Konane: simplify code, easier gameplay
[vchess.git] / client / src / variants / Football.js
1 import { ChessRules } from "@/base_rules";
2 import { randInt, shuffle } from "@/utils/alea";
3 import { ArrayFun } from "@/utils/array";
4
5 export class FootballRules extends ChessRules {
6
7 static get HasEnpassant() {
8 return false;
9 }
10
11 static get HasFlags() {
12 return false;
13 }
14
15 static get size() {
16 return { x: 9, y: 9 };
17 }
18
19 static get Lines() {
20 return [
21 // White goal:
22 [[0, 4], [0, 5]],
23 [[0, 5], [1, 5]],
24 [[1, 4], [0, 4]],
25 // Black goal:
26 [[9, 4], [9, 5]],
27 [[9, 5], [8, 5]],
28 [[8, 4], [9, 4]]
29 ];
30 }
31
32 static get BALL() {
33 // 'b' is already taken:
34 return "aa";
35 }
36
37 // Check that exactly one ball is on the board
38 // + at least one piece per color.
39 static IsGoodPosition(position) {
40 if (position.length == 0) return false;
41 const rows = position.split("/");
42 if (rows.length != V.size.x) return false;
43 let pieces = { "w": 0, "b": 0 };
44 let ballCount = 0;
45 for (let row of rows) {
46 let sumElts = 0;
47 for (let i = 0; i < row.length; i++) {
48 const lowerRi = row[i].toLowerCase();
49 if (!!lowerRi.match(/^[a-z]$/)) {
50 if (V.PIECES.includes(lowerRi))
51 pieces[row[i] == lowerRi ? "b" : "w"]++;
52 else if (lowerRi == 'a') ballCount++;
53 else return false;
54 sumElts++;
55 }
56 else {
57 const num = parseInt(row[i], 10);
58 if (isNaN(num)) return false;
59 sumElts += num;
60 }
61 }
62 if (sumElts != V.size.y) return false;
63 }
64 if (ballCount != 1 || Object.values(pieces).some(v => v == 0))
65 return false;
66 return true;
67 }
68
69 static board2fen(b) {
70 if (b == V.BALL) return 'a';
71 return ChessRules.board2fen(b);
72 }
73
74 static fen2board(f) {
75 if (f == 'a') return V.BALL;
76 return ChessRules.fen2board(f);
77 }
78
79 getPpath(b) {
80 if (b == V.BALL) return "Football/ball";
81 return b;
82 }
83
84 canIplay(side, [x, y]) {
85 return (
86 side == this.turn &&
87 (this.board[x][y] == V.BALL || this.getColor(x, y) == side)
88 );
89 }
90
91 // No checks or king tracking etc. But, track ball
92 setOtherVariables() {
93 // Stack of "kicked by" coordinates, to avoid infinite loops
94 this.kickedBy = [ {} ];
95 this.subTurn = 1;
96 this.ballPos = [-1, -1];
97 for (let i=0; i < V.size.x; i++) {
98 for (let j=0; j< V.size.y; j++) {
99 if (this.board[i][j] == V.BALL) {
100 this.ballPos = [i, j];
101 return;
102 }
103 }
104 }
105 }
106
107 static GenRandInitFen(randomness) {
108 if (randomness == 0)
109 return "rnbq1knbr/9/9/9/4a4/9/9/9/RNBQ1KNBR w 0";
110
111 let pieces = { w: new Array(8), b: new Array(8) };
112 for (let c of ["w", "b"]) {
113 if (c == 'b' && randomness == 1) {
114 pieces['b'] = pieces['w'];
115 break;
116 }
117
118 // Get random squares for every piece, totally freely
119 let positions = shuffle(ArrayFun.range(8));
120 const composition = ['b', 'b', 'r', 'r', 'n', 'n', 'k', 'q'];
121 // Fix bishops (on different colors)
122 const realOddity =
123 (pos) => { return (pos <= 3 ? pos % 2 : (pos + 1) % 2); };
124 const rem2 = realOddity(positions[0]);
125 if (rem2 == realOddity(positions[1])) {
126 for (let i=2; i<8; i++) {
