Draft code reorganisation (+ fix Alice rules + stateless VariantRules object)

[vchess.git] / public / javascripts / variants / Crazyhouse.js

class CrazyhouseRules extends ChessRules
{
	static IsGoodFen(fen)
	{
		if (!ChessRules.IsGoodFen(fen))
			return false;
		const fenParsed = V.ParseFen(fen);
		// 5) Check reserves
		if (!fenParsed.reserve || !fenParsed.reserve.match(/^[0-9]{10,10}$/))
			return false;
		// 6) Check promoted array
		if (!fenParsed.promoted)
			return false;
		if (fenParsed.promoted == "-")
			return true; //no promoted piece on board
		const squares = fenParsed.promoted.split(",");
		for (let square of squares)
		{
			const c = V.SquareToCoords(square);
			if (c.y < 0 || c.y > V.size.y || isNaN(c.x) || c.x < 0 || c.x > V.size.x)
				return false;
		}
		return true;
	}

	static ParseFen(fen)
	{
		const fenParts = fen.split(" ");
		return Object.assign(
			ChessRules.ParseFen(fen),
			{
				reserve: fenParts[5],
				promoted: fenParts[6],
			}
		);
	}

	static GenRandInitFen()
	{
		return ChessRules.GenRandInitFen() + " 0000000000 -";
	}

	getFen()
	{
		return super.getFen() + " " + this.getReserveFen() + " " + this.getPromotedFen();
	}

	getReserveFen()
	{
		let counts = new Array(10);
		for (let i=0; i<V.PIECES.length-1; i++) //-1: no king reserve
		{
			counts[i] = this.reserve["w"][V.PIECES[i]];
			counts[5+i] = this.reserve["b"][V.PIECES[i]];
		}
		return counts.join("");
	}

	getPromotedFen()
	{
		let res = "";
		for (let i=0; i<V.size.x; i++)
		{
			for (let j=0; j<V.size.y; j++)
			{
				if (this.promoted[i][j])
					res += V.CoordsToSquare({x:i,y:j});
			}
		}
		if (res.length > 0)
			res = res.slice(0,-1); //remove last comma
		else
			res = "-";
		return res;
	}

	setOtherVariables(fen)
	{
		super.setOtherVariables(fen);
		const fenParsed = V.ParseFen(fen);
		// Also init reserves (used by the interface to show landable pieces)
		this.reserve =
		{
			"w":
			{
				[V.PAWN]: parseInt(fenParsed.reserve[0]),
				[V.ROOK]: parseInt(fenParsed.reserve[1]),
				[V.KNIGHT]: parseInt(fenParsed.reserve[2]),
				[V.BISHOP]: parseInt(fenParsed.reserve[3]),
				[V.QUEEN]: parseInt(fenParsed.reserve[4]),
			},
			"b":
			{
				[V.PAWN]: parseInt(fenParsed.reserve[5]),
				[V.ROOK]: parseInt(fenParsed.reserve[6]),
				[V.KNIGHT]: parseInt(fenParsed.reserve[7]),
				[V.BISHOP]: parseInt(fenParsed.reserve[8]),
				[V.QUEEN]: parseInt(fenParsed.reserve[9]),
			}
		};
		this.promoted = doubleArray(V.size.x, V.size.y, false);
		if (fenParsed.promoted != "-")
		{
			for (let square of fenParsed.promoted.split(","))
			{
				const [x,y] = V.SquareToCoords(square);
				promoted[x][y] = true;
			}
		}
	}

	getColor(i,j)
	{
		if (i >= V.size.x)
			return (i==V.size.x ? "w" : "b");
		return this.board[i][j].charAt(0);
	}

	getPiece(i,j)
	{
		if (i >= V.size.x)
			return V.RESERVE_PIECES[j];
		return this.board[i][j].charAt(1);
	}

	// Used by the interface:
	getReservePpath(color, index)
	{
		return color + V.RESERVE_PIECES[index];
	}

