add castling commands

app/src/main/java/chess/controller/commands/GetAllowedCastlingsCommand.java

@@ -0,0 +1,37 @@
+package chess.controller.commands;
+
+import chess.controller.Command;
+import chess.controller.event.GameListener;
+import chess.model.Game;
+
+public class GetAllowedCastlingsCommand extends Command{
+
+	public enum CastlingResult {
+		None, Small, Big, Both;
+	}
+
+	private CastlingResult castlingResult;
+
+	public GetAllowedCastlingsCommand() {}
+
+	@Override
+	public CommandResult execute(Game game, GameListener outputSystem) {
+		boolean canSmallCastle = game.getBoard().canSmallCastle(game.getPlayerTurn());
+		boolean canBigCastle = game.getBoard().canBigCastle(game.getPlayerTurn());
+
+		int result = 0;
+		if (canSmallCastle)
+			result += 1;
+		if (canBigCastle)
+			result += 2;
+
+		this.castlingResult = CastlingResult.values()[result];
+
+		return CommandResult.NotMoved;
+	}
+
+	public CastlingResult getCastlingResult() {
+		return castlingResult;
+	}
+	
+}