127 if (realOddity(positions[i]) != rem2) {
128 [positions[1], positions[i]] = [positions[i], positions[1]];
129 break;
130 }
131 }
132 }
133 for (let i = 0; i < 8; i++) pieces[c][positions[i]] = composition[i];
134 }
135 const piecesB = pieces["b"].join("") ;
136 const piecesW = pieces["w"].join("").toUpperCase();
137 return (
138 piecesB.substr(0, 4) + "1" + piecesB.substr(4) +
139 "/9/9/9/4a4/9/9/9/" +
140 piecesW.substr(0, 4) + "1" + piecesW.substr(4) +
141 " w 0"
142 );
143 }
144
145 tryKickFrom([x, y]) {
146 const bp = this.ballPos;
147 const emptySquare = (i, j) => {
148 return V.OnBoard(i, j) && this.board[i][j] == V.EMPTY;
149 };
150 // Kick the (adjacent) ball from x, y with current turn:
151 const step = [bp[0] - x, bp[1] - y];
152 const piece = this.getPiece(x, y);
153 let moves = [];
154 if (piece == V.KNIGHT) {
155 // The knight case is particular
156 V.steps[V.KNIGHT].forEach(s => {
157 const [i, j] = [bp[0] + s[0], bp[1] + s[1]];
158 if (
159 V.OnBoard(i, j) &&
160 this.board[i][j] == V.EMPTY &&
161 (
162 // In a corner? The, allow all ball moves
163 ([0, 8].includes(bp[0]) && [0, 8].includes(bp[1])) ||
164 // Do not end near the knight
165 (Math.abs(i - x) >= 2 || Math.abs(j - y) >= 2)
166 )
167 ) {
168 moves.push(super.getBasicMove(bp, [i, j]));
169 }
170 });
171 }
172 else {
173 let compatible = false,
174 oneStep = false;
175 switch (piece) {
176 case V.ROOK:
177 compatible = (step[0] == 0 || step[1] == 0);
178 break;
179 case V.BISHOP:
180 compatible = (step[0] != 0 && step[1] != 0);
181 break;
182 case V.QUEEN:
183 compatible = true;
184 break;
185 case V.KING:
186 compatible = true;
187 oneStep = true;
188 break;
189 }
190 if (!compatible) return [];
191 let [i, j] = [bp[0] + step[0], bp[1] + step[1]];
192 const horizontalStepOnGoalRow =
193 ([0, 8].includes(bp[0]) && step.some(s => s == 0));
194 if (
195 emptySquare(i, j) &&
196 (this.movesCount >= 2 || j != 4 || ![0, 8].includes(i)) &&
197 (!horizontalStepOnGoalRow || j != 4)
198 ) {
199 moves.push(super.getBasicMove(bp, [i, j]));
200 if (!oneStep) {
201 do {
202 i += step[0];
203 j += step[1];
204 if (!emptySquare(i, j)) break;
205 if (
206 (this.movesCount >= 2 || j != 4 || ![0, 8].includes(i)) &&
207 (!horizontalStepOnGoalRow || j != 4)
208 ) {
209 moves.push(super.getBasicMove(bp, [i, j]));
210 }
211 } while (true);
212 }
213 }
214 // Try the other direction (TODO: experimental)
215 [i, j] = [bp[0] - 2*step[0], bp[1] - 2*step[1]];
216 if (
217 emptySquare(i, j) &&
218 (this.movesCount >= 2 || j != 4 || ![0, 8].includes(i)) &&
219 (!horizontalStepOnGoalRow || j != 4)
220 ) {
221 moves.push(super.getBasicMove(bp, [i, j]));
222 if (!oneStep) {
223 do {
224 i -= step[0];
225 j -= step[1];
226 if (!emptySquare(i, j)) break;
227 if (
228 (this.movesCount >= 2 || j != 4 || ![0, 8].includes(i)) &&
229 (!horizontalStepOnGoalRow || j != 4)
230 ) {
231 moves.push(super.getBasicMove(bp, [i, j]));
232 }
233 } while (true);
234 }
235 }
236 }
237 const kickedFrom = x + "-" + y;
238 moves.forEach(m => m.start.by = kickedFrom)
239 return moves;
240 }
241
242 getPotentialMovesFrom([x, y], computer) {
243 const piece = this.getPiece(x, y);
244 if (V.PIECES.includes(piece)) {
