/**
 *   $Id: CheckersBoard.java 152 2008-04-27 02:04:31Z mbroeker $
 *  $URL: http://localhost/svn/eclipse/Schachspiel/trunk/org/homelinux/largo/games/board/checkersboard/CheckersBoard.java $
 */

package org.homelinux.largo.games.board.checkersboard;

import java.awt.Image;

import org.homelinux.largo.games.board.Board;
import org.homelinux.largo.games.board.History;
import org.homelinux.largo.games.board.Piece;
import org.homelinux.largo.utils.ImgComponent;

public class CheckersBoard extends Board {
	static final long serialVersionUID = 250408;

	static final int PIECE = 1;
	static final int QUEEN = 2;

	final Piece white_super_sun =
		new Piece(new ImgComponent("images/white_super_sun.png").getImage(), "white", QUEEN, 50);

	final Piece black_super_sun =
		new Piece(new ImgComponent("images/black_super_sun.png").getImage(), "black", QUEEN, 50);

	void initBoard () {
		for (int i=1;i<8;i+=2)
			add (new ImgComponent ("images/black_sun.png").getImage (), i, "black", PIECE);
		for (int i=8;i<15;i+=2)
			add (new ImgComponent ("images/black_sun.png").getImage (), i, "black", PIECE);
		for (int i=17;i<=23;i+=2)
			add (new ImgComponent ("images/black_sun.png").getImage (), i, "black", PIECE);

		for (int i=40;i<47;i+=2)
			add (new ImgComponent ("images/white_sun.png").getImage (), i, "white", PIECE);
		for (int i=49;i<=55;i+=2)
			add (new ImgComponent ("images/white_sun.png").getImage (), i, "white", PIECE);
		for (int i=56;i<63;i+=2)
			add (new ImgComponent ("images/white_sun.png").getImage (), i, "white", PIECE);
	}

	/**
	 * The init method initializes a complete checkers board with figures and a history.
	 */
	public void init() {
		super.init();
		initBoard();
		board_pieces = getPieces();
		repaint();
	}

	public CheckersBoard (int w, int h) {
		super(w, h);
	}

	void add (Image img, int i, String c, int t) {
		int v = 0;

		switch(t) {
		case PIECE:
			v=10;
		}

		setPiece(i, new Piece(img, c, t, v));
	}

	/**
	 * Checks, wether this move is possible or not.
	 */
	public boolean validMove (int t, int o) {
		int steps;
		int rows;
		int dx;

		if ( t == o )
			return false;

		if (isSamePiece(t, o))
			return false;

		if (getType(o) == EMPTY)
			return false;

		/*
		 *	00 01 02 03 04 05 06 07
		 *	08 09 10 11 12 13 14 15
		 *	16 17 18 19 20 21 22 23
		 *	24 25 26 27 28 29 30 31
		 *	32 33 34 35 36 37 38 39
		 *	40 41 42 43 44 45 46 47
		 *	48 49 50 51 52 53 54 55
		 *	56 57 58 59 60 61 62 63
		 */

		steps = Math.abs(t-o);
		rows = Math.abs(t/8 - o/8);

		switch( getType(o) ) {
		case PIECE:
			if (steps % 7 == 0 ) {
				if (steps == 7 && rows == 1 && isEmpty(t)) {
					if ( isBlack(o) && (t>o) )
						return true;
					if ( isWhite(o) && (t<o) )
						return true;
				}

				if (steps == 14 && rows == 2  && isEmpty(t)) {
					if ( isBlack(o) && (t>o) && isEnemy(o+7, o) )
						return true;
					if ( isWhite(o) && (t<o) && isEnemy(o-7, o) )
						return true;
				}
			}

			if (steps % 9 == 0 ) {
				if (steps == 9 && rows == 1 && isEmpty(t)) {
					if ( isBlack(o) && (t>o) )
						return true;
					if ( isWhite(o) && (t<o) )
						return true;
				}

				if (steps == 18 && rows == 2  && isEmpty(t)) {
					if ( isBlack(o) && (t>o) && isEnemy(o+9, o) )
						return true;
					if ( isWhite(o) && (t<o) && isEnemy(o-9, o) )
						return true;
				}
			}
			break;
		case QUEEN:
			if (steps % 7 == 0 && isEmpty(t) ) {
				if (steps == 7 && rows == 1)
					return true;
				if (steps == 14 && rows == 2)
					return true;
				if (steps == 21 && rows == 3)
					return true;
				if (steps == 28 && rows == 4)
					return true;
				if (steps == 35 && rows == 5)
					return true;
				if (steps == 42 && rows == 6)
					return true;
				if (steps == 49 && rows == 7)
					return true;
			}

			if (steps % 9 == 0 && isEmpty(t) ) {
				if (steps == 9 && rows == 1)
					return true;
				if (steps == 18 && rows == 2)
					return true;
				if (steps == 27 && rows == 3)
					return true;
				if (steps == 36 && rows == 4)
					return true;
				if (steps == 45 && rows == 5)
					return true;
				if (steps == 54 && rows == 6)
					return true;
				if (steps == 63 && rows == 7)
					return true;
			}
			break;
		}
		return false;
	}

