client/src/variants/Schess.js

   1 import { ChessRules, PiPo } from "@/base_rules";
   2
   3 export class SchessRules extends ChessRules {
   4   static get PawnSpecs() {
   5     return Object.assign(
   6       {},
   7       ChessRules.PawnSpecs,
   8       {
   9         promotions:
  10           ChessRules.PawnSpecs.promotions.concat([V.HAWK, V.ELEPHANT])
  11       }
  12     );
  13   }
  14
  15   static get HAWK() {
  16     return 'h';
  17   }
  18
  19   static get ELEPHANT() {
  20     return 'e';
  21   }
  22
  23   static get NOTHING() {
  24     return 'o';
  25   }
  26
  27   static get PIECES() {
  28     return ChessRules.PIECES.concat([V.HAWK, V.ELEPHANT]);
  29   }
  30
  31   getPpath(b) {
  32     if ([V.HAWK, V.ELEPHANT, V.NOTHING].includes(b[1])) return "Schess/" + b;
  33     return b;
  34   }
  35
  36   static IsGoodFen(fen) {
  37     if (!ChessRules.IsGoodFen(fen)) return false;
  38     const fenParsed = V.ParseFen(fen);
  39     // Check pocket state
  40     if (!fenParsed.pocket || !fenParsed.pocket.match(/^[0-1]{4,4}$/))
  41       return false;
  42     return true;
  43   }
  44
  45   static IsGoodFlags(flags) {
  46     // 4 for castle + 16 for generators
  47     return !!flags.match(/^[a-z]{4,4}[01]{16,16}$/);
  48   }
  49
  50   setFlags(fenflags) {
  51     super.setFlags(fenflags); //castleFlags
  52     this.pieceFlags = {
  53       w: [...Array(8)], //pieces can generate Hawk or Elephant?
  54       b: [...Array(8)]
  55     };
  56     const flags = fenflags.substr(4); //skip first 4 letters, for castle
  57     for (let c of ["w", "b"]) {
  58       for (let i = 0; i < 8; i++)
  59         this.pieceFlags[c][i] = flags.charAt((c == "w" ? 0 : 8) + i) == "1";
  60     }
  61   }
  62
  63   aggregateFlags() {
  64     return [this.castleFlags, this.pieceFlags];
  65   }
  66
  67   disaggregateFlags(flags) {
  68     this.castleFlags = flags[0];
  69     this.pieceFlags = flags[1];
  70   }
  71
  72   static ParseFen(fen) {
  73     const fenParts = fen.split(" ");
  74     return Object.assign(
  75       ChessRules.ParseFen(fen),
  76       { pocket: fenParts[5] }
  77     );
  78   }
  79
  80   static GenRandInitFen(randomness) {
  81     return (
  82       ChessRules.GenRandInitFen(randomness).slice(0, -2) +
  83       // Add pieceFlags + pocket
  84       "1111111111111111 - 1111"
  85     );
  86   }
  87
  88   getFen() {
  89     return (
  90       super.getFen() + " " +
  91       this.getPocketFen()
  92     );
  93   }
  94
  95   getFenForRepeat() {
  96     return (
  97       super.getFenForRepeat() + "_" +
  98       this.getPocketFen()
  99     );
 100   }
 101
 102   getFlagsFen() {
 103     let fen = super.getFlagsFen();
 104     // Add pieces flags
 105     for (let c of ["w", "b"])
 106       for (let i = 0; i < 8; i++) fen += (this.pieceFlags[c][i] ? "1" : "0");
 107     return fen;
 108   }
 109
 110   getPocketFen() {
 111     let res = "";
 112     for (let c of ["w", "b"])
 113       res += this.pocket[c][V.HAWK] + this.pocket[c][V.ELEPHANT];
 114     return res;
 115   }
 116
 117   setOtherVariables(fen) {
 118     super.setOtherVariables(fen);
 119     const fenParsed = V.ParseFen(fen);
 120     this.pocket = {
 121       "w": {
 122         h: parseInt(fenParsed.pocket[0], 10),
 123         e: parseInt(fenParsed.pocket[1], 10)
 124       },
 125       "b": {
 126         h: parseInt(fenParsed.pocket[2], 10),
 127         e: parseInt(fenParsed.pocket[3], 10)
 128       }
 129     };
 130   }
 131
 132   getPotentialMovesFrom([x, y]) {
 133     let moves = undefined;
 134     switch (this.getPiece(x, y)) {
 135       case V.HAWK:
 136         moves = this.getPotentialHawkMoves([x, y]);
 137         break;
 138       case V.ELEPHANT:
 139         moves = this.getPotentialElephantMoves([x, y]);
 140         break;
 141       default:
 142         moves = super.getPotentialMovesFrom([x, y]);
 143     }
 144     // For moves presentation when choices:
 145     const unshiftNothing = (m) => {
 146       const a = m.appear[0];
 147       m.appear.unshift(new PiPo({
 148         p: V.NOTHING,
 149         c: 'o',
 150         x: a.x,
 151         y: a.y
 152       }));
 153     };
 154     // Post-processing: add choices for hawk and elephant,
 155     // except for moves letting the king under check.
