Refactoring for Lesson 5 Exercise 9

app/src/main/java/com/example/paktalin/agilejava_exercises/BlackSide.java

+package com.example.paktalin.agilejava_exercises;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+/**
+ * Created by Paktalin on 26/05/2018.
+ */
+
+class BlackSide implements Side {
+
+    private List<Piece> pieces = new ArrayList<>();
+
+    @Override
+    public List<Piece> getPieces() {
+        return pieces;
+    }
+
+    @Override
+    public double getStrength() {
+        double strength = 0.0;
+        for (Piece piece : pieces)
+            strength += piece.getStrength();
+        return strength;
+    }
+
+    @Override
+    public int getPiecesCount() {
+        return pieces.size();
+    }
+
+    @Override
+    public int getPiecesCount(Piece.Type type) {
+        int count = 0;
+
+        for (Piece piece : pieces)
+            if (piece.isType(type))
+                count++;
+
+        return count;
+    }
+
+    @Override
+    public void addPiece(Piece piece) {
+        pieces.add(piece);
+        Collections.sort(pieces);
+    }
+}

app/src/main/java/com/example/paktalin/agilejava_exercises/Board.java

 package com.example.paktalin.agilejava_exercises;
 
-import java.util.ArrayList;
-import java.util.Collections;
 import java.util.List;
 
+import static com.example.paktalin.agilejava_exercises.Piece.Color.*;
 import static com.example.paktalin.agilejava_exercises.util.StringUtil.NEW_LINE;
 
 /**
@@ -16,8 +15,8 @@ class Board {
 
     private Piece[][] pieces = new Piece[ROW_COUNT][COLUMN_COUNT];
 
-    private List<Piece> blackPieces = new ArrayList<>();
-    private List<Piece> whitePieces = new ArrayList<>();
+    private WhiteSide whiteSide = new WhiteSide();
+    private BlackSide blackSide = new BlackSide();
 
     private Board() {}
 
@@ -32,10 +31,10 @@ class Board {
     }
 
     private void initialize() {
-       initializeKingRank(Piece.Color.Black, 0);
-       initializePawnRank(Piece.Color.Black, 1);
-       initializePawnRank(Piece.Color.White, 6);
-       initializeKingRank(Piece.Color.White, 7);
+       initializeKingRank(Black, 0);
+       initializePawnRank(Black, 1);
+       initializePawnRank(White, 6);
+       initializeKingRank(White, 7);
     }
 
     private void initializeKingRank(Piece.Color color, int row) {
@@ -54,6 +53,9 @@ class Board {
             placePiece(Piece.createPawn(color), row, column);
     }
 
+    void placePiece(Piece piece, String position) {
+        placePiece(piece, retrieveRow(position), retrieveColumn(position));
+    }
     private void placePiece(Piece piece, int row, char file) {
         placePiece(piece, row, fileToColumn(file));
     }
@@ -63,18 +65,8 @@ class Board {
         addToCollection(piece);
     }
 
-    void placePiece(Piece piece, String position) {
-        placePiece(piece, retrieveRow(position), retrieveColumn(position));
-    }
-
     void addToCollection(Piece piece) {
-        if (piece.isWhite()) {
-            whitePieces.add(piece);
-            Collections.sort(whitePieces);
-        } else {
-            blackPieces.add(piece);
-            Collections.sort(blackPieces);
-        }
+        getSide(piece.getColor()).addPiece(piece);
     }
 
     private void setPieceStrength(Piece piece, int column) {
@@ -113,32 +105,10 @@ class Board {
     private int retrieveRow(String position) {
         return ROW_COUNT - Integer.parseInt(position.split("")[1]);
     }
-
     private int retrieveColumn(String position) {
         return fileToColumn(position.toCharArray()[0]);
     }
 
-    int getPiecesCount() {
-        return getBlackPiecesCount() + getWhitePiecesCount();
-    }
-
-    int getPiecesCount(Piece.Type type, List<Piece> pieces) {
-        int count = 0;
-
-        for (Piece piece : pieces)
-            if (piece.isType(type))
-                count++;
-
-        return count;
-    }
-
-    int getWhitePiecesCount(Piece.Type type) {
-        return getPiecesCount(type, whitePieces);
-    }
-    int getBlackPiecesCount(Piece.Type type) {
-        return getPiecesCount(type, blackPieces);
-    }
-
     String print() {
         StringBuilder buffer = new StringBuilder();
         for (int row = 0; row < ROW_COUNT; row++) {
@@ -167,38 +137,25 @@ class Board {
         return getPieceAtPosition(retrieveRow(position), retrieveColumn(position));
     }
 
