Almost debugged Eightpieces variant
[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 const VariantRules = 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 static get MARSHALL() {
91 return "m";
92 } //rook+knight
93 static get CARDINAL() {
94 return "c";
95 } //bishop+knight
96
97 static get PIECES() {
98 return ChessRules.PIECES.concat([V.MARSHALL, V.CARDINAL]);
99 }
100
101 // There may be 2 enPassant squares (if pawn jump 3 squares)
102 getEnpassantFen() {
103 const L = this.epSquares.length;
104 if (!this.epSquares[L - 1]) return "-"; //no en-passant
105 let res = "";
106 this.epSquares[L - 1].forEach(sq => {
107 res += V.CoordsToSquare(sq) + ",";
108 });
109 return res.slice(0, -1); //remove last comma
110 }
111
112 // En-passant after 2-sq or 3-sq jumps
113 getEpSquare(moveOrSquare) {
114 if (!moveOrSquare) return undefined;
115 if (typeof moveOrSquare === "string") {
116 const square = moveOrSquare;
117 if (square == "-") return undefined;
118 let res = [];
119 square.split(",").forEach(sq => {
120 res.push(V.SquareToCoords(sq));
121 });
122 return res;
123 }
124 // Argument is a move:
125 const move = moveOrSquare;
126 const [sx, sy, ex] = [move.start.x, move.start.y, move.end.x];
127 if (this.getPiece(sx, sy) == V.PAWN && Math.abs(sx - ex) >= 2) {
128 const step = (ex - sx) / Math.abs(ex - sx);
129 let res = [
130 {
131 x: sx + step,
132 y: sy
133 }
134 ];
135 if (sx + 2 * step != ex) {
136 //3-squares move
137 res.push({
138 x: sx + 2 * step,
139 y: sy
140 });
141 }
142 return res;
143 }
144 return undefined; //default
145 }
146
147 getPotentialMovesFrom([x, y]) {
148 switch (this.getPiece(x, y)) {
149 case V.MARSHALL:
150 return this.getPotentialMarshallMoves([x, y]);
151 case V.CARDINAL:
152 return this.getPotentialCardinalMoves([x, y]);
153 default:
154 return super.getPotentialMovesFrom([x, y]);
155 }
156 }
157
158 // Special pawn rules: promotions to captured friendly pieces,
159 // optional on ranks 8-9 and mandatory on rank 10.
160 getPotentialPawnMoves([x, y]) {
161 const color = this.turn;
162 let moves = [];
163 const [sizeX, sizeY] = [V.size.x, V.size.y];
164 const shiftX = color == "w" ? -1 : 1;
165 const startRanks = color == "w" ? [sizeX - 2, sizeX - 3] : [1, 2];
166 const lastRanks =
167 color == "w" ? [0, 1, 2] : [sizeX - 1, sizeX - 2, sizeX - 3];
168 const promotionPieces = [
169 V.ROOK,
170 V.KNIGHT,
171 V.BISHOP,
172 V.QUEEN,
173 V.MARSHALL,
174 V.CARDINAL
175 ];
176
177 // Always x+shiftX >= 0 && x+shiftX < sizeX, because no pawns on last rank
178 let finalPieces = undefined;
179 if (lastRanks.includes(x + shiftX)) {
180 finalPieces = promotionPieces.filter(p => this.captured[color][p] > 0);
181 if (x + shiftX != lastRanks[0]) finalPieces.push(V.PAWN);
182 } else finalPieces = [V.PAWN];
183 if (this.board[x + shiftX][y] == V.EMPTY) {
184 // One square forward
185 for (let piece of finalPieces)
186 moves.push(
187 this.getBasicMove([x, y], [x + shiftX, y], { c: color, p: piece })
188 );
189 if (startRanks.includes(x)) {
190 if (this.board[x + 2 * shiftX][y] == V.EMPTY) {
191 // Two squares jump
192 moves.push(this.getBasicMove([x, y], [x + 2 * shiftX, y]));
193 if (x == startRanks[0] && this.board[x + 3 * shiftX][y] == V.EMPTY) {
194 // Three squares jump
195 moves.push(this.getBasicMove([x, y], [x + 3 * shiftX, y]));
196 }
197 }
198 }
199 }
200 // Captures
201 for (let shiftY of [-1, 1]) {
202 if (
203 y + shiftY >= 0 &&
204 y + shiftY < sizeY &&
205 this.board[x + shiftX][y + shiftY] != V.EMPTY &&
206 this.canTake([x, y], [x + shiftX, y + shiftY])
207 ) {
208 for (let piece of finalPieces) {
209 moves.push(
210 this.getBasicMove([x, y], [x + shiftX, y + shiftY], {
211 c: color,
212 p: piece
213 })
214 );
215 }
216 }
217 }
218
219 // En passant
220 const Lep = this.epSquares.length;
221 const epSquare = this.epSquares[Lep - 1];
222 if (epSquare) {
223 for (let epsq of epSquare) {
224 // TODO: some redundant checks
225 if (epsq.x == x + shiftX && Math.abs(epsq.y - y) == 1) {
226 var enpassantMove = this.getBasicMove([x, y], [epsq.x, epsq.y]);
227 // WARNING: the captured pawn may be diagonally behind us,
228 // if it's a 3-squares jump and we take on 1st passing square
229 const px = this.board[x][epsq.y] != V.EMPTY ? x : x - shiftX;
230 enpassantMove.vanish.push({
231 x: px,
232 y: epsq.y,
233 p: "p",
234 c: this.getColor(px, epsq.y)
235 });
236 moves.push(enpassantMove);
237 }
238 }
239 }
240
241 return moves;
242 }
243
244 // TODO: different castle?
