/**
* @param MoveInterface $move
*
* @return string
*/
public static function toNotation(MoveInterface $move)
{
if (null === $move->getPiece()) {
return '';
}
$notation = '';
$piece = $move->getPiece();
$toLabel = strtolower($move->getToLabel());
$isPawn = $piece->getType() === PieceInterface::TYPE_PAWN;
$pieceLetter = PieceDecorator::toLetter($piece);
if (null !== ($capture = $move->getCapture())) {
if ($isPawn) {
$column = BoardHelper::getColumnFromPosition($move->getFrom());
$pieceLetter = BoardHelper::columnNumberToLetter($column);
}
$notation .= sprintf('%sx%s', $pieceLetter, $toLabel);
if ($isPawn) {
if ($move->getType() === MoveInterface::TYPE_CAPTURE_EN_PASSANT) {
$notation .= 'e.p.';
}
}
return $notation;
}
if ($isPawn) {
return $toLabel;
}
return sprintf('%s%s', $pieceLetter, $toLabel);
}
/**
* {@inheritdoc}
*/
public function configureWalker(BoardWalker $walker, GameInterface $game)
{
$walker->omnidirectional(1);
$kingPosition = BoardHelper::getKingPosition($game->getBoard(), $game->getCurrentColor());
$kingColumn = BoardHelper::getColumnFromPosition($kingPosition);
$kingRow = BoardHelper::getRowFromPosition($kingPosition);
$board = $game->getBoard();
$king = $board->getSquare($kingPosition)->getPiece();
$track = $kingPosition === SquareInterface::POSITION_E1;
// check for possible castle move
if (empty($game->getMovesByPiece($king->getId()))) {
// see if one of the rooks did not make any moves
$rookCriteria = ['piece_type' => PieceInterface::TYPE_ROOK, 'piece_color' => $game->getCurrentColor()];
foreach ($board->getPiecesBy($rookCriteria) as $rookPosition => $rook) {
if (empty($game->getMovesByPiece($rook->getId()))) {
// see if there are no pieces between the king and this rook
$rookColumn = BoardHelper::getColumnFromPosition($rookPosition);
$columnDiff = abs($kingColumn - $rookColumn) - 1;
$track = $track === true && $columnDiff === 3;
if ($columnDiff > 1) {
$skip = false;
for ($x = 1; $x <= $columnDiff; $x++) {
if ($rookColumn > $kingColumn) {
$cursor = $rookColumn - $x . $kingRow;
} else {
$cursor = $rookColumn + $x . $kingRow;
}
if (null !== ($piece = $board->getSquare($cursor)->getPiece())) {
$skip = true;
break;
}
}
if ($skip) {
continue;
}
if ($kingColumn > $rookColumn) {
if ($game->getCurrentColor() === Color::WHITE) {
$walker->jump(BoardWalker::DIRECTION_LEFT, 2);
} else {
$walker->jump(BoardWalker::DIRECTION_RIGHT, 2);
}
} else {
if ($game->getCurrentColor() === Color::WHITE) {
$walker->jump(BoardWalker::DIRECTION_RIGHT, 2);
} else {
$walker->jump(BoardWalker::DIRECTION_LEFT, 2);
}
}
}
}
}
}
}
/**
* {@inheritdoc}
*/
public function getIndexedSquares($indexedBy = 'row')
{
$squares = [];
switch ($indexedBy) {
case 'row':
$squares = [];
foreach ($this->getSquares() as $square) {
$row = BoardHelper::getRowFromPosition($square->getPosition());
if (!array_key_exists($row, $squares)) {
$squares[$row] = [];
}
$squares[$row][$square->getPosition()] = $square;
}
break;
case 'column':
$squares = [];
foreach ($this->getSquares() as $square) {
$column = BoardHelper::getColumnFromPosition($square->getPosition());
if (!array_key_exists($column, $squares)) {
$squares[$column] = [];
}
$squares[$column][$square->getPosition()] = $square;
}
break;
}
ksort($squares);
return $squares;
}
/**
* @param int $direction The direction to step into
* @param int $jumps The number of jumps to make in this direction
* @param int|null $startingPosition
* @param bool $ignoreCapture
*
* @return int|null The expected position, or null if the move is not possible
*
* @throws \InvalidArgumentException
*/
public function peek($direction, $jumps = 1, $startingPosition = null, $ignoreCapture = false, $requireAttack = false)
{
$newPosition = null;
if ($startingPosition !== null) {
$column = BoardHelper::getColumnFromPosition($startingPosition);
$row = BoardHelper::getRowFromPosition($startingPosition);
} else {
$column = $this->getColumn();
$row = $this->getRow();
}
switch ($direction) {
case self::DIRECTION_FORWARD:
if ($this->color === Color::WHITE) {
