better undo

app/src/main/java/chess/io/CommandExecutor.java

@@ -32,7 +32,7 @@ public class CommandExecutor {
 			return;
 
 		if (command instanceof MoveCommand move) {
-			boolean needsPromote = this.game.checkPromotion(move.getMove().getFinish());
+			boolean needsPromote = this.game.pawnShouldBePromoted();
 			if (needsPromote)
 				this.outputSystem.promotePawn(move.getMove().getFinish());
 			

app/src/main/java/chess/io/commands/MoveCommand.java

@@ -10,10 +10,13 @@ import chess.model.Piece;
 import chess.model.visitor.PiecePathChecker;
 
 public class MoveCommand extends PlayerCommand {
+	
 	private final Move move;
+	private Piece deadPiece;
 
 	public MoveCommand(Move move) {
 		this.move = move;
+		this.deadPiece = null;
 	}
 
 	public Move getMove() {
@@ -39,6 +42,7 @@ public class MoveCommand extends PlayerCommand {
 		if (!valid)
 			return CommandResult.NotAllowed;
 
+		this.deadPiece = board.pieceAt(move.getFinish());
 		board.applyMove(move);
 
 		if (board.isKingInCheck(game.getPlayerTurn())) {
@@ -51,7 +55,9 @@ public class MoveCommand extends PlayerCommand {
 
 	@Override
 	public void undo(Game game, OutputSystem outputSystem) {
-		game.getBoard().undoLastMove();
+		final ChessBoard board = game.getBoard();
+
+		board.undoMove(move, deadPiece);
 	}
 
 }

app/src/main/java/chess/io/commands/NewGameCommand.java

@@ -16,7 +16,9 @@ import chess.model.pieces.Rook;
 
 public class NewGameCommand extends Command {
 	public CommandResult execute(Game game, OutputSystem outputSystem) {
-		ChessBoard board = game.getBoard();
+		final ChessBoard board = game.getBoard();
+
+		board.clearBoard();
 
 		for (int i = 0; i < 8; i++) {
 			board.pieceComes(new Pawn(Color.Black), new Coordinate(i, 1));

app/src/main/java/chess/io/commands/PromoteCommand.java

@@ -24,17 +24,21 @@ public class PromoteCommand extends PlayerCommand {
 	}
 
 	private final PromoteType promoteType;
-	private final Coordinate pieceCoords;
+	private Coordinate pieceCoords;
 
-	public PromoteCommand(PromoteType promoteType, Coordinate pieceCoords) {
+	public PromoteCommand(PromoteType promoteType) {
 		this.promoteType = promoteType;
-		this.pieceCoords = pieceCoords;
 	}
 
 	@Override
 	public CommandResult execute(Game game, OutputSystem outputSystem) {
 		final ChessBoard board = game.getBoard();
 
+		this.pieceCoords = game.pawnPromotePosition();
+
+		if (this.pieceCoords == null)
+			return CommandResult.NotAllowed;
+
 		Piece pawn = board.pieceAt(this.pieceCoords);
 		if (pawn == null || !(pawn instanceof Pawn))
 			return CommandResult.NotAllowed;
@@ -46,7 +50,6 @@ public class PromoteCommand extends PlayerCommand {
 		if (destY != enemyLine)
 			return CommandResult.NotAllowed;
 
-		board.pieceLeaves(this.pieceCoords);
 		board.pieceComes(createPiece(this.promoteType, pawn.getColor()), this.pieceCoords);
 
 		return CommandResult.Moved;
@@ -80,7 +83,6 @@ public class PromoteCommand extends PlayerCommand {
 		assert promoted != null;
 
 		Color player = promoted.getColor();
-		board.pieceLeaves(this.pieceCoords);
 		board.pieceComes(new Pawn(player), this.pieceCoords);
 	}
 

app/src/main/java/chess/model/ChessBoard.java

@@ -57,19 +57,14 @@ public class ChessBoard {
 	public void undoLastMove() {
 		assert this.lastMove != null: "Can't undo at the beginning!";
 
