client/src/variants/Iceage.js

   1 import { ChessRules } from "@/base_rules";
   2
   3 export class IceageRules extends ChessRules {
   4
   5   static get IgnoreRepetition() {
   6     return true;
   7   }
   8
   9   static get ICECUBE() {
  10     return "cc";
  11   }
  12
  13   static board2fen(b) {
  14     if (b[0] == 'c') return 'c';
  15     return ChessRules.board2fen(b);
  16   }
  17
  18   static fen2board(f) {
  19     if (f == 'c') return V.ICECUBE;
  20     return ChessRules.fen2board(f);
  21   }
  22
  23   getPpath(b) {
  24     if (b[0] == 'c') return "Iceage/icecube";
  25     return b;
  26   }
  27
  28   static IsGoodPosition(position) {
  29     if (position.length == 0) return false;
  30     const rows = position.split("/");
  31     if (rows.length != V.size.x) return false;
  32     let kings = { "k": 0, "K": 0 };
  33     for (let row of rows) {
  34       let sumElts = 0;
  35       for (let i = 0; i < row.length; i++) {
  36         if (['K','k'].includes(row[i])) kings[row[i]]++;
  37         if (['c'].concat(V.PIECES).includes(row[i].toLowerCase())) sumElts++;
  38         else {
  39           const num = parseInt(row[i], 10);
  40           if (isNaN(num)) return false;
  41           sumElts += num;
  42         }
  43       }
  44       if (sumElts != V.size.y) return false;
  45     }
  46     if (Object.values(kings).some(v => v != 1)) return false;
  47     return true;
  48   }
  49
  50   static GenRandInitFen(options) {
  51     return ChessRules.GenRandInitFen(options).replace(/8/g, "cccccccc");
  52   }
  53
  54   play(move) {
  55     const iceAgeAfterMove = (this.movesCount % 40 == 39);
  56     if (iceAgeAfterMove)
  57       // Next ice age after this move:
  58       move.state = JSON.stringify(this.board);
  59     super.play(move);
  60     if (iceAgeAfterMove) {
  61       for (let i=0; i<8; i++) {
  62         for (let j=0; j<8; j++) {
  63           if (this.board[i][j] == V.EMPTY) {
  64             const surrounded = V.steps[V.ROOK].every(s => {
  65               const [ii, jj] = [i + s[0], j + s[1]];
  66               return (
  67                 !V.OnBoard(ii, jj) ||
  68                 ![V.EMPTY, V.ICECUBE].includes(this.board[ii][jj])
  69               );
  70             });
  71             if (!surrounded) this.board[i][j] = V.ICECUBE;
  72           }
  73           else if (this.board[i][j] != V.ICECUBE) {
  74             const steps = V.steps[V.ROOK].concat(V.steps[V.BISHOP]);
  75             const connected = steps.some(s => {
  76               const [ii, jj] = [i + s[0], j + s[1]];
  77               return (
  78                 V.OnBoard(ii, jj) &&
  79                 ![V.EMPTY, V.ICECUBE].includes(this.board[ii][jj])
  80               );
  81             });
  82             if (!connected) this.board[i][j] = V.ICECUBE;
  83           }
  84         }
  85       }
  86       // Update king position (no need to update flags: game over)
  87       const kp = this.kingPos;
  88       if (this.getPiece(kp['w'][0], kp['w'][1]) != V.KING)
  89         this.kingPos['w'] = [-1, -1];
  90       if (this.getPiece(kp['b'][0], kp['b'][1]) != V.KING)
  91         this.kingPos['b'] = [-1, -1];
  92     }
  93   }
  94
  95   undo(move) {
  96     super.undo(move);
  97     if (!!move.state) {
  98       this.board = JSON.parse(move.state);
  99       if (this.kingPos['w'][0] < 0 || this.kingPos['b'][0] < 0) {
 100         for (let i=0; i<8; i++) {
 101           for (let j=0; j<8; j++) {
 102             if (this.board[i][j] != V.EMPTY && this.getPiece(i, j) == V.KING)
 103               this.kingPos[this.getColor(i, j)] = [i, j];
 104           }
 105         }
 106       }
 107     }
 108   }
 109
 110   getCheckSquares() {
 111     if (this.kingPos[this.turn][0] < 0) return [];
 112     return super.getCheckSquares();
 113   }
 114
 115   getCurrentScore() {
 116     const kingDisappear = {
 117       w: this.kingPos['w'][0] < 0,
 118       b: this.kingPos['b'][0] < 0
 119     };
 120     if (kingDisappear['w'] && kingDisappear['b']) return "1/2";
 121     if (kingDisappear['w']) return "0-1";
 122     if (kingDisappear['b']) return "1-0";
 123     return super.getCurrentScore();
 124   }
 125
 126   static get SEARCH_DEPTH() {
 127     return 2;
 128   }
 129
 130   evalPosition() {
 131     let evaluation = 0;
 132     for (let i = 0; i < V.size.x; i++) {
 133       for (let j = 0; j < V.size.y; j++) {
 134         if (![V.EMPTY,V.ICECUBE].includes(this.board[i][j])) {
 135           const sign = this.getColor(i, j) == "w" ? 1 : -1;
 136           evaluation += sign * V.VALUES[this.getPiece(i, j)];
 137         }
 138       }
 139     }
 140     return evaluation;
 141   }
 142
 143 };