-    private double getStrength(Piece.Color color) {
-        double strength = 0;
-
-        for (int row = 0; row < ROW_COUNT; row++) {
-            for (int column = 0; column < COLUMN_COUNT; column++) {
-                Piece piece = getPieceAtPosition(row, column);
-                if (piece != null && piece.getColor() == color) {
-                    strength += piece.getStrength();
-                }
-            }
-        }
-        return strength;
+    Side getSide(Piece.Color color){
+        if (color == White)
+            return whiteSide;
+        return blackSide;
     }
 
-    List<Piece> getBlackPieces() {
-        return blackPieces;
-    }
-    List<Piece> getWhitePieces() {
-        return whitePieces;
+    int getPiecesCount() {
+        return getPiecesCount(Black) + getPiecesCount(White);
     }
-
-    double getBlackStrength() {
-        return getStrength(Piece.Color.Black);
+    double getStrength(Piece.Color color) {
+        return getSide(color).getStrength();
     }
-    double getWhiteStrength() {
-        return getStrength(Piece.Color.White);
+    List<Piece> getPieces(Piece.Color color) {
+        return getSide(color).getPieces();
     }
-
-    int getBlackPiecesCount() {
-        return blackPieces.size();
+    int getPiecesCount(Piece.Color color){
+        return getSide(color).getPiecesCount();
     }
-    int getWhitePiecesCount() {
-        return whitePieces.size();
+    int getPiecesCount(Piece.Color color, Piece.Type type){
+        return getSide(color).getPiecesCount(type);
     }
 }
\ No newline at end of file

app/src/main/java/com/example/paktalin/agilejava_exercises/Side.java

+package com.example.paktalin.agilejava_exercises;
+
+import java.util.List;
+
+/**
+ * Created by Paktalin on 26/05/2018.
+ */
+
+interface Side {
+
+    List<Piece> getPieces();
+    double getStrength();
+    int getPiecesCount();
+    int getPiecesCount(Piece.Type type);
+    void addPiece(Piece piece);
+}

app/src/main/java/com/example/paktalin/agilejava_exercises/WhiteSide.java

+package com.example.paktalin.agilejava_exercises;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+/**
+ * Created by Paktalin on 26/05/2018.
+ */
+
+public class WhiteSide implements Side {
+
+    private List<Piece> pieces = new ArrayList<>();
+
+    @Override
+    public List<Piece> getPieces() {
+        return pieces;
+    }
+
+    @Override
+    public double getStrength() {
+        double strength = 0.0;
+        for (Piece piece : pieces)
+            strength += piece.getStrength();
+        return strength;
+    }
+
+    @Override
+    public int getPiecesCount() {
+        return pieces.size();
+    }
+
+    @Override
+    public int getPiecesCount(Piece.Type type) {
+        int count = 0;
+
+        for (Piece piece : pieces)
+            if (piece.isType(type))
+                count++;
+
+        return count;
+    }
+
+    @Override
+    public void addPiece(Piece piece) {
+        pieces.add(piece);
+        Collections.sort(pieces);
+    }
+}

app/src/test/java/com/example/paktalin/agilejava_exercises/BoardTest.java

@@ -18,8 +18,8 @@ public class BoardTest extends TestCase {
         board = Board.createInitialized();
 
         assertEquals(32, board.getPiecesCount());
-        assertEquals(16, board.getBlackPiecesCount());
-        assertEquals(16, board.getWhitePiecesCount());
+        assertEquals(16, board.getPiecesCount(Black));
+        assertEquals(16, board.getPiecesCount(White));
     }
 
     public void testPlacePieces() {
@@ -77,15 +77,15 @@ public class BoardTest extends TestCase {
     private void verifyStrength(Piece piece, String position,
                                 double blackStrength, double whiteStrength, double pieceStrength) {
         board.placePiece(piece, position);
-        assertEquals(blackStrength, board.getBlackStrength());
-        assertEquals(whiteStrength, board.getWhiteStrength());
+        assertEquals(blackStrength, board.getStrength(Black));
+        assertEquals(whiteStrength, board.getStrength(White));
         assertEquals(pieceStrength, piece.getStrength());
     }
 
     public void testColorCollections() {
         board = Board.createInitialized();
 
-        List<Piece> blackPieces = board.getBlackPieces();
+        List<Piece> blackPieces = board.getPieces(Black);
         assertEquals(9.0, blackPieces.get(0).getStrength());
         assertEquals(5.0, blackPieces.get(1).getStrength());
         assertEquals(5.0, blackPieces.get(2).getStrength());