-import { ChessRules, Move, PiPo } from "@/base_rules";
-
-export class Checkered2Rules extends ChessRules {
-
- static board2fen(b) {
- const checkered_codes = {
- p: "s",
- q: "t",
- r: "u",
- b: "c",
- n: "o"
- };
- if (b[0] == "c") return checkered_codes[b[1]];
- return ChessRules.board2fen(b);
- }
-
- static fen2board(f) {
- // Tolerate upper-case versions of checkered pieces (why not?)
- const checkered_pieces = {
- s: "p",
- S: "p",
- t: "q",
- T: "q",
- u: "r",
- U: "r",
- c: "b",
- C: "b",
- o: "n",
- O: "n"
- };
- if (Object.keys(checkered_pieces).includes(f))
- return "c" + checkered_pieces[f];
- return ChessRules.fen2board(f);
- }
-
- static get PIECES() {
- return ChessRules.PIECES.concat(["s", "t", "u", "c", "o"]);
- }
-
- getPpath(b) {
- return (b[0] == "c" ? "Checkered/" : "") + b;
- }
-
- setOtherVariables(fen) {
- super.setOtherVariables(fen);
- // Local stack of non-capturing checkered moves:
- this.cmoves = [];
- const cmove = V.ParseFen(fen).cmove;
- if (cmove == "-") this.cmoves.push(null);
- else {
- this.cmoves.push({
- start: ChessRules.SquareToCoords(cmove.substr(0, 2)),
- end: ChessRules.SquareToCoords(cmove.substr(2))
- });
- }
- }
-
- static IsGoodFen(fen) {
- if (!ChessRules.IsGoodFen(fen)) return false;
- const fenParts = fen.split(" ");
- if (fenParts.length != 6) return false;
- if (fenParts[5] != "-" && !fenParts[5].match(/^([a-h][1-8]){2}$/))
- return false;
- return true;
- }
-
- static IsGoodFlags(flags) {
- // 4 for castle + 16 for pawns
- return !!flags.match(/^[a-z]{4,4}[01]{16,16}$/);
- }
-
- setFlags(fenflags) {
- super.setFlags(fenflags); //castleFlags
- this.pawnFlags = {
- w: [...Array(8)], //pawns can move 2 squares?
- b: [...Array(8)]
- };
- const flags = fenflags.substr(4); //skip first 4 letters, for castle
- for (let c of ["w", "b"]) {
- for (let i = 0; i < 8; i++)
- this.pawnFlags[c][i] = flags.charAt((c == "w" ? 0 : 8) + i) == "1";
- }
- }
-
- aggregateFlags() {
- return [this.castleFlags, this.pawnFlags];
- }
-
- disaggregateFlags(flags) {
- this.castleFlags = flags[0];
- this.pawnFlags = flags[1];
- }
-
- getEpSquare(moveOrSquare) {
- if (typeof moveOrSquare !== "object" || moveOrSquare.appear[0].c != 'c')
- return super.getEpSquare(moveOrSquare);
- // Checkered move: no en-passant
- return undefined;
- }
-
- getCmove(move) {
- if (move.appear[0].c == "c" && move.vanish.length == 1)
- return { start: move.start, end: move.end };
- return null;
- }
-
- canTake([x1, y1], [x2, y2]) {
- const color1 = this.getColor(x1, y1);
- const color2 = this.getColor(x2, y2);
- // Checkered aren't captured
- return (
- color1 != color2 &&
- color2 != "c" &&
- (color1 != "c" || color2 != this.turn)
- );
- }
-
- // Post-processing: apply "checkerization" of standard moves
- getPotentialMovesFrom([x, y]) {
- let standardMoves = super.getPotentialMovesFrom([x, y]);
- const lastRank = this.turn == "w" ? 0 : 7;
- // King is treated differently: it never turn checkered
- if (this.getPiece(x, y) == V.KING) return standardMoves;
- let moves = [];
- standardMoves.forEach(m => {
- if (m.vanish[0].p == V.PAWN) {
- if (
- Math.abs(m.end.x - m.start.x) == 2 &&
- !this.pawnFlags[this.turn][m.start.y]
- ) {
- return; //skip forbidden 2-squares jumps
- }
- if (
- this.board[m.end.x][m.end.y] == V.EMPTY &&
- m.vanish.length == 2 &&
- this.getColor(m.start.x, m.start.y) == "c"
- ) {
- return; //checkered pawns cannot take en-passant
- }
- }
- if (m.vanish.length == 1)
- // No capture
- moves.push(m);
- else {
- // A capture occured (m.vanish.length == 2)
- m.appear[0].c = "c";
- moves.push(m);
- if (
- // Avoid promotions (already treated):
- m.appear[0].p != m.vanish[1].p &&
- (m.vanish[0].p != V.PAWN || m.end.x != lastRank)
- ) {
- // Add transformation into captured piece
- let m2 = JSON.parse(JSON.stringify(m));
- m2.appear[0].p = m.vanish[1].p;
- moves.push(m2);
- }
- }
- });
- return moves;
- }
-
- getPotentialPawnMoves([x, y]) {
- let moves = super.getPotentialPawnMoves([x, y]);
- // Post-process: set right color for checkered moves
- if (this.getColor(x, y) == 'c') {
- moves.forEach(m => {
- m.appear[0].c = 'c'; //may be done twice if capture
- m.vanish[0].c = 'c';
- });
- }
- return moves;
