client/src/variants/Recycle.js

   1 import { ChessRules, PiPo, Move } from "@/base_rules";
   2 import { ArrayFun } from "@/utils/array";
   3
   4 export const VariantRules = class RecycleRules extends ChessRules {
   5   static IsGoodFen(fen) {
   6     if (!ChessRules.IsGoodFen(fen)) return false;
   7     const fenParsed = V.ParseFen(fen);
   8     // 5) Check reserves
   9     if (!fenParsed.reserve || !fenParsed.reserve.match(/^[0-9]{10,10}$/))
  10       return false;
  11     return true;
  12   }
  13
  14   static ParseFen(fen) {
  15     const fenParts = fen.split(" ");
  16     return Object.assign(ChessRules.ParseFen(fen), {
  17       reserve: fenParts[5],
  18     });
  19   }
  20
  21   static GenRandInitFen() {
  22     return ChessRules.GenRandInitFen() + " 0000000000";
  23   }
  24
  25   getFen() {
  26     return (
  27       super.getFen() + " " + this.getReserveFen()
  28     );
  29   }
  30
  31   getReserveFen() {
  32     let counts = new Array(10);
  33     for (
  34       let i = 0;
  35       i < V.PIECES.length - 1;
  36       i++ //-1: no king reserve
  37     ) {
  38       counts[i] = this.reserve["w"][V.PIECES[i]];
  39       counts[5 + i] = this.reserve["b"][V.PIECES[i]];
  40     }
  41     return counts.join("");
  42   }
  43
  44   setOtherVariables(fen) {
  45     super.setOtherVariables(fen);
  46     const fenParsed = V.ParseFen(fen);
  47     // Also init reserves (used by the interface to show landable pieces)
  48     this.reserve = {
  49       w: {
  50         [V.PAWN]: parseInt(fenParsed.reserve[0]),
  51         [V.ROOK]: parseInt(fenParsed.reserve[1]),
  52         [V.KNIGHT]: parseInt(fenParsed.reserve[2]),
  53         [V.BISHOP]: parseInt(fenParsed.reserve[3]),
  54         [V.QUEEN]: parseInt(fenParsed.reserve[4])
  55       },
  56       b: {
  57         [V.PAWN]: parseInt(fenParsed.reserve[5]),
  58         [V.ROOK]: parseInt(fenParsed.reserve[6]),
  59         [V.KNIGHT]: parseInt(fenParsed.reserve[7]),
  60         [V.BISHOP]: parseInt(fenParsed.reserve[8]),
  61         [V.QUEEN]: parseInt(fenParsed.reserve[9])
  62       }
  63     };
  64   }
  65
  66   getColor(i, j) {
  67     if (i >= V.size.x) return i == V.size.x ? "w" : "b";
  68     return this.board[i][j].charAt(0);
  69   }
  70
  71   getPiece(i, j) {
  72     if (i >= V.size.x) return V.RESERVE_PIECES[j];
  73     return this.board[i][j].charAt(1);
  74   }
  75
  76   // Used by the interface:
  77   getReservePpath(color, index) {
  78     return color + V.RESERVE_PIECES[index];
  79   }
  80
  81   // Ordering on reserve pieces
  82   static get RESERVE_PIECES() {
  83     return [V.PAWN, V.ROOK, V.KNIGHT, V.BISHOP, V.QUEEN];
  84   }
  85
  86   getReserveMoves([x, y]) {
  87     const color = this.turn;
  88     const p = V.RESERVE_PIECES[y];
  89     if (this.reserve[color][p] == 0) return [];
  90     let moves = [];
  91     const pawnShift = p == V.PAWN ? 1 : 0;
  92     for (let i = pawnShift; i < V.size.x - pawnShift; i++) {
  93       for (let j = 0; j < V.size.y; j++) {
  94         if (this.board[i][j] == V.EMPTY) {
  95           let mv = new Move({
  96             appear: [
  97               new PiPo({
  98                 x: i,
  99                 y: j,
 100                 c: color,
 101                 p: p
 102               })
 103             ],
 104             vanish: [],
 105             start: { x: x, y: y }, //a bit artificial...
