client/src/variants/Atomic.js

   1 import { ChessRules, Move, PiPo } from "@/base_rules";
   2
   3 export class AtomicRules extends ChessRules {
   4
   5   static get Options() {
   6     return {
   7       check: [
   8         {
   9           label: "Balanced",
  10           defaut: false,
  11           variable: "balanced"
  12         }
  13       ],
  14       select: ChessRules.Options.select
  15     };
  16   }
  17
  18   static AbbreviateOptions(opts) {
  19     return opts["balanced"] ? 'B' : '';
  20   }
  21
  22   static GenRandInitFen(options) {
  23     return ChessRules.GenRandInitFen(options) + (options.balanced ? " B" : "");
  24   }
  25
  26   setOtherVariables(fen) {
  27     super.setOtherVariables(fen);
  28     this.balanced = !!V.ParseFen(fen).balanced;
  29   }
  30
  31   static ParseFen(fen) {
  32     return Object.assign(
  33       { balanced: fen.split(" ")[5] },
  34       ChessRules.ParseFen(fen)
  35     );
  36   }
  37
  38   static IsGoodFen(fen) {
  39     if (!ChessRules.IsGoodFen(fen)) return false;
  40     const balanced = V.ParseFen(fen).balanced;
  41     return (!balanced || balanced == 'B');
  42   }
  43
  44   getFen() {
  45     return super.getFen() + (this.balanced ? " B" : "");
  46   }
  47
  48   hoverHighlight([x, y]) {
  49     return this.balanced && this.movesCount == 0 && [1, 6].includes(x);
  50   }
  51
  52   canIplay(side, [x, y]) {
  53     if (this.balanced && this.movesCount == 0)
  54       return (this.turn == side && this.getPiece(x, y) == V.PAWN);
  55     return super.canIplay(side, [x, y]);
  56   }
  57
  58   doClick(square) {
  59     if (!this.balanced || this.movesCount >= 1) return null;
  60     const [x, y] = [square[0], square[1]];
  61     if (![1, 6].includes(x)) return null;
  62     return new Move({
  63       appear: [],
  64       vanish: [
  65         new PiPo({
  66           x: x,
  67           y: y,
  68           c: this.getColor(x, y),
  69           p: V.PAWN
  70         })
  71       ],
  72       start: { x: x, y: y },
  73       end: { x: x, y: y }
  74     });
  75   }
  76
  77   getPotentialMovesFrom([x, y]) {
  78     if (this.balanced && this.movesCount == 0) {
  79       if ([1, 6].includes(x)) {
  80         const c = this.getColor(x, y);
  81         return [
  82           new Move({
  83             appear: [],
  84             vanish: [
  85               new PiPo({ x: x, y: y, p: V.PAWN, c: c })
  86             ],
  87             start: { x: x, y: y },
  88             end: { x: x, y: y }
  89           })
  90         ];
  91       }
  92       return [];
  93     }
  94
  95     let moves = super.getPotentialMovesFrom([x, y]);
  96     if (this.getPiece(x, y) == V.PAWN) {
  97       // Promotions by captures can be reduced to only one deterministic
  98       // move (because of the explosion).
  99       moves = moves.filter(m => {
 100         return (
 101           m.vanish.length == 1 ||
 102           [V.PAWN, V.QUEEN].includes(m.appear[0].p)
 103         );
 104       });
 105     }
 106     // Handle explosions
 107     moves.forEach(m => {
 108       // NOTE: if vanish.length==2 and appear.length==2, this is castle
 109       if (m.vanish.length > 1 && m.appear.length <= 1) {
 110         // Explosion! (TODO?: drop moves which explode our king here)
 111         let steps = [
 112           [-1, -1],
 113           [-1, 0],
 114           [-1, 1],
 115           [0, -1],
 116           [0, 1],
 117           [1, -1],
 118           [1, 0],
 119           [1, 1]
 120         ];
 121         for (let step of steps) {
 122           let x = m.end.x + step[0];
 123           let y = m.end.y + step[1];
 124           if (
 125             V.OnBoard(x, y) &&
 126             this.board[x][y] != V.EMPTY &&
 127             this.getPiece(x, y) != V.PAWN
 128           ) {
 129             m.vanish.push(
 130               new PiPo({
 131                 p: this.getPiece(x, y),
 132                 c: this.getColor(x, y),
 133                 x: x,
 134                 y: y
 135               })
 136             );
 137           }
 138         }
 139         m.end = { x: m.appear[0].x, y: m.appear[0].y };
 140         m.appear.pop(); //Nothin appears in this case
 141       }