- }
-
- canIplay(side, [x, y]) {
- return side == this.turn && [side, "c"].includes(this.getColor(x, y));
- }
-
- // Does m2 un-do m1 ? (to disallow undoing checkered moves)
- oppositeMoves(m1, m2) {
- return (
- !!m1 &&
- m2.appear[0].c == "c" &&
- m2.appear.length == 1 &&
- m2.vanish.length == 1 &&
- m1.start.x == m2.end.x &&
- m1.end.x == m2.start.x &&
- m1.start.y == m2.end.y &&
- m1.end.y == m2.start.y
- );
- }
-
- filterValid(moves) {
- if (moves.length == 0) return [];
- const color = this.turn;
- const L = this.cmoves.length; //at least 1: init from FEN
- return moves.filter(m => {
- if (this.oppositeMoves(this.cmoves[L - 1], m)) return false;
- this.play(m);
- const res = !this.underCheck(color);
- this.undo(m);
- return res;
- });
- }
-
- getAllValidMoves() {
- const oppCol = V.GetOppCol(this.turn);
- let potentialMoves = [];
- for (let i = 0; i < V.size.x; i++) {
- for (let j = 0; j < V.size.y; j++) {
- // NOTE: just testing == color isn't enough because of checkered pieces
- if (this.board[i][j] != V.EMPTY && this.getColor(i, j) != oppCol) {
- Array.prototype.push.apply(
- potentialMoves,
- this.getPotentialMovesFrom([i, j])
- );
- }
- }
- }
- return this.filterValid(potentialMoves);
- }
-
- atLeastOneMove() {
- const oppCol = V.GetOppCol(this.turn);
- for (let i = 0; i < V.size.x; i++) {
- for (let j = 0; j < V.size.y; j++) {
- // NOTE: just testing == color isn't enough because of checkered pieces
- if (this.board[i][j] != V.EMPTY && this.getColor(i, j) != oppCol) {
- const moves = this.getPotentialMovesFrom([i, j]);
- if (moves.length > 0) {
- for (let k = 0; k < moves.length; k++) {
- if (this.filterValid([moves[k]]).length > 0) return true;
- }
- }
- }
- }
- }
- return false;
- }
-
- // colors: array, generally 'w' and 'c' or 'b' and 'c'
- isAttacked(sq, colors) {
- if (!Array.isArray(colors)) colors = [colors];
- return (
- this.isAttackedByPawn(sq, colors) ||
- this.isAttackedByRook(sq, colors) ||
- this.isAttackedByKnight(sq, colors) ||
- this.isAttackedByBishop(sq, colors) ||
- this.isAttackedByQueen(sq, colors) ||
- this.isAttackedByKing(sq, colors)
- );
- }
-
- isAttackedByPawn([x, y], colors) {
- for (let c of colors) {
- const color = (c == "c" ? this.turn : c);
- let pawnShift = color == "w" ? 1 : -1;
- if (x + pawnShift >= 0 && x + pawnShift < 8) {
- for (let i of [-1, 1]) {
- if (
- y + i >= 0 &&
- y + i < 8 &&
- this.getPiece(x + pawnShift, y + i) == V.PAWN &&
- this.getColor(x + pawnShift, y + i) == c
- ) {
- return true;
- }
- }
- }
- }
- return false;
- }
-
- isAttackedBySlideNJump([x, y], colors, piece, steps, oneStep) {
- for (let step of steps) {
- let rx = x + step[0],
- ry = y + step[1];
- while (V.OnBoard(rx, ry) && this.board[rx][ry] == V.EMPTY && !oneStep) {
- rx += step[0];
- ry += step[1];
- }
- if (
- V.OnBoard(rx, ry) &&
- this.getPiece(rx, ry) === piece &&
- colors.includes(this.getColor(rx, ry))
- ) {
- return true;
- }
- }
- return false;
- }
-
- isAttackedByRook(sq, colors) {
- return this.isAttackedBySlideNJump(sq, colors, V.ROOK, V.steps[V.ROOK]);
- }
-
- isAttackedByKnight(sq, colors) {
- return this.isAttackedBySlideNJump(
- sq,
- colors,
- V.KNIGHT,
- V.steps[V.KNIGHT],
- "oneStep"
- );
- }
-
- isAttackedByBishop(sq, colors) {
- return this.isAttackedBySlideNJump(
- sq, colors, V.BISHOP, V.steps[V.BISHOP]);
- }
-
- isAttackedByQueen(sq, colors) {
- return this.isAttackedBySlideNJump(
- sq,
- colors,
- V.QUEEN,
- V.steps[V.ROOK].concat(V.steps[V.BISHOP])
- );
- }
-
- isAttackedByKing(sq, colors) {
- return this.isAttackedBySlideNJump(
- sq,
- colors,
- V.KING,
- V.steps[V.ROOK].concat(V.steps[V.BISHOP]),
- "oneStep"
- );
- }
-
- underCheck(color) {
- return this.isAttacked(this.kingPos[color], [V.GetOppCol(color), "c"]);
- }
-
- getCheckSquares() {
- const color = this.turn;
- // Artifically change turn, for checkered pawns
- this.turn = V.GetOppCol(color);
- const kingAttacked =
- this.isAttacked(
- this.kingPos[color],
- [this.turn, 'c']
- );
- let res = kingAttacked
- ? [JSON.parse(JSON.stringify(this.kingPos[color]))]
- : [];
- this.turn = color;
- return res;
- }
-
- postPlay(move) {
- super.postPlay(move);
- // Does this move turn off a 2-squares pawn flag?
