client/src/variants/Squatter1.js

   1 import { ChessRules } from "@/base_rules";
   2
   3 export class Squatter1Rules extends ChessRules {
   4
   5   static get Lines() {
   6     return [
   7       [[1, 0], [1, 8]],
   8       [[7, 0], [7, 8]]
   9     ];
  10   }
  11
  12   // Find possible captures by opponent on [x, y]
  13   findCaptures([x, y]) {
  14     const color = this.getColor(x, y);
  15     const forward = (color == 'w' ? -1 : 1);
  16     let moves = [];
  17     const steps = {
  18       // Rook and bishop: included in queen case
  19       p: { s: [[forward, -1], [forward, 1]], one: true },
  20       n: { s: V.steps[V.KNIGHT], one: true },
  21       q: { s: V.steps[V.ROOK].concat(V.steps[V.BISHOP]) },
  22       k: { s: V.steps[V.ROOK].concat(V.steps[V.BISHOP]), one: true }
  23     };
  24     const oppCol = V.GetOppCol(color);
  25     Object.keys(steps).forEach(piece => {
  26       outerLoop: for (let loop = 0; loop < steps[piece].s.length; loop++) {
  27         const step = steps[piece].s[loop];
  28         let i = x + step[0];
  29         let j = y + step[1];
  30         while (V.OnBoard(i, j) && this.board[i][j] == V.EMPTY) {
  31           if (steps[piece].one) continue outerLoop;
  32           i += step[0];
  33           j += step[1];
  34         }
  35         if (
  36           V.OnBoard(i, j) &&
  37           this.board[i][j] != V.EMPTY &&
  38           this.getColor(i, j) == oppCol
  39         ) {
  40           const oppPiece = this.getPiece(i, j);
  41           if (
  42             oppPiece == piece ||
  43             (
  44               piece == V.QUEEN &&
  45               (
  46                 (oppPiece == V.ROOK && step.some(e => e == 0)) ||
  47                 (oppPiece == V.BISHOP && step.every(e => e != 0))
  48               )
  49             )
  50           )
  51           // Possible capture (do not care about promotions):
  52           moves.push(this.getBasicMove([i, j], [x, y]));
  53         }
  54       }
  55     });
  56     return moves;
  57   }
  58
  59   someValid(moves, color) {
  60     // Stop at first valid move found:
  61     for (let m of moves) {
  62       this.play(m);
  63       const res = !this.underCheck(color);
  64       this.undo(m);
  65       if (res) return true;
  66     }
  67     return false;
  68   }
  69
  70   getCurrentScore() {
  71     // Try both colors (to detect potential suicides)
  72     for (let c of ['w', 'b']) {
  73       const oppCol = V.GetOppCol(c);
  74       const goal = (c == 'w' ? 0 : 7);
  75       if (
  76         this.board[goal].some(
  77           (b,j) => {
  78             return (
  79               b[0] == c &&
  80               (
  81                 !this.isAttacked([goal, j], oppCol) ||
  82                 !this.someValid(this.findCaptures([goal, j]), oppCol)
  83               )
  84             );
  85           }
  86         )
  87       ) {
  88         return c == 'w' ? "1-0" : "0-1";
  89       }
  90     }
  91     return super.getCurrentScore();
  92   }
  93
  94   static get SEARCH_DEPTH() {
  95     return 2;
  96   }
  97
  98 };