/*
 * ImageEncoder.java
 *
 * Copyright (C) 2002-2013 Takis Diakoumis
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 3
 * of the License, or any later version.
 *
 * This program 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 for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 *
 */

package org.executequery.imageio.acme.encoders;

import java.awt.Image;
import java.awt.image.ColorModel;
import java.awt.image.ImageConsumer;
import java.awt.image.ImageProducer;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Hashtable;

/// Abstract class for writing out an image.
// <P>
// A framework for classes that encode and write out an image in
// a particular file format.
// <P>
// This provides a simplified rendition of the ImageConsumer interface.
// It always delivers the pixels as ints in the RGBdefault color model.
// It always provides them in top-down left-right order.
// If you want more flexibility you can always implement ImageConsumer
// directly.
// <P>
// <A HREF="/resources/classes/Acme/JPM/Encoders/ImageEncoder.java">Fetch the software.</A><BR>
// <A HREF="/resources/classes/Acme.tar.gz">Fetch the entire Acme package.</A>
// <P>
// @see GifEncoder
// @see PpmEncoder
// @see Acme.JPM.Decoders.ImageDecoder

public abstract class ImageEncoder implements ImageConsumer
    {

    protected OutputStream out;

    private ImageProducer producer;
    private int width = -1;
    private int height = -1;
    private int hintflags = 0;
    private boolean started = false;
    private boolean encoding;
    private IOException iox;
    private static final ColorModel rgbModel = ColorModel.getRGBdefault();

    /// Constructor.
    // @param img The image to encode.
    // @param out The stream to write the bytes to.
    public ImageEncoder( Image img, OutputStream out ) throws IOException
	{
	this( img.getSource(), out );
	}

    /// Constructor.
    // @param producer The ImageProducer to encode.
    // @param out The stream to write the bytes to.
    public ImageEncoder( ImageProducer producer, OutputStream out ) throws IOException
	{
	this.producer = producer;
	this.out = out;
	}


    // Methods that subclasses implement.

    /// Subclasses implement this to initialize an encoding.
    abstract void encodeStart( int w, int h ) throws IOException;

    /// Subclasses implement this to actually write out some bits.  They
    // are guaranteed to be delivered in top-down-left-right order.
    // One int per pixel, index is row * scansize + off + col,
    // RGBdefault (AARRGGBB) color model.
    abstract void encodePixels(
	int x, int y, int w, int h, int[] rgbPixels, int off, int scansize )
	throws IOException;

    /// Subclasses implement this to finish an encoding.
    abstract void encodeDone() throws IOException;


    // Our own methods.

    /// Call this after initialization to get things going.
    public synchronized void encode() throws IOException
	{
	encoding = true;
	iox = null;
	producer.startProduction( this );
	while ( encoding )
	    try
		{
		wait();
		}
	    catch ( InterruptedException e ) {}
	if ( iox != null )
	    throw iox;
	}

    private boolean accumulate = false;
    private int[] accumulator;

    private void encodePixelsWrapper(
	int x, int y, int w, int h, int[] rgbPixels, int off, int scansize )
	throws IOException
	{
	if ( ! started )
	    {
	    started = true;
	    encodeStart( width, height );
	    if ( ( hintflags & TOPDOWNLEFTRIGHT ) == 0 )
		{
		accumulate = true;
		accumulator = new int[width * height];
		}
	    }
	if ( accumulate )
	    for ( int row = 0; row < h; ++row )
		System.arraycopy(
		    rgbPixels, row * scansize + off,
		    accumulator, ( y + row ) * width + x,
		    w );
	else
	    encodePixels( x, y, w, h, rgbPixels, off, scansize );
	}

    private void encodeFinish() throws IOException
	{
	if ( accumulate )
	    {
	    encodePixels( 0, 0, width, height, accumulator, 0, width );
	    accumulator = null;
	    accumulate = false;
	    }
	}

    private synchronized void stop()
	{
	encoding = false;
	notifyAll();
	}


    // Methods from ImageConsumer.

    public void setDimensions( int width, int height )
	{
	this.width = width;
	this.height = height;
	}

    public void setColorModel( ColorModel model )
	{
	// Ignore.
	}

    public void setHints( int hintflags )
	{
	this.hintflags = hintflags;
	}

    public void setPixels(
	int x, int y, int w, int h, ColorModel model, byte[] pixels,
	int off, int scansize )
	{
	int[] rgbPixels = new int[w];
	for ( int row = 0; row < h; ++row )
	    {
	    int rowOff = off + row * scansize;
	    for ( int col = 0; col < w; ++col )
		rgbPixels[col] = model.getRGB( pixels[rowOff + col] & 0xff );
	    try
		{
		encodePixelsWrapper( x, y + row, w, 1, rgbPixels, 0, w );
		}
	    catch ( IOException e )
		{
		iox = e;
		stop();
		return;
		}
	    }
	}

    public void setPixels(
	int x, int y, int w, int h, ColorModel model, int[] pixels,
	int off, int scansize )
	{
	if ( model == rgbModel )
	    {
	    try
		{
		encodePixelsWrapper( x, y, w, h, pixels, off, scansize );
		}
	    catch ( IOException e )
		{
		iox = e;
		stop();
		return;
		}
	    }
	else
	    {
	    int[] rgbPixels = new int[w];
            for ( int row = 0; row < h; ++row )
		{
		int rowOff = off + row * scansize;
                for ( int col = 0; col < w; ++col )
                    rgbPixels[col] = model.getRGB( pixels[rowOff + col] );
		try
		    {
		    encodePixelsWrapper( x, y + row, w, 1, rgbPixels, 0, w );
		    }
		catch ( IOException e )
		    {
		    iox = e;
		    stop();
		    return;
		    }
		}
	    }
	}

    public void setProperties(Hashtable<?, ?> props) {}
    
    public void imageComplete( int status )
	{
	producer.removeConsumer( this );
	if ( status == ImageConsumer.IMAGEABORTED )
	    iox = new IOException( "image aborted" );
	else
	    {
	    try
		{
		encodeFinish();
		encodeDone();
		}
	    catch ( IOException e )
		{
		iox = e;
		}
	    }
	stop();
	}

    }






