Simplified underCheck / getCheckSquares logic. Debugging Berolina
[vchess.git] / public / javascripts / variants / Alice.js
1 // NOTE: alternative implementation, probably cleaner = use only 1 board
2 class AliceRules extends ChessRules
3 {
4 static get ALICE_PIECES()
5 {
6 return {
7 's': 'p',
8 't': 'q',
9 'u': 'r',
10 'c': 'b',
11 'o': 'n',
12 'l': 'k',
13 };
14 }
15 static get ALICE_CODES()
16 {
17 return {
18 'p': 's',
19 'q': 't',
20 'r': 'u',
21 'b': 'c',
22 'n': 'o',
23 'k': 'l',
24 };
25 }
26
27 static getPpath(b)
28 {
29 return (Object.keys(this.ALICE_PIECES).includes(b[1]) ? "Alice/" : "") + b;
30 }
31
32 static get PIECES()
33 {
34 return ChessRules.PIECES.concat(Object.keys(V.ALICE_PIECES));
35 }
36
37 setOtherVariables(fen)
38 {
39 super.setOtherVariables(fen);
40 const rows = V.ParseFen(fen).position.split("/");
41 if (this.kingPos["w"][0] < 0 || this.kingPos["b"][0] < 0)
42 {
43 // INIT_COL_XXX won't be required if Alice kings are found (means 'king moved')
44 for (let i=0; i<rows.length; i++)
45 {
46 let k = 0; //column index on board
47 for (let j=0; j<rows[i].length; j++)
48 {
49 switch (rows[i].charAt(j))
50 {
51 case 'l':
52 this.kingPos['b'] = [i,k];
53 break;
54 case 'L':
55 this.kingPos['w'] = [i,k];
56 break;
57 default:
58 const num = parseInt(rows[i].charAt(j));
59 if (!isNaN(num))
60 k += (num-1);
61 }
62 k++;
63 }
64 }
65 }
66 }
67
68 // Return the (standard) color+piece notation at a square for a board
69 getSquareOccupation(i, j, mirrorSide)
70 {
71 const piece = this.getPiece(i,j);
72 if (mirrorSide==1 && Object.keys(V.ALICE_CODES).includes(piece))
73 return this.board[i][j];
74 else if (mirrorSide==2 && Object.keys(V.ALICE_PIECES).includes(piece))
75 return this.getColor(i,j) + V.ALICE_PIECES[piece];
76 return "";
77 }
78
79 // Build board of the given (mirror)side
80 getSideBoard(mirrorSide)
81 {
82 // Build corresponding board from complete board
83 let sideBoard = doubleArray(V.size.x, V.size.y, "");
84 for (let i=0; i<V.size.x; i++)
85 {
86 for (let j=0; j<V.size.y; j++)
87 sideBoard[i][j] = this.getSquareOccupation(i, j, mirrorSide);
88 }
89 return sideBoard;
90 }
91
92 // NOTE: castle & enPassant https://www.chessvariants.com/other.dir/alice.html
93 getPotentialMovesFrom([x,y], sideBoard)
94 {
95 const pieces = Object.keys(V.ALICE_CODES);
96 const codes = Object.keys(V.ALICE_PIECES);
97 const mirrorSide = (pieces.includes(this.getPiece(x,y)) ? 1 : 2);
98
99 // Search valid moves on sideBoard
100 let saveBoard = this.board;
101 this.board = sideBoard || this.getSideBoard(mirrorSide);
102 let moves = super.getPotentialMovesFrom([x,y]);
103 this.board = saveBoard;
104
105 // Finally filter impossible moves
106 let res = moves.filter(m => {
107 if (m.appear.length == 2) //castle
108 {
109 // appear[i] must be an empty square on the other board
110 for (let psq of m.appear)
111 {
112 if (this.getSquareOccupation(psq.x,psq.y,3-mirrorSide) != V.EMPTY)
113 return false;
114 }
115 }
116 else if (this.board[m.end.x][m.end.y] != V.EMPTY)
117 {
118 // Attempt to capture
119 const piece = this.getPiece(m.end.x,m.end.y);
120 if ((mirrorSide==1 && codes.includes(piece))
121 || (mirrorSide==2 && pieces.includes(piece)))
122 {
123 return false;
124 }
125 }
126 // If the move is computed on board1, m.appear change for Alice pieces.