 142     });
 143     return moves;
 144   }
 145
 146   getPotentialKingMoves([x, y]) {
 147     // King cannot capture:
 148     let moves = [];
 149     const steps = V.steps[V.ROOK].concat(V.steps[V.BISHOP]);
 150     for (let step of steps) {
 151       const i = x + step[0];
 152       const j = y + step[1];
 153       if (V.OnBoard(i, j) && this.board[i][j] == V.EMPTY)
 154         moves.push(this.getBasicMove([x, y], [i, j]));
 155     }
 156     return moves.concat(this.getCastleMoves([x, y]));
 157   }
 158
 159   isAttacked(sq, color) {
 160     if (
 161       this.getPiece(sq[0], sq[1]) == V.KING &&
 162       this.isAttackedByKing(sq, color)
 163     ) {
 164       // A king next to the enemy king is immune to attacks
 165       return false;
 166     }
 167     return (
 168       this.isAttackedByPawn(sq, color) ||
 169       this.isAttackedByRook(sq, color) ||
 170       this.isAttackedByKnight(sq, color) ||
 171       this.isAttackedByBishop(sq, color) ||
 172       this.isAttackedByQueen(sq, color)
 173       // No "attackedByKing": it cannot take
 174     );
 175   }
 176
 177   postPlay(move) {
 178     super.postPlay(move);
 179     // NOTE: (harmless) condition on movesCount for Atomic2
 180     if (move.appear.length == 0 && this.movesCount >= 2) {
 181       // Capture
 182       const firstRank = { w: 7, b: 0 };
 183       for (let c of ["w", "b"]) {
 184         // Did we explode king of color c ? (TODO: remove move earlier)
 185         if (
 186           Math.abs(this.kingPos[c][0] - move.end.x) <= 1 &&
 187           Math.abs(this.kingPos[c][1] - move.end.y) <= 1
 188         ) {
 189           this.kingPos[c] = [-1, -1];
 190           this.castleFlags[c] = [8, 8];
 191         }
 192         else {
 193           // Now check if init rook(s) exploded
 194           if (Math.abs(move.end.x - firstRank[c]) <= 1) {
 195             if (Math.abs(move.end.y - this.castleFlags[c][0]) <= 1)
 196               this.castleFlags[c][0] = 8;
 197             if (Math.abs(move.end.y - this.castleFlags[c][1]) <= 1)
 198               this.castleFlags[c][1] = 8;
 199           }
 200         }
 201       }
 202     }
 203   }
 204
 205   postUndo(move) {
 206     super.postUndo(move);
 207     const c = this.turn;
 208     const oppCol = V.GetOppCol(c);
 209     // NOTE: condition on movesCount for balanced setting
 210     if (
 211       this.movesCount >= 1 &&
 212       [this.kingPos[c][0], this.kingPos[oppCol][0]].some(e => e < 0)
 213     ) {
 214       // There is a chance that last move blowed some king away..
 215       for (let psq of move.vanish) {
 216         if (psq.p == "k")
 217           this.kingPos[psq.c == c ? c : oppCol] = [psq.x, psq.y];
 218       }
 219     }
 220   }
 221
 222   underCheck(color) {
 223     const oppCol = V.GetOppCol(color);
 224     let res = undefined;
 225     // If our king disappeared, move is not valid
 226     if (this.kingPos[color][0] < 0) res = true;
 227     // If opponent king disappeared, move is valid
 228     else if (this.kingPos[oppCol][0] < 0) res = false;
 229     // Otherwise, if we remain under check, move is not valid
 230     else res = this.isAttacked(this.kingPos[color], oppCol);
 231     return res;
 232   }
 233
 234   getCheckSquares() {
 235     const color = this.turn;
 236     let res = [];
 237     if (
 238       this.kingPos[color][0] >= 0 && //king might have exploded
 239       this.isAttacked(this.kingPos[color], V.GetOppCol(color))
 240     ) {
 241       res = [JSON.parse(JSON.stringify(this.kingPos[color]))];
 242     }
 243     return res;
 244   }
 245
 246   getCurrentScore() {
 247     const color = this.turn;
 248     const kp = this.kingPos[color];
 249     if (kp[0] < 0)
 250       // King disappeared
 251       return color == "w" ? "0-1" : "1-0";
 252     if (this.atLeastOneMove()) return "*";
 253     if (!this.isAttacked(kp, V.GetOppCol(color))) return "1/2";
 254     return color == "w" ? "0-1" : "1-0"; //checkmate
 255   }
 256
 257   getNotation(move) {
 258     if (move.appear.length == 0 && move.vanish.length == 1)
 259       // First move in game (balanced == true)
 260       return V.CoordsToSquare(move.start) + "X";
 261     return super.getNotation(move);
 262   }
 263
 264 };