package org.hwo.image.tiff;

import java.nio.ByteBuffer;

import org.hwo.compressor.LZW;
import org.hwo.image.UnsupportedFormatException;

class Strip
{
	/**
	 * 
	 */
	private final IFD ifd;
	int offset,
		length,
		rowcount;
	
	public Strip(IFD ifd, int offset,int length,int rowcount)
	{
		this.ifd = ifd;
		this.offset = offset;
		this.length = length;
		this.rowcount = rowcount;
	}
	
	public int getOffset()
	{
		return offset;
	}
	public int getLength()
	{
		return length;
	}
	public int getRowCount()
	{
		return rowcount;
	}
	
	public ByteBuffer getBuffer()
	{
		ByteBuffer result;
		
		switch (this.ifd.getCompression())
		{
		case 1:
			this.ifd.tiffFile.sourceBuffer.position(offset);
			result = this.ifd.tiffFile.sourceBuffer.slice();
			break;
		case 5:
			byte[] source = new byte[ length ];
			this.ifd.tiffFile.sourceBuffer.position(offset);
			this.ifd.tiffFile.sourceBuffer.get(source);
			
			LZW lzw = new LZW();
			lzw.setCompressedData(source);
			
			if (this.ifd.getFillOrder()==2)
				lzw.setByteOrder(true);
			
			lzw.decompress();
			
			result = ByteBuffer.wrap(lzw.getUncompressedData());
			break;
		default:
			throw new UnsupportedFormatException("Unsupported compression scheme");
		}
		
		return result;
	}
	
}