client/src/variants/Hiddenqueen.js

   1 import { ChessRules, PiPo, Move } from "@/base_rules";
   2 import { ArrayFun } from "@/utils/array";
   3 import { randInt } from "@/utils/alea";
   4
   5 export const VariantRules = class HiddenqueenRules extends ChessRules {
   6   // Analyse in Hiddenqueen mode makes no sense
   7   static get CanAnalyze() {
   8     return false;
   9   }
  10
  11   static get HIDDEN_QUEEN() {
  12     return 't';
  13   }
  14
  15   static get PIECES() {
  16     return ChessRules.PIECES.concat(Object.values(V.HIDDEN_CODE));
  17   }
  18
  19   getPiece(i, j) {
  20     const piece = this.board[i][j].charAt(1);
  21     if (
  22       piece != V.HIDDEN_QUEEN ||
  23       // 'side' is used to determine what I see: a pawn or a (hidden)queen?
  24       this.getColor(i, j) == this.side
  25     ) {
  26       return piece;
  27     }
  28     return V.PAWN;
  29   }
  30
  31   getPpath(b, color, score) {
  32     if (b[1] == V.HIDDEN_QUEEN) {
  33       // Supposed to be hidden.
  34       if (score == "*" && (!color || color != b[0]))
  35         return b[0] + "p";
  36       return "Hiddenqueen/" + b[0] + "t";
  37     }
  38     return b;
  39   }
  40
  41   isValidPawnMove(move) {
  42     const color = move.vanish[0].c;
  43     const pawnShift = color == "w" ? -1 : 1;
  44     const startRank = color == "w" ? V.size.x - 2 : 1;
  45     const lastRank = color == "w" ? 0 : V.size.x - 1;
  46     return (
  47       // The queen is discovered if she reaches the 8th rank,
  48       // even if this would be a technically valid pawn move.
  49       move.end.x != lastRank &&
  50       (
  51         (
  52           move.end.x - move.start.x == pawnShift &&
  53           (
  54             (
  55               // Normal move
  56               move.end.y == move.start.y &&
  57               this.board[move.end.x][move.end.y] == V.EMPTY
  58             )
  59             ||
  60             (
  61               // Capture
  62               Math.abs(move.end.y - move.start.y) == 1 &&
  63               this.board[move.end.x][move.end.y] != V.EMPTY
  64             )
  65           )
  66         )
  67         ||
  68         (
  69           // Two-spaces initial jump
  70           move.start.x == startRank &&
  71           move.end.y == move.start.y &&
  72           move.end.x - move.start.x == 2 * pawnShift &&
  73           this.board[move.end.x][move.end.y] == V.EMPTY
  74         )
  75       )
  76     );
  77   }
  78
  79   getPotentialMovesFrom([x, y]) {
  80     if (this.getPiece(x, y) == V.HIDDEN_QUEEN) {
  81       const pawnMoves = super.getPotentialPawnMoves([x, y]);
  82       let queenMoves = super.getPotentialQueenMoves([x, y]);
  83       // Remove from queen moves those corresponding to a pawn move:
  84       queenMoves = queenMoves
  85         .filter(m => !this.isValidPawnMove(m))
  86         // Hidden queen is revealed if moving like a queen:
  87         .map(m => {
  88           m.appear[0].p = V.QUEEN;
  89           return m;
  90         });
  91       return pawnMoves.concat(queenMoves);
  92     }
  93     return super.getPotentialMovesFrom([x, y]);
  94   }
  95
  96   getPossibleMovesFrom(sq) {
  97     this.side = this.turn;
  98     return this.filterValid(this.getPotentialMovesFrom(sq));
  99   }
 100
 101   static GenRandInitFen() {
 102     let fen = ChessRules.GenRandInitFen();
 103     // Place hidden queens at random:
 104     let hiddenQueenPos = randInt(8);
 105     let pawnRank = "PPPPPPPP".split("");
 106     pawnRank[hiddenQueenPos] = "T";
 107     fen = fen.replace("PPPPPPPP", pawnRank.join(""));
 108     hiddenQueenPos = randInt(8);
 109     pawnRank = "pppppppp".split("");
 110     pawnRank[hiddenQueenPos] = "t";
 111     fen = fen.replace("pppppppp", pawnRank.join(""));
 112     return fen;
 113   }
 114
 115   updateVariables(move) {
 116     super.updateVariables(move);
 117     if (move.vanish.length == 2 && move.vanish[1].p == V.KING)
 118       // We took opponent king
 119       this.kingPos[this.turn] = [-1, -1];
 120   }
 121
 122   unupdateVariables(move) {
 123     super.unupdateVariables(move);
 124     const c = move.vanish[0].c;
 125     const oppCol = V.GetOppCol(c);
 126     if (this.kingPos[oppCol][0] < 0)
 127       // Last move took opponent's king:
 128       this.kingPos[oppCol] = [move.vanish[1].x, move.vanish[1].y];
 129   }
 130
 131   getCurrentScore() {
 132     const color = this.turn;
 133     if (this.kingPos[color][0] < 0)
 134       // King disappeared
 135       return color == "w" ? "0-1" : "1-0";
 136     return super.getCurrentScore();
 137   }
 138
 139   // Search is biased, so not really needed to explore deeply
 140   static get SEARCH_DEPTH() {
 141     return 2;
 142   }
 143
 144   static get VALUES() {
 145     return Object.assign(
 146       { t: 9 },
 147       ChessRules.VALUES
 148     );
 149   }
 150
 151   getComputerMove() {
 152     this.side = this.turn;
 153     return super.getComputerMove();
 154   }
 155 };