| 1 | import { ChessRules, Move, PiPo } from "@/base_rules"; |
| 2 | |
| 3 | export class DynamoRules extends ChessRules { |
| 4 | // TODO: later, allow to push out pawns on a and h files |
| 5 | static get HasEnpassant() { |
| 6 | return false; |
| 7 | } |
| 8 | |
| 9 | canIplay(side, [x, y]) { |
| 10 | // Sometimes opponent's pieces can be moved directly |
| 11 | return true; |
| 12 | } |
| 13 | |
| 14 | setOtherVariables(fen) { |
| 15 | super.setOtherVariables(fen); |
| 16 | this.subTurn = 1; |
| 17 | // Local stack of "action moves" |
| 18 | this.amoves = []; |
| 19 | const amove = V.ParseFen(fen).amove; |
| 20 | if (amove != "-") { |
| 21 | const amoveParts = amove.split("/"); |
| 22 | let amove = { |
| 23 | // No need for start & end |
| 24 | appear: [], |
| 25 | vanish: [] |
| 26 | }; |
| 27 | [0, 1].map(i => { |
| 28 | amoveParts[i].split(".").forEach(av => { |
| 29 | // Format is "bpe3" |
| 30 | const xy = V.SquareToCoords(av.substr(2)); |
| 31 | move[i == 0 ? "appear" : "vanish"].push( |
| 32 | new PiPo({ |
| 33 | x: xy.x, |
| 34 | y: xy.y, |
| 35 | c: av[0], |
| 36 | p: av[1] |
| 37 | }) |
| 38 | ); |
| 39 | }); |
| 40 | }); |
| 41 | this.amoves.push(move); |
| 42 | } |
| 43 | this.subTurn = 1; |
| 44 | // Stack "first moves" (on subTurn 1) to merge and check opposite moves |
| 45 | this.firstMove = []; |
| 46 | } |
| 47 | |
| 48 | static ParseFen(fen) { |
| 49 | return Object.assign( |
| 50 | ChessRules.ParseFen(fen), |
| 51 | { amove: fen.split(" ")[4] } |
| 52 | ); |
| 53 | } |
| 54 | |
| 55 | static IsGoodFen(fen) { |
| 56 | if (!ChessRules.IsGoodFen(fen)) return false; |
| 57 | const fenParts = fen.split(" "); |
| 58 | if (fenParts.length != 6) return false; |
| 59 | if (fenParts[5] != "-" && !fenParts[5].match(/^([a-h][1-8]){2}$/)) |
| 60 | return false; |
| 61 | return true; |
| 62 | } |
| 63 | |
| 64 | getFen() { |
| 65 | return super.getFen() + " " + this.getAmoveFen(); |
| 66 | } |
| 67 | |
| 68 | getFenForRepeat() { |
| 69 | return super.getFenForRepeat() + "_" + this.getAmoveFen(); |
| 70 | } |
| 71 | |
| 72 | getAmoveFen() { |
| 73 | const L = this.amoves.length; |
| 74 | if (L == 0) return "-"; |
| 75 | return ( |
| 76 | ["appear","vanish"].map( |
| 77 | mpart => { |
| 78 | return ( |
| 79 | this.amoves[L-1][mpart].map( |
| 80 | av => { |
| 81 | const square = V.CoordsToSquare({ x: av.x, y: av.y }); |
| 82 | return av.c + av.p + square; |
| 83 | } |
| 84 | ).join(".") |
| 85 | ); |
| 86 | } |
| 87 | ).join("/") |
| 88 | ); |
| 89 | } |
| 90 | |
| 91 | canTake() { |
| 92 | // Captures don't occur (only pulls & pushes) |
| 93 | return false; |
| 94 | } |
| 95 | |
| 96 | // Step is right, just add (push/pull) moves in this direction |
| 97 | // Direction is assumed normalized. |
| 98 | getMovesInDirection([x, y], [dx, dy], nbSteps) { |
| 99 | nbSteps = nbSteps || 8; //max 8 steps anyway |
