[tdd-diamond] Refactor: Delegate rendering to Board

tdd-diamond/build.gradle

@@ -20,6 +20,9 @@ repositories {
 }
 
 dependencies {
+    compile group: 'com.google.guava', name: 'guava', version: '21.0'
+    compile group: 'org.apache.commons', name: 'commons-lang3', version: '3.5'
+
     testCompile 'org.codehaus.groovy:groovy-all:2.4.7'
     testCompile 'org.spockframework:spock-core:1.0-groovy-2.4'
     testCompile 'junit:junit:4.12'

tdd-diamond/src/main/java/com/michaelszymczak/diamond/Board.java

@@ -0,0 +1,52 @@
+package com.michaelszymczak.diamond;
+
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.stream.Collectors;
+
+import static java.util.Arrays.asList;
+
+public class Board {
+
+  private final PositionedLetter[][] board;
+  private final String emptyCell;
+
+  public Board(PositionedLetter... cells) {
+    this(" ", asList(cells));
+  }
+
+  public Board(Collection<PositionedLetter> cells) {
+    this(" ", cells);
+  }
+
+  public Board(String emptyCell, Collection<PositionedLetter> cells) {
+    this.emptyCell = emptyCell;
+    this.board = boardWith(cells);
+  }
+
+
+  private static PositionedLetter[][] boardWith(Collection<PositionedLetter> cells) {
+    int maxCellPosition = cells.stream()
+            .mapToInt(PositionedLetter::maxXorY)
+            .max()
+            .orElse(0);
+    PositionedLetter[][] board = new PositionedLetter[maxCellPosition+1][maxCellPosition+1];
+    cells.forEach(cell -> board[cell.getY()][cell.getX()] = cell);
+
+    return board;
+  }
+
+  @Override
+  public String toString() {
+    return Arrays.stream(board)
+            .map(this::rendered)
+            .collect(Collectors.joining("\n"));
+  }
+
+  private String rendered(PositionedLetter[] row) {
+    return Arrays.stream(row)
+            .map(cell -> (cell != null) ? cell.letterAsString() : emptyCell)
+            .collect(Collectors.joining());
+  }
+
+}

tdd-diamond/src/main/java/com/michaelszymczak/diamond/Coordinates.java

@@ -0,0 +1,29 @@
+package com.michaelszymczak.diamond;
+
+public class Coordinates extends ValueObject {
+
+  private final int y;
+  private final int x;
+
+  public static Coordinates ofYX(int y, int x)
+  {
+    return new Coordinates(y, x);
+  }
+
+  private Coordinates(int y, int x) {
+    this.y = y;
+    this.x = x;
+  }
+
+  public int getY() {
+    return y;
+  }
+
+  public int getX() {
+    return x;
+  }
+
+  public int maxXorY() {
+    return x > y ? x : y;
+  }
+}

tdd-diamond/src/main/java/com/michaelszymczak/diamond/Diamond.java

@@ -1,5 +1,9 @@
 package com.michaelszymczak.diamond;
 
+import static com.michaelszymczak.diamond.Coordinates.ofYX;
+import static com.michaelszymczak.diamond.Letter.A;
+import static com.michaelszymczak.diamond.Letter.B;
+
 public class Diamond {
 
   private Letter letter;
@@ -13,6 +17,11 @@ private Diamond(Letter letter) {
   }
 
   public String rendered() {
-    return letter == Letter.A ? "A" : " A \nB B\n A ";
+    return letter == A ? new Board(new PositionedLetter(ofYX(0,0), A)).toString()
+            : new Board(
+            new PositionedLetter(ofYX(0,1), A),
+            new PositionedLetter(ofYX(1,0), B), new PositionedLetter(ofYX(1,2), B),
+            new PositionedLetter(ofYX(2,1), A)
+    ).toString();
   }
 }

tdd-diamond/src/main/java/com/michaelszymczak/diamond/Letter.java

@@ -1,5 +1,5 @@
 package com.michaelszymczak.diamond;
 
 public enum Letter {
-  A, B
+  A, B, C, D
 }

tdd-diamond/src/main/java/com/michaelszymczak/diamond/PositionedLetter.java

@@ -0,0 +1,27 @@
+package com.michaelszymczak.diamond;
+
+public class PositionedLetter extends ValueObject {
+  private final Coordinates coordinates;
+  private final Letter letter;
+
+  public PositionedLetter(Coordinates coordinates, Letter letter) {
+    this.coordinates = coordinates;
+    this.letter = letter;
+  }
+
+  public int maxXorY() {
+    return coordinates.maxXorY();
+  }
+
+  public String letterAsString() {
+    return letter.toString();
+  }
+
+  public int getX() {
+    return coordinates.getX();
+  }
+
+  public int getY() {
+    return coordinates.getY();
+  }
+}

tdd-diamond/src/main/java/com/michaelszymczak/diamond/ValueObject.java

@@ -0,0 +1,24 @@
+package com.michaelszymczak.diamond;
+
+import org.apache.commons.lang3.builder.EqualsBuilder;
+import org.apache.commons.lang3.builder.HashCodeBuilder;
+import org.apache.commons.lang3.builder.ToStringBuilder;
+import org.apache.commons.lang3.builder.ToStringStyle;
+
+public class ValueObject {
+
+  @Override
+  public boolean equals(Object obj) {
+    return EqualsBuilder.reflectionEquals(this, obj);
+  }
+
+  @Override
+  public String toString() {
+    return ToStringBuilder.reflectionToString(this, ToStringStyle.JSON_STYLE);
+  }
+
+  @Override
+  public int hashCode() {
+    return HashCodeBuilder.reflectionHashCode(this);
+  }
+}

tdd-diamond/src/test/groovy/com/michaelszymczak/diamond/BoardShould.groovy

@@ -0,0 +1,46 @@
+package com.michaelszymczak.diamond
+
+import spock.lang.Specification
+
+class BoardShould extends Specification {
+
+  def "should print a symbol"() {
+    expect: new Board([new PositionedLetter(Coordinates.ofYX(0,0),Letter.B)]).toString() == "B"
+  }
+
+  def "should print symbols respecting their positions"() {
+    expect:
+    new Board([
+            new PositionedLetter(Coordinates.ofYX(0,0),Letter.A),
+            new PositionedLetter(Coordinates.ofYX(0,1),Letter.B),
+            new PositionedLetter(Coordinates.ofYX(1,0),Letter.C),
+            new PositionedLetter(Coordinates.ofYX(1,1),Letter.D),
+    ]).toString() == shapeOf("""
+AB
+CD
+""")
+  }
+
+  def "should fill gaps with defined symbol "() {
+    expect:
+    new Board("_", [
+            new PositionedLetter(Coordinates.ofYX(0,2),Letter.A),
+            new PositionedLetter(Coordinates.ofYX(1,1),Letter.B),
+            new PositionedLetter(Coordinates.ofYX(1,3),Letter.B),
+            new PositionedLetter(Coordinates.ofYX(2,0),Letter.C),
+            new PositionedLetter(Coordinates.ofYX(2,4),Letter.C),
+            new PositionedLetter(Coordinates.ofYX(3,1),Letter.B),
+            new PositionedLetter(Coordinates.ofYX(3,3),Letter.B),
+            new PositionedLetter(Coordinates.ofYX(4,2),Letter.A),
+    ]).toString() == shapeOf("""
+__A__
+_B_B_
+C___C
+_B_B_
+__A__
+""")
+  }
+  private static String shapeOf(String shape) {
+    shape.replaceAll("^\n", "").replaceAll("\n\$", "")
+  }
+}