f4a96ce17256d3d42be225f5ec46944f28622fc8
[vchess.git] / client / src / variants / Grand.js
1 import { ChessRules } from "@/base_rules";
2 import { ArrayFun } from "@/utils/array";
3 import { randInt } from "@/utils/alea";
4
5 // NOTE: initial setup differs from the original; see
6 // https://www.chessvariants.com/large.dir/freeling.html
7 export class GrandRules extends ChessRules {
8 static IsGoodFen(fen) {
9 if (!ChessRules.IsGoodFen(fen)) return false;
10 const fenParsed = V.ParseFen(fen);
11 // 5) Check captures
12 if (!fenParsed.captured || !fenParsed.captured.match(/^[0-9]{14,14}$/))
13 return false;
14 return true;
15 }
16
17 static IsGoodEnpassant(enpassant) {
18 if (enpassant != "-") {
19 const squares = enpassant.split(",");
20 if (squares.length > 2) return false;
21 for (let sq of squares) {
22 const ep = V.SquareToCoords(sq);
23 if (isNaN(ep.x) || !V.OnBoard(ep)) return false;
24 }
25 }
26 return true;
27 }
28
29 static ParseFen(fen) {
30 const fenParts = fen.split(" ");
31 return Object.assign(ChessRules.ParseFen(fen), { captured: fenParts[5] });
32 }
33
34 getPpath(b) {
35 return ([V.MARSHALL, V.CARDINAL].includes(b[1]) ? "Grand/" : "") + b;
36 }
37
38 getFen() {
39 return super.getFen() + " " + this.getCapturedFen();
40 }
41
42 getFenForRepeat() {
43 return super.getFenForRepeat() + "_" + this.getCapturedFen();
44 }
45
46 getCapturedFen() {
47 let counts = [...Array(14).fill(0)];
48 let i = 0;
49 for (let j = 0; j < V.PIECES.length; j++) {
50 if (V.PIECES[j] == V.KING)
51 //no king captured
52 continue;
53 counts[i] = this.captured["w"][V.PIECES[i]];
54 counts[7 + i] = this.captured["b"][V.PIECES[i]];
55 i++;
56 }
57 return counts.join("");
58 }
59
60 setOtherVariables(fen) {
61 super.setOtherVariables(fen);
62 const fenParsed = V.ParseFen(fen);
63 // Initialize captured pieces' counts from FEN
64 this.captured = {
65 w: {
66 [V.PAWN]: parseInt(fenParsed.captured[0]),
67 [V.ROOK]: parseInt(fenParsed.captured[1]),
68 [V.KNIGHT]: parseInt(fenParsed.captured[2]),
69 [V.BISHOP]: parseInt(fenParsed.captured[3]),
70 [V.QUEEN]: parseInt(fenParsed.captured[4]),
71 [V.MARSHALL]: parseInt(fenParsed.captured[5]),
72 [V.CARDINAL]: parseInt(fenParsed.captured[6])
73 },
74 b: {
75 [V.PAWN]: parseInt(fenParsed.captured[7]),
76 [V.ROOK]: parseInt(fenParsed.captured[8]),
77 [V.KNIGHT]: parseInt(fenParsed.captured[9]),
78 [V.BISHOP]: parseInt(fenParsed.captured[10]),
79 [V.QUEEN]: parseInt(fenParsed.captured[11]),
80 [V.MARSHALL]: parseInt(fenParsed.captured[12]),
81 [V.CARDINAL]: parseInt(fenParsed.captured[13])
82 }
83 };
84 }
85
86 static get size() {
87 return { x: 10, y: 10 };
88 }
89
90 // Rook + knight:
91 static get MARSHALL() {
92 return "m";
93 }
94
95 // Bishop + knight
96 static get CARDINAL() {
97 return "c";
98 }
99
100 static get PIECES() {
101 return ChessRules.PIECES.concat([V.MARSHALL, V.CARDINAL]);
102 }
103
104 // There may be 2 enPassant squares (if pawn jump 3 squares)
105 getEnpassantFen() {
106 const L = this.epSquares.length;
107 if (!this.epSquares[L - 1]) return "-"; //no en-passant
108 let res = "";
109 this.epSquares[L - 1].forEach(sq => {
110 res += V.CoordsToSquare(sq) + ",";
111 });
112 return res.slice(0, -1); //remove last comma
113 }
114
115 // En-passant after 2-sq or 3-sq jumps
116 getEpSquare(moveOrSquare) {
117 if (!moveOrSquare) return undefined;
118 if (typeof moveOrSquare === "string") {
119 const square = moveOrSquare;
120 if (square == "-") return undefined;
121 let res = [];
122 square.split(",").forEach(sq => {
123 res.push(V.SquareToCoords(sq));
124 });
125 return res;
126 }
127 // Argument is a move:
128 const move = moveOrSquare;
129 const [sx, sy, ex] = [move.start.x, move.start.y, move.end.x];
130 if (this.getPiece(sx, sy) == V.PAWN && Math.abs(sx - ex) >= 2) {
131 const step = (ex - sx) / Math.abs(ex - sx);
132 let res = [
133 {
134 x: sx + step,
135 y: sy
136 }
137 ];
138 if (sx + 2 * step != ex) {
139 //3-squares move
140 res.push({
141 x: sx + 2 * step,
142 y: sy
143 });
144 }
145 return res;
146 }
147 return undefined; //default
148 }
149
150 getPotentialMovesFrom([x, y]) {
151 switch (this.getPiece(x, y)) {
152 case V.MARSHALL:
153 return this.getPotentialMarshallMoves([x, y]);
154 case V.CARDINAL:
155 return this.getPotentialCardinalMoves([x, y]);
156 default:
157 return super.getPotentialMovesFrom([x, y]);
158 }
159 }
160
161 // Special pawn rules: promotions to captured friendly pieces,
162 // optional on ranks 8-9 and mandatory on rank 10.