| 100 | let [i, j] = [x + dx, y + dy]; |
| 101 | let moves = []; |
| 102 | const color = this.getColor(x, y); |
| 103 | const piece = this.getPiece(x, y); |
| 104 | const lastRank = (color == 'w' ? 0 : 7); |
| 105 | let counter = 1; |
| 106 | while (V.OnBoard(i, j) && this.board[i][j] == V.EMPTY) { |
| 107 | if (i == lastRank && piece == V.PAWN) { |
| 108 | // Promotion by push or pull |
| 109 | V.PawnSpecs.promotions.forEach(p => { |
| 110 | let move = super.getBasicMove([x, y], [i, j], { c: color, p: p }); |
| 111 | moves.push(move); |
| 112 | }); |
| 113 | } |
| 114 | else moves.push(super.getBasicMove([x, y], [i, j])); |
| 115 | if (++counter > nbSteps) break; |
| 116 | i += dx; |
| 117 | j += dy; |
| 118 | } |
| 119 | if (!V.OnBoard(i, j) && piece != V.KING) { |
| 120 | // Add special "exit" move, by "taking king" |
| 121 | moves.push( |
| 122 | new Move({ |
| 123 | start: { x: x, y: y }, |
| 124 | end: { x: this.kingPos[color][0], y: this.kingPos[color][1] }, |
| 125 | appear: [], |
| 126 | vanish: [{ x: x, y: y, c: color, p: piece }] |
| 127 | }) |
| 128 | ); |
| 129 | } |
| 130 | return moves; |
| 131 | } |
| 132 | |
| 133 | // Normalize direction to know the step |
| 134 | getNormalizedDirection([dx, dy]) { |
| 135 | const absDir = [Math.abs(dx), Math.abs(dy)]; |
| 136 | let divisor = 0; |
| 137 | if (absDir[0] != 0 && absDir[1] != 0 && absDir[0] != absDir[1]) |
| 138 | // Knight |
| 139 | divisor = Math.min(absDir[0], absDir[1]); |
| 140 | else |
| 141 | // Standard slider (or maybe a pawn or king: same) |
| 142 | divisor = Math.max(absDir[0], absDir[1]); |
| 143 | return [dx / divisor, dy / divisor]; |
| 144 | } |
| 145 | |
| 146 | // There is something on x2,y2, maybe our color, pushed/pulled |
| 147 | static IsAprioriValidMove([x1, y1], [x2, y2]) { |
| 148 | const color1 = this.getColor(x1, y1); |
| 149 | const color2 = this.getColor(x2, y2); |
| 150 | const pawnShift = (color1 == 'w' ? -1 : 1); |
| 151 | const pawnStartRank = (color1 == 'w' ? 6 : 1); |
| 152 | const deltaX = Math.abs(x1 - x2); |
| 153 | const deltaY = Math.abs(y1 - y2); |
| 154 | switch (this.getPiece(x1, y1)) { |
| 155 | case V.PAWN: |
| 156 | return ( |
| 157 | ( |
| 158 | color1 == color2 && |
| 159 | y1 == y2 && |
| 160 | ( |
| 161 | x1 + pawnShift == x2 || |
| 162 | x1 == pawnStartRank && x1 + 2 * pawnShift == x2 |
| 163 | ) |
| 164 | ) |
| 165 | || |
| 166 | ( |
| 167 | color1 != color2 && |
| 168 | deltaY == 1 && |
| 169 | x1 + pawnShift == x2 |
| 170 | ) |
| 171 | ); |
| 172 | case V.ROOK: |
| 173 | return (x1 == x2 || y1 == y2); |
| 174 | case V.KNIGHT: { |
| 175 | return (deltaX + deltaY == 3 && (deltaX == 1 || deltaY == 1)); |
| 176 | } |
| 177 | case V.BISHOP: |
| 178 | return (deltaX == deltaY); |
| 179 | case V.QUEEN: |
| 180 | return ( |
| 181 | (deltaX == 0 || deltaY == 0 || deltaX == deltaY) |
