client/src/variants/Joker.js

   1 import { ChessRules, Move, PiPo } from "@/base_rules";
   2 import { Antiking2Rules } from "@/variants/Antiking2";
   3
   4 export class JokerRules extends ChessRules {
   5
   6   static get PawnSpecs() {
   7     return Object.assign(
   8       {},
   9       ChessRules.PawnSpecs,
  10       { promotions: ChessRules.PawnSpecs.promotions.concat([V.JOKER]) }
  11     );
  12   }
  13
  14   static GenRandInitFen(options) {
  15     const antikingFen = Antiking2Rules.GenRandInitFen(options);
  16     return antikingFen.replace('a', 'J').replace('A', 'j');
  17   }
  18
  19   static get JOKER() {
  20     return 'j';
  21   }
  22
  23   static get PIECES() {
  24     return ChessRules.PIECES.concat([V.JOKER]);
  25   }
  26
  27   getPpath(b) {
  28     return (b.charAt(1) == 'j' ? "Joker/" : "") + b;
  29   }
  30
  31   getPotentialMovesFrom([x, y]) {
  32     const piece = this.getPiece(x, y);
  33     if (piece == V.JOKER) return this.getPotentialJokerMoves([x, y]);
  34     let moves = super.getPotentialMovesFrom([x, y]);
  35     if (piece == V.PAWN) {
  36       const c = this.turn;
  37       const alreadyOneJoker = this.board.some(row =>
  38         row.some(cell => cell == c + 'j'));
  39       if (alreadyOneJoker) moves = moves.filter(m => m.appear[0].p != V.JOKER)
  40     }
  41     return moves;
  42   }
  43
  44   canTake([x1, y1], [x2, y2]) {
  45     if (this.getPiece(x1, y1) == V.JOKER) return false;
  46     return super.canTake([x1, y1], [x2, y2]);
  47   }
  48
  49   getPotentialJokerMoves([x, y]) {
  50     const moving =
  51       super.getSlideNJumpMoves([x, y], V.steps[V.KNIGHT], 1)
  52       .concat(super.getSlideNJumpMoves([x, y],
  53         V.steps[V.ROOK].concat(V.steps[V.BISHOP])));
  54     let swapping = [];
  55     const c = this.turn;
  56     for (let i=0; i<8; i++) {
  57       for (let j=0; j<8; j++) {
  58         // Following test is OK because only one Joker on board at a time
  59         if (this.board[i][j] != V.EMPTY && this.getColor(i, j) == c) {
  60           const p = this.getPiece(i, j);
  61           const lastRank = (c == 'w' ? 0 : 7);
  62           if (p != V.KING && (p != V.PAWN || x != lastRank)) {
  63             swapping.push(
  64               new Move({
  65                 vanish: [
  66                   new PiPo({ x: x, y: y, c: c, p: V.JOKER }),
  67                   new PiPo({ x: i, y: j, c: c, p: p })
  68                 ],
  69                 appear: [
  70                   new PiPo({ x: i, y: j, c: c, p: V.JOKER }),
  71                   new PiPo({ x: x, y: y, c: c, p: p })
  72                 ]
  73               })
  74             );
  75           }
  76         }
  77       }
  78     }
  79     return moving.concat(swapping);
  80   }
  81
  82   postPlay(move) {
  83     super.postPlay(move);
  84     // Was my king swapped?
  85     if (move.vanish.length == 2 && move.vanish[1].p == V.KING)
  86       this.kingPos[move.appear[1].c] = [move.appear[1].x, move.appear[1].y];
  87   }
  88
  89   postUndo(move) {
  90     super.postUndo(move);
  91     if (move.vanish.length == 2 && move.vanish[1].p == V.KING)
  92       this.kingPos[move.vanish[1].c] = [move.vanish[1].x, move.vanish[1].y];
  93   }
  94
  95   static get VALUES() {
  96     return Object.assign({ j: 2 }, ChessRules.VALUES);
  97   }
  98
  99   static get SEARCH_DEPTH() {
 100     return 2;
 101   }
 102
 103 };