src/main/java/org/hedgecode/chess/fen/FEN.java

   1 /*
   2  * Copyright (c) 2018. Developed by Hedgecode.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  *   http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 package org.hedgecode.chess.fen;
  18
  19 import java.util.HashMap;
  20 import java.util.Map;
  21
  22 import org.hedgecode.chess.position.Castle;
  23 import org.hedgecode.chess.position.Color;
  24 import org.hedgecode.chess.position.ColorPiece;
  25 import org.hedgecode.chess.position.Piece;
  26 import org.hedgecode.chess.position.Square;
  27
  28 /**
  29  * Forsyth–Edwards Notation (FEN) constants.
  30  *
  31  * @author Dmitry Samoshin aka gotty
  32  */
  33 public final class FEN {
  34
  35     enum Fields {
  36         PIECES     (0, "[pPnNbBrRqQkK1-8]+/?"),
  37         MOVE       (1, "[wb]"),
  38         CASTLE     (2, "[qQkK]+|-"),
  39         EN_PASSANT (3, "[a-h][36]|-"),
  40         HALFMOVE   (4, "[0-9]+"),
  41         FULLMOVE   (5, "[1-9][0-9]*");
  42
  43         private int index;
  44         private String regex;
  45
  46         Fields(int index, String regex) {
  47             this.index = index;
  48             this.regex = regex;
  49         }
  50
  51         public int index() {
  52             return index;
  53         }
  54
  55         public String regex() {
  56             return regex;
  57         }
  58     }
  59
  60     public static final char WHITE = 'w';
  61     public static final char BLACK = 'b';
  62     public static final char HYPHEN = '-';
  63
  64     public static final String FIELDS_SEP = " ";
  65     public static final String LINE_SEP = "/";
  66
  67     public static final char WHITE_PAWN   = 'P';
  68     public static final char WHITE_KNIGHT = 'N';
  69     public static final char WHITE_BISHOP = 'B';
  70     public static final char WHITE_ROOK   = 'R';
  71     public static final char WHITE_QUEEN  = 'Q';
  72     public static final char WHITE_KING   = 'K';
  73
  74     public static final char BLACK_PAWN   = 'p';
  75     public static final char BLACK_KNIGHT = 'n';
  76     public static final char BLACK_BISHOP = 'b';
  77     public static final char BLACK_ROOK   = 'r';
  78     public static final char BLACK_QUEEN  = 'q';
  79     public static final char BLACK_KING   = 'k';
  80
  81     private static final Map<Color, Character> COLORS = new HashMap<Color, Character>() {
  82         {
  83             put(Color.WHITE, WHITE);
  84             put(Color.BLACK, BLACK);
  85         }
  86     };
  87
  88     private static final Map<ColorPiece, Character> PIECES = new HashMap<ColorPiece, Character>() {
  89         {
  90             put(ColorPiece.WHITE_PAWN, WHITE_PAWN);     put(ColorPiece.BLACK_PAWN, BLACK_PAWN);
  91             put(ColorPiece.WHITE_KNIGHT, WHITE_KNIGHT); put(ColorPiece.BLACK_KNIGHT, BLACK_KNIGHT);
  92             put(ColorPiece.WHITE_BISHOP, WHITE_BISHOP); put(ColorPiece.BLACK_BISHOP, BLACK_BISHOP);
  93             put(ColorPiece.WHITE_ROOK, WHITE_ROOK);     put(ColorPiece.BLACK_ROOK, BLACK_ROOK);
  94             put(ColorPiece.WHITE_QUEEN, WHITE_QUEEN);   put(ColorPiece.BLACK_QUEEN, BLACK_QUEEN);
  95             put(ColorPiece.WHITE_KING, WHITE_KING);     put(ColorPiece.BLACK_KING, BLACK_KING);
  96         }
  97     };
  98
  99     private FEN() {
 100     }
 101
 102     public static Color getColor(char color) {
 103         for (Map.Entry<Color, Character> entry : COLORS.entrySet()) {
 104             if (entry.getValue() == color)
 105                 return entry.getKey();
 106         }
 107         return null;
 108     }
 109
 110     public static String getColor(Color color) {
 111         return String.valueOf(
 112                 color != null
 113                         ? COLORS.get(color)
 114                         : COLORS.get(Color.WHITE)
 115         );
 116     }
 117
 118     public static ColorPiece getColorPiece(char piece) {
 119         for (Map.Entry<ColorPiece, Character> entry : PIECES.entrySet()) {
 120             if (entry.getValue() == piece)
 121                 return entry.getKey();
 122         }
 123         return null;
 124     }
 125
 126     public static char getFenPiece(Color color, Piece piece) {
 127         return getFenPiece(
 128                 ColorPiece.getColorPiece(color, piece)
 129         );
 130     }
 131
 132     public static char getFenPiece(ColorPiece colorPiece) {
 133         return PIECES.get(colorPiece);
 134     }
 135
 136     public static Castle getCastle(Color color, String castles) {
 137         Castle castle;
 138         if (castles.indexOf(HYPHEN) >= 0) {
 139             castle = Castle.NONE;
 140         } else {
 141             boolean isKing = false, isQueen = false;
 142             switch (color) {
 143                 case WHITE:
 144                     isKing = (castles.indexOf(WHITE_KING) >= 0);
 145                     isQueen = (castles.indexOf(WHITE_QUEEN) >= 0);
 146                     break;
 147                 case BLACK:
 148                     isKing = (castles.indexOf(BLACK_KING) >= 0);
 149                     isQueen = (castles.indexOf(BLACK_QUEEN) >= 0);
 150                     break;
 151             }
 152             castle = isKing && isQueen ? Castle.BOTH
 153                     : isKing ? Castle.KING
 154                     : isQueen ? Castle.QUEEN
 155                     : Castle.NONE;
 156         }
 157         return castle;
 158     }
 159
 160     public static String getCastle(Castle whiteCastle, Castle blackCastle) {
 161         StringBuilder sb = new StringBuilder();
 162         switch (whiteCastle) {
 163             case KING:
 164                 sb.append(WHITE_KING);
 165                 break;
 166             case QUEEN:
 167                 sb.append(WHITE_QUEEN);
 168                 break;
 169             case BOTH:
 170                 sb.append(WHITE_KING).append(WHITE_QUEEN);
 171                 break;
 172         }
 173         switch (blackCastle) {
 174             case KING:
 175                 sb.append(BLACK_KING);
 176                 break;
 177             case QUEEN:
 178                 sb.append(BLACK_QUEEN);
 179                 break;
 180             case BOTH:
 181                 sb.append(BLACK_KING).append(BLACK_QUEEN);
 182                 break;
 183         }
 184         String castles = sb.toString();
 185         return castles.isEmpty()
 186                 ? String.valueOf(HYPHEN)
 187                 : castles;
 188     }
 189
 190     public static Square getEnPassant(String enPassant) {
 191         if (enPassant.indexOf(HYPHEN) < 0) {
 192             return Square.getSquare(enPassant);
 193         }
 194         return null;
 195     }
 196
 197     public static String getEnPassant(Square square){
 198         return (square != null)
 199                 ? square.name().toLowerCase()
 200                 : String.valueOf(HYPHEN);
 201     }
 202
 203 }