client/src/variants/Cannibal1.js

   1 import { ChessRules } from "@/base_rules";
   2
   3 export class Cannibal1Rules extends ChessRules {
   4
   5   static get KING_CODE() {
   6     return {
   7       'p': 's',
   8       'r': 'u',
   9       'n': 'o',
  10       'b': 'c',
  11       'q': 't'
  12     };
  13   }
  14
  15   static get KING_DECODE() {
  16     return {
  17       's': 'p',
  18       'u': 'r',
  19       'o': 'n',
  20       'c': 'b',
  21       't': 'q'
  22     };
  23   }
  24
  25   // Kings may be disguised:
  26   getPiece(x, y) {
  27     const piece = this.board[x][y].charAt(1);
  28     if (Object.keys(V.KING_DECODE).includes(piece))
  29       return V.KING_DECODE[piece];
  30     return piece;
  31   }
  32
  33   getPpath(b) {
  34     return (Object.keys(V.KING_DECODE).includes(b[1]) ? "Cannibal/" : "") + b;
  35   }
  36
  37   static IsGoodPosition(position) {
  38     if (position.length == 0) return false;
  39     const rows = position.split("/");
  40     if (rows.length != V.size.x) return false;
  41     let kings = { "w": 0, "b": 0 };
  42     const allPiecesCodes = V.PIECES.concat(Object.keys(V.KING_DECODE));
  43     const kingBlackCodes = Object.keys(V.KING_DECODE).concat(['k']);
  44     const kingWhiteCodes =
  45       Object.keys(V.KING_DECODE).map(k => k.toUpperCase()).concat(['K']);
  46     for (let row of rows) {
  47       let sumElts = 0;
  48       for (let i = 0; i < row.length; i++) {
  49         if (kingBlackCodes.includes(row[i])) kings['b']++;
  50         else if (kingWhiteCodes.includes(row[i])) kings['w']++;
  51         if (allPiecesCodes.includes(row[i].toLowerCase())) sumElts++;
  52         else {
  53           const num = parseInt(row[i], 10);
  54           if (isNaN(num)) return false;
  55           sumElts += num;
  56         }
  57       }
  58       if (sumElts != V.size.y) return false;
  59     }
  60     // Both kings should be on board, only one of each color:
  61     if (Object.values(kings).some(v => v != 1)) return false;
  62     return true;
  63   }
  64
  65   // Kings may be disguised:
  66   setOtherVariables(fen) {
  67     super.setOtherVariables(fen);
  68     const rows = V.ParseFen(fen).position.split("/");
  69     if (this.kingPos["w"][0] < 0 || this.kingPos["b"][0] < 0) {
  70       for (let i = 0; i < rows.length; i++) {
  71         let k = 0; //column index on board
  72         for (let j = 0; j < rows[i].length; j++) {
  73           const piece = rows[i].charAt(j);
  74           if (Object.keys(V.KING_DECODE).includes(piece.toLowerCase())) {
  75             const color = (piece.charCodeAt(0) <= 90 ? 'w' : 'b');
  76             this.kingPos[color] = [i, k];
  77           } else {
  78             const num = parseInt(rows[i].charAt(j), 10);
  79             if (!isNaN(num)) k += num - 1;
  80           }
  81           k++;
  82         }
  83       }
  84     }
  85   }
  86
  87   // Because of the disguised kings, getPiece() could be wrong:
  88   // use board[x][y][1] instead (always valid).
  89   getBasicMove([sx, sy], [ex, ey], tr) {
  90     let mv = super.getBasicMove([sx, sy], [ex, ey], tr);
  91
  92     if (this.board[ex][ey] != V.EMPTY) {
  93       // If the captured piece has a different nature: take it as well
  94       if (mv.vanish[0].p != mv.vanish[1].p) {
  95         if (
  96           mv.vanish[0].p == V.KING ||
  97           Object.keys(V.KING_DECODE).includes(mv.vanish[0].p)
  98         ) {
  99           mv.appear[0].p = V.KING_CODE[mv.vanish[1].p];
 100         }
 101         else mv.appear[0].p = mv.vanish[1].p;
 102       }
 103     }
 104     else if (!!tr && mv.vanish[0].p != V.PAWN)
 105       // Special case of a non-capturing king-as-pawn promotion
 106       mv.appear[0].p = V.KING_CODE[tr.p];
 107
 108     return mv;
 109   }
 110
 111   getPotentialMovesFrom([x, y]) {
 112     const piece = this.board[x][y].charAt(1);
 113     if (Object.keys(V.KING_DECODE).includes(piece))
 114       return super.getPotentialMovesFrom([x, y], V.KING_DECODE[piece]);
 115     return super.getPotentialMovesFrom([x, y], piece);
 116   }
 117
 118   postPlay(move) {
 119     const c = V.GetOppCol(this.turn);
 120     const piece = move.appear[0].p;
 121     // Update king position + flags
 122     if (piece == V.KING || Object.keys(V.KING_DECODE).includes(piece)) {
 123       this.kingPos[c][0] = move.appear[0].x;
 124       this.kingPos[c][1] = move.appear[0].y;
 125       this.castleFlags[c] = [V.size.y, V.size.y];
 126     }
 127     // Next call is still required because the king may eat an opponent's rook
 128     // TODO: castleFlags will be turned off twice then.
 129     super.updateCastleFlags(move, piece);
 130   }
 131
 132   postUndo(move) {
 133     // (Potentially) Reset king position
 134     const c = this.getColor(move.start.x, move.start.y);
 135     const piece = move.appear[0].p;
 136     if (piece == V.KING || Object.keys(V.KING_DECODE).includes(piece))
 137       this.kingPos[c] = [move.start.x, move.start.y];
 138   }
 139
 140   static get VALUES() {
 141     return {
 142       p: 1,
 143       r: 5,
 144       n: 3,
 145       b: 3,
 146       q: 9,
 147       k: 5
 148     };
 149   }
 150
 151   getNotation(move) {
 152     let notation = super.getNotation(move);
 153     const lastRank = (move.appear[0].c == "w" ? 0 : 7);
 154     if (
 155       move.end.x != lastRank &&
 156       this.getPiece(move.start.x, move.start.y) == V.PAWN &&
 157       move.vanish.length == 2 &&
 158       move.appear[0].p != V.PAWN
 159     ) {
 160       // Fix "promotion" (transform indicator) from base_rules notation
 161       notation = notation.slice(0, -2);
 162     }
 163     return notation;
 164   }
 165
 166 };