 106             end: { x: i, y: j }
 107           });
 108           moves.push(mv);
 109         }
 110       }
 111     }
 112     return moves;
 113   }
 114
 115   getPotentialMovesFrom([x, y]) {
 116     if (x >= V.size.x) {
 117       // Reserves, outside of board: x == sizeX(+1)
 118       return this.getReserveMoves([x, y]);
 119     }
 120     // Standard moves
 121     return super.getPotentialMovesFrom([x, y]);
 122   }
 123
 124   getPotentialPawnMoves([x, y]) {
 125     const color = this.turn;
 126     let moves = [];
 127     const [sizeX, sizeY] = [V.size.x, V.size.y];
 128     const shiftX = color == "w" ? -1 : 1;
 129     const startRank = color == "w" ? sizeX - 2 : 1;
 130     const lastRank = color == "w" ? 0 : sizeX - 1;
 131
 132     // One square forward
 133     if (this.board[x + shiftX][y] == V.EMPTY) {
 134       moves.push(
 135         this.getBasicMove([x, y], [x + shiftX, y])
 136       );
 137       // Next condition because pawns on 1st rank can generally jump
 138       if (
 139         x == startRank &&
 140         this.board[x + 2 * shiftX][y] == V.EMPTY
 141       ) {
 142         // Two squares jump
 143         moves.push(this.getBasicMove([x, y], [x + 2 * shiftX, y]));
 144       }
 145     }
 146     // Captures
 147     for (let shiftY of [-1, 1]) {
 148       if (
 149         y + shiftY >= 0 &&
 150         y + shiftY < sizeY &&
 151         this.board[x + shiftX][y + shiftY] != V.EMPTY &&
 152         this.canTake([x, y], [x + shiftX, y + shiftY])
 153       ) {
 154         moves.push(
 155           this.getBasicMove([x, y], [x + shiftX, y + shiftY])
 156         );
 157       }
 158     }
 159
 160     // En passant
 161     const Lep = this.epSquares.length;
 162     const epSquare = this.epSquares[Lep - 1]; //always at least one element
 163     if (
 164       !!epSquare &&
 165       epSquare.x == x + shiftX &&
 166       Math.abs(epSquare.y - y) == 1
 167     ) {
 168       let enpassantMove = this.getBasicMove([x, y], [epSquare.x, epSquare.y]);
 169       enpassantMove.vanish.push({
 170         x: x,
 171         y: epSquare.y,
 172         p: "p",
 173         c: this.getColor(x, epSquare.y)
 174       });
 175       moves.push(enpassantMove);
 176     }
 177
 178     // Post-processing: remove falling pawns
 179     if (x + shiftX == lastRank) {
 180       moves.forEach(m => {
 181         m.appear.pop();
 182       });
 183     }
 184
 185     return moves;
 186   }
 187
 188   getAllValidMoves() {
 189     let moves = super.getAllValidMoves();
 190     const color = this.turn;
 191     for (let i = 0; i < V.RESERVE_PIECES.length; i++)
 192       moves = moves.concat(
 193         this.getReserveMoves([V.size.x + (color == "w" ? 0 : 1), i])
 194       );
 195     return this.filterValid(moves);
 196   }
 197
 198   atLeastOneMove() {
 199     if (!super.atLeastOneMove()) {
 200       // Search one reserve move
 201       for (let i = 0; i < V.RESERVE_PIECES.length; i++) {
 202         let moves = this.filterValid(
 203           this.getReserveMoves([V.size.x + (this.turn == "w" ? 0 : 1), i])
 204         );
 205         if (moves.length > 0) return true;
 206       }
 207       return false;
 208     }
 209     return true;
 210   }
 211
 212   canTake([x1, y1], [x2, y2]) {
 213     // Self-captures allowed, except for the king:
 214     return this.getPiece(x2, y2) != V.KING;
 215   }
 216
 217   updateVariables(move) {
 218     super.updateVariables(move);
 219     if (move.vanish.length == 2 && move.appear.length == 2) return; //skip castle
 220     const color = V.GetOppCol(this.turn);
 221     if (move.vanish.length == 0) {
 222       this.reserve[color][move.appear[0].p]--;
 223       return;
 224     }
 225     else if (move.vanish.length == 2 && move.vanish[1].c == color) {
 226       // Self-capture
 227       this.reserve[color][move.vanish[1].p]++;
 228     }
 229   }
 230
 231   unupdateVariables(move) {
 232     super.unupdateVariables(move);
 233     if (move.vanish.length == 2 && move.appear.length == 2) return;
 234     const color = this.turn;
 235     if (move.vanish.length == 0) {
 236       this.reserve[color][move.appear[0].p]++;
 237       return;
 238     }
 239     else if (move.vanish.length == 2 && move.vanish[1].c == color) {
 240       this.reserve[color][move.vanish[1].p]--;
 241     }
 242   }
 243
 244   static get SEARCH_DEPTH() {
 245     return 2;
 246   }
 247
 248   evalPosition() {
 249     let evaluation = super.evalPosition();
 250     // Add reserves:
 251     for (let i = 0; i < V.RESERVE_PIECES.length; i++) {
 252       const p = V.RESERVE_PIECES[i];
 253       evaluation += this.reserve["w"][p] * V.VALUES[p];
 254       evaluation -= this.reserve["b"][p] * V.VALUES[p];
 255     }
 256     return evaluation;
 257   }
 258
 259   getNotation(move) {
 260     const finalSquare = V.CoordsToSquare(move.end);
 261     if (move.vanish.length > 0) {
 262       if (move.appear.length > 0) {
 263         // Standard move
 264         return super.getNotation(move);
 265       } else {
 266         // Pawn fallen: capturing or not
 267         let res = "";
 268         if (move.vanish.length == 2)
 269           res += V.CoordToColumn(move.start.y) + "x";
 270         return res + finalSquare;
 271       }
 272     }
 273     // Rebirth:
 274     const piece =
 275       move.appear[0].p != V.PAWN ? move.appear[0].p.toUpperCase() : "";
 276     return piece + "@" + V.CoordsToSquare(move.end);
 277   }
 278 };