163 getPotentialPawnMoves([x, y]) {
164 const color = this.turn;
165 let moves = [];
166 const [sizeX, sizeY] = [V.size.x, V.size.y];
167 const shiftX = color == "w" ? -1 : 1;
168 const startRanks = color == "w" ? [sizeX - 2, sizeX - 3] : [1, 2];
169 const lastRanks =
170 color == "w" ? [0, 1, 2] : [sizeX - 1, sizeX - 2, sizeX - 3];
171 const promotionPieces = [
172 V.ROOK,
173 V.KNIGHT,
174 V.BISHOP,
175 V.QUEEN,
176 V.MARSHALL,
177 V.CARDINAL
178 ];
179
180 // Always x+shiftX >= 0 && x+shiftX < sizeX, because no pawns on last rank
181 let finalPieces = undefined;
182 if (lastRanks.includes(x + shiftX)) {
183 finalPieces = promotionPieces.filter(p => this.captured[color][p] > 0);
184 if (x + shiftX != lastRanks[0]) finalPieces.push(V.PAWN);
185 } else finalPieces = [V.PAWN];
186 if (this.board[x + shiftX][y] == V.EMPTY) {
187 // One square forward
188 for (let piece of finalPieces)
189 moves.push(
190 this.getBasicMove([x, y], [x + shiftX, y], { c: color, p: piece })
191 );
192 if (startRanks.includes(x)) {
193 if (this.board[x + 2 * shiftX][y] == V.EMPTY) {
194 // Two squares jump
195 moves.push(this.getBasicMove([x, y], [x + 2 * shiftX, y]));
196 if (x == startRanks[0] && this.board[x + 3 * shiftX][y] == V.EMPTY) {
197 // Three squares jump
198 moves.push(this.getBasicMove([x, y], [x + 3 * shiftX, y]));
199 }
200 }
201 }
202 }
203 // Captures
204 for (let shiftY of [-1, 1]) {
205 if (
206 y + shiftY >= 0 &&
207 y + shiftY < sizeY &&
208 this.board[x + shiftX][y + shiftY] != V.EMPTY &&
209 this.canTake([x, y], [x + shiftX, y + shiftY])
210 ) {
211 for (let piece of finalPieces) {
212 moves.push(
213 this.getBasicMove([x, y], [x + shiftX, y + shiftY], {
214 c: color,
215 p: piece
216 })
217 );
218 }
219 }
220 }
221
222 // En passant
223 const Lep = this.epSquares.length;
224 const epSquare = this.epSquares[Lep - 1];
225 if (epSquare) {
226 for (let epsq of epSquare) {
227 // TODO: some redundant checks
228 if (epsq.x == x + shiftX && Math.abs(epsq.y - y) == 1) {
229 let enpassantMove = this.getBasicMove([x, y], [epsq.x, epsq.y]);
230 // WARNING: the captured pawn may be diagonally behind us,
231 // if it's a 3-squares jump and we take on 1st passing square
232 const px = this.board[x][epsq.y] != V.EMPTY ? x : x - shiftX;
233 enpassantMove.vanish.push({
234 x: px,
235 y: epsq.y,
236 p: "p",
237 c: this.getColor(px, epsq.y)
238 });
239 moves.push(enpassantMove);
240 }
241 }
242 }
243
244 return moves;
245 }
246
247 // TODO: different castle?
