client/src/variants/Horde.js

   1 import { ChessRules } from "@/base_rules";
   2
   3 export class HordeRules extends ChessRules {
   4   static get HasFlags() {
   5     return false;
   6   }
   7
   8   static IsGoodPosition() {
   9     // At least one white unit, and exactly one black king:
  10     if (position.length == 0) return false;
  11     const rows = position.split("/");
  12     if (rows.length != V.size.x) return false;
  13     let things = { "k": 0, "w": false };
  14     for (let row of rows) {
  15       let sumElts = 0;
  16       for (let i = 0; i < row.length; i++) {
  17         if (row[i] == 'k') things['k']++;
  18         if (V.PIECES.includes(row[i].toLowerCase())) {
  19           const rowCharCode = row[i].charCodeAt(0);
  20           if (rowCharCode >= 65 && rowCharCode <= 90) {
  21             // No white king:
  22             if (row[i] == 'K') return false;
  23             if (!things['w']) things['w'] = true;
  24           }
  25           sumElts++;
  26         } else {
  27           const num = parseInt(row[i]);
  28           if (isNaN(num)) return false;
  29           sumElts += num;
  30         }
  31       }
  32       if (sumElts != V.size.y) return false;
  33     }
  34     if (things[''] != 1 || !things['w']) return false;
  35     return true;
  36   }
  37
  38   static GenRandInitFen(randomness) {
  39     if (randomness == 2) randomness--;
  40     const fen = ChessRules.GenRandInitFen(randomness);
  41     return (
  42       // 20 first chars are 3 rows + 3 slashes
  43       fen.substr(0, 20)
  44       // En passant available, but no castle:
  45       .concat("1PP2PP1/PPPPPPPP/PPPPPPPP/PPPPPPPP/PPPPPPPP w 0 -")
  46     );
  47   }
  48
  49   filterValid(moves) {
  50     if (this.turn == 'w') return moves;
  51     return super.filterValid(moves);
  52   }
  53
  54   getCheckSquares() {
  55     if (this.turn == 'w') return [];
  56     return (
  57       this.underCheck('b')
  58         ? [JSON.parse(JSON.stringify(this.kingPos['b']))]
  59         : []
  60     );
  61   }
  62
  63   getCurrentScore() {
  64     if (this.turn == 'w') {
  65       // Do I have any unit remaining? If not, I lost.
  66       // If yes and no available move, draw.
  67       let somethingRemains = false;
  68       outerLoop: for (let i=0; i<8; i++) {
  69         for (let j=0; j<8; j++) {
  70           if (this.board[i][j] != V.EMPTY && this.getColor(i, j) == 'w') {
  71             somethingRemains = true;
  72             break outerLoop;
  73           }
  74         }
  75       }
  76       if (!somethingRemains) return "0-1";
  77       if (this.atLeastOneMove()) return "*";
  78       return "1/2";
  79     }
  80     // From black side, just run usual checks:
  81     return super.getCurrentScore();
  82   }
  83 };