) 2003, 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 com.sun.imageio.plugins.wbmp;

import java.awt.Rectangle;
import java.awt.image.BufferedImage;
import java.awt.image.DataBufferByte;
import java.awt.image.MultiPixelPackedSampleModel;
import java.awt.image.Raster;
import java.awt.image.WritableRaster;

import javax.imageio.IIOException;
import javax.imageio.ImageReader;
import javax.imageio.ImageReadParam;
import javax.imageio.ImageTypeSpecifier;
import javax.imageio.metadata.IIOMetadata;
import javax.imageio.spi.ImageReaderSpi;
import javax.imageio.stream.ImageInputStream;

import java.io.*;
import java.util.ArrayList;
import java.util.Iterator;

import com.sun.imageio.plugins.common.I18N;
import com.sun.imageio.plugins.common.ReaderUtil;

This class is the Java Image IO plugin reader for WBMP images.
 It may subsample the image, clip the image,
 and shift the decoded image origin if the proper decoding parameter
 are set in the provided WBMPImageReadParam.
/** This class is the Java Image IO plugin reader for WBMP images.
 *  It may subsample the image, clip the image,
 *  and shift the decoded image origin if the proper decoding parameter
 *  are set in the provided <code>WBMPImageReadParam</code>.
 */
public class WBMPImageReader extends ImageReader {
    
The input stream where reads from /** The input stream where reads from */
    private ImageInputStream iis = null;

    
Indicates whether the header is read. /** Indicates whether the header is read. */
    private boolean gotHeader = false;

    
The original image width. /** The original image width. */
    private int width;

    
The original image height. /** The original image height. */
    private int height;

    private int wbmpType;

    private WBMPMetadata metadata;

    
Constructs WBMPImageReader from the provided
 ImageReaderSpi.
/** Constructs <code>WBMPImageReader</code> from the provided
     *  <code>ImageReaderSpi</code>.
     */
    public WBMPImageReader(ImageReaderSpi originator) {
        super(originator);
    }

    
Overrides the method defined in the superclass. /** Overrides the method defined in the superclass. */
    public void setInput(Object input,
                         boolean seekForwardOnly,
                         boolean ignoreMetadata) {
        super.setInput(input, seekForwardOnly, ignoreMetadata);
        iis = (ImageInputStream) input; // Always works
        gotHeader = false;
    }

    
Overrides the method defined in the superclass. /** Overrides the method defined in the superclass. */
    public int getNumImages(boolean allowSearch) throws IOException {
        if (iis == null) {
            throw new IllegalStateException(I18N.getString("GetNumImages0"));
        }
        if (seekForwardOnly && allowSearch) {
            throw new IllegalStateException(I18N.getString("GetNumImages1"));
        }
        return 1;
    }

    public int getWidth(int imageIndex) throws IOException {
        checkIndex(imageIndex);
        readHeader();
        return width;
    }

    public int getHeight(int imageIndex) throws IOException {
        checkIndex(imageIndex);
        readHeader();
        return height;
    }

    public boolean isRandomAccessEasy(int imageIndex) throws IOException {
        checkIndex(imageIndex);
        return true;
    }

    private void checkIndex(int imageIndex) {
        if (imageIndex != 0) {
            throw new IndexOutOfBoundsException(I18N.getString("WBMPImageReader0"));
        }
    }

    public void readHeader() throws IOException {
        if (gotHeader)
            return;

        if (iis == null) {
            throw new IllegalStateException("Input source not set!");
        }

        metadata = new WBMPMetadata();

        wbmpType = iis.readByte();   // TypeField
        byte fixHeaderField = iis.readByte();

        // check for valid wbmp image
        if (fixHeaderField != 0
            || !isValidWbmpType(wbmpType))
        {
            throw new IIOException(I18N.getString("WBMPImageReader2"));
        }

        metadata.wbmpType = wbmpType;

        // Read image width
        width = ReaderUtil.readMultiByteInteger(iis);
        metadata.width = width;

        // Read image height
        height = ReaderUtil.readMultiByteInteger(iis);
        metadata.height = height;

        gotHeader = true;
    }

    public Iterator getImageTypes(int imageIndex)
        throws IOException {
        checkIndex(imageIndex);
        readHeader();

