lots of things

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

@@ -3,15 +3,17 @@ package chess.model;
 public abstract class Piece {
 
 	private final Color color;
-	private boolean moved;
+	private int moved;
+	private int ejectedMoveNumber;
 
 	public Piece(Color color) {
 		this.color = color;
-		this.moved = false;
+		this.moved = 0;
+		this.ejectedMoveNumber = -1;
 	}
 
 	public void move() {
-		this.moved = true;
+		this.moved++;
 	}
 
 	public Color getColor() {
@@ -19,11 +21,23 @@ public abstract class Piece {
 	}
 
 	public boolean hasMoved() {
-		return moved;
+		return moved > 0;
 	}
 
-	public void eject() {
-		// for later
+	public void unMove() {
+		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);