private void removeAnyCapturedPieces(Move move, CheckersBoard nextState) {
int takenPieceXCoord = (move.getFrom().getXCoord() + move.getTo().getXCoord()) / 2;
int takenPieceYCoord = (move.getFrom().getYCoord() + move.getTo().getYCoord()) / 2;
Position takenPosition = new Position(takenPieceXCoord, takenPieceYCoord);
if (!move.getFrom().equals(takenPosition)
&& !move.getTo()
.equals(
takenPosition)) { // neither the from or the 2 are the calculated middle position
// then it has moved more then one place. Thus we must be
// capturing a piece
for (Piece<CheckersPieceDescription> removedPiece :
nextState.getPiecesAtPlacement(takenPosition)) {
nextState.removePiece(
removedPiece); // no need to check whether this is an opponents piece as this move will
// become invalidated in the game service.
}
}
}
public CheckersBoard playMove(Iterable<Move> moves) throws GameFinishedException {
CheckersBoard board = gameService.getCurrentState();
CheckersBoard nextState = new CheckersBoard(boardIdService.nextId(), board);
Iterable<Move> reverseStack = Lists.reverse(Lists.newArrayList(moves));
for (Move move : reverseStack) {
Piece<CheckersPieceDescription> piece = getPieceAtPossition(move.getFrom(), nextState);
if (!board.isValidBoardPosition(move.getTo())) {
throw new IllegalArgumentException(
"The move to: " + move.getTo() + " is not within the confines of the board");
}
nextState.removePiece(piece);
CheckersPieceDescription pieceToPlace =
upgradePieceIfRequired(piece.getPiece(), move.getTo(), nextState);
Piece<CheckersPieceDescription> nextPiece =
new Piece<CheckersPieceDescription>(move.getTo(), pieceToPlace);
nextState.addPiece(nextPiece);
// create new state from current state
// remove any opponents that might have been captured with this move
removeAnyCapturedPieces(move, nextState);
}
gameService.playNextMove(nextState);
return gameService.getCurrentState();
}