	/**
	 * pop: undo the push operation.
	 */
	public void undo() {
		History h1 = null;
		History h2 = null;
		int size = stack.size();
		int pos;

		if ( size < 2 )
			return;

		h1 = stack.elementAt(size-1);
		h2 = stack.elementAt(size-2);

		setPiece(h1.pos(), h1.piece());
		setPiece(h2.pos(), h2.piece());

		if ( getType(h2.pos()) != EMPTY ) {
			pos = 2*h2.pos()-h1.pos();
			if ( pos >= 0 && pos <64)
				setPiece(pos, new Piece(null, null, EMPTY, 0));
		}

		stack.setSize(size-2);

		/* Reset the current player */
		setBlacksTurn(h2.turn());
	}

	/**
	 * simulates a "valid" move or returns false.
	 * all changes are relative to pieces and will not be painted.
	 */
	public boolean simulateMove(int t, int o) {
		int steps = Math.abs(t-o);
		int rows = Math.abs(t/8 - o/8);
		int pos;

		if ( !validMove(t, o) ) {
			return false;
		}

		if ( rows == 2 && getType(o) == PIECE) {
			pos =  (t-o)/2 + o;
			push(getPiece(pos), pos, getPiece(o), o);
			setPiece(pos, new Piece(null, null, EMPTY, 0));
		} else
			push(getPiece(t), t, getPiece(o), o);

		setPiece(t, new Piece(getPiece(o)));
		setPiece(o, new Piece(null, null, EMPTY, 0));

		return true;
	}

	/**
	 * performs a "valid" move or returns false.
	 * all changes are relative to board_pieces and will be painted.
	 */
	public boolean doMove(int t, int o) {
		int steps = Math.abs(t-o);
		int rows = Math.abs(t/8-o/8);
		int pos;

		if ( !validMove(t, o) ) {
			return false;
		}

		if ( rows == 2 && getType(o) == PIECE) {
			pos =  (t-o)/2 + o;
			push(getPiece(pos), pos, getPiece(o), o);
			setPiece(pos, new Piece(null, null, EMPTY, 0));
		} else	if ( rows >= 2 && getType(o) == QUEEN ) {
			if (steps % 7 == 0 ) {
				if ( t > o )
					for ( pos=o+7;pos <= t-7;pos+=7 ) {
						if ( isEnemy(pos, o) ) {
							push(getPiece(pos), pos, getPiece(o), o);
							setPiece(pos, new Piece(null, null, EMPTY, 0));
						}
					}
				else {
					for ( pos=o-7;pos >= t+7;pos-=7 ) {
						if ( isEnemy(pos, o) ) {
							push(getPiece(pos), pos, getPiece(o), o);
							setPiece(pos, new Piece(null, null, EMPTY, 0));
						}
					}
				}
			}

			if (steps % 9 == 0 ) {
				if ( t > o )
					for ( pos=o+9;pos <= t-9;pos+=9 ) {
						if ( isEnemy(pos, o) ) {
							push(getPiece(pos), pos, getPiece(o), o);
							setPiece(pos, new Piece(null, null, EMPTY, 0));
						}
					}
				else {
					for ( pos=o-9;pos >= t+9;pos-=9 ) {
						if ( isEnemy(pos, o) ) {
							push(getPiece(pos), pos, getPiece(o), o);
							setPiece(pos, new Piece(null, null, EMPTY, 0));
						}
					}
				}
			}
		}

		if ( t <= 7 && getType(o) == PIECE)
			setPiece(t, new Piece(white_super_sun));
		else if (t >=56 && getType(o) == PIECE)
			setPiece(t, new Piece(black_super_sun));
		else
			setPiece(t, new Piece(getPiece(o)));

		setPiece(o, new Piece(null, null, EMPTY, 0));

		board_pieces = getPieces();
		repaint();

		moveNr = stack.size();

		return true;
	}
}