- if (
- [1, 6].includes(move.start.x) &&
- move.vanish[0].p == V.PAWN &&
- Math.abs(move.end.x - move.start.x) == 2
- ) {
- this.pawnFlags[move.start.x == 6 ? "w" : "b"][move.start.y] = false;
- }
- this.cmoves.push(this.getCmove(move));
- }
-
- postUndo(move) {
- super.postUndo(move);
- this.cmoves.pop();
- }
-
- getCurrentScore() {
- if (this.atLeastOneMove()) return "*";
- const color = this.turn;
- // Artifically change turn, for checkered pawns
- this.turn = V.GetOppCol(this.turn);
- const res = this.isAttacked(this.kingPos[color], [V.GetOppCol(color), "c"])
- ? color == "w"
- ? "0-1"
- : "1-0"
- : "1/2";
- this.turn = V.GetOppCol(this.turn);
- return res;
- }
-
- evalPosition() {
- let evaluation = 0;
- // Just count material for now, considering checkered neutral (...)
- for (let i = 0; i < V.size.x; i++) {
- for (let j = 0; j < V.size.y; j++) {
- if (this.board[i][j] != V.EMPTY) {
- const sqColor = this.getColor(i, j);
- if (["w","b"].includes(sqColor)) {
- const sign = sqColor == "w" ? 1 : -1;
- evaluation += sign * V.VALUES[this.getPiece(i, j)];
- }
- }
- }
- }
- return evaluation;
- }
-
- static GenRandInitFen(randomness) {
- // Add 16 pawns flags + empty cmove:
- return ChessRules.GenRandInitFen(randomness)
- .slice(0, -2) + "1111111111111111 - -";
- }
-
- static ParseFen(fen) {
- return Object.assign(
- ChessRules.ParseFen(fen),
- { cmove: fen.split(" ")[5] }
- );
- }
-
- getCmoveFen() {
- const L = this.cmoves.length;
- return (
- !this.cmoves[L - 1]
- ? "-"
- : ChessRules.CoordsToSquare(this.cmoves[L - 1].start) +
- ChessRules.CoordsToSquare(this.cmoves[L - 1].end)
- );
- }
-
- getFen() {
- return super.getFen() + " " + this.getCmoveFen();
- }
-
- getFenForRepeat() {
- return super.getFenForRepeat() + "_" + this.getCmoveFen();
- }
-
- getFlagsFen() {
- let fen = super.getFlagsFen();
- // Add pawns flags
- for (let c of ["w", "b"])
- for (let i = 0; i < 8; i++) fen += (this.pawnFlags[c][i] ? "1" : "0");
- return fen;
- }
-
- static get SEARCH_DEPTH() {
- return 2;
- }
-
- getNotation(move) {
- if (move.appear.length == 2) {
- // Castle
- if (move.end.y < move.start.y) return "0-0-0";
- return "0-0";
- }
-
- const finalSquare = V.CoordsToSquare(move.end);
- const piece = this.getPiece(move.start.x, move.start.y);
- let notation = "";
- if (piece == V.PAWN) {
- // Pawn move
- if (move.vanish.length > 1) {
- // Capture
- const startColumn = V.CoordToColumn(move.start.y);
- notation = startColumn + "x" + finalSquare;
- } else notation = finalSquare;
- } else {
- // Piece movement
- notation =
- piece.toUpperCase() +
- (move.vanish.length > 1 ? "x" : "") +
- finalSquare;
- }
- if (move.appear[0].p != move.vanish[0].p)
- notation += "=" + move.appear[0].p.toUpperCase();
- return notation;
- }
-
-};