245 if (this.subTurn > 1) return [];
246 const moves = super.getPotentialMovesFrom([x, y])
247 .filter(m => m.end.y != 4 || ![0, 8].includes(m.end.x));
248 // If bishop stuck in a corner: allow to jump over the next obstacle
249 if (moves.length == 0 && piece == V.BISHOP) {
250 if (
251 x == 0 && y == 0 &&
252 this.board[1][1] != V.EMPTY &&
253 this.board[2][2] == V.EMPTY
254 ) {
255 return [super.getBasicMove([x, y], [2, 2])];
256 }
257 if (
258 x == 0 && y == 8 &&
259 this.board[1][7] != V.EMPTY &&
260 this.board[2][6] == V.EMPTY
261 ) {
262 return [super.getBasicMove([x, y], [2, 6])];
263 }
264 if (
265 x == 8 && y == 0 &&
266 this.board[7][1] != V.EMPTY &&
267 this.board[6][2] == V.EMPTY
268 ) {
269 return [super.getBasicMove([x, y], [6, 2])];
270 }
271 if (
272 x == 8 && y == 8 &&
273 this.board[7][7] != V.EMPTY &&
274 this.board[6][6] == V.EMPTY
275 ) {
276 return [super.getBasicMove([x, y], [6, 6])];
277 }
278 }
279 return moves;
280 }
281 // Kicking the ball: look for adjacent pieces.
282 const steps = V.steps[V.ROOK].concat(V.steps[V.BISHOP]);
283 const c = this.turn;
284 let moves = [];
285 let atLeastOnePotentialKick = false;
286 for (let s of steps) {
287 const [i, j] = [x + s[0], y + s[1]];
288 if (
289 V.OnBoard(i, j) &&
290 this.board[i][j] != V.EMPTY &&
291 this.getColor(i, j) == c
292 ) {
293 if (!atLeastOnePotentialKick) atLeastOnePotentialKick = true;
294 Array.prototype.push.apply(moves, this.tryKickFrom([i, j]));
295 }
296 }
297 if (atLeastOnePotentialKick) {
298 // And, always add the "end" move. For computer, keep only one
299 outerLoop: for (let i=0; i < V.size.x; i++) {
300 for (let j=0; j < V.size.y; j++) {
301 if (this.board[i][j] != V.EMPTY && this.getColor(i, j) == c) {
302 moves.push(super.getBasicMove([x, y], [i, j]));
303 if (!!computer) break outerLoop;
304 }
305 }
306 }
307 }
308 return moves;
309 }
310
311 // No captures:
312 getSlideNJumpMoves([x, y], steps, oneStep) {
313 let moves = [];
314 outerLoop: for (let step of steps) {
315 let i = x + step[0];
316 let j = y + step[1];
317 let stepCount = 1;
318 while (V.OnBoard(i, j) && this.board[i][j] == V.EMPTY) {
319 moves.push(this.getBasicMove([x, y], [i, j]));
320 if (!!oneStep) continue outerLoop;
321 i += step[0];
322 j += step[1];
323 stepCount++;
324 }
325 }
326 return moves;
327 }
328
329 // Extra arg "computer" to avoid trimming all redundant pass moves:
330 getAllPotentialMoves(computer) {
331 const color = this.turn;
332 let potentialMoves = [];
333 for (let i = 0; i < V.size.x; i++) {
334 for (let j = 0; j < V.size.y; j++) {
335 if (this.board[i][j] != V.EMPTY && this.getColor(i, j) == color) {
336 Array.prototype.push.apply(
337 potentialMoves,
338 this.getPotentialMovesFrom([i, j], computer)
339 );
340 }
341 }
342 }
343 return potentialMoves;
344 }
345
346 getAllValidMoves() {
347 return this.filterValid(this.getAllPotentialMoves("computer"));
348 }
349
350 filterValid(moves) {
351 const L = this.kickedBy.length;
352 const kb = this.kickedBy[L-1];
353 return moves.filter(m => !m.start.by || !kb[m.start.by]);
354 }
355
356 getCheckSquares() {
357 return [];
358 }
359
360 allowAnotherPass(color) {
361 // Two cases: a piece moved, or the ball moved.