 156     const color = this.turn;
 157     if (Object.values(this.pocket[color]).some(v => v > 0)) {
 158       const firstRank = (color == "w" ? 7 : 0);
 159       let validMoves = [];
 160       moves.forEach(m => {
 161         let inCheckAfter = false;
 162         this.play(m);
 163         if (this.underCheck(color)) inCheckAfter = true;
 164         this.undo(m);
 165         if (!inCheckAfter) {
 166           for (let pp of ['h', 'e']) {
 167             if (this.pocket[color][pp] > 0) {
 168               let shift = (m.appear[0].p == V.NOTHING ? 1 : 0);
 169               if (
 170                 m.start.x == firstRank &&
 171                 this.pieceFlags[color][m.start.y] &&
 172                 (
 173                   m.appear.length == shift+1 ||
 174                   // Special castle case: is initial king square free?
 175                   ![m.appear[shift].y, m.appear[shift+1].y]
 176                     .includes(m.vanish[0].y)
 177                 )
 178               ) {
 179                 let pMove = JSON.parse(JSON.stringify(m));
 180                 if (shift == 1) pMove.appear.shift();
 181                 // NOTE: unshift instead of push, for choices presentation
 182                 pMove.appear.unshift(new PiPo({
 183                   p: pp,
 184                   c: color,
 185                   x: x,
 186                   y: y
 187                 }));
 188                 validMoves.push(pMove);
 189                 if (shift == 0) unshiftNothing(m);
 190               }
 191               shift = (m.appear[0].p == V.NOTHING ? 1 : 0);
 192               if (
 193                 m.appear.length >= 2 + shift &&
 194                 m.vanish.length == 2 &&
 195                 ![m.appear[shift].y, m.appear[shift+1].y]
 196                   .includes(m.vanish[1].y)
 197               ) {
 198                 // Special castle case: rook flag was necessarily on
 199                 let pMove = JSON.parse(JSON.stringify(m));
 200                 if (shift == 1) pMove.appear.shift();
 201                 pMove.appear.unshift(new PiPo({
 202                   p: pp,
 203                   c: color,
 204                   x: m.vanish[1].x,
 205                   y: m.vanish[1].y
 206                 }));
 207                 validMoves.push(pMove);
 208                 if (shift == 0) unshiftNothing(m);
 209               }
 210             }
 211           }
 212           // Unshift, to show the empty square on the left:
 213           validMoves.unshift(m);
 214         }
 215       });
 216       moves = validMoves;
 217     }
 218     return moves;
 219   }
 220
 221   getPotentialHawkMoves(sq) {
 222     return this.getSlideNJumpMoves(sq, V.steps[V.BISHOP]).concat(
 223       this.getSlideNJumpMoves(sq, V.steps[V.KNIGHT], "oneStep")
 224     );
 225   }
 226
 227   getPotentialElephantMoves(sq) {
 228     return this.getSlideNJumpMoves(sq, V.steps[V.ROOK]).concat(
 229       this.getSlideNJumpMoves(sq, V.steps[V.KNIGHT], "oneStep")
 230     );
 231   }
 232
 233   isAttacked(sq, color) {
 234     return (
 235       super.isAttacked(sq, color) ||
 236       this.isAttackedByHawk(sq, color) ||
 237       this.isAttackedByElephant(sq, color)
 238     );
 239   }
 240
 241   isAttackedByHawk(sq, color) {
 242     return (
 243       this.isAttackedBySlideNJump(sq, color, V.HAWK, V.steps[V.BISHOP]) ||
 244       this.isAttackedBySlideNJump(
 245         sq,
