client/src/variants/Synchrone2.js

   1 import { ChessRules, Move } from "@/base_rules";
   2 import { Synchrone1Rules } from "@/variants/Synchrone1";
   3 import { randInt } from "@/utils/alea";
   4
   5 export class Synchrone2Rules extends Synchrone1Rules {
   6
   7   static get CanAnalyze() {
   8     return false;
   9   }
  10
  11   static get HasEnpassant() {
  12     return false;
  13   }
  14
  15   static IsGoodFen(fen) {
  16     if (!Synchrone1Rules.IsGoodFen(fen)) return false;
  17     const fenParsed = V.ParseFen(fen);
  18     // 5) Check initFen (not really... TODO?)
  19     if (!fenParsed.initFen) return false;
  20     return true;
  21   }
  22
  23   static ParseFen(fen) {
  24     const fenParts = fen.split(" ");
  25     return Object.assign(
  26       {
  27         initFen: fenParts[4],
  28         whiteMove: fenParts[5]
  29       },
  30       ChessRules.ParseFen(fen)
  31     );
  32   }
  33
  34   getInitfenFen() {
  35     const L = this.initfenStack.length;
  36     return L > 0 ? this.initfenStack[L-1] : "-";
  37   }
  38
  39   getFen() {
  40     return (
  41       super.getBaseFen() + " " +
  42       super.getTurnFen() + " " +
  43       this.movesCount + " " +
  44       super.getFlagsFen() + " " +
  45       this.getInitfenFen() + " " +
  46       this.getWhitemoveFen()
  47     );
  48   }
  49
  50   static GenRandInitFen(randomness) {
  51     const res = ChessRules.GenRandInitFen(randomness);
  52     // Add initFen field:
  53     return res.slice(0, -1) + res.split(' ')[0] + " -";
  54   }
  55
  56   setOtherVariables(fen) {
  57     const parsedFen = V.ParseFen(fen);
  58     this.setFlags(parsedFen.flags);
  59     super.scanKings(fen);
  60     // Also init whiteMove
  61     this.whiteMove =
  62       parsedFen.whiteMove != "-"
  63         ? JSON.parse(parsedFen.whiteMove)
  64         : null;
  65     // And initFen (could be empty)
  66     this.initfenStack = [];
  67     if (parsedFen.initFen != "-") this.initfenStack.push(parsedFen.initFen);
  68   }
  69
  70   getPotentialMovesFrom([x, y]) {
  71     if (this.movesCount % 4 <= 1) return super.getPotentialMovesFrom([x, y]);
  72     // Diff current and old board to know which pieces have moved,
  73     // and to deduce possible moves at stage 2.
  74     const L = this.initfenStack.length;
  75     let initBoard = V.GetBoard(this.initfenStack[L-1]);
  76     let appeared = [];
  77     const c = this.turn;
  78     const oppCol = V.GetOppCol(c);
  79     for (let i=0; i<8; i++) {
  80       for (let j=0; j<8; j++) {
  81         if (this.board[i][j] != initBoard[i][j]) {
  82           if (this.board[i][j] != V.EMPTY) {
  83             const color = this.board[i][j].charAt(0);
  84             appeared.push({ c: color, x: i, y: j });
  85             // Pawns capture in diagonal => the following fix.
  86             // (Other way would be to redefine getPotentialPawnMoves()...)
  87             if (color == oppCol) initBoard[i][j] = this.board[i][j];
  88           }
  89         }
  90       }
  91     }
  92     const saveBoard = this.board;
  93     this.board = initBoard;
  94     const movesInit = super.getPotentialMovesFrom([x, y]);
  95     this.board = saveBoard;
  96     const target = appeared.find(a => a.c == oppCol);
  97     let movesNow = super.getPotentialMovesFrom([x, y]).filter(m => {
  98       return (
  99         m.end.x == target.x &&
 100         m.end.y == target.y &&
 101         movesInit.some(mi => mi.end.x == m.end.x && mi.end.y == m.end.y)
 102       );
 103     });
 104     const passTarget =
 105       (x != this.kingPos[c][0] || y != this.kingPos[c][1]) ? c : oppCol;
 106     movesNow.push(
 107       new Move({
 108         start: { x: x, y: y },
 109         end: {
 110           x: this.kingPos[passTarget][0],
 111           y: this.kingPos[passTarget][1]
 112         },
 113         appear: [],
 114         vanish: []
 115       })
 116     );
 117     return movesNow;
 118   }
 119
 120   filterValid(moves) {
 121     if (moves.length == 0) return [];
 122     if (moves.length == 1 && moves[0].vanish.length == 0) return moves;
 123     // filterValid can be called when it's "not our turn":
 124     const color = moves.find(m => m.vanish.length > 0).vanish[0].c;
 125     return moves.filter(m => {
 126       if (m.vanish.length == 0) return true;
 127       const piece = m.vanish[0].p;
 128       if (piece == V.KING) {
 129         this.kingPos[color][0] = m.appear[0].x;
 130         this.kingPos[color][1] = m.appear[0].y;
 131       }
 132       V.PlayOnBoard(this.board, m);
 133       let res = !this.underCheck(color);
 134       V.UndoOnBoard(this.board, m);
 135       if (piece == V.KING) this.kingPos[color] = [m.start.x, m.start.y];
 136       return res;
 137     });
 138   }
 139
 140   getPossibleMovesFrom([x, y]) {
 141     return this.filterValid(this.getPotentialMovesFrom([x, y]));
 142   }
 143
 144   play(move) {
 145     if (this.movesCount % 4 == 0) this.initfenStack.push(this.getBaseFen());
 146     move.flags = JSON.stringify(this.aggregateFlags());
 147     // Do not play on board (would reveal the move...)
