added missing classes

Java/src/main/java/com/gildedrose/Category.java

@@ -0,0 +1,29 @@
+package com.gildedrose;
+
+import java.util.Arrays;
+
+public enum Category {
+  AGED_BRIE("^Aged Brie$"),
+  BACKSTAGE_PASS("^Backstage passes to a TAFKAL80ETC concert$"),
+  SULFURAS("^Sulfuras, Hand of Ragnaros$"),
+  CONJURED("^Conjured Mana Cake$"),
+  OTHER;
+
+  private final String nameRegex;
+
+  Category() {
+    this(null);
+  }
+
+  Category(String nameRegex) {
+    this.nameRegex = nameRegex;
+  }
+
+  private boolean matches(String actualName) {
+    return nameRegex != null && actualName.matches(nameRegex);
+  }
+
+  static Category fromName(String name) {
+    return Arrays.stream(Category.values()).filter(e -> e.matches(name)).findFirst().orElse(OTHER);
+  }
+}

Java/src/main/java/com/gildedrose/GildedRose.java

@@ -1,62 +1,25 @@
 package com.gildedrose;
 
+import java.util.Arrays;
+
 class GildedRose {
-    Item[] items;
 
-    public GildedRose(Item[] items) {
-        this.items = items;
+  private Item[] items;
+
+  public GildedRose(Item[] items) {
+    this.items = items;
+  }
+
+  public void updateQuality() {
+    Arrays.stream(items).forEach(this::updateQuality);
+  }
+
+  void updateQuality(Item item) {
+    Category category = Category.fromName(item.name);
+
+    if (category != Category.SULFURAS) {
+      item.sellIn = item.sellIn - 1;
+      QualityApplierFactory.applyQuality(item, category);
     }
-
-    public void updateQuality() {
-        for (int i = 0; i < items.length; i++) {
-            if (!items[i].name.equals("Aged Brie")
-                    && !items[i].name.equals("Backstage passes to a TAFKAL80ETC concert")) {
-                if (items[i].quality > 0) {
-                    if (!items[i].name.equals("Sulfuras, Hand of Ragnaros")) {
-                        items[i].quality = items[i].quality - 1;
-                    }
-                }
-            } else {
-                if (items[i].quality < 50) {
-                    items[i].quality = items[i].quality + 1;
-
-                    if (items[i].name.equals("Backstage passes to a TAFKAL80ETC concert")) {
-                        if (items[i].sellIn < 11) {
-                            if (items[i].quality < 50) {
-                                items[i].quality = items[i].quality + 1;
-                            }
-                        }
-
-                        if (items[i].sellIn < 6) {
-                            if (items[i].quality < 50) {
-                                items[i].quality = items[i].quality + 1;
-                            }
-                        }
-                    }
-                }
-            }
-
-            if (!items[i].name.equals("Sulfuras, Hand of Ragnaros")) {
-                items[i].sellIn = items[i].sellIn - 1;
-            }
-
-            if (items[i].sellIn < 0) {
-                if (!items[i].name.equals("Aged Brie")) {
-                    if (!items[i].name.equals("Backstage passes to a TAFKAL80ETC concert")) {
-                        if (items[i].quality > 0) {
-                            if (!items[i].name.equals("Sulfuras, Hand of Ragnaros")) {
-                                items[i].quality = items[i].quality - 1;
-                            }
-                        }
-                    } else {
-                        items[i].quality = items[i].quality - items[i].quality;
-                    }
-                } else {
-                    if (items[i].quality < 50) {
-                        items[i].quality = items[i].quality + 1;
-                    }
-                }
-            }
-        }
-    }
-}
+  }
+}

Java/src/main/java/com/gildedrose/ItemBuilder.java

@@ -0,0 +1,42 @@
+package com.gildedrose;
+
+class ItemBuilder {
+
+  private String name;
+  private Category category;
+  private int sellIn;
+  private int quality;
+
+  ItemBuilder() {}
+
+  ItemBuilder name(String name) {
+    this.name = name;
+    this.category = Category.fromName(name);
+    return this;
+  }
+
+  ItemBuilder sellIn(int sellIn) {
+    this.sellIn = sellIn;
+    return this;
+  }
+
+  ItemBuilder quality(int quality) {
+    this.quality = quality;
+    return this;
+  }
+
+  Item build() {
+    if (name == null) {
+      throw new IllegalArgumentException("name cannot be null");
+    }
+    if (Category.SULFURAS != category && quality > 50) {
+      throw new IllegalArgumentException("quality cannot be higher than 50");
+    } else if (Category.SULFURAS == category && quality != 80) {
+      throw new IllegalArgumentException("Sulfuras quality must always be 80");
+    }
+    if (quality < 0) {
+      throw new IllegalArgumentException("quality can not be negative");
+    }
+    return new Item(name, sellIn, quality);
+  }
+}

Java/src/main/java/com/gildedrose/QualityApplier.java

@@ -0,0 +1,97 @@
+package com.gildedrose;
+
+import java.util.EnumSet;
+
+public interface QualityApplier {
+  boolean matches(Item item, Category category);
+
+  int apply(Item item);
+}
+
+abstract class BaseQualityApplier implements QualityApplier {
+  protected final EnumSet<Category> matchingCategories;
+
+  public BaseQualityApplier(EnumSet<Category> matchingCategories) {
+    this.matchingCategories = matchingCategories;
+  }
+
+  @Override
+  public boolean matches(Item item, Category category) {
+    return matchingCategories.contains(category);
+  }
+}
+
+class DegradingQualityApplier extends BaseQualityApplier {
+
+  private final int positiveSellInDegradeBy;
+  private final int negativeSellInDegradeBy;
+
+  DegradingQualityApