Update TODO
[vchess.git] / client / src / variants / Dynamo.js
CommitLineData
b866a62a 1import { ChessRules, Move, PiPo } from "@/base_rules";
ad1e629e 2import { randInt } from "@/utils/alea";
b866a62a 3
0d5335de 4export class DynamoRules extends ChessRules {
7ddfec38 5 // TODO: later, allow to push out pawns on a and h files
61656127
BA
6 static get HasEnpassant() {
7 return false;
8 }
9
c7550017
BA
10 canIplay(side, [x, y]) {
11 // Sometimes opponent's pieces can be moved directly
e78633db 12 return this.turn == side;
c7550017
BA
13 }
14
61656127
BA
15 setOtherVariables(fen) {
16 super.setOtherVariables(fen);
17 this.subTurn = 1;
18 // Local stack of "action moves"
19 this.amoves = [];
20 const amove = V.ParseFen(fen).amove;
93ce6119 21 if (amove != "-") {
61656127 22 const amoveParts = amove.split("/");
ad1e629e 23 let move = {
61656127
BA
24 // No need for start & end
25 appear: [],
26 vanish: []
27 };
28 [0, 1].map(i => {
ad1e629e
BA
29 if (amoveParts[i] != "-") {
30 amoveParts[i].split(".").forEach(av => {
31 // Format is "bpe3"
32 const xy = V.SquareToCoords(av.substr(2));
33 move[i == 0 ? "appear" : "vanish"].push(
34 new PiPo({
35 x: xy.x,
36 y: xy.y,
37 c: av[0],
38 p: av[1]
39 })
40 );
41 });
42 }
61656127
BA
43 });
44 this.amoves.push(move);
c7550017 45 }
7b53b5a7 46 this.subTurn = 1;
a443d256
BA
47 // Stack "first moves" (on subTurn 1) to merge and check opposite moves
48 this.firstMove = [];
c7550017
BA
49 }
50
61656127
BA
51 static ParseFen(fen) {
52 return Object.assign(
53 ChessRules.ParseFen(fen),
93ce6119 54 { amove: fen.split(" ")[4] }
61656127
BA
55 );
56 }
57
58 static IsGoodFen(fen) {
59 if (!ChessRules.IsGoodFen(fen)) return false;
60 const fenParts = fen.split(" ");
ad1e629e
BA
61 if (fenParts.length != 5) return false;
62 if (fenParts[4] != "-") {
63 // TODO: a single regexp instead.
64 // Format is [bpa2[.wpd3]] || '-'/[bbc3[.wrd5]] || '-'
65 const amoveParts = fenParts[4].split("/");
66 if (amoveParts.length != 2) return false;
67 for (let part of amoveParts) {
68 if (part != "-") {
69 for (let psq of part.split("."))
70 if (!psq.match(/^[a-r]{3}[1-8]$/)) return false;
71 }
72 }
73 }
61656127
BA
74 return true;
75 }
76
93ce6119
BA
77 getFen() {
78 return super.getFen() + " " + this.getAmoveFen();
61656127
BA
79 }
80
93ce6119
BA
81 getFenForRepeat() {
82 return super.getFenForRepeat() + "_" + this.getAmoveFen();
83 }
84
85 getAmoveFen() {
86 const L = this.amoves.length;
7b53b5a7 87 if (L == 0) return "-";
93ce6119
BA
88 return (
89 ["appear","vanish"].map(
90 mpart => {
156986e6 91 if (this.amoves[L-1][mpart].length == 0) return "-";
93ce6119
BA
92 return (
93 this.amoves[L-1][mpart].map(
94 av => {
95 const square = V.CoordsToSquare({ x: av.x, y: av.y });
96 return av.c + av.p + square;
97 }
98 ).join(".")
99 );
100 }
101 ).join("/")
102 );
61656127
BA
103 }
104
105 canTake() {
106 // Captures don't occur (only pulls & pushes)
107 return false;
108 }
109
b2655276
BA
110 // Step is right, just add (push/pull) moves in this direction
111 // Direction is assumed normalized.
