client/src/variants/Arena.js

   1 import { ChessRules } from "@/base_rules";
   2
   3 export class ArenaRules extends ChessRules {
   4
   5   static get HasFlags() {
   6     return false;
   7   }
   8
   9   static get PawnSpecs() {
  10     return Object.assign(
  11       {},
  12       ChessRules.PawnSpecs,
  13       { captureBackward: true }
  14     );
  15   }
  16
  17   static IsGoodPosition(position) {
  18     if (position.length == 0) return false;
  19     const rows = position.split("/");
  20     if (rows.length != V.size.x) return false;
  21     // At most and at least one king or queen per color
  22     let royals = { "k": 0, "K": 0, "q": 0, "Q": 0 };
  23     for (let row of rows) {
  24       let sumElts = 0;
  25       for (let i = 0; i < row.length; i++) {
  26         if (['K','k','Q','q'].includes(row[i])) royals[row[i]]++;
  27         if (V.PIECES.includes(row[i].toLowerCase())) sumElts++;
  28         else {
  29           const num = parseInt(row[i], 10);
  30           if (isNaN(num)) return false;
  31           sumElts += num;
  32         }
  33       }
  34       if (sumElts != V.size.y) return false;
  35     }
  36     if (
  37       Object.values(royals).some(v => v >= 2) ||
  38       royals['K'] + royals['Q'] == 0 ||
  39       royals['k'] + royals['q'] == 0
  40     ) {
  41       return false;
  42     }
  43     return true;
  44   }
  45
  46   scanKings() {}
  47
  48   static GenRandInitFen(randomness) {
  49     return ChessRules.GenRandInitFen(randomness).slice(0, -6) + "-";
  50   }
  51
  52   static InArena(x) {
  53     return Math.abs(3.5 - x) <= 1.5;
  54   }
  55
  56   getPotentialMovesFrom([x, y]) {
  57     const moves = super.getPotentialMovesFrom([x, y]);
  58     // Eliminate moves which neither enter the arena or capture something
  59     return moves.filter(m => {
  60       const startInArena = V.InArena(m.start.x);
  61       const endInArena = V.InArena(m.end.x);
  62       return (
  63         (startInArena && endInArena && m.vanish.length == 2) ||
  64         (!startInArena && endInArena)
  65       );
  66     });
  67
  68     return moves;
  69   }
  70
  71   getPotentialQueenMoves(sq) {
  72     return this.getSlideNJumpMoves(
  73       sq,
  74       V.steps[V.ROOK].concat(V.steps[V.BISHOP])
  75     ).filter(m => {
  76       // Filter out moves longer than 3 squares
  77       return Math.max(
  78         Math.abs(m.end.x - m.start.x),
  79         Math.abs(m.end.y - m.start.y)) <= 3;
  80     });
  81   }
  82
  83   getPotentialKingMoves(sq) {
  84     return this.getSlideNJumpMoves(
  85       sq,
  86       V.steps[V.ROOK].concat(V.steps[V.BISHOP])
  87     ).filter(m => {
  88       // Filter out moves longer than 3 squares
  89       return Math.max(
  90         Math.abs(m.end.x - m.start.x),
  91         Math.abs(m.end.y - m.start.y)) <= 3;
  92     });
  93   }
  94
  95   getCheckSquares() {
  96     return [];
  97   }
  98
  99   filterValid(moves) {
 100     // No check conditions
 101     return moves;
 102   }
 103
 104   postPlay() {} //no kingPos no castleFlags
 105   postUndo() {}
 106
 107   getCurrentScore() {
 108     const color = this.turn;
 109     if (!this.atLeastOneMove())
 110       // I cannot move anymore
 111       return color == "w" ? "0-1" : "1-0";
 112     // Win if the opponent has no more pieces left (in the Arena),
 113     // (and/)or if he lost both his dukes.
 114     let someUnitRemain = false;
 115     let atLeastOneDuke = false;
 116     let somethingInArena = false;
 117     outerLoop: for (let i=0; i<V.size.x; i++) {
 118       for (let j=0; j<V.size.y; j++) {
 119         if (this.getColor(i,j) == color) {
 120           someUnitRemain = true;
 121           if (this.movesCount >= 2 && V.InArena(i)) {
 122             somethingInArena = true;
 123             if (atLeastOneDuke)
 124               break outerLoop;
 125           }
 126           if ([V.QUEEN,V.KING].includes(this.getPiece(i,j))) {
 127             atLeastOneDuke = true;
 128             if (this.movesCount < 2 || somethingInArena)
 129               break outerLoop;
 130           }
 131         }
 132       }
 133     }
 134     if (
 135       !someUnitRemain ||
 136       !atLeastOneDuke ||
 137       (this.movesCount >= 2 && !somethingInArena)
 138     ) {
 139       return color == "w" ? "0-1" : "1-0";
 140     }
 141     return "*";
 142   }
 143
 144   static get SEARCH_DEPTH() {
 145     return 4;
 146   }
 147
 148 };