Fixed bigger board variants. Still buggish

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

//https://www.chessvariants.com/large.dir/wildebeest.html
class WildebeestRules extends ChessRules
{
	static getPpath(b)
	{
		const V = VariantRules;
		return ([V.CAMEL,V.WILDEBEEST].includes(b[1]) ? "Wildebeest/" : "") + b;
	}

	static get size() { return [10,11]; }

	static get CAMEL() { return 'c'; }
	static get WILDEBEEST() { return 'w'; }

	static get steps() {
		return Object.assign(
			ChessRules.steps, //add camel moves:
			{'c': [ [-3,-1],[-3,1],[-1,-3],[-1,3],[1,-3],[1,3],[3,-1],[3,1] ]}
		);
	}

	// En-passant after 2-sq or 3-sq jumps
	getEpSquare(move)
	{
		const [sx,sy,ex] = [move.start.x,move.start.y,move.end.x];
		if (this.getPiece(sx,sy) == VariantRules.PAWN && Math.abs(sx - ex) >= 2)
		{
			const step = (ex-sx) / Math.abs(ex-sx);
			let res = [{
				x: sx + step,
				y: sy
			}];
			if (sx + 2*step != ex) //3-squares move
			{
				res.push({
					x: sx + 2*step,
					y: sy
				});
			}
			return res;
		}
		return undefined; //default
	}

	getPotentialMovesFrom([x,y])
	{
		switch (this.getPiece(x,y))
		{
			case VariantRules.CAMEL:
				return this.getPotentialCamelMoves([x,y]);
			case VariantRules.WILDEBEEST:
				return this.getPotentialWildebeestMoves([x,y]);
			default:
				return super.getPotentialMovesFrom([x,y])
		}
	}

	// Pawns jump 2 or 3 squares, and promote to queen or wildebeest
	getPotentialPawnMoves([x,y])
	{
		const color = this.turn;
		let moves = [];
		const V = VariantRules;
		const [sizeX,sizeY] = VariantRules.size;
		const shift = (color == "w" ? -1 : 1);
		const startRanks = (color == "w" ? [sizeY-2,sizeY-3] : [1,2]);
		const lastRank = (color == "w" ? 0 : sizeY-1);

		if (x+shift >= 0 && x+shift < sizeX && x+shift != lastRank)
		{
			// Normal moves
			if (this.board[x+shift][y] == V.EMPTY)
			{
				moves.push(this.getBasicMove([x,y], [x+shift,y]));
				if (startRanks.includes(x) && this.board[x+2*shift][y] == V.EMPTY)
				{
					// Two squares jump
					moves.push(this.getBasicMove([x,y], [x+2*shift,y]));
					if (x == startRanks[0] && this.board[x+3*shift][y] == V.EMPTY)
					{
						// 3-squares jump
						moves.push(this.getBasicMove([x,y], [x+3*shift,y]));
					}
				}
			}
			// Captures
			if (y>0 && this.canTake([x,y], [x+shift,y-1]) && this.board[x+shift][y-1] != V.EMPTY)
				moves.push(this.getBasicMove([x,y], [x+shift,y-1]));
			if (y<sizeY-1 && this.canTake([x,y], [x+shift,y+1]) && this.board[x+shift][y+1] != V.EMPTY)
				moves.push(this.getBasicMove([x,y], [x+shift,y+1]));
		}

		if (x+shift == lastRank)
		{
			// Promotion
			let promotionPieces = [V.QUEEN,V.WILDEBEEST];
			promotionPieces.forEach(p => {
				// Normal move
				if (this.board[x+shift][y] == V.EMPTY)
					moves.push(this.getBasicMove([x,y], [x+shift,y], {c:color,p:p}));
				// Captures
				if (y>0 && this.canTake([x,y], [x+shift,y-1]) && this.board[x+shift][y-1] != V.EMPTY)
					moves.push(this.getBasicMove([x,y], [x+shift,y-1], {c:color,p:p}));
				if (y<sizeY-1 && this.canTake([x,y], [x+shift,y+1]) && this.board[x+shift][y+1] != V.EMPTY)
					moves.push(this.getBasicMove([x,y], [x+shift,y+1], {c:color,p:p}));
			});
		}

