add castling + fix promote undo

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

@@ -2,23 +2,62 @@ package chess.controller.commands;
 
 import chess.controller.OutputSystem;
 import chess.controller.PlayerCommand;
+import chess.model.ChessBoard;
+import chess.model.Color;
+import chess.model.Coordinate;
 import chess.model.Game;
+import chess.model.Move;
 
 public class CastlingCommand extends PlayerCommand {
 
+	private Move kingMove;
+	private Move rookMove;
+	private final boolean bigCastling;
+
+	public CastlingCommand(boolean bigCastling) {
+		this.bigCastling = bigCastling;
+	}
+
 	@Override
 	public CommandResult execute(Game game, OutputSystem outputSystem) {
 		// we must promote the pending pawn before
 		if (game.pawnShouldBePromoted())
 			return CommandResult.NotAllowed;
 
-		return CommandResult.NotAllowed;
+		final ChessBoard board = game.getBoard();
+
+		if (bigCastling && !board.canBigCastle(game.getPlayerTurn()))
+			return CommandResult.NotAllowed;
+
+		if (!bigCastling && !board.canSmallCastle(game.getPlayerTurn()))
+			return CommandResult.NotAllowed;
+
+		int rookBeginX = bigCastling ? 0 : 7;
+		int rookEndX = bigCastling ? 3 : 5;
+
+		int kingBeginX = 4;
+		int kingEndX = bigCastling ? 2 : 6;
+
+		int colorLine = game.getPlayerTurn() == Color.White ? 7 : 0;
+		
+		Coordinate kingCoords = new Coordinate(kingBeginX, colorLine);
+		Coordinate rookCoords = new Coordinate(rookBeginX, colorLine);
+
+		this.kingMove = new Move(kingCoords, new Coordinate(kingEndX, colorLine));
+		this.rookMove = new Move(rookCoords, new Coordinate(rookEndX, colorLine));
+
+		board.applyMove(this.kingMove);
+		board.applyMove(this.rookMove);
+
+		return CommandResult.Moved;
 	}
 
 	@Override
 	protected CommandResult undoImpl(Game game, OutputSystem outputSystem) {
-		// TODO Auto-generated method stub
-		throw new UnsupportedOperationException("Unimplemented method 'undo'");
+		game.getBoard().undoMove(this.kingMove, null);
+		game.getBoard().undoMove(this.rookMove, null);
+
+		return CommandResult.Moved;
 	}
 
 }