public function getPiecePossibleMoves(Piece $piece)
{
$player = $piece->getPlayer();
$isKingAttacked = $this->isKingAttacked($player);
$allOpponentPieces = PieceFilter::filterNotClass(PieceFilter::filterAlive($player->getOpponent()->getPieces()), 'King');
$king = $player->getKing();
$kingSquareKey = $king->getSquareKey();
$pieceOriginalX = $piece->getX();
$pieceOriginalY = $piece->getY();
$opponentPieces = PieceFilter::filterProjection($allOpponentPieces);
//if we are not moving the king, and the king is not attacked, don't check pawns nor knights
if (!$piece instanceof King && !$isKingAttacked) {
$opponentPieces = PieceFilter::filterProjection($opponentPieces);
}
$squares = $this->board->keysToSquares($piece->getBasicTargetKeys());
if ($piece instanceof King && !$isKingAttacked && !$piece->hasMoved()) {
$squares = $this->addCastlingSquares($piece, $squares);
}
foreach ($squares as $it => $square) {
// kings move to its target so we update its position
if ($piece instanceof King) {
$kingSquareKey = $square->getKey();
}
// kill opponent piece
if ($killedPiece = $square->getPiece()) {
$killedPiece->setIsDead(true);
}
$this->board->move($piece, $square->getX(), $square->getY());
foreach ($opponentPieces as $opponentPiece) {
if (null !== $killedPiece && $opponentPiece->getIsDead()) {
continue;
}
// if our king gets attacked
if (in_array($kingSquareKey, $this->getPieceControlledKeys($opponentPiece, $piece instanceof King))) {
// can't go here
unset($squares[$it]);
break;
}
}
$this->board->move($piece, $pieceOriginalX, $pieceOriginalY);
// if a piece has been killed, bring it back to life
if ($killedPiece) {
$killedPiece->setIsDead(false);
$this->board->add($killedPiece);
}
}
return $this->board->squaresToKeys($squares);
}
/**
* @return array key => array keys
*/
public function getPlayerPossibleMoves(Player $player, $isKingAttacked = null)
{
$possibleMoves = array();
$isKingAttacked = null === $isKingAttacked ? $this->isKingAttacked($player) : $isKingAttacked;
$allOpponentPieces = PieceFilter::filterAlive($player->getOpponent()->getPieces());
$attackOpponentPieces = PieceFilter::filterNotClass($allOpponentPieces, 'King');
$projectionOpponentPieces = PieceFilter::filterProjection($allOpponentPieces);
$king = $player->getKing();
foreach (PieceFilter::filterAlive($player->getPieces()) as $piece) {
$kingSquareKey = $king->getSquareKey();
$pieceOriginalX = $piece->getX();
$pieceOriginalY = $piece->getY();
$pieceClass = $piece->getClass();
//if we are not moving the king, and the king is not attacked, don't check pawns nor knights
if ('King' === $pieceClass) {
$opponentPieces = $allOpponentPieces;
} elseif ($isKingAttacked) {
$opponentPieces = $attackOpponentPieces;
} else {
$opponentPieces = $projectionOpponentPieces;
}
$squares = $this->board->keysToSquares($piece->getBasicTargetKeys());
foreach ($squares as $it => $square) {
// king move to its target so we update its position
if ('King' === $pieceClass) {
$kingSquareKey = $square->getKey();
}
// kill opponent piece
if ($killedPiece = $square->getPiece()) {
$killedPiece->setIsDead(true);
} elseif ('Pawn' === $pieceClass && $square->getX() !== $pieceOriginalX) {
$killedPiece = $square->getSquareByRelativePos(0, $player->isWhite() ? -1 : 1)->getPiece();
$killedPiece->setIsDead(true);
}
$this->board->move($piece, $square->getX(), $square->getY());
foreach ($opponentPieces as $opponentPiece) {
if (null !== $killedPiece && $opponentPiece->getIsDead()) {
continue;
}
// if our king gets attacked
if (in_array($kingSquareKey, $opponentPiece->getAttackTargetKeys())) {
// can't go here
unset($squares[$it]);
break;
}
}
$this->board->move($piece, $pieceOriginalX, $pieceOriginalY);
// if a piece has been killed, bring it back to life
if ($killedPiece) {
$killedPiece->setIsDead(false);
$this->board->add($killedPiece);
}
}
if ('King' === $pieceClass && !$isKingAttacked && !$piece->hasMoved()) {
$squares = $this->addCastlingSquares($piece, $squares);
}
if (!empty($squares)) {
$possibleMoves[$piece->getSquareKey()] = $this->board->squaresToKeys($squares);
}
}
return $possibleMoves;
}