        BufferedImage bi =
            new BufferedImage(1, 1, BufferedImage.TYPE_BYTE_BINARY);
        ArrayList list = new ArrayList(1);
        list.add(new ImageTypeSpecifier(bi));
        return list.iterator();
    }

    public ImageReadParam getDefaultReadParam() {
        return new ImageReadParam();
    }

    public IIOMetadata getImageMetadata(int imageIndex)
        throws IOException {
        checkIndex(imageIndex);
        if (metadata == null) {
            readHeader();
        }
        return metadata;
    }

    public IIOMetadata getStreamMetadata() throws IOException {
        return null;
    }

    public BufferedImage read(int imageIndex, ImageReadParam param)
        throws IOException {

        if (iis == null) {
            throw new IllegalStateException(I18N.getString("WBMPImageReader1"));
        }

        checkIndex(imageIndex);
        clearAbortRequest();
        processImageStarted(imageIndex);
        if (param == null)
            param = getDefaultReadParam();

        //read header
        readHeader();

        Rectangle sourceRegion = new Rectangle(0, 0, 0, 0);
        Rectangle destinationRegion = new Rectangle(0, 0, 0, 0);

        computeRegions(param, this.width, this.height,
                       param.getDestination(),
                       sourceRegion,
                       destinationRegion);

        int scaleX = param.getSourceXSubsampling();
        int scaleY = param.getSourceYSubsampling();
        int xOffset = param.getSubsamplingXOffset();
        int yOffset = param.getSubsamplingYOffset();

        // If the destination is provided, then use it.  Otherwise, create new one
        BufferedImage bi = param.getDestination();

        if (bi == null)
            bi = new BufferedImage(destinationRegion.x + destinationRegion.width,
                              destinationRegion.y + destinationRegion.height,
                              BufferedImage.TYPE_BYTE_BINARY);

        boolean noTransform =
            destinationRegion.equals(new Rectangle(0, 0, width, height)) &&
            destinationRegion.equals(new Rectangle(0, 0, bi.getWidth(), bi.getHeight()));

        // Get the image data.
        WritableRaster tile = bi.getWritableTile(0, 0);

        // Get the SampleModel.
        MultiPixelPackedSampleModel sm =
            (MultiPixelPackedSampleModel)bi.getSampleModel();

        if (noTransform) {
            if (abortRequested()) {
                processReadAborted();
                return bi;
            }

            // If noTransform is necessary, read the data.
            iis.read(((DataBufferByte)tile.getDataBuffer()).getData(),
                     0, height*sm.getScanlineStride());
            processImageUpdate(bi,
                               0, 0,
                               width, height, 1, 1,
                               new int[]{0});
            processImageProgress(100.0F);
        } else {
            int len = (this.width + 7) / 8;
            byte[] buf = new byte[len];
            byte[] data = ((DataBufferByte)tile.getDataBuffer()).getData();
            int lineStride = sm.getScanlineStride();
            iis.skipBytes(len * sourceRegion.y);
            int skipLength = len * (scaleY - 1);

            // cache the values to avoid duplicated computation
            int[] srcOff = new int[destinationRegion.width];
            int[] destOff = new int[destinationRegion.width];
            int[] srcPos = new int[destinationRegion.width];
            int[] destPos = new int[destinationRegion.width];

            for (int i = destinationRegion.x, x = sourceRegion.x, j = 0;
                i < destinationRegion.x + destinationRegion.width;
                    i++, j++, x += scaleX) {
                srcPos[j] = x >> 3;
                srcOff[j] = 7 - (x & 7);
                destPos[j] = i >> 3;
                destOff[j] = 7 - (i & 7);
            }

            for (int j = 0, y = sourceRegion.y,
                k = destinationRegion.y * lineStride;
                j < destinationRegion.height; j++, y+=scaleY) {

                if (abortRequested())
                    break;
                iis.read(buf, 0, len);
                for (int i = 0; i < destinationRegion.width; i++) {
                    //get the bit and assign to the data buffer of the raster
                    int v = (buf[srcPos[i]] >> srcOff[i]) & 1;
                    data[k + destPos[i]] |= v << destOff[i];
                }

                k += lineStride;
                iis.skipBytes(skipLength);
                        processImageUpdate(bi,
                                           0, j,
                                           destinationRegion.width, 1, 1, 1,
                                           new int[]{0});
                        processImageProgress(100.0F*j/destinationRegion.height);
            }
        }

        if (abortRequested())
            processReadAborted();
        else
            processImageComplete();
        return bi;
    }

    public boolean canReadRaster() {
        return true;
    }

    public Raster readRaster(int imageIndex,
                             ImageReadParam param) throws IOException {
        BufferedImage bi = read(imageIndex, param);
        return bi.getData();
    }

    public void reset() {
        super.reset();
        iis = null;
        gotHeader = false;
    }

    /*
     * This method verifies that given byte is valid wbmp type marker.
     * At the moment only 0x0 marker is described by wbmp spec.
     */
    boolean isValidWbmpType(int type) {
        return type == 0;
    }
}