xchess/lib/board-view.js

Chess Engine

export {BoardView}

import {white, black} from './color.js'
import {King, Queen, Rook, Bishop, Knight, Pawn} from './piece.js'
import {PieceSet} from './piece-set.js'
import {inspect} from './inspect.js'
import {Weight, Advantage, PiecesStat} from './piece-stat.js'
import {InsertEvent, DeleteEvent, TransferEvent} from './events.js'

class BoardView {

	#context;

	constructor(context){
		this.#context = context;
	}

	get #board(){
		return this.#context.board;
	}

	// read

	get size(){
		return this.#board.size;
	}

	keys(){
		return this.#board.keys();
	}

	values(){
		return this.#board.values();
	}

	entries(){
		return this.#board.entries();
	}

	at(x, y){
		return this.#board.at(x, y);
	}

	has(square){
		return this.#board.has(square);
	}

	get(square){
		return this.#board.get(square);
	}

	find(piece){
		return this.#board.find(piece);
	}

	contains(piece){
		return this.#board.contains(piece);
	}

	byColor(color){
		const pieces = new PieceSet();
		for(const piece of this.values())
			if(piece.color.eq(color))
				pieces.add(piece);
		return pieces;
	}

	white(){
		return this.byColor(white);
	}

	black(){
		return this.byColor(black);
	}

	// Stat

	get weight(){
		return Weight(this.values());
	}

	advantage(color){
		return Advantage(this.values(), color);
	}

	stat(){
		return PiecesStat(this.values());
	}

	// I/O

	[inspect.custom](){
		return `${this.constructor.name}(${this.size}) {}`;
	}

	* [Symbol.iterator](){
		yield * this.#board;
	}

	toString(){
		return this.fen;
	}

	hash(){
		return this.#board.hash();
	}

	toJSON(){
		return this.#board.toJSON();
	}

	text(opts){
		return this.#board.text(opts);
	}

	log(opts){
		this.#board.log(opts);
	}

	get fen(){
		return this.#board.fen;
	}

	// write

	#access(){
		this.#context.access();
	}

	#onInsert(piece, square){
		this.#context.dispatch(new InsertEvent(piece, square));
	}

	#onDelete(piece, square){
		this.#context.dispatch(new DeleteEvent(piece, square));
	}

	#onTransfer(piece, from, to){
		this.#context.dispatch(new TransferEvent(piece, from, to));
	}

	set fen(fen){
		this.#access();
		const deleted = new Map(this.#board);
		this.#board.fen = fen;
		for(const [square, piece] of deleted)
			this.#onDelete(piece, square);
		for(const [square, piece] of this)
			this.#onInsert(piece, square);
	}

	setAll(board){
		this.#access();
		const deleted = new Map(this.#board);
		this.#board.setAll(board);
		for(const [square, piece] of deleted)
			this.#onDelete(piece, square);
		for(const [square, piece] of this)
			this.#onInsert(piece, square);
	}

	set(square, piece){
		this.#access();
		const report = this.#board.set(square, piece);
		if(report.deleted)
			this.#onDelete(report.deleted, report.to);
		if(report.inserted)
			this.#onInsert(report.inserted, report.to);
		if(report.moved)
			this.#onTransfer(report.moved, report.from, report.to);
		return report;
	}

	move(from, to){
		this.#access();
		const report = this.#board.move(from, to);
		if(report.deleted)
			this.#onDelete(report.deleted, report.to);
		if(report.moved)
			this.#onTransfer(report.moved, report.from, report.to);
		return report;
	}

	delete(square){
		this.#access();
		const {change, from, deleted} = this.#board.delete(square);
		if(change){
			this.#onDelete(deleted, from);
			return {change, from, deleted};
		}	return {change};
	}

	clear(){
		this.#access();
		const board = new Map(this.#board);
		const count = this.#board.clear();
		for(const [square, piece] of board)
			this.#onDelete(piece, square);
		return count;
	}

	// Piece

	king(square, color){
		const piece = new King(color);
		this.set(square, piece);
		return piece;
	}

	queen(square, color){
		const piece = new Queen(color);
		this.set(square, piece);
		return piece;
	}

	rook(square, color){
		const piece = new Rook(color);
		this.set(square, piece);
		return piece;
	}

	bishop(square, color){
		const piece = new Bishop(color);
		this.set(square, piece);
		return piece;
	}

	knight(square, color){
		const piece = new Knight(color);
		this.set(square, piece);
		return piece;
	}

	pawn(square, color){
		const piece = new Pawn(color);
		this.set(square, piece);
		return piece;
	}

	k(square){
		return this.king(square, black);
	}

	q(square){
		return this.queen(square, black);
	}

	r(square){
		return this.rook(square, black);
	}

	b(square){
		return this.bishop(square, black);
	}

	n(square){
		return this.knight(square, black);
	}

	p(square){
		return this.pawn(square, black);
	}

	K(square){
		return this.king(square, white);
	}

	Q(square){
		return this.queen(square, white);
	}

	R(square){
		return this.rook(square, white);
	}

	B(square){
		return this.bishop(square, white);
	}

	N(square){
		return this.knight(square, white);
	}

	P(square){
		return this.pawn(square, white);
	}

	setup(){

		this.clear();

		// Black

		this.r('a8');
		this.n('b8');
		this.b('c8');
		this.q('d8');
		this.k('e8');
		this.b('f8');
		this.n('g8');
		this.r('h8');

		this.p('a7');
		this.p('b7');
		this.p('c7');
		this.p('d7');
		this.p('e7');
		this.p('f7');
		this.p('g7');
		this.p('h7');

		// White

		this.P('a2');
		this.P('b2');
		this.P('c2');
		this.P('d2');
		this.P('e2');
		this.P('f2');
		this.P('g2');
		this.P('h2');

		this.R('a1');
		this.N('b1');
		this.B('c1');
		this.Q('d1');
		this.K('e1');
		this.B('f1');
		this.N('g1');
		this.R('h1');

		return this;
	}
}