 246         color,
 247         V.HAWK,
 248         V.steps[V.KNIGHT],
 249         "oneStep"
 250       )
 251     );
 252   }
 253
 254   isAttackedByElephant(sq, color) {
 255     return (
 256       this.isAttackedBySlideNJump(sq, color, V.ELEPHANT, V.steps[V.ROOK]) ||
 257       this.isAttackedBySlideNJump(
 258         sq,
 259         color,
 260         V.ELEPHANT,
 261         V.steps[V.KNIGHT],
 262         "oneStep"
 263       )
 264     );
 265   }
 266
 267   filterValid(moves) {
 268     if (Object.values(this.pocket[this.turn]).some(v => v > 0))
 269       // Undercheck tests done in getPotentialMovesFrom()
 270       return moves;
 271     return super.filterValid(moves);
 272   }
 273
 274   prePlay(move) {
 275     super.prePlay(move);
 276     if (move.appear.length >= 2) {
 277       if ([V.HAWK, V.ELEPHANT].includes(move.appear[0].p)) {
 278         // A pocket piece is used
 279         const color = this.turn;
 280         this.pocket[color][move.appear[0].p] = 0;
 281       }
 282     }
 283   }
 284
 285   postPlay(move) {
 286     const color = move.vanish[0].c;
 287     const piece = move.vanish[0].p;
 288     // Update king position + flags
 289     if (piece == V.KING) {
 290       const shift =
 291         ([V.HAWK, V.ELEPHANT, V.NOTHING].includes(move.appear[0].p) ? 1 : 0);
 292       this.kingPos[color][0] = move.appear[shift].x;
 293       this.kingPos[color][1] = move.appear[shift].y;
 294     }
 295     this.updateCastleFlags(move, piece);
 296
 297     const oppCol = this.turn;
 298     const firstRank = (color == 'w' ? 7 : 0);
 299     const oppFirstRank = 7 - firstRank;
 300     // Does this move turn off a piece init square flag?
 301     if (move.start.x == firstRank) {
 302       if (this.pieceFlags[color][move.start.y])
 303         this.pieceFlags[color][move.start.y] = false;
 304       // Special castle case:
 305       if (move.appear.length >= 2 && move.vanish.length == 2) {
 306         const L = move.appear.length;
 307         if (move.appear[L-1].p == V.ROOK)
 308           this.pieceFlags[color][move.vanish[1].y] = false;
 309       }
 310     }
 311     if (move.end.x == oppFirstRank && this.pieceFlags[oppCol][move.end.y])
 312       this.pieceFlags[oppCol][move.end.y] = false;
 313   }
 314
 315   postUndo(move) {
 316     super.postUndo(move);
 317     if (move.appear.length >= 2) {
 318       if ([V.HAWK, V.ELEPHANT].includes(move.appear[0].p)) {
 319         // A pocket piece was used
 320         const color = this.turn;
 321         this.pocket[color][move.appear[0].p] = 1;
 322       }
 323     }
 324   }
 325
 326   static get SEARCH_DEPTH() {
 327     return 2;
 328   }
 329
 330   static get VALUES() {
 331     return Object.assign(
 332       {},
 333       ChessRules.VALUES,
 334       { 'h': 5, 'e': 7 }
 335     );
 336   }
 337
 338   getNotation(move) {
 339     if (move.appear.length >= 2) {
 340       const pPieceAppear = [V.HAWK, V.ELEPHANT].includes(move.appear[0].p);
 341       const nothingAppear = (move.appear[0].p == V.NOTHING);
 342       if (pPieceAppear || nothingAppear) {
 343         let suffix = "";
 344         if (pPieceAppear) suffix = "/" + move.appear[0].p.toUpperCase();
 345         let cmove = JSON.parse(JSON.stringify(move));
 346         cmove.appear.shift();
 347         return super.getNotation(cmove) + suffix;
 348       }
 349     }
 350     return super.getNotation(move);
 351   }
 352 };