$newRow = $this->formatNumber($row + $jumps);
} else {
$newRow = $this->formatNumber($row - $jumps);
}
if ($newRow !== null) {
$newPosition = intval($column . $newRow);
}
break;
case self::DIRECTION_FORWARDRIGHT:
if ($this->color === Color::WHITE) {
$newColumn = $this->formatNumber($column + $jumps);
$newRow = $this->formatNumber($row + $jumps);
} else {
$newColumn = $this->formatNumber($column - $jumps);
$newRow = $this->formatNumber($row - $jumps);
}
if ($newColumn !== null && $newRow !== null) {
$newPosition = intval($newColumn . $newRow);
}
break;
case self::DIRECTION_RIGHT:
if ($this->color === Color::WHITE) {
$newColumn = $this->formatNumber($column + $jumps);
} else {
$newColumn = $this->formatNumber($column - $jumps);
}
if ($newColumn !== null) {
$newPosition = intval($newColumn . $row);
}
break;
case self::DIRECTION_BACKWARDRIGHT:
if ($this->color === Color::WHITE) {
$newColumn = $this->formatNumber($column + $jumps);
$newRow = $this->formatNumber($row - $jumps);
} else {
$newColumn = $this->formatNumber($column - $jumps);
$newRow = $this->formatNumber($row + $jumps);
}
if ($newColumn !== null && $newRow !== null) {
$newPosition = intval($newColumn . $newRow);
}
break;
case self::DIRECTION_BACKWARD:
if ($this->color === Color::WHITE) {
$newRow = $this->formatNumber($row - $jumps);
} else {
$newRow = $this->formatNumber($row + $jumps);
}
if ($newRow !== null) {
$newPosition = intval($column . $newRow);
}
break;
case self::DIRECTION_BACKWARDLEFT:
if ($this->color === Color::WHITE) {
$newColumn = $this->formatNumber($column - $jumps);
$newRow = $this->formatNumber($row - $jumps);
} else {
$newColumn = $this->formatNumber($column + $jumps);
$newRow = $this->formatNumber($row + $jumps);
}
if ($newColumn !== null && $newRow !== null) {
$newPosition = intval($newColumn . $newRow);
}
break;
case self::DIRECTION_LEFT:
if ($this->color === Color::WHITE) {
$newColumn = $this->formatNumber($column - $jumps);
} else {
$newColumn = $this->formatNumber($column + $jumps);
}
if ($newColumn !== null) {
$newPosition = intval($newColumn . $row);
}
break;
case self::DIRECTION_FORWARDLEFT:
if ($this->color === Color::WHITE) {
$newColumn = $this->formatNumber($column - $jumps);
$newRow = $this->formatNumber($row + $jumps);
} else {
$newColumn = $this->formatNumber($column + $jumps);
$newRow = $this->formatNumber($row - $jumps);
}
if ($newColumn !== null && $newRow !== null) {
$newPosition = intval($newColumn . $newRow);
}
break;
default:
throw new \InvalidArgumentException(sprintf('Unknown direction to calculate: %s', $direction));
}
if ($ignoreCapture !== true && $newPosition !== null) {
$toPiece = $this->board->getSquare($newPosition)->getPiece();
if (null !== $toPiece) {
if ($toPiece->getColor() === $this->getColor()) {
// own piece, can't capture
return null;
}
} elseif ($requireAttack === true) {
return null;
}
}
return $newPosition;
}
/**
* @param MoveInterface $move
* @param GameInterface $game
*
* @return int|null
*/
private static function determineEnPassantType(MoveInterface $move, GameInterface $game)
{
if (null !== ($lastMove = $game->getLastMove())) {
if ($lastMove->getPiece()->getType() === PieceInterface::TYPE_PAWN) {
if (abs(BoardHelper::getColumnFromPosition($lastMove->getTo()) - BoardHelper::getColumnFromPosition($move->getFrom())) === 1 && abs(BoardHelper::getRowFromPosition($lastMove->getTo()) - BoardHelper::getRowFromPosition($lastMove->getFrom())) === 2 && BoardHelper::getRowFromPosition($move->getFrom()) === BoardHelper::getRowFromPosition($lastMove->getTo())) {
$toPiece = $game->getBoard()->getSquare($move->getTo())->getPiece();
$rowDiff = abs(BoardHelper::getRowFromPosition($move->getFrom()) - BoardHelper::getRowFromPosition($move->getTo()));
$columnDiff = abs(BoardHelper::getColumnFromPosition($move->getFrom()) - BoardHelper::getColumnFromPosition($move->getTo()));
if ($rowDiff === 1 && $columnDiff === 1) {
if ($toPiece === null) {
// en passant capture
return MoveInterface::TYPE_CAPTURE_EN_PASSANT;
} else {
return MoveInterface::TYPE_CAPTURE;
}
}
}
}
}
return null;
}