362 // In both cases, check our pieces and ball proximity,
363 // so the move played doesn't matter (if ball position updated)
364 const bp = this.ballPos;
365 const steps = V.steps[V.ROOK].concat(V.steps[V.BISHOP]);
366 for (let s of steps) {
367 const [i, j] = [this.ballPos[0] + s[0], this.ballPos[1] + s[1]];
368 if (
369 V.OnBoard(i, j) &&
370 this.board[i][j] != V.EMPTY &&
371 this.getColor(i, j) == color
372 ) {
373 return true; //potentially...
374 }
375 }
376 return false;
377 }
378
379 prePlay(move) {
380 if (move.appear[0].p == 'a')
381 this.ballPos = [move.appear[0].x, move.appear[0].y];
382 }
383
384 play(move) {
385 // Special message saying "passes are over"
386 const passesOver = (move.vanish.length == 2);
387 if (!passesOver) {
388 this.prePlay(move);
389 V.PlayOnBoard(this.board, move);
390 }
391 move.turn = [this.turn, this.subTurn]; //easier undo
392 if (passesOver || !this.allowAnotherPass(this.turn)) {
393 this.turn = V.GetOppCol(this.turn);
394 this.subTurn = 1;
395 this.movesCount++;
396 this.kickedBy.push( {} );
397 }
398 else {
399 this.subTurn++;
400 if (!!move.start.by) {
401 const L = this.kickedBy.length;
402 this.kickedBy[L-1][move.start.by] = true;
403 }
404 }
405 }
406
407 undo(move) {
408 const passesOver = (move.vanish.length == 2);
409 if (move.turn[0] != this.turn) {
410 [this.turn, this.subTurn] = move.turn;
411 this.movesCount--;
412 this.kickedBy.pop();
413 }
414 else {
415 this.subTurn--;
416 if (!!move.start.by) {
417 const L = this.kickedBy.length;
418 delete this.kickedBy[L-1][move.start.by];
419 }
420 }
421 if (!passesOver) {
422 V.UndoOnBoard(this.board, move);
423 this.postUndo(move);
424 }
425 }
426
427 postUndo(move) {
428 if (move.vanish[0].p == 'a')
429 this.ballPos = [move.vanish[0].x, move.vanish[0].y];
430 }
431
432 getCurrentScore() {
433 if (this.board[0][4] == V.BALL) return "1-0";
434 if (this.board[8][4] == V.BALL) return "0-1";
435 return "*";
436 }
437
438 getComputerMove() {
439 let initMoves = this.getAllValidMoves();
440 if (initMoves.length == 0) return null;
441 let moves = JSON.parse(JSON.stringify(initMoves));
442 let mvArray = [];
443 let mv = null;
444 // Just play random moves (for now at least. TODO?)
445 const c = this.turn;
446 while (moves.length > 0) {
447 mv = moves[randInt(moves.length)];
448 mvArray.push(mv);
449 this.play(mv);
450 if (mv.vanish.length == 1 && this.allowAnotherPass(c))
451 // Potential kick
452 moves = this.getPotentialMovesFrom(this.ballPos);
453 else break;
454 }
455 for (let i = mvArray.length - 1; i >= 0; i--) this.undo(mvArray[i]);
456 return (mvArray.length > 1 ? mvArray : mvArray[0]);
457 }
458
459 // NOTE: evalPosition() is wrong, but unused since bot plays at random
460
461 getNotation(move) {
462 if (move.vanish.length == 2) return "pass";
463 if (move.vanish[0].p != 'a') return super.getNotation(move);
464 // Kick: simple notation (TODO?)
465 return V.CoordsToSquare(move.end);
466 }
467
468 };