112 getMovesInDirection([x, y], [dx, dy], nbSteps) {
113 nbSteps = nbSteps || 8; //max 8 steps anyway
114 let [i, j] = [x + dx, y + dy];
61656127 115 let moves = [];
b2655276
BA
116 const color = this.getColor(x, y);
117 const piece = this.getPiece(x, y);
118 const lastRank = (color == 'w' ? 0 : 7);
7b53b5a7 119 let counter = 1;
b2655276
BA
120 while (V.OnBoard(i, j) && this.board[i][j] == V.EMPTY) {
121 if (i == lastRank && piece == V.PAWN) {
122 // Promotion by push or pull
123 V.PawnSpecs.promotions.forEach(p => {
124 let move = super.getBasicMove([x, y], [i, j], { c: color, p: p });
125 moves.push(move);
126 });
127 }
128 else moves.push(super.getBasicMove([x, y], [i, j]));
7b53b5a7
BA
129 if (++counter > nbSteps) break;
130 i += dx;
131 j += dy;
b2655276
BA
132 }
133 if (!V.OnBoard(i, j) && piece != V.KING) {
134 // Add special "exit" move, by "taking king"
135 moves.push(
136 new Move({
137 start: { x: x, y: y },
7b53b5a7 138 end: { x: this.kingPos[color][0], y: this.kingPos[color][1] },
b2655276
BA
139 appear: [],
140 vanish: [{ x: x, y: y, c: color, p: piece }]
141 })
142 );
143 }
61656127
BA
144 return moves;
145 }
146
b2655276
BA
147 // Normalize direction to know the step
148 getNormalizedDirection([dx, dy]) {
149 const absDir = [Math.abs(dx), Math.abs(dy)];
150 let divisor = 0;
151 if (absDir[0] != 0 && absDir[1] != 0 && absDir[0] != absDir[1])
152 // Knight
153 divisor = Math.min(absDir[0], absDir[1]);
154 else
155 // Standard slider (or maybe a pawn or king: same)
156 divisor = Math.max(absDir[0], absDir[1]);
157 return [dx / divisor, dy / divisor];
158 }
159
ad1e629e
BA
160 // There was something on x2,y2, maybe our color, pushed/pulled.
161 // Also, the pushed/pulled piece must exit the board.
162 isAprioriValidExit([x1, y1], [x2, y2], color2) {
b2655276 163 const color1 = this.getColor(x1, y1);
b2655276 164 const pawnShift = (color1 == 'w' ? -1 : 1);
ad1e629e 165 const lastRank = (color1 == 'w' ? 0 : 7);
b2655276
BA
166 const deltaX = Math.abs(x1 - x2);
167 const deltaY = Math.abs(y1 - y2);
ad1e629e
BA
168 const checkSlider = () => {
169 const dir = this.getNormalizedDirection([x2 - x1, y2 - y1]);
170 let [i, j] = [x1 + dir[0], y1 + dir[1]];
171 while (V.OnBoard(i, j) && this.board[i][j] == V.EMPTY) {
172 i += dir[0];
173 j += dir[1];
174 }
175 return !V.OnBoard(i, j);
176 };
b2655276
BA
177 switch (this.getPiece(x1, y1)) {
178 case V.PAWN:
179 return (
ad1e629e 180 x1 + pawnShift == x2 &&
b2655276 181 (
ad1e629e
BA
182 (color1 == color2 && x2 == lastRank && y1 == y2) ||
183 (color1 != color2 && deltaY == 1 && !V.OnBoard(x2, 2 * y2 - y1))
b2655276
BA
184 )
185 );
186 case V.ROOK:
ad1e629e
BA
187 if (x1 != x2 && y1 != y2) return false;
188 return checkSlider();
189 case V.KNIGHT:
190 return (
191 deltaX + deltaY == 3 &&
192 (deltaX == 1 || deltaY == 1) &&
193 !V.OnBoard(2 * x2 - x1, 2 * y2 - y1)
194 );
b2655276 195 case V.BISHOP:
ad1e629e
BA
196 if (deltaX != deltaY) return false;
197 return checkSlider();
b2655276 198 case V.QUEEN:
ad1e629e
BA
199 if (deltaX != 0 && deltaY != 0 && deltaX != deltaY) return false;
200 return checkSlider();
201 case V.KING:
b2655276 202 return (
ad1e629e
BA
203 deltaX <= 1 &&
204 deltaY <= 1 &&
205 !V.OnBoard(2 * x2 - x1, 2 * y2 - y1)
b2655276 206 );
93ce6119 207 }
b2655276 208 return false;
b866a62a
BA
209 }
210
93ce6119 211 // NOTE: for pushes, play the pushed piece first.