	// Ordering on reserve pieces
	static get RESERVE_PIECES()
	{
		return [V.PAWN,V.ROOK,V.KNIGHT,V.BISHOP,V.QUEEN];
	}

	getReserveMoves([x,y])
	{
		const color = this.turn;
		const p = V.RESERVE_PIECES[y];
		if (this.reserve[color][p] == 0)
			return [];
		let moves = [];
		const pawnShift = (p==V.PAWN ? 1 : 0);
		for (let i=pawnShift; i<V.size.x-pawnShift; i++)
		{
			for (let j=0; j<V.size.y; j++)
			{
				if (this.board[i][j] == V.EMPTY)
				{
					let mv = new Move({
						appear: [
							new PiPo({
								x: i,
								y: j,
								c: color,
								p: p
							})
						],
						vanish: [],
						start: {x:x, y:y}, //a bit artificial...
						end: {x:i, y:j}
					});
					moves.push(mv);
				}
			}
		}
		return moves;
	}

	getPotentialMovesFrom([x,y])
	{
		if (x >= V.size.x)
		{
			// Reserves, outside of board: x == sizeX(+1)
			return this.getReserveMoves([x,y]);
		}
		// Standard moves
		return super.getPotentialMovesFrom([x,y]);
	}

	getAllValidMoves()
	{
		let moves = super.getAllValidMoves();
		const color = this.turn;
		for (let i=0; i<V.RESERVE_PIECES.length; i++)
			moves = moves.concat(this.getReserveMoves([V.size.x+(color=="w"?0:1),i]));
		return this.filterValid(moves);
	}

	atLeastOneMove()
	{
		if (!super.atLeastOneMove())
		{
			const color = this.turn;
			// Search one reserve move
			for (let i=0; i<V.RESERVE_PIECES.length; i++)
			{
				let moves = this.filterValid(
					this.getReserveMoves([V.size.x+(this.turn=="w"?0:1), i]) );
				if (moves.length > 0)
					return true;
			}
			return false;
		}
		return true;
	}

	updateVariables(move)
	{
		super.updateVariables(move);
		if (move.vanish.length == 2 && move.appear.length == 2)
			return; //skip castle
		const color = move.appear[0].c;
		if (move.vanish.length == 0)
		{
			this.reserve[color][move.appear[0].p]--;
			return;
		}
		move.movePromoted = this.promoted[move.start.x][move.start.y];
		move.capturePromoted = this.promoted[move.end.x][move.end.y]
		this.promoted[move.start.x][move.start.y] = false;
		this.promoted[move.end.x][move.end.y] = move.movePromoted
			|| (move.vanish[0].p == V.PAWN && move.appear[0].p != V.PAWN);
		if (move.capturePromoted)
			this.reserve[color][V.PAWN]++;
		else if (move.vanish.length == 2)
			this.reserve[color][move.vanish[1].p]++;
	}

	unupdateVariables(move)
	{
		super.unupdateVariables(move);
		if (move.vanish.length == 2 && move.appear.length == 2)
			return;
		const color = this.turn;
		if (move.vanish.length == 0)
		{
			this.reserve[color][move.appear[0].p]++;
			return;
		}
		if (move.movePromoted)
			this.promoted[move.start.x][move.start.y] = true;
		this.promoted[move.end.x][move.end.y] = move.capturePromoted;
		if (move.capturePromoted)
			this.reserve[color][V.PAWN]--;
		else if (move.vanish.length == 2)
			this.reserve[color][move.vanish[1].p]--;
	}

	static get SEARCH_DEPTH() { return 2; } //high branching factor

	evalPosition()
	{
		let evaluation = super.evalPosition();
		// Add reserves:
		for (let i=0; i<V.RESERVE_PIECES.length; i++)
		{
			const p = V.RESERVE_PIECES[i];
			evaluation += this.reserve["w"][p] * V.VALUES[p];
			evaluation -= this.reserve["b"][p] * V.VALUES[p];
		}
		return evaluation;
	}

	getNotation(move)
	{
		if (move.vanish.length > 0)
			return super.getNotation(move);
		// Rebirth:
		const piece =
			(move.appear[0].p != V.PAWN ? move.appear[0].p.toUpperCase() : "");
		return piece + "@" + V.CoordsToSquare(move.end);
	}

	getLongNotation(move)
	{
		if (move.vanish.length > 0)
			return super.getLongNotation(move);
		return "@" + V.CoordsToSquare(move.end);
	}
}

const VariantRules = CrazyhouseRules;