-		Move move = this.lastMove;
+		undoMove(this.lastMove, this.lastEjectedPiece);
+	}
 
+	public void undoMove(Move move, Piece deadPiece) {
 		Piece movingPiece = pieceAt(move.getFinish());
 		pieceComes(movingPiece, move.getStart());
-		pieceLeaves(move.getFinish());
+		pieceComes(deadPiece, move.getFinish());
 		movingPiece.unMove();
-
-		if (this.lastEjectedPiece == null)
-			return;
-
-		Piece piece = this.lastEjectedPiece;
-
-		pieceComes(piece, move.getFinish());
 	}
 
 	public boolean isCellEmpty(Coordinate coordinate) {

app/src/main/java/chess/model/Game.java

@@ -30,23 +30,6 @@ public class Game {
 		playerTurn = Color.getEnemy(playerTurn);
 	}
 
-	public boolean checkPromotion(Coordinate pieceCoords) {
-
-		Piece piece = getBoard().pieceAt(pieceCoords);
-
-		if (piece == null || !(piece instanceof Pawn))
-			return false;
-
-		int destY = pieceCoords.getY();
-
-		int enemyLine = piece.getColor() == Color.White ? 0 : 7;
-
-		if (destY != enemyLine)
-			return false;
-
-		return true;
-	}
-
 	public GameStatus checkGameStatus() {
 		final Color enemy = Color.getEnemy(getPlayerTurn());
 
@@ -63,20 +46,38 @@ public class Game {
 	}
 
 	public boolean pawnShouldBePromoted() {
-		if (pawnShouldBePromoted(Color.White))
-			return true;
-		return pawnShouldBePromoted(Color.Black);
+		return pawnPromotePosition() != null;
 	}
 
-	private boolean pawnShouldBePromoted(Color color) {
+	/**
+	 * 
+	 * @return Null if there is no pawn to promote
+	 */
+	public Coordinate pawnPromotePosition() {
+		Coordinate piecePos = pawnPromotePosition(Color.White);
+		if (piecePos != null)
+			return piecePos;
+		return pawnPromotePosition(Color.Black);
+	}
+
+	/**
+	 * 
+	 * @return Null if there is no pawn to promote
+	 */
+	private Coordinate pawnPromotePosition(Color color) {
 		int enemyLineY = color == Color.White ? 0 : 7;
 
 		for (int x = 0; x < Coordinate.VALUE_MAX; x++) {
-			if (checkPromotion(new Coordinate(x, enemyLineY)))
-				return true;
+			Coordinate pieceCoords = new Coordinate(x, enemyLineY);
+			Piece piece = getBoard().pieceAt(pieceCoords);
+
+			if (piece == null || !(piece instanceof Pawn) || piece.getColor() != color)
+				continue;
+
+			return pieceCoords;
 		}
 
-		return false;
+		return null;
 	}
 
 }

app/src/main/java/chess/model/Piece.java

@@ -4,12 +4,10 @@ public abstract class Piece {
 
 	private final Color color;
 	private int moved;
-	private int ejectedMoveNumber;
 
 	public Piece(Color color) {
 		this.color = color;
 		this.moved = 0;
-		this.ejectedMoveNumber = -1;
 	}
 
 	public void move() {
@@ -28,18 +26,6 @@ public abstract class Piece {
 		this.moved--;
 	}
 
-	public boolean isEjected() {
-		return this.ejectedMoveNumber != -1;
-	}
-
-	public int getEjectedMoveNumber() {
-		return ejectedMoveNumber;
-	}
-
-	public void eject(int moveNumber) {
-		this.ejectedMoveNumber = moveNumber;
-	}
-
 	public abstract <T> T accept(PieceVisitor<T> visitor);
 
 }

app/src/main/java/chess/simplerender/Window.java

@@ -237,7 +237,7 @@ public class Window extends JFrame implements OutputSystem {
 			}
 
 			if (choosedType != null)
-				sendCommand(new PromoteCommand(choosedType, pieceCoords));
+				sendCommand(new PromoteCommand(choosedType));
 		});
 	}