/**

  * 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);

                 }

             }

         }

     }

 }