| 182 | ); |
| 183 | case V.KING: |
| 184 | return (deltaX <= 1 && deltaY <= 1); |
| 185 | } |
| 186 | return false; |
| 187 | } |
| 188 | |
| 189 | // NOTE: for pushes, play the pushed piece first. |
| 190 | // for pulls: play the piece doing the action first |
| 191 | // NOTE: to push a piece out of the board, make it slide until its king |
| 192 | getPotentialMovesFrom([x, y]) { |
| 193 | const color = this.turn; |
| 194 | if (this.subTurn == 1) { |
| 195 | const getMoveHash = (m) => { |
| 196 | return V.CoordsToSquare(m.start) + V.CoordsToSquare(m.end); |
| 197 | }; |
| 198 | const addMoves = (dir, nbSteps) => { |
| 199 | const newMoves = |
| 200 | this.getMovesInDirection([x, y], [-dir[0], -dir[1]], nbSteps) |
| 201 | .filter(m => !movesHash[getMoveHash(m)]); |
| 202 | newMoves.forEach(m => { movesHash[getMoveHash(m)] = true; }); |
| 203 | Array.prototype.push.apply(moves, newMoves); |
| 204 | }; |
| 205 | // Free to play any move: |
| 206 | const moves = super.getPotentialMovesFrom([x, y]) |
| 207 | const pawnShift = (color == 'w' ? -1 : 1); |
| 208 | const pawnStartRank = (color == 'w' ? 6 : 1); |
| 209 | // Structure to avoid adding moves twice (can be action & move) |
| 210 | let movesHash = {}; |
| 211 | moves.forEach(m => { movesHash[getMoveHash(m)] = true; }); |
| 212 | // [x, y] is pushed by 'color' |
| 213 | for (let step of V.steps[V.KNIGHT]) { |
| 214 | const [i, j] = [x + step[0], y + step[1]]; |
| 215 | if ( |
| 216 | V.OnBoard(i, j) && |
| 217 | this.board[i][j] != V.EMPTY && |
| 218 | this.getColor(i, j) == color && |
| 219 | this.getPiece(i, j) == V.KNIGHT |
| 220 | ) { |
| 221 | addMoves(step, 1); |
| 222 | } |
| 223 | } |
| 224 | for (let step of V.steps[V.ROOK].concat(V.steps[V.BISHOP])) { |
| 225 | let [i, j] = [x + step[0], y + step[1]]; |
| 226 | while (V.OnBoard(i, j) && this.board[i][j] == V.EMPTY) { |
| 227 | i += step[0]; |
| 228 | j += step[1]; |
| 229 | } |
| 230 | if ( |
| 231 | V.OnBoard(i, j) && |
| 232 | this.board[i][j] != V.EMPTY && |
| 233 | this.getColor(i, j) == color |
| 234 | ) { |
| 235 | const deltaX = Math.abs(i - x); |
| 236 | const deltaY = Math.abs(j - y); |
| 237 | // Can a priori go both ways, except with pawns |
| 238 | switch (this.getPiece(i, j)) { |
| 239 | case V.PAWN: |
| 240 | if (deltaX <= 2 && deltaY <= 1) { |
| 241 | const pColor = this.getColor(x, y); |
| 242 | if (pColor == color && deltaY == 0) { |
| 243 | // Pushed forward |
| 244 | const maxSteps = (i == pawnStartRank && deltaX == 1 ? 2 : 1); |
| 245 | addMoves(step, maxSteps); |
| 246 | } |
| 247 | else if (pColor != color && deltaY == 1 && deltaX == 1) |
| 248 | // Pushed diagonally |
| 249 | addMoves(step, 1); |
| 250 | } |
| 251 | break; |
| 252 | case V.ROOK: |
| 253 | if (deltaX == 0 || deltaY == 0) addMoves(step); |
| 254 | break; |
| 255 | case V.BISHOP: |