 148     this.turn = V.GetOppCol(this.turn);
 149     this.movesCount++;
 150     if ([0, 3].includes(this.movesCount % 4)) this.postPlay(move);
 151     else super.postPlay(move); //resolve synchrone move
 152   }
 153
 154   postPlay(move) {
 155     if (this.turn == 'b') {
 156       // NOTE: whiteMove is used read-only, so no need to copy
 157       this.whiteMove = move;
 158       return;
 159     }
 160
 161     // A full "deterministic" turn just ended: no need to resolve
 162     const smove = {
 163       appear: this.whiteMove.appear.concat(move.appear),
 164       vanish: this.whiteMove.vanish.concat(move.vanish)
 165     };
 166     V.PlayOnBoard(this.board, smove);
 167     move.whiteMove = this.whiteMove; //for undo
 168     this.whiteMove = null;
 169
 170     // Update king position + flags
 171     let kingAppear = { 'w': false, 'b': false };
 172     for (let i=0; i < smove.appear.length; i++) {
 173       if (smove.appear[i].p == V.KING) {
 174         const c = smove.appear[i].c;
 175         kingAppear[c] = true;
 176         this.kingPos[c][0] = smove.appear[i].x;
 177         this.kingPos[c][1] = smove.appear[i].y;
 178       }
 179     }
 180     for (let i = 0; i < smove.vanish.length; i++) {
 181       if (smove.vanish[i].p == V.KING) {
 182         const c = smove.vanish[i].c;
 183         if (!kingAppear[c]) {
 184           this.kingPos[c][0] = -1;
 185           this.kingPos[c][1] = -1;
 186         }
 187         break;
 188       }
 189     }
 190     super.updateCastleFlags(smove);
 191     move.smove = smove;
 192   }
 193
 194   undo(move) {
 195     this.disaggregateFlags(JSON.parse(move.flags));
 196     if (this.turn == 'w')
 197       // Back to the middle of the move
 198       V.UndoOnBoard(this.board, move.smove);
 199     this.turn = V.GetOppCol(this.turn);
 200     this.movesCount--;
 201     if (this.movesCount % 4 == 0) this.initfenStack.pop();
 202     this.postUndo(move);
 203   }
 204
 205   postUndo(move) {
 206     if (this.turn == 'w') {
 207       // Reset king positions: scan board (TODO: could be more efficient)
 208       if (move.vanish.length > 0) this.scanKings();
 209       // Also reset whiteMove
 210       this.whiteMove = null;
 211     }
 212     else this.whiteMove = move.whiteMove;
 213   }
 214
 215   getCurrentScore() {
 216     if (this.movesCount % 4 != 0)
 217       // Turn (2 x [white + black]) not over yet
 218       return "*";
 219     // Was a king captured?
 220     if (this.kingPos['w'][0] < 0) return "0-1";
 221     if (this.kingPos['b'][0] < 0) return "1-0";
 222     const whiteCanMove = this.atLeastOneMove('w');
 223     const blackCanMove = this.atLeastOneMove('b');
 224     if (whiteCanMove && blackCanMove) return "*";
 225     // Game over
 226     const whiteInCheck = this.underCheck('w');
 227     const blackInCheck = this.underCheck('b');
 228     if (
 229       (whiteCanMove && !this.underCheck('b')) ||
 230       (blackCanMove && !this.underCheck('w'))
 231     ) {
 232       return "1/2";
 233     }
 234     // Checkmate: could be mutual
 235     if (!whiteCanMove && !blackCanMove) return "1/2";
 236     return (whiteCanMove ? "1-0" : "0-1");
 237   }
 238
 239   getNotation(move) {
 240     if (move.vanish.length == 0) return "pass";
 241     return super.getNotation(move);
 242   }
 243
 244 };