@ayshrj/checkers.js/dist/index.d.mts

A TypeScript-based headless Checker game engine for simulating game logic, AI moves, and game state management.

import { EventEmitter } from 'events';

/**
 * Player colors in Checkers
 */
type Color = "red" | "black";
/**
 * Type of checker piece
 */
type PieceType = "man" | "king";
/**
 * Represents a game piece
 */
interface Piece {
    color: Color;
    type: PieceType;
}
/**
 * Board position (row, column)
 */
interface Position {
    row: number;
    col: number;
}
/**
 * Complete move definition including captures
 */
interface CheckersMove {
    from: Position;
    path: Position[];
    captures: Position[];
}
/**
 * Possible game states
 */
type GameState = "redTurn" | "blackTurn" | "gameOver";
/**
 * Complete game state snapshot
 */
interface CheckersGameState {
    board: (Piece | null)[][];
    turn: Color;
    allowedMoves: CheckersMove[];
    gameState: GameState;
    boardStatus: string;
    isGameOver: boolean;
}

/**
 * Main Checkers game class with event emitting
 */
declare class Checkers extends EventEmitter {
    private _board;
    private _turn;
    constructor();
    /**
     * Reset game to initial state
     */
    reset(): void;
    /**
     * Returns the piece at the given position (or null).
     */
    getPiece(pos: Position): Piece | null;
    /**
     * Get current game state
     */
    getCurrentState(): CheckersGameState;
    /**
     * Execute a move if valid
     */
    move(move: CheckersMove): boolean;
    /**
     * Generate best move using minimax algorithm
     */
    bestMove(depth: number): CheckersMove | null;
    private _emitStateChange;
    private _promoteIfNeeded;
    private validateMove;
    /**
     * Generate all allowed moves for the player whose turn is `turn` on the given board.
     * If any capturing moves are available, they are mandatory.
     */
    static getAllowedMovesForBoard(board: (Piece | null)[][], turn: Color): CheckersMove[];
    /**
     * Recursively generate all capturing (jump) moves for a piece starting from `pos` on the given board.
     */
    static getCapturesForPiece(board: (Piece | null)[][], pos: Position, piece: Piece, currentMove?: CheckersMove): CheckersMove[];
    /**
     * Generate simple (non-capturing) moves for a piece at position `pos` on the given board.
     */
    static getSimpleMovesForPiece(board: (Piece | null)[][], pos: Position, piece: Piece): CheckersMove[];
    /**
     * Deep-clone a board (8x8 array).
     */
    static cloneBoard(board: (Piece | null)[][]): (Piece | null)[][];
    /**
     * Returns the allowed movement directions for a piece.
     * For a man: red moves upward (row decreases) and black moves downward (row increases).
     * Kings move in all four diagonal directions.
     */
    static getDirections(piece: Piece): number[][];
    /**
     * Returns a new board state after applying the given move.
     * This function does not modify the original board.
     */
    static updateBoard(board: (Piece | null)[][], move: CheckersMove): (Piece | null)[][];
    /**
     * Evaluate the board state from the perspective of the given player.
     * Positive values favor `perspective`, negative values favor the opponent.
     */
    static evaluateBoard(board: (Piece | null)[][], perspective: Color): number;
    /**
     * Helper: Shuffle an array (Fisher–Yates shuffle).
     */
    static shuffle<T>(array: T[]): T[];
    /**
     * Minimax algorithm (without alpha–beta pruning) to search for the best move.
     * @param board The board state to evaluate.
     * @param depth How many plies to search.
     * @param isMax Whether we are maximizing or minimizing.
     * @param turn Which color is to move on this board.
     * @param perspective The original player for whom we are evaluating.
     * @returns An object with a score and the best move found.
     */
    static minimax(board: (Piece | null)[][], depth: number, isMax: boolean, turn: Color, perspective: Color): {
        score: number;
        move: CheckersMove | null;
    };
    /**
     * Helper: Compare two moves for equality.
     */
    static compareMoves(m1: CheckersMove, m2: CheckersMove): boolean;
}

export { Checkers, type CheckersGameState, type CheckersMove, type Color, type GameState, type Piece, type PieceType, type Position };