| 256 | if (deltaX == deltaY) addMoves(step); |
| 257 | break; |
| 258 | case V.QUEEN: |
| 259 | if (deltaX == 0 || deltaY == 0 || deltaX == deltaY) |
| 260 | addMoves(step); |
| 261 | break; |
| 262 | case V.KING: |
| 263 | if (deltaX <= 1 && deltaY <= 1) addMoves(step, 1); |
| 264 | break; |
| 265 | } |
| 266 | } |
| 267 | } |
| 268 | return moves; |
| 269 | } |
| 270 | // If subTurn == 2 then we should have a first move, |
| 271 | // which restrict what we can play now: only in the first move direction |
| 272 | // NOTE: no need for knight or pawn checks, because the move will be |
| 273 | // naturally limited in those cases. |
| 274 | const L = this.firstMove.length; |
| 275 | const fm = this.firstMove[L-1]; |
| 276 | if (fm.appear.length == 2 && fm.vanish.length == 2) |
| 277 | // Castle: no real move playable then. |
| 278 | return []; |
| 279 | if (fm.appear.length == 0) { |
| 280 | // Piece at subTurn 1 just exited the board. |
| 281 | // Can I be a piece which caused the exit? |
| 282 | this.undo(fm); |
| 283 | const moveOk = V.IsAprioriValidMove([x, y], [fm.start.x, fm.start.y]); |
| 284 | this.play(fm); |
| 285 | if (moveOk) { |
| 286 | // Seems so: |
| 287 | const dir = this.getNormalizedDirection( |
| 288 | [fm.start.x - x, fm.start.y - y]); |
| 289 | return this.getMovesInDirection([x, y], dir); |
| 290 | } |
| 291 | } |
| 292 | else { |
| 293 | const dirM = this.getNormalizedDirection( |
| 294 | [fm.end.x - fm.start.x, fm.end.y - fm.start.y]); |
| 295 | const dir = this.getNormalizedDirection( |
| 296 | [fm.start.x - x, fm.start.y - y]); |
| 297 | // Normalized directions should match: |
| 298 | if (dir[0] == dirM[0] && dir[1] == dirM[1]) |
| 299 | return this.getMovesInDirection([x, y], dir); |
| 300 | } |
| 301 | return []; |
| 302 | } |
| 303 | |
| 304 | // Does m2 un-do m1 ? (to disallow undoing actions) |
| 305 | oppositeMoves(m1, m2) { |
| 306 | const isEqual = (av1, av2) => { |
| 307 | // Precondition: av1 and av2 length = 2 |
| 308 | for (let av of av1) { |
| 309 | const avInAv2 = av2.find(elt => { |
| 310 | return ( |
| 311 | elt.x == av.x && |
| 312 | elt.y == av.y && |
| 313 | elt.c == av.c && |
| 314 | elt.p == av.p |
| 315 | ); |
| 316 | }); |
| 317 | if (!avInAv2) return false; |
| 318 | } |
| 319 | return true; |
| 320 | }; |
| 321 | return ( |
| 322 | m1.appear.length == 2 && |
| 323 | m2.appear.length == 2 && |
| 324 | m1.vanish.length == 2 && |
| 325 | m2.vanish.length == 2 && |
| 326 | isEqual(m1.appear, m2.vanish) && |
| 327 | isEqual(m1.vanish, m2.appear) |
| 328 | ); |
| 329 | } |
| 330 | |
| 331 | getAmove(move1, move2) { |
| 332 | // Just merge (one is action one is move, one may be empty) |
| 333 | return { |
| 334 | appear: move1.appear.concat(move2.appear), |
| 335 | vanish: move1.vanish.concat(move2.vanish) |
| 336 | } |
| 337 | } |
