change project structure

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

@@ -0,0 +1,88 @@
+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.Piece;
+import chess.model.pieces.Bishop;
+import chess.model.pieces.Knight;
+import chess.model.pieces.Pawn;
+import chess.model.pieces.Queen;
+import chess.model.pieces.Rook;
+
+public class PromoteCommand extends PlayerCommand {
+
+	public enum PromoteType {
+		Queen,
+		Rook,
+		Bishop,
+		Knight
+	}
+
+	private final PromoteType promoteType;
+	private Coordinate pieceCoords;
+
+	public PromoteCommand(PromoteType promoteType) {
+		this.promoteType = promoteType;
+	}
+
+	@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;
+
+		int destY = this.pieceCoords.getY();
+
+		int enemyLine = pawn.getColor() == Color.White ? 0 : 7;
+
+		if (destY != enemyLine)
+			return CommandResult.NotAllowed;
+
+		board.pieceComes(createPiece(this.promoteType, pawn.getColor()), this.pieceCoords);
+
+		return CommandResult.Moved;
+	}
+
+	private Piece createPiece(PromoteType promoteType, Color color) {
+		switch (promoteType) {
+			case Queen:
+				return new Queen(color);
+
+			case Bishop:
+				return new Bishop(color);
+
+			case Knight:
+				return new Knight(color);
+
+			case Rook:
+				return new Rook(color);
+
+			default:
+				return null;
+		}
+	}
+
+	@Override
+	public void undo(Game game, OutputSystem outputSystem) {
+		final ChessBoard board = game.getBoard();
+
+		Piece promoted = board.pieceAt(this.pieceCoords);
+
+		assert promoted != null;
+
+		Color player = promoted.getColor();
+		board.pieceComes(new Pawn(player), this.pieceCoords);
+	}
+
+}