client/src/variants/Horde.js

   1 import { ChessRules } from "@/base_rules";
   2
   3 export class HordeRules extends ChessRules {
   4
   5   static get HasFlags() {
   6     return false;
   7   }
   8
   9   static IsGoodPosition() {
  10     // At least one white unit, and exactly one black king:
  11     if (position.length == 0) return false;
  12     const rows = position.split("/");
  13     if (rows.length != V.size.x) return false;
  14     let things = { "k": 0, "w": false };
  15     for (let row of rows) {
  16       let sumElts = 0;
  17       for (let i = 0; i < row.length; i++) {
  18         if (row[i] == 'k') things['k']++;
  19         if (V.PIECES.includes(row[i].toLowerCase())) {
  20           const rowCharCode = row[i].charCodeAt(0);
  21           if (rowCharCode >= 65 && rowCharCode <= 90) {
  22             // No white king:
  23             if (row[i] == 'K') return false;
  24             if (!things['w']) things['w'] = true;
  25           }
  26           sumElts++;
  27         } else {
  28           const num = parseInt(row[i], 10);
  29           if (isNaN(num)) return false;
  30           sumElts += num;
  31         }
  32       }
  33       if (sumElts != V.size.y) return false;
  34     }
  35     if (things[''] != 1 || !things['w']) return false;
  36     return true;
  37   }
  38
  39   static GenRandInitFen(randomness) {
  40     if (randomness == 2) randomness--;
  41     const fen = ChessRules.GenRandInitFen(randomness);
  42     return (
  43       // 20 first chars are 3 rows + 3 slashes
  44       fen.substr(0, 20)
  45       // En passant available, but no castle:
  46       .concat("1PP2PP1/PPPPPPPP/PPPPPPPP/PPPPPPPP/PPPPPPPP w 0 -")
  47     );
  48   }
  49
  50   filterValid(moves) {
  51     if (this.turn == 'w') return moves;
  52     return super.filterValid(moves);
  53   }
  54
  55   getCheckSquares() {
  56     if (this.turn == 'w') return [];
  57     return (
  58       this.underCheck('b')
  59         ? [JSON.parse(JSON.stringify(this.kingPos['b']))]
  60         : []
  61     );
  62   }
  63
  64   getCurrentScore() {
  65     if (this.turn == 'w') {
  66       // Do I have any unit remaining? If not, I lost.
  67       // If yes and no available move, draw.
  68       let somethingRemains = false;
  69       outerLoop: for (let i=0; i<8; i++) {
  70         for (let j=0; j<8; j++) {
  71           if (this.board[i][j] != V.EMPTY && this.getColor(i, j) == 'w') {
  72             somethingRemains = true;
  73             break outerLoop;
  74           }
  75         }
  76       }
  77       if (!somethingRemains) return "0-1";
  78       if (this.atLeastOneMove()) return "*";
  79       return "1/2";
  80     }
  81     // From black side, just run usual checks:
  82     return super.getCurrentScore();
  83   }
  84
  85 };