127 if (mirrorSide==1)
128 {
129 m.appear.forEach(psq => { //forEach: castling taken into account
130 psq.p = V.ALICE_CODES[psq.p]; //goto board2
131 });
132 }
133 else //move on board2: mark vanishing pieces as Alice
134 {
135 m.vanish.forEach(psq => {
136 psq.p = V.ALICE_CODES[psq.p];
137 });
138 }
139 // Fix en-passant captures
140 if (m.vanish[0].p == V.PAWN && m.vanish.length == 2
141 && this.board[m.end.x][m.end.y] == V.EMPTY)
142 {
143 m.vanish[1].c = this.getOppCol(this.getColor(x,y));
144 // In the special case of en-passant, if
145 // - board1 takes board2 : vanish[1] --> Alice
146 // - board2 takes board1 : vanish[1] --> normal
147 let van = m.vanish[1];
148 if (mirrorSide==1 && codes.includes(this.getPiece(van.x,van.y)))
149 van.p = V.ALICE_CODES[van.p];
150 else if (mirrorSide==2 && pieces.includes(this.getPiece(van.x,van.y)))
151 van.p = V.ALICE_PIECES[van.p];
152 }
153 return true;
154 });
155 return res;
156 }
157
158 filterValid(moves)
159 {
160 if (moves.length == 0)
161 return [];
162 let sideBoard = [this.getSideBoard(1), this.getSideBoard(2)];
163 const color = this.turn;
164 return moves.filter(m => {
165 this.playSide(m, sideBoard); //no need to track flags
166 const res = !this.underCheck(color, sideBoard);
167 this.undoSide(m, sideBoard);
168 return res;
169 });
170 }
171
172 getAllValidMoves()
173 {
174 const color = this.turn;
175 const oppCol = this.getOppCol(color);
176 var potentialMoves = [];
177 let sideBoard = [this.getSideBoard(1), this.getSideBoard(2)];
178 for (var i=0; i<V.size.x; i++)
179 {
180 for (var j=0; j<V.size.y; j++)
181 {
182 if (this.board[i][j] != V.EMPTY && this.getColor(i,j) == color)
183 {
184 const mirrorSide =
185 Object.keys(V.ALICE_CODES).includes(this.getPiece(i,j))
186 ? 1
187 : 2;
188 Array.prototype.push.apply(potentialMoves,
189 this.getPotentialMovesFrom([i,j], sideBoard[mirrorSide-1]));
190 }
191 }
192 }
193 return this.filterValid(potentialMoves, sideBoard);
194 }
195
196 // Play on sideboards [TODO: only one sideBoard required]
197 playSide(move, sideBoard)
198 {
199 const pieces = Object.keys(V.ALICE_CODES);
200 move.vanish.forEach(psq => {
201 const mirrorSide = (pieces.includes(psq.p) ? 1 : 2);
202 sideBoard[mirrorSide-1][psq.x][psq.y] = V.EMPTY;
203 });
204 move.appear.forEach(psq => {
205 const mirrorSide = (pieces.includes(psq.p) ? 1 : 2);
206 const piece = (mirrorSide == 1 ? psq.p : V.ALICE_PIECES[psq.p]);
207 sideBoard[mirrorSide-1][psq.x][psq.y] = psq.c + piece;
208 if (piece == V.KING)
209 this.kingPos[psq.c] = [psq.x,psq.y];
210 });
211 }
212
213 // Undo on sideboards
214 undoSide(move, sideBoard)
215 {
216 const pieces = Object.keys(V.ALICE_CODES);
217 move.appear.forEach(psq => {
218 const mirrorSide = (pieces.includes(psq.p) ? 1 : 2);
219 sideBoard[mirrorSide-1][psq.x][psq.y] = V.EMPTY;
220 });
221 move.vanish.forEach(psq => {
222 const mirrorSide = (pieces.includes(psq.p) ? 1 : 2);
223 const piece = (mirrorSide == 1 ? psq.p : V.ALICE_PIECES[psq.p]);
224 sideBoard[mirrorSide-1][psq.x][psq.y] = psq.c + piece;
225 if (piece == V.KING)