61656127 212 // for pulls: play the piece doing the action first
b2655276 213 // NOTE: to push a piece out of the board, make it slide until its king
b866a62a
BA
214 getPotentialMovesFrom([x, y]) {
215 const color = this.turn;
93ce6119 216 if (this.subTurn == 1) {
b2655276
BA
217 const getMoveHash = (m) => {
218 return V.CoordsToSquare(m.start) + V.CoordsToSquare(m.end);
219 };
220 const addMoves = (dir, nbSteps) => {
221 const newMoves =
222 this.getMovesInDirection([x, y], [-dir[0], -dir[1]], nbSteps)
223 .filter(m => !movesHash[getMoveHash(m)]);
7b53b5a7 224 newMoves.forEach(m => { movesHash[getMoveHash(m)] = true; });
b2655276
BA
225 Array.prototype.push.apply(moves, newMoves);
226 };
8c267d0c
BA
227 // Free to play any move (if piece of my color):
228 const moves =
229 this.getColor(x, y) == color
230 ? super.getPotentialMovesFrom([x, y])
231 : [];
b2655276
BA
232 const pawnShift = (color == 'w' ? -1 : 1);
233 const pawnStartRank = (color == 'w' ? 6 : 1);
7b53b5a7
BA
234 // Structure to avoid adding moves twice (can be action & move)
235 let movesHash = {};
236 moves.forEach(m => { movesHash[getMoveHash(m)] = true; });
b2655276
BA
237 // [x, y] is pushed by 'color'
238 for (let step of V.steps[V.KNIGHT]) {
239 const [i, j] = [x + step[0], y + step[1]];
7b53b5a7
BA
240 if (
241 V.OnBoard(i, j) &&
242 this.board[i][j] != V.EMPTY &&
243 this.getColor(i, j) == color &&
244 this.getPiece(i, j) == V.KNIGHT
245 ) {
246 addMoves(step, 1);
b2655276
BA
247 }
248 }
7b53b5a7 249 for (let step of V.steps[V.ROOK].concat(V.steps[V.BISHOP])) {
b2655276
BA
250 let [i, j] = [x + step[0], y + step[1]];
251 while (V.OnBoard(i, j) && this.board[i][j] == V.EMPTY) {
252 i += step[0];
253 j += step[1];
254 }
255 if (
256 V.OnBoard(i, j) &&
257 this.board[i][j] != V.EMPTY &&
258 this.getColor(i, j) == color
259 ) {
260 const deltaX = Math.abs(i - x);
261 const deltaY = Math.abs(j - y);
262 // Can a priori go both ways, except with pawns
263 switch (this.getPiece(i, j)) {
264 case V.PAWN:
ad1e629e
BA
265 if (
266 (x - i) / deltaX == pawnShift &&
267 deltaX <= 2 &&
268 deltaY <= 1
269 ) {
b2655276
BA
270 const pColor = this.getColor(x, y);
271 if (pColor == color && deltaY == 0) {
272 // Pushed forward
273 const maxSteps = (i == pawnStartRank && deltaX == 1 ? 2 : 1);
274 addMoves(step, maxSteps);
275 }
276 else if (pColor != color && deltaY == 1 && deltaX == 1)
277 // Pushed diagonally
278 addMoves(step, 1);
279 }
280 break;
281 case V.ROOK:
282 if (deltaX == 0 || deltaY == 0) addMoves(step);
283 break;
b2655276
BA
284 case V.BISHOP:
285 if (deltaX == deltaY) addMoves(step);
286 break;
287 case V.QUEEN:
288 if (deltaX == 0 || deltaY == 0 || deltaX == deltaY)
289 addMoves(step);
290 break;
291 case V.KING:
292 if (deltaX <= 1 && deltaY <= 1) addMoves(step, 1);
293 break;
294 }
295 }
296 }
297 return moves;
b866a62a 298 }
93ce6119 299 // If subTurn == 2 then we should have a first move,
b2655276
BA
300 // which restrict what we can play now: only in the first move direction
301 // NOTE: no need for knight or pawn checks, because the move will be
302 // naturally limited in those cases.