248
249 getPotentialMarshallMoves(sq) {
250 return this.getSlideNJumpMoves(sq, V.steps[V.ROOK]).concat(
251 this.getSlideNJumpMoves(sq, V.steps[V.KNIGHT], "oneStep")
252 );
253 }
254
255 getPotentialCardinalMoves(sq) {
256 return this.getSlideNJumpMoves(sq, V.steps[V.BISHOP]).concat(
257 this.getSlideNJumpMoves(sq, V.steps[V.KNIGHT], "oneStep")
258 );
259 }
260
261 isAttacked(sq, color) {
262 return (
263 super.isAttacked(sq, color) ||
264 this.isAttackedByMarshall(sq, color) ||
265 this.isAttackedByCardinal(sq, color)
266 );
267 }
268
269 isAttackedByMarshall(sq, color) {
270 return (
271 this.isAttackedBySlideNJump(sq, color, V.MARSHALL, V.steps[V.ROOK]) ||
272 this.isAttackedBySlideNJump(
273 sq,
274 color,
275 V.MARSHALL,
276 V.steps[V.KNIGHT],
277 "oneStep"
278 )
279 );
280 }
281
282 isAttackedByCardinal(sq, color) {
283 return (
284 this.isAttackedBySlideNJump(sq, color, V.CARDINAL, V.steps[V.BISHOP]) ||
285 this.isAttackedBySlideNJump(
286 sq,
287 color,
288 V.CARDINAL,
289 V.steps[V.KNIGHT],
290 "oneStep"
291 )
292 );
293 }
294
295 postPlay(move) {
296 super.postPlay(move);
297 if (move.vanish.length == 2 && move.appear.length == 1) {
298 // Capture: update this.captured
299 this.captured[move.vanish[1].c][move.vanish[1].p]++;
300 }
301 if (move.vanish[0].p != move.appear[0].p) {
302 // Promotion: update this.captured
303 this.captured[move.vanish[0].c][move.appear[0].p]--;
304 }
305 }
306
307 postUndo(move) {
308 super.postUndo(move);
309 if (move.vanish.length == 2 && move.appear.length == 1)
310 this.captured[move.vanish[1].c][move.vanish[1].p]--;
311 if (move.vanish[0].p != move.appear[0].p)
312 this.captured[move.vanish[0].c][move.appear[0].p]++;
313 }
314
315 static get VALUES() {
316 return Object.assign(
317 { c: 5, m: 7 }, //experimental
318 ChessRules.VALUES
319 );
320 }
321
322 static get SEARCH_DEPTH() {
323 return 2;
324 }
325
326 static GenRandInitFen(randomness) {
327 if (randomness == 0) {
328 // No castling in the official initial setup
329 return "r8r/1nbqkmcbn1/pppppppppp/10/10/10/10/PPPPPPPPPP/1NBQKMCBN1/R8R " +
330 "w 0 zzzz - 00000000000000";
331 }
332
333 let pieces = { w: new Array(10), b: new Array(10) };
334 // Shuffle pieces on first and last rank
335 for (let c of ["w", "b"]) {
336 if (c == 'b' && randomness == 1) {
337 pieces['b'] = pieces['w'];
338 break;
339 }
340
341 let positions = ArrayFun.range(10);
342
343 // Get random squares for bishops
344 let randIndex = 2 * randInt(5);
345 let bishop1Pos = positions[randIndex];
346 // The second bishop must be on a square of different color
347 let randIndex_tmp = 2 * randInt(5) + 1;
348 let bishop2Pos = positions[randIndex_tmp];
349 // Remove chosen squares
350 positions.splice(Math.max(randIndex, randIndex_tmp), 1);
351 positions.splice(Math.min(randIndex, randIndex_tmp), 1);
352
353 // Get random squares for knights
354 randIndex = randInt(8);
355 let knight1Pos = positions[randIndex];
356 positions.splice(randIndex, 1);
357 randIndex = randInt(7);
358 let knight2Pos = positions[randIndex];
359 positions.splice(randIndex, 1);
360
361 // Get random square for queen
362 randIndex = randInt(6);
363 let queenPos = positions[randIndex];
364 positions.splice(randIndex, 1);
365
366 // ...random square for marshall
367 randIndex = randInt(5);
368 let marshallPos = positions[randIndex];
369 positions.splice(randIndex, 1);
370
371 // ...random square for cardinal
372 randIndex = randInt(4);
373 let cardinalPos = positions[randIndex];
374 positions.splice(randIndex, 1);
375
376 // Rooks and king positions are now fixed, because of the ordering rook-king-rook
377 let rook1Pos = positions[0];
378 let kingPos = positions[1];
379 let rook2Pos = positions[2];
380
381 // Finally put the shuffled pieces in the board array
382 pieces[c][rook1Pos] = "r";
383 pieces[c][knight1Pos] = "n";
384 pieces[c][bishop1Pos] = "b";
385 pieces[c][queenPos] = "q";
386 pieces[c][marshallPos] = "m";
387 pieces[c][cardinalPos] = "c";
388 pieces[c][kingPos] = "k";
389 pieces[c][bishop2Pos] = "b";
390 pieces[c][knight2Pos] = "n";
391 pieces[c][rook2Pos] = "r";
392 }
393 return (
394 pieces["b"].join("") +
395 "/pppppppppp/10/10/10/10/10/10/PPPPPPPPPP/" +
396 pieces["w"].join("").toUpperCase() +
397 " w 0 1111 - 00000000000000"
398 );
399 }
400 };