@chess-fu/chess-game/dist/src/chessUtils.js

Chess game logic

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
var constants_1 = require("./constants");
var lowerA = 'a';
var lowerZ = 'z';
var upperA = 'A';
var upperZ = 'Z';
var lowerACode = 'a'.charCodeAt(0);
var NUMBER = 'number';
function isPieceColor(boardPiece, color) {
    return ((color === constants_1.WHITE && boardPiece >= upperA && boardPiece <= upperZ) ||
        (color !== constants_1.WHITE && boardPiece >= lowerA && boardPiece <= lowerZ));
}
exports.isPieceColor = isPieceColor;
function indexToSquare(index) {
    if (typeof index !== NUMBER || index < 0)
        return constants_1.NONE;
    var file = Math.floor(index / constants_1.BOARD_WIDTH);
    var rank = index - (file * constants_1.BOARD_WIDTH);
    return String.fromCharCode(lowerACode + rank) + (constants_1.BOARD_HEIGHT - file).toString();
}
exports.indexToSquare = indexToSquare;
function indexToOffset(index) {
    var y = Math.floor(index / constants_1.BOARD_WIDTH);
    var x = index - (y * constants_1.BOARD_WIDTH);
    return { x: x, y: y };
}
exports.indexToOffset = indexToOffset;
function squareColor(index) {
    var y = Math.floor(index / constants_1.BOARD_WIDTH);
    var x = index - (y * constants_1.BOARD_WIDTH);
    return (y + x) % 2 === 0 ? constants_1.BLACK : constants_1.WHITE;
}
exports.squareColor = squareColor;
function offsetToIndex(offset) {
    return (offset.y * constants_1.BOARD_WIDTH) + offset.x;
}
exports.offsetToIndex = offsetToIndex;
function offsetValid(offset) {
    return offset.x >= 0 && offset.y >= 0 && offset.x < constants_1.BOARD_WIDTH && offset.y < constants_1.BOARD_HEIGHT;
}
exports.offsetValid = offsetValid;
function addOffsets(a, b) {
    return { x: a.x + b.x, y: a.y + b.y };
}
exports.addOffsets = addOffsets;
function deltaOffsets(a, b) {
    return {
        x: Math.abs(a.x - b.x),
        y: Math.abs(a.y - b.y)
    };
}
exports.deltaOffsets = deltaOffsets;
function buildSAN(move, conflicts) {
    var result = move.piece !== constants_1.PAWN ? [move.piece.toUpperCase()] : [];
    if (conflicts && conflicts.length > 1) {
        var counts = { ranks: {}, files: {} };
        for (var _i = 0, conflicts_1 = conflicts; _i < conflicts_1.length; _i++) {
            var from = conflicts_1[_i];
            counts.ranks[from[1]] = (counts.ranks[from[1]] || 0) + 1;
            counts.files[from[0]] = (counts.files[from[0]] || 0) + 1;
        }
        if (Object.keys(counts.ranks).length === conflicts.length) {
            result.push(move.from[1]);
        }
        else if (Object.keys(counts.files).length === conflicts.length) {
            result.push(move.from[0]);
        }
        else {
            result.push(move.from);
        }
    }
    if (move.captured) {
        if (move.piece === constants_1.PAWN && result.length === 0) {
            result.push(move.from[0]);
        }
        result.push(constants_1.SAN_CAPTURE);
    }
    if (move.castle) {
        result[0] = move.castle < move.from ? 'O-O-O' : 'O-O';
    }
    else {
        result.push(move.to);
        if (move.promotion) {
            result.push("=" + move.promotion.toUpperCase());
        }
    }
    if (move.check) {
        result.push(move.check);
    }
    return result.join('');
}
exports.buildSAN = buildSAN;
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