93ce6119
BA
303 const L = this.firstMove.length;
304 const fm = this.firstMove[L-1];
b2655276
BA
305 if (fm.appear.length == 2 && fm.vanish.length == 2)
306 // Castle: no real move playable then.
307 return [];
308 if (fm.appear.length == 0) {
309 // Piece at subTurn 1 just exited the board.
310 // Can I be a piece which caused the exit?
ad1e629e
BA
311 if (
312 this.isAprioriValidExit(
313 [x, y],
314 [fm.start.x, fm.start.y],
315 fm.vanish[0].c
316 )
317 ) {
b2655276
BA
318 // Seems so:
319 const dir = this.getNormalizedDirection(
320 [fm.start.x - x, fm.start.y - y]);
321 return this.getMovesInDirection([x, y], dir);
322 }
93ce6119
BA
323 }
324 else {
b2655276
BA
325 const dirM = this.getNormalizedDirection(
326 [fm.end.x - fm.start.x, fm.end.y - fm.start.y]);
327 const dir = this.getNormalizedDirection(
328 [fm.start.x - x, fm.start.y - y]);
ad1e629e
BA
329 // Normalized directions should match
330 if (dir[0] == dirM[0] && dir[1] == dirM[1]) {
331 // And nothing should stand between [x, y] and the square fm.start
332 let [i, j] = [x + dir[0], y + dir[1]];
333 while (
334 (i != fm.start.x || j != fm.start.y) &&
335 this.board[i][j] == V.EMPTY
336 ) {
337 i += dir[0];
338 j += dir[1];
339 }
340 if (i == fm.start.x && j == fm.start.y)
341 return this.getMovesInDirection([x, y], dir);
342 }
93ce6119 343 }
b2655276 344 return [];
61656127
BA
345 }
346
347 // Does m2 un-do m1 ? (to disallow undoing actions)
348 oppositeMoves(m1, m2) {
349 const isEqual = (av1, av2) => {
350 // Precondition: av1 and av2 length = 2
351 for (let av of av1) {
352 const avInAv2 = av2.find(elt => {
353 return (
354 elt.x == av.x &&
355 elt.y == av.y &&
356 elt.c == av.c &&
357 elt.p == av.p
358 );
359 });
360 if (!avInAv2) return false;
361 }
362 return true;
363 };
364 return (
61656127
BA
365 m1.appear.length == 2 &&
366 m2.appear.length == 2 &&
367 m1.vanish.length == 2 &&
368 m2.vanish.length == 2 &&
369 isEqual(m1.appear, m2.vanish) &&
370 isEqual(m1.vanish, m2.appear)
371 );
372 }
373
93ce6119
BA
374 getAmove(move1, move2) {
375 // Just merge (one is action one is move, one may be empty)
376 return {
377 appear: move1.appear.concat(move2.appear),
378 vanish: move1.vanish.concat(move2.vanish)
379 }
380 }
381
61656127 382 filterValid(moves) {
93ce6119
BA
383 const color = this.turn;
384 if (this.subTurn == 1) {
385 return moves.filter(m => {
386 // A move is valid either if it doesn't result in a check,
387 // or if a second move is possible to counter the check
388 // (not undoing a potential move + action of the opponent)
389 this.play(m);
390 let res = this.underCheck(color);
391 if (res) {
392 const moves2 = this.getAllPotentialMoves();
ad1e629e 393 for (let m2 of moves2) {
93ce6119
BA
394 this.play(m2);
395 const res2 = this.underCheck(color);
396 this.undo(m2);
397 if (!res2) {
398 res = false;
399 break;
400 }
401 }
402 }
403 this.undo(m);
404 return !res;
405 });
406 }
407 const Lf = this.firstMove.length;
408 const La = this.amoves.length;
409 if (La == 0) return super.filterValid(moves);
a443d256 410 return (
93ce6119 411 super.filterValid(
a443d256
BA
412 moves.filter(m => {