| 338 | |
| 339 | filterValid(moves) { |
| 340 | const color = this.turn; |
| 341 | if (this.subTurn == 1) { |
| 342 | return moves.filter(m => { |
| 343 | // A move is valid either if it doesn't result in a check, |
| 344 | // or if a second move is possible to counter the check |
| 345 | // (not undoing a potential move + action of the opponent) |
| 346 | this.play(m); |
| 347 | let res = this.underCheck(color); |
| 348 | if (res) { |
| 349 | const moves2 = this.getAllPotentialMoves(); |
| 350 | for (m2 of moves2) { |
| 351 | this.play(m2); |
| 352 | const res2 = this.underCheck(color); |
| 353 | this.undo(m2); |
| 354 | if (!res2) { |
| 355 | res = false; |
| 356 | break; |
| 357 | } |
| 358 | } |
| 359 | } |
| 360 | this.undo(m); |
| 361 | return !res; |
| 362 | }); |
| 363 | } |
| 364 | const Lf = this.firstMove.length; |
| 365 | const La = this.amoves.length; |
| 366 | if (La == 0) return super.filterValid(moves); |
| 367 | return ( |
| 368 | super.filterValid( |
| 369 | moves.filter(m => { |
| 370 | // Move shouldn't undo another: |
| 371 | const amove = this.getAmove(this.firstMove[Lf-1], m); |
| 372 | return !this.oppositeMoves(this.amoves[La-1], amove); |
| 373 | }) |
| 374 | ) |
| 375 | ); |
| 376 | } |
| 377 | |
| 378 | isAttackedBySlideNJump([x, y], color, piece, steps, oneStep) { |
| 379 | for (let step of steps) { |
| 380 | let rx = x + step[0], |
| 381 | ry = y + step[1]; |
| 382 | while (V.OnBoard(rx, ry) && this.board[rx][ry] == V.EMPTY && !oneStep) { |
| 383 | rx += step[0]; |
| 384 | ry += step[1]; |
| 385 | } |
| 386 | if ( |
| 387 | V.OnBoard(rx, ry) && |
| 388 | this.getPiece(rx, ry) == piece && |
| 389 | this.getColor(rx, ry) == color |
| 390 | ) { |
| 391 | // Now step in the other direction: if end of the world, then attacked |
| 392 | rx = x - step[0]; |
| 393 | ry = y - step[1]; |
| 394 | while ( |
| 395 | V.OnBoard(rx, ry) && |
| 396 | this.board[rx][ry] == V.EMPTY && |
| 397 | !oneStep |
| 398 | ) { |
| 399 | rx -= step[0]; |
| 400 | ry -= step[1]; |
| 401 | } |
| 402 | if (!V.OnBoard(rx, ry)) return true; |
| 403 | } |
| 404 | } |
| 405 | return false; |
| 406 | } |
| 407 | |
| 408 | isAttackedByPawn([x, y], color) { |
| 409 | const lastRank = (color == 'w' ? 0 : 7); |
| 410 | if (y != lastRank) |
| 411 | // The king can be pushed out by a pawn only on last rank |
| 412 | return false; |
| 413 | const pawnShift = (color == "w" ? 1 : -1); |
| 414 | for (let i of [-1, 1]) { |
| 415 | if ( |
| 416 | y + i >= 0 && |
| 417 | y + i < V.size.y && |
| 418 | this.getPiece(x + pawnShift, y + i) == V.PAWN && |
| 419 | this.getColor(x + pawnShift, y + i) == color |
| 420 | ) { |
| 421 | return true; |
| 422 | } |
| 423 | } |
| 424 | return false; |
| 425 | } |
| 426 | |
| 427 | getCurrentScore() { |
| 428 | if (this.subTurn == 2) |
| 429 | // Move not over |
| 430 | return "*"; |