245
246 getPotentialMarshallMoves(sq) {
247 return this.getSlideNJumpMoves(sq, V.steps[V.ROOK]).concat(
248 this.getSlideNJumpMoves(sq, V.steps[V.KNIGHT], "oneStep")
249 );
250 }
251
252 getPotentialCardinalMoves(sq) {
253 return this.getSlideNJumpMoves(sq, V.steps[V.BISHOP]).concat(
254 this.getSlideNJumpMoves(sq, V.steps[V.KNIGHT], "oneStep")
255 );
256 }
257
258 isAttacked(sq, colors) {
259 return (
260 super.isAttacked(sq, colors) ||
261 this.isAttackedByMarshall(sq, colors) ||
262 this.isAttackedByCardinal(sq, colors)
263 );
264 }
265
266 isAttackedByMarshall(sq, colors) {
267 return (
268 this.isAttackedBySlideNJump(sq, colors, V.MARSHALL, V.steps[V.ROOK]) ||
269 this.isAttackedBySlideNJump(
270 sq,
271 colors,
272 V.MARSHALL,
273 V.steps[V.KNIGHT],
274 "oneStep"
275 )
276 );
277 }
278
279 isAttackedByCardinal(sq, colors) {
280 return (
281 this.isAttackedBySlideNJump(sq, colors, V.CARDINAL, V.steps[V.BISHOP]) ||
282 this.isAttackedBySlideNJump(
283 sq,
284 colors,
285 V.CARDINAL,
286 V.steps[V.KNIGHT],
287 "oneStep"
288 )
289 );
290 }
291
292 updateVariables(move) {
293 super.updateVariables(move);
294 if (move.vanish.length == 2 && move.appear.length == 1) {
295 // Capture: update this.captured
296 this.captured[move.vanish[1].c][move.vanish[1].p]++;
297 }
298 if (move.vanish[0].p != move.appear[0].p) {
299 // Promotion: update this.captured
300 this.captured[move.vanish[0].c][move.appear[0].p]--;
301 }
302 }
303
304 unupdateVariables(move) {
305 super.unupdateVariables(move);
306 if (move.vanish.length == 2 && move.appear.length == 1)
307 this.captured[move.vanish[1].c][move.vanish[1].p]--;
308 if (move.vanish[0].p != move.appear[0].p)
309 this.captured[move.vanish[0].c][move.appear[0].p]++;
310 }
311
312 static get VALUES() {
313 return Object.assign(
314 { c: 5, m: 7 }, //experimental
315 ChessRules.VALUES
316 );
317 }
318
319 static get SEARCH_DEPTH() {
320 return 2;
321 }
322
323 static GenRandInitFen(randomness) {
324 if (randomness == 0) {
325 // No castling in the official initial setup
326 return "r8r/1nbqkmcbn1/pppppppppp/10/10/10/10/PPPPPPPPPP/1NBQKMCBN1/R8R " +
327 "w 0 0000 - 00000000000000";
328 }
329
330 let pieces = { w: new Array(10), b: new Array(10) };
331 // Shuffle pieces on first and last rank
332 for (let c of ["w", "b"]) {
333 if (c == 'b' && randomness == 1) {
334 pieces['b'] = pieces['w'];
335 break;
336 }
337
338 let positions = ArrayFun.range(10);
339
340 // Get random squares for bishops
341 let randIndex = 2 * randInt(5);
342 let bishop1Pos = positions[randIndex];
343 // The second bishop must be on a square of different color
344 let randIndex_tmp = 2 * randInt(5) + 1;
345 let bishop2Pos = positions[randIndex_tmp];
346 // Remove chosen squares
347 positions.splice(Math.max(randIndex, randIndex_tmp), 1);
348 positions.splice(Math.min(randIndex, randIndex_tmp), 1);
349
350 // Get random squares for knights
351 randIndex = randInt(8);
352 let knight1Pos = positions[randIndex];
353 positions.splice(randIndex, 1);
354 randIndex = randInt(7);
355 let knight2Pos = positions[randIndex];
356 positions.splice(randIndex, 1);
357
358 // Get random square for queen
359 randIndex = randInt(6);
360 let queenPos = positions[randIndex];
361 positions.splice(randIndex, 1);
362
363 // ...random square for marshall
364 randIndex = randInt(5);
365 let marshallPos = positions[randIndex];
366 positions.splice(randIndex, 1);
367
368 // ...random square for cardinal
369 randIndex = randInt(4);
370 let cardinalPos = positions[randIndex];
371 positions.splice(randIndex, 1);
372
373 // Rooks and king positions are now fixed, because of the ordering rook-king-rook
374 let rook1Pos = positions[0];
375 let kingPos = positions[1];
376 let rook2Pos = positions[2];
377
378 // Finally put the shuffled pieces in the board array
379 pieces[c][rook1Pos] = "r";
380 pieces[c][knight1Pos] = "n";
381 pieces[c][bishop1Pos] = "b";
382 pieces[c][queenPos] = "q";
383 pieces[c][marshallPos] = "m";
384 pieces[c][cardinalPos] = "c";
385 pieces[c][kingPos] = "k";
386 pieces[c][bishop2Pos] = "b";
387 pieces[c][knight2Pos] = "n";
388 pieces[c][rook2Pos] = "r";
389 }
390 return (
391 pieces["b"].join("") +
392 "/pppppppppp/10/10/10/10/10/10/PPPPPPPPPP/" +
393 pieces["w"].join("").toUpperCase() +
394 " w 0 1111 - 00000000000000"
395 );
396 }
397 };