refac: piece, move, move strategy and move comparison

Co-authored-by: Raquel Andrade <raqueelfa@gmail.com>

.gitignore

@@ -142,3 +142,7 @@ gradle-app.setting
 # Docs specific
 venv/
 site/
+
+# Others
+jcc.settings.json
+platform_auto.conf

src/main/java/puzzle/Move.java

@@ -1,9 +1,11 @@
 package puzzle;
 
 import java.io.Serializable;
+import java.util.List;
+import java.util.ArrayList;
 
 /**
- *  A move consisting of a start and an end point.
+ *  A move consisting of a start and an end point, possibly capturing pieces.
  */
 public class Move	implements Serializable
 {
@@ -15,17 +17,30 @@ public class Move	implements Serializable
 	/** The end position. */
 	protected Position end;
 
+    /** The list of captured positions (if any). */
+    protected List<Position> captured;
+
 	//-------- constructors --------
 
 	/**
-	 *  Create a position.
+	 *  Create a move (no captures).
 	 */
 	public Move(Position start, Position end)
 	{
 		this.start = start;
 		this.end = end;
+        this.captured = new ArrayList<>();
 	}
 
+	/**
+     *  Create a move with start, end, and captured positions (for multiple captures).
+     */
+    public Move(Position start, Position end, List<Position> captured) {
+        this.start = start;
+        this.end = end;
+        this.captured = captured;
+    }
+
 	//-------- methods --------
 
 	/**
@@ -44,16 +59,24 @@ public Position getEnd()
 		return end;
 	}
 
+	/**
+     *  Get the list of captured positions (if any).
+     */
+    public List<Position> getCaptured() {
+        return captured;
+    }
+
 	/**
 	 *  Test if it is a jump move.
 	 */
 	public boolean isJumpMove()
 	{
-		return Math.abs(start.getX()-end.getX())==2 || Math.abs(start.getY()-end.getY())==2;
+		// Check if this move has any captures
+		return !captured.isEmpty();
 	}
 
 	/**
-	 *  Test if two positions are equal.
+	 *  Test if two positions are equal (start and end of a move).
 	 *  @return True, if equal.
 	 */
 	public boolean equals(Object o)
@@ -84,6 +107,11 @@ public int hashCode()
 	 */
 	public String toString()
 	{
-		return getStart()+" "+getEnd();
+        if (isJumpMove()) {
+            String capturedPositions = captured.toString();
+            return "Jump from " + start + " to " + end + " capturing " + capturedPositions;
+        } else {
+            return "Move from " + start + " to " + end;
+        }
 	}
 }

src/main/java/puzzle/MoveComparator.java

@@ -7,30 +7,27 @@
  */
 public class MoveComparator implements Comparator<Move>
 {
-	//-------- constants --------
+    //-------- constants --------
 
-	/** No strategy: try moves in order of appearance. */
+    /** No strategy: try moves in order of appearance. */
 	public static final String STRATEGY_NONE	= "none";
-
-	/** The strategy preferring jump moves, but ignoring colors. */
-	public static final String STRATEGY_LONG	= "long";
 
-	/** The strategy preferring jump moves of same color. */
-	public static final String STRATEGY_SAME_LONG	= "same_long";
-	
-	/** The strategy preferring jump moves of different colors. */
-	public static final String STRATEGY_ALTER_LONG	= "alter_long";
-	
-	//-------- attributes --------
-	
+    /** The strategy preferring moves with the highest number of captures. */
+    public static final String STRATEGY_MAX_CAPTURES = "max_captures";
+
+    /** The strategy preferring moves that involve queens over normal pieces then number of captures. */
+    public static final String STRATEGY_PREFER_QUEENS = "prefer_queens";
+
+    //-------- attributes --------
+
 	/** The board (required for checking which piece is in a given position). */
 	protected IBoard	board;
 
 	/** The strategy. */
 	protected String	strategy;
-	
-	//-------- constructors --------
-	
+
+    //-------- constructors --------
+
 	/**
 	 *  Create a move comparator.
 	 */
@@ -42,40 +39,27 @@ public MoveComparator(IBoard board, String strategy)
 
 	//-------- Coparator interface --------
 
-	/**
-	 *  Compare two moves.
-	 *  @return A negative number when the first move should come before the second.
-	 */
-	public int compare(Move move1, Move move2)
+    /**
+     *  Compare two moves.
+     *  @return A negative number when the first move should come before the second.
+     */
+    public int compare(Move move1, Move move2)
 	{
-		boolean same1 = board.wasLastMoveWhite()==board.getPiece(move1.getStart()).isWhite();
-		boolean same2 = board.wasLastMoveWhite()==board.getPiece(move2.getStart()).isWhite();
-
-		int compare_same	= same1 && !same2 ? -1
-				: same2 && !same1 ? 1
-				: 0;
-
-		int	compare_long	= move1.isJumpMove() && !move2.isJumpMove() ? -1
-							: move2.isJumpMove() && !move1.isJumpMove() ? 1
-							: 0;
-
-		int	ret	= 0;
-
-		if(STRATEGY_LONG.equals(strategy))
-		{
-			ret	= compare_long;	
-		}
-		else if(STRATEGY_SAME_LONG.equals(strategy))
-		{
-			ret	= compare_same!=0 ? compare_same : compare_long;
-//			ret	= compare_long!=0 ? compare_long : compare_same;
-		}
-		else if(STRATEGY_ALTER_LONG.equals(strategy))
-		{
-			ret	= compare_same!=0 ? -compare_same : compare_long;
-//			ret	= compare_long!=0 ? compare_long : -compare_same;
-		}
-
-		return ret;
-	}
+
+        int compareCaptureCount = Integer.compare(move2.getCaptured().size(), move1.getCaptured().size());
+
+        boolean isQueen1 = board.getPiece(move1.getStart()).isQueen();
+        boolean isQueen2 = board.getPiece(move2.getStart()).isQueen();
+        int compareQueen = Boolean.compare(isQueen2, isQueen1);
+
+        int ret = 0;
+
+        if (STRATEGY_MAX_CAPTURES.equals(strategy)) {
+            ret = compareCaptureCount;
+        } else if (STRATEGY_PREFER_QUEENS.equals(strategy)) {
+            ret = compareQueen != 0 ? compareQueen : compareCaptureCount;
+        }
+
+        return ret;
+    }
 }

src/main/java/puzzle/Piece.java

@@ -11,15 +11,19 @@ public class Piece	implements Serializable
 
 	/** The piece color (white or black). */
 	protected boolean is_white;
+
+	/** The piece type (normal or queen). */
+    protected boolean is_queen;
 
 	//-------- constructors --------
 
 	/**
-	 *  Create a new board.
+	 *  Create a new piece.
 	 */
 	public Piece(boolean is_white)
 	{
 		this.is_white = is_white;
+		this.is_queen = false;
 	}
 
 	//-------- methods --------
@@ -33,12 +37,30 @@ public boolean isWhite()
 		return is_white;
 	}
 
+	/**
+	 *  Test, if it is a queen piece.
+	 *  @return True, if it a queen piece.
+	 */
+	public boolean isQueen()
+	{
+		return is_queen;
+	}
+
+	/**
+     * Promote the piece to a queen.
+     */
+    public void promoteToQueen() {
+        this.is_queen = true;
+    }
+
 	/**
 	 *  Get the string representation.
 	 *  @return The string representation.
 	 */
 	public String toString()
 	{
-		return isWhite()? "white": "black";
+		String color = isWhite() ? "white" : "black";
+		String type = isQueen() ? "queen" : "normal";
+		return color + " " + type;
 	}
 }