/**

 * The MIT License (MIT)

 *

 * Copyright (C) 2013 Jaroslav Tulach <jaroslav.tulach@apidesign.org>

 *

 * Permission is hereby granted, free of charge, to any person obtaining a copy

 * of this software and associated documentation files (the "Software"), to deal

 * in the Software without restriction, including without limitation the rights

 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

 * copies of the Software, and to permit persons to whom the Software is

 * furnished to do so, subject to the following conditions:

 *

 * The above copyright notice and this permission notice shall be included in

 * all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE

 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN

 * THE SOFTWARE.

 */

package org.apidesign.html.demo.chess;

/** Common chess rules.

 *

 * @author Jaroslav Tulach <jtulach@netbeans.org>

 */

class Rules {

    static void computeAccessible(Board b, Square s) {

        for (Row r : b.getRows()) {

            for (Square ts : r.getColumns()) {

                ts.setAccessible(false);

            }

        }

        if (s == null) {

            return;

        }

        switch (s.getPiece()) {

            case BISHOP: 

                moveBishop(b, s);

                break;

            case KING:

                computeAccessible(b, s, 1, 1, 1);

                computeAccessible(b, s, 1, -1, 1);

                computeAccessible(b, s, -1, -1, 1);

                computeAccessible(b, s, -1, 1, 1);

                computeAccessible(b, s, 1, 0, 1);

                computeAccessible(b, s, 0, -1, 1);

                computeAccessible(b, s, 0, 1, 1);

                computeAccessible(b, s, -1, 0, 1);

                break;

            case ROCK:

                moveRock(b, s);

                break;

            case QUEEN:

                moveRock(b, s);

                moveBishop(b, s);

                break;

            case KNIGHT:

                computeAccessible(b, s, 2, 1, 1);

                computeAccessible(b, s, 2, -1, 1);

                computeAccessible(b, s, -2, -1, 1);

                computeAccessible(b, s, -2, 1, 1);

                computeAccessible(b, s, 1, 2, 1);

                computeAccessible(b, s, -1, 2, 1);

                computeAccessible(b, s, -1, -2, 1);

                computeAccessible(b, s, 1, -2, 1);

                break;

            case PAWN:

                pawns(b, s);

                break;

        }

    }

    private static void moveRock(Board b, Square s) {

        computeAccessible(b, s, 1, 0, 8);

        computeAccessible(b, s, 0, -1, 8);

        computeAccessible(b, s, -1, 0, 8);

        computeAccessible(b, s, 0, 1, 8);

    }

    private static void moveBishop(Board b, Square s) {

        computeAccessible(b, s, 1, 1, 8);

        computeAccessible(b, s, 1, -1, 8);

        computeAccessible(b, s, -1, -1, 8);

        computeAccessible(b, s, -1, 1, 8);

    }

    private static void computeAccessible(

        Board b, Square s, int dx, int dy,

        int limit

    ) {

        int x = s.getX();

        int y = s.getY();

        while (limit-- > 0) {

            x += dx;

            y += dy;

            Square next = BoardModel.findSquare(b, (char)x, y);

            if (next == null) {

                break;

            }

            if (next.getPieceColor() == s.getPieceColor()) {

                break;

            }

            next.setAccessible(true);

            if (next.getPieceColor() != null) {

                break;

            }

        }

    }

    private static void pawns(Board b, Square s) {

        final boolean white = s.getPieceColor() == BoardModel.ColorType.WHITE;

        int dy = white ? 1 : -1;

        Square step = BoardModel.findSquare(b, (char)s.getX(), s.getY() + dy);

        if (step != null && step.getPiece() == null) {

            step.setAccessible(true);

            if ((s.getY() == 2 && white) || (s.getY() == 7 && !white)) {

                Square nextSTep = BoardModel.findSquare(b, (char)s.getX(), step.getY() + dy);

                if (nextSTep != null && step.getPiece() == null) {

                    nextSTep.setAccessible(true);

                }

            }

        }

    }

}