		// En passant
		const Lep = this.epSquares.length;
		const epSquare = Lep>0 ? this.epSquares[Lep-1] : undefined;
		if (!!epSquare)
		{
			for (let epsq of epSquare)
			{
				// TODO: some redundant checks
				if (epsq.x == x+shift && Math.abs(epsq.y - y) == 1)
				{
					let epStep = epsq.y - y;
					var enpassantMove = this.getBasicMove([x,y], [x+shift,y+epStep]);
					enpassantMove.vanish.push({
						x: x,
						y: y+epStep,
						p: 'p',
						c: this.getColor(x,y+epStep)
					});
					moves.push(enpassantMove);
				}
			}
		}

		return moves;
	}

	// TODO: wildebeest castle

	getPotentialCamelMoves(sq)
	{
		return this.getSlideNJumpMoves(sq, VariantRules.steps[VariantRules.CAMEL], "oneStep");
	}

	getPotentialWildebeestMoves(sq)
	{
		const V = VariantRules;
		return this.getSlideNJumpMoves(sq, V.steps[V.KNIGHT].concat(V.steps[V.CAMEL]), "oneStep");
	}

	isAttacked(sq, colors)
	{
		return super.isAttacked(sq, colors)
			|| this.isAttackedByCamel(sq, colors)
			|| this.isAttackedByWildebeest(sq, colors);
	}

	isAttackedByCamel(sq, colors)
	{
		return this.isAttackedBySlideNJump(sq, colors,
			VariantRules.CAMEL, VariantRules.steps[VariantRules.CAMEL]);
	}

	isAttackedByWildebeest(sq, colors)
	{
		const V = VariantRules;
		return this.isAttackedBySlideNJump(sq, colors, V.WILDEBEEST,
			V.steps[V.KNIGHT].concat(V.steps[V.CAMEL]));
	}

	static get VALUES() {
		return Object.assign(
			ChessRules.VALUES,
			{'c': 3, 'w': 7} //experimental
		);
	}

	static get SEARCH_DEPTH() { return 2; }

	static GenRandInitFen()
	{
		let pieces = [new Array(10), new Array(10)];
		// Shuffle pieces on first and last rank
		for (let c = 0; c <= 1; c++)
		{
			let positions = _.range(11);

			// Get random squares for bishops
			let randIndex = 2 * _.random(5);
			let bishop1Pos = positions[randIndex];
			// The second bishop must be on a square of different color
			let randIndex_tmp = 2 * _.random(4) + 1;
			let bishop2Pos = positions[randIndex_tmp];
			// Remove chosen squares
			positions.splice(Math.max(randIndex,randIndex_tmp), 1);
			positions.splice(Math.min(randIndex,randIndex_tmp), 1);

			// Get random squares for knights
			randIndex = _.random(8);
			let knight1Pos = positions[randIndex];
			positions.splice(randIndex, 1);
			randIndex = _.random(7);
			let knight2Pos = positions[randIndex];
			positions.splice(randIndex, 1);

			// Get random square for queen
			randIndex = _.random(6);
			let queenPos = positions[randIndex];
			positions.splice(randIndex, 1);

			// ...random square for camels
			randIndex = _.random(5);
			let camel1Pos = positions[randIndex];
			positions.splice(randIndex, 1);
			randIndex = _.random(4);
			let camel2Pos = positions[randIndex];
			positions.splice(randIndex, 1);

			// ...random square for wildebeest
			randIndex = _.random(3);
			let wildebeestPos = positions[randIndex];
			positions.splice(randIndex, 1);

			// Rooks and king positions are now fixed, because of the ordering rook-king-rook
			let rook1Pos = positions[0];
			let kingPos = positions[1];
			let rook2Pos = positions[2];

			// Finally put the shuffled pieces in the board array
			pieces[c][rook1Pos] = 'r';
			pieces[c][knight1Pos] = 'n';
			pieces[c][bishop1Pos] = 'b';
			pieces[c][queenPos] = 'q';
			pieces[c][camel1Pos] = 'c';
			pieces[c][camel2Pos] = 'c';
			pieces[c][wildebeestPos] = 'w';
			pieces[c][kingPos] = 'k';
			pieces[c][bishop2Pos] = 'b';
			pieces[c][knight2Pos] = 'n';
			pieces[c][rook2Pos] = 'r';
		}
		let fen = pieces[0].join("") +
			"/ppppppppppp/11/11/11/11/11/11/PPPPPPPPPPP/" +
			pieces[1].join("").toUpperCase() +
			" 1111";
		return fen;
	}
}