| 431 | return super.getCurrentScore(); |
| 432 | } |
| 433 | |
| 434 | doClick(square) { |
| 435 | // If subTurn == 2 && square is empty && !underCheck, |
| 436 | // then return an empty move, allowing to "pass" subTurn2 |
| 437 | if ( |
| 438 | this.subTurn == 2 && |
| 439 | this.board[square[0]][square[1]] == V.EMPTY && |
| 440 | !this.underCheck(this.turn) |
| 441 | ) { |
| 442 | return { |
| 443 | start: { x: -1, y: -1 }, |
| 444 | end: { x: -1, y: -1 }, |
| 445 | appear: [], |
| 446 | vanish: [] |
| 447 | }; |
| 448 | } |
| 449 | return null; |
| 450 | } |
| 451 | |
| 452 | play(move) { |
| 453 | move.flags = JSON.stringify(this.aggregateFlags()); |
| 454 | V.PlayOnBoard(this.board, move); |
| 455 | if (this.subTurn == 2) { |
| 456 | const L = this.firstMove.length; |
| 457 | this.amoves.push(this.getAmove(this.firstMove[L-1], move)); |
| 458 | this.turn = V.GetOppCol(this.turn); |
| 459 | this.movesCount++; |
| 460 | } |
| 461 | else this.firstMove.push(move); |
| 462 | this.subTurn = 3 - this.subTurn; |
| 463 | this.postPlay(move); |
| 464 | } |
| 465 | |
| 466 | postPlay(move) { |
| 467 | if (move.start.x < 0) return; |
| 468 | for (let a of move.appear) |
| 469 | if (a.p == V.KING) this.kingPos[a.c] = [a.x, a.y]; |
| 470 | this.updateCastleFlags(move); |
| 471 | } |
| 472 | |
| 473 | updateCastleFlags(move) { |
| 474 | const firstRank = { 'w': V.size.x - 1, 'b': 0 }; |
| 475 | for (let v of move.vanish) { |
| 476 | if (v.p == V.KING) this.castleFlags[v.c] = [V.size.y, V.size.y]; |
| 477 | else if (v.x == firstRank[v.c] && this.castleFlags[v.c].includes(v.y)) { |
| 478 | const flagIdx = (v.y == this.castleFlags[v.c][0] ? 0 : 1); |
| 479 | this.castleFlags[v.c][flagIdx] = V.size.y; |
| 480 | } |
| 481 | } |
| 482 | } |
| 483 | |
| 484 | undo(move) { |
| 485 | this.disaggregateFlags(JSON.parse(move.flags)); |
| 486 | V.UndoOnBoard(this.board, move); |
| 487 | if (this.subTurn == 1) { |
| 488 | this.turn = V.GetOppCol(this.turn); |
| 489 | this.movesCount--; |
| 490 | } |
| 491 | else this.firstMove.pop(); |
| 492 | this.subTurn = 3 - this.subTurn; |
| 493 | this.postUndo(move); |
| 494 | } |
| 495 | |
| 496 | postUndo(move) { |
| 497 | // (Potentially) Reset king position |
| 498 | for (let v of move.vanish) |
| 499 | if (v.p == V.KING) this.kingPos[v.c] = [v.x, v.y]; |
| 500 | } |
| 501 | |
| 502 | getNotation(move) { |
| 503 | if (move.start.x < 0) |
| 504 | // A second move is always required, but may be empty |
| 505 | return "-"; |
| 506 | const initialSquare = V.CoordsToSquare(move.start); |
| 507 | const finalSquare = V.CoordsToSquare(move.end); |
| 508 | if (move.appear.length == 0) |
| 509 | // Pushed or pulled out of the board |
| 510 | return initialSquare + "R"; |
| 511 | return move.appear[0].p.toUpperCase() + initialSquare + finalSquare; |
| 512 | } |
| 513 | }; |