226 this.kingPos[psq.c] = [psq.x,psq.y];
227 });
228 }
229
230 underCheck(color, sideBoard) //sideBoard arg always provided
231 {
232 const kp = this.kingPos[color];
233 const mirrorSide = (sideBoard[0][kp[0]][kp[1]] != V.EMPTY ? 1 : 2);
234 let saveBoard = this.board;
235 this.board = sideBoard[mirrorSide-1];
236 let res = this.isAttacked(kp, [this.getOppCol(color)]);
237 this.board = saveBoard;
238 return res;
239 }
240
241 getCheckSquares(color)
242 {
243 const pieces = Object.keys(V.ALICE_CODES);
244 const kp = this.kingPos[color];
245 const mirrorSide = (pieces.includes(this.getPiece(kp[0],kp[1])) ? 1 : 2);
246 let sideBoard = this.getSideBoard(mirrorSide);
247 let saveBoard = this.board;
248 this.board = sideBoard;
249 let res = this.isAttacked(this.kingPos[color], [this.getOppCol(color)])
250 ? [ JSON.parse(JSON.stringify(this.kingPos[color])) ]
251 : [ ];
252 this.board = saveBoard;
253 return res;
254 }
255
256 updateVariables(move)
257 {
258 super.updateVariables(move); //standard king
259 const piece = move.vanish[0].p;
260 const c = move.vanish[0].c;
261 // "l" = Alice king
262 if (piece == "l")
263 {
264 this.kingPos[c][0] = move.appear[0].x;
265 this.kingPos[c][1] = move.appear[0].y;
266 this.castleFlags[c] = [false,false];
267 }
268 }
269
270 unupdateVariables(move)
271 {
272 super.unupdateVariables(move);
273 const c = move.vanish[0].c;
274 if (move.vanish[0].p == "l")
275 this.kingPos[c] = [move.start.x, move.start.y];
276 }
277
278 checkGameEnd()
279 {
280 const pieces = Object.keys(V.ALICE_CODES);
281 const color = this.turn;
282 const kp = this.kingPos[color];
283 const mirrorSide = (pieces.includes(this.getPiece(kp[0],kp[1])) ? 1 : 2);
284 let sideBoard = this.getSideBoard(mirrorSide);
285 let saveBoard = this.board;
286 this.board = sideBoard;
287 let res = "*";
288 if (!this.isAttacked(this.kingPos[color], [this.getOppCol(color)]))
289 res = "1/2";
290 else
291 res = (color == "w" ? "0-1" : "1-0");
292 this.board = saveBoard;
293 return res;
294 }
295
296 static get VALUES()
297 {
298 return Object.assign(
299 ChessRules.VALUES,
300 {
301 's': 1,
302 'u': 5,
303 'o': 3,
304 'c': 3,
305 't': 9,
306 'l': 1000,
307 }
308 );
309 }
310
311 getNotation(move)
312 {
313 if (move.appear.length == 2 && move.appear[0].p == V.KING)
314 {
315 if (move.end.y < move.start.y)
316 return "0-0-0";
317 else
318 return "0-0";
319 }
320
321 const finalSquare = V.CoordsToSquare(move.end);
322 const piece = this.getPiece(move.start.x, move.start.y);
323
324 const captureMark = (move.vanish.length > move.appear.length ? "x" : "");
325 let pawnMark = "";
326 if (["p","s"].includes(piece) && captureMark.length == 1)
327 pawnMark = V.GetColumn(move.start.y); //start column
328
329 // Piece or pawn movement
330 let notation = piece.toUpperCase() + pawnMark + captureMark + finalSquare;
331 if (['s','p'].includes(piece) && !['s','p'].includes(move.appear[0].p))
332 {
333 // Promotion
334 notation += "=" + move.appear[0].p.toUpperCase();
335 }
336 return notation;
337 }
338 }
339
340 const VariantRules = AliceRules;