413 // Move shouldn't undo another:
93ce6119
BA
414 const amove = this.getAmove(this.firstMove[Lf-1], m);
415 return !this.oppositeMoves(this.amoves[La-1], amove);
a443d256
BA
416 })
417 )
418 );
b866a62a
BA
419 }
420
c7550017
BA
421 isAttackedBySlideNJump([x, y], color, piece, steps, oneStep) {
422 for (let step of steps) {
423 let rx = x + step[0],
424 ry = y + step[1];
425 while (V.OnBoard(rx, ry) && this.board[rx][ry] == V.EMPTY && !oneStep) {
426 rx += step[0];
427 ry += step[1];
428 }
429 if (
430 V.OnBoard(rx, ry) &&
431 this.getPiece(rx, ry) == piece &&
432 this.getColor(rx, ry) == color
433 ) {
8c267d0c
BA
434 // Continue some steps in the same direction (pull)
435 rx += step[0];
436 ry += step[1];
437 while (
438 V.OnBoard(rx, ry) &&
439 this.board[rx][ry] == V.EMPTY &&
440 !oneStep
441 ) {
442 rx += step[0];
443 ry += step[1];
444 }
445 if (!V.OnBoard(rx, ry)) return true;
446 // Step in the other direction (push)
c7550017
BA
447 rx = x - step[0];
448 ry = y - step[1];
2c5d7b20
BA
449 while (
450 V.OnBoard(rx, ry) &&
451 this.board[rx][ry] == V.EMPTY &&
452 !oneStep
453 ) {
c7550017
BA
454 rx -= step[0];
455 ry -= step[1];
456 }
457 if (!V.OnBoard(rx, ry)) return true;
458 }
459 }
460 return false;
461 }
462
463 isAttackedByPawn([x, y], color) {
464 const lastRank = (color == 'w' ? 0 : 7);
ad1e629e 465 if (x != lastRank)
c7550017
BA
466 // The king can be pushed out by a pawn only on last rank
467 return false;
468 const pawnShift = (color == "w" ? 1 : -1);
469 for (let i of [-1, 1]) {
470 if (
471 y + i >= 0 &&
472 y + i < V.size.y &&
473 this.getPiece(x + pawnShift, y + i) == V.PAWN &&
474 this.getColor(x + pawnShift, y + i) == color
475 ) {
476 return true;
477 }
478 }
479 return false;
480 }
61656127 481
156986e6
BA
482 // No consideration of color: all pieces could be played
483 getAllPotentialMoves() {
484 let potentialMoves = [];
485 for (let i = 0; i < V.size.x; i++) {
486 for (let j = 0; j < V.size.y; j++) {
487 if (this.board[i][j] != V.EMPTY) {
488 Array.prototype.push.apply(
489 potentialMoves,
490 this.getPotentialMovesFrom([i, j])
491 );
492 }
493 }
494 }
495 return potentialMoves;
496 }
497
61656127
BA
498 getCurrentScore() {
499 if (this.subTurn == 2)
500 // Move not over
501 return "*";
502 return super.getCurrentScore();
503 }
504
93ce6119 505 doClick(square) {
b2655276
BA
506 // If subTurn == 2 && square is empty && !underCheck,
507 // then return an empty move, allowing to "pass" subTurn2
93ce6119
BA
508 if (
509 this.subTurn == 2 &&
7b53b5a7 510 this.board[square[0]][square[1]] == V.EMPTY &&
b2655276 511 !this.underCheck(this.turn)
93ce6119
BA
512 ) {
513 return {
7b53b5a7
BA
514 start: { x: -1, y: -1 },
515 end: { x: -1, y: -1 },
93ce6119
BA
516 appear: [],
517 vanish: []
518 };
519 }
520 return null;
521 }
522
61656127
BA
523 play(move) {
524 move.flags = JSON.stringify(this.aggregateFlags());
525 V.PlayOnBoard(this.board, move);
7ddfec38 526 if (this.subTurn == 2) {
7b53b5a7
BA
527 const L = this.firstMove.length;
528 this.amoves.push(this.getAmove(this.firstMove[L-1], move));
61656127 529 this.turn = V.GetOppCol(this.turn);
7ddfec38 530 this.movesCount++;
61656127 531 }
a443d256 532 else this.firstMove.push(move);
7ddfec38 533 this.subTurn = 3 - this.subTurn;
61656127
BA
534 this.postPlay(move);
535 }
536
7b53b5a7
BA
537 postPlay(move) {
538 if (move.start.x < 0) return;
539 for (let a of move.appear)
540 if (a.p == V.KING) this.kingPos[a.c] = [a.x, a.y];
541 this.updateCastleFlags(move);
542 }
543
544 updateCastleFlags(move) {
545 const firstRank = { 'w': V.size.x - 1, 'b': 0 };
7ddfec38 546 for (let v of move.vanish) {
7b53b5a7
BA
547 if (v.p == V.KING) this.castleFlags[v.c] = [V.size.y, V.size.y];
548 else if (v.x == firstRank[v.c] && this.castleFlags[v.c].includes(v.y)) {
549 const flagIdx = (v.y == this.castleFlags[v.c][0] ? 0 : 1);
550 this.castleFlags[v.c][flagIdx] = V.size.y;
7ddfec38 551 }
61656127
BA
552 }
553 }
554
555 undo(move) {
556 this.disaggregateFlags(JSON.parse(move.flags));
557 V.UndoOnBoard(this.board, move);
7ddfec38 558 if (this.subTurn == 1) {
61656127 559 this.turn = V.GetOppCol(this.turn);
7ddfec38 560 this.movesCount--;
61656127 561 }
a443d256 562 else this.firstMove.pop();
7ddfec38 563 this.subTurn = 3 - this.subTurn;
61656127
BA
564 this.postUndo(move);
565 }
7b53b5a7
BA
566
567 postUndo(move) {
568 // (Potentially) Reset king position
569 for (let v of move.vanish)
570 if (v.p == V.KING) this.kingPos[v.c] = [v.x, v.y];
571 }
572
ad1e629e
BA
573 getComputerMove() {
574 let moves = this.getAllValidMoves();
575 if (moves.length == 0) return null;
576 // "Search" at depth 1 for now
577 const maxeval = V.INFINITY;
578 const color = this.turn;
579 const emptyMove = {
580 start: { x: -1, y: -1 },
581 end: { x: -1, y: -1 },
582 appear: [],
583 vanish: []
584 };
585 moves.forEach(m => {
586 this.play(m);
587 m.eval = (color == "w" ? -1 : 1) * maxeval;
588 const moves2 = this.getAllValidMoves().concat([emptyMove]);
589 m.next = moves2[0];
590 moves2.forEach(m2 => {
591 this.play(m2);
592 const score = this.getCurrentScore();
593 let mvEval = 0;
594 if (score != "1/2") {
595 if (score != "*") mvEval = (score == "1-0" ? 1 : -1) * maxeval;
596 else mvEval = this.evalPosition();
597 }
598 if (
599 (color == 'w' && mvEval > m.eval) ||
600 (color == 'b' && mvEval < m.eval)
601 ) {
602 m.eval = mvEval;
603 m.next = m2;
604 }
605 this.undo(m2);
606 });
607 this.undo(m);
608 });
609 moves.sort((a, b) => {
610 return (color == "w" ? 1 : -1) * (b.eval - a.eval);
611 });
612 let candidates = [0];
613 for (let i = 1; i < moves.length && moves[i].eval == moves[0].eval; i++)
614 candidates.push(i);
615 const mIdx = candidates[randInt(candidates.length)];
616 const move2 = moves[mIdx].next;
617 delete moves[mIdx]["next"];
618 return [moves[mIdx], move2];
619 }
620
7b53b5a7
BA
621 getNotation(move) {
622 if (move.start.x < 0)
623 // A second move is always required, but may be empty
624 return "-";
625 const initialSquare = V.CoordsToSquare(move.start);
626 const finalSquare = V.CoordsToSquare(move.end);
627 if (move.appear.length == 0)
628 // Pushed or pulled out of the board
629 return initialSquare + "R";
630 return move.appear[0].p.toUpperCase() + initialSquare + finalSquare;
631 }
0d5335de 632};