package com.jotuntech.sketcher.common;

import java.awt.Point;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map.Entry;

public class BitmapUndoData extends HashMap<Point, BitmapTileDiff> implements UndoData {
	protected Iterator<Entry<Point, BitmapTileDiff>> tileIterator = null;
	protected static DiffPacker packer;
	protected static DiffUnpacker unpacker;

	public void reset() {
		tileIterator = null;
	}

	public byte[] encode() {
		if(tileIterator == null) {
			tileIterator = entrySet().iterator();
		}

		if(tileIterator.hasNext()) {
			Entry<Point, BitmapTileDiff> e = tileIterator.next();
			Point p = e.getKey();
			BitmapTileDiff btd = e.getValue();
			byte[] encoded = new byte[BitmapTile.SIZE * BitmapTile.SIZE * 8 + 2];
			int offset = 0;
			encoded[offset++] = (byte) p.x;
			encoded[offset++] = (byte) p.y;

			if(packer == null) {
				packer = new DiffPacker();
			}

			packer.pack(btd.diffAlpha, btd.diffRed, btd.diffGreen, btd.diffBlue, encoded, offset, encoded.length - offset);

			return encoded;
		} else {
			tileIterator = null;
			return null;
		}
	}

	public void decode(byte[] in) {
		int offset = 0;
		int x = 0xFF & in[offset++];
		int y = 0xFF & in[offset++];
		Point p = new Point(x, y);
		BitmapTileDiff btd = new BitmapTileDiff();
		if(unpacker == null) {
			unpacker = new DiffUnpacker();
		}
		unpacker.unpack(in, offset, in.length - offset, btd.diffAlpha, btd.diffRed, btd.diffGreen, btd.diffBlue);
		put(p, btd);
	}
}