client/src/variants/Balaklava.js

   1 import { ChessRules } from "@/base_rules";
   2
   3 export class BalaklavaRules extends ChessRules {
   4   static get PawnSpecs() {
   5     return Object.assign(
   6       {},
   7       ChessRules.PawnSpecs,
   8       { promotions: [V.ROOK, V.MAMMOTH, V.BISHOP, V.QUEEN] }
   9     );
  10   }
  11
  12   static get HasEnpassant() {
  13     return false;
  14   }
  15
  16   getPpath(b) {
  17     return (b[1] == V.MAMMOTH ? "Balaklava/" : "") + b;
  18   }
  19
  20   // Alfil + Dabbaba:
  21   static get MAMMOTH() {
  22     return "m";
  23   }
  24
  25   static get PIECES() {
  26     return [V.PAWN, V.ROOK, V.MAMMOTH, V.BISHOP, V.QUEEN, V.KING];
  27   }
  28
  29   static get steps() {
  30     return Object.assign(
  31       {},
  32       ChessRules.steps,
  33       {
  34         m: [
  35           [-2, -2],
  36           [-2, 0],
  37           [-2, 2],
  38           [0, -2],
  39           [0, 2],
  40           [2, -2],
  41           [2, 0],
  42           [2, 2],
  43         ]
  44       }
  45     );
  46   }
  47
  48   static GenRandInitFen(randomness) {
  49     // No collision between 'n' and castle flags, so next replacement is fine
  50     return (
  51       ChessRules.GenRandInitFen(randomness)
  52         .replace(/n/g, 'm').replace(/N/g, 'M')
  53     );
  54   }
  55
  56   getPotentialMovesFrom([x, y]) {
  57     const piece = this.getPiece(x, y);
  58     let moves =
  59       piece == V.MAMMOTH
  60         ? this.getPotentialMammothMoves([x, y])
  61         : super.getPotentialMovesFrom([x, y]);
  62     if (piece != V.KING) {
  63       // Add non-capturing knight movements
  64       const lastRank = (this.turn == 'w' ? 0 : 7);
  65       V.steps[V.KNIGHT].forEach(step => {
  66         const [i, j] = [x + step[0], y + step[1]];
  67         if (
  68           V.OnBoard(i, j) &&
  69           this.board[i][j] == V.EMPTY &&
  70           // Pawns don't promote with a knight move
  71           (piece != V.PAWN || i != lastRank)
  72         ) {
  73           moves.push(this.getBasicMove([x, y], [i, j]));
  74         }
  75       });
  76     }
  77     return moves;
  78   }
  79
  80   getPotentialMammothMoves(sq) {
  81     return this.getSlideNJumpMoves(sq, V.steps[V.MAMMOTH], "oneStep");
  82   }
  83
  84   isAttacked(sq, color) {
  85     return (
  86       super.isAttacked(sq, color) ||
  87       this.isAttackedByMammoth(sq, color)
  88     );
  89   }
  90
  91   isAttackedByMammoth(sq, color) {
  92     return (
  93       this.isAttackedBySlideNJump(
  94         sq, color, V.MAMMOTH, V.steps[V.MAMMOTH], "oneStep")
  95     );
  96   }
  97
  98   static get SEARCH_DEPTH() {
  99     return 2;
 100   }
 101
 102   static get VALUES() {
 103     return Object.assign(
 104       // A mammoth is probably worth a little more than a knight
 105       { m: 4 },
 106       ChessRules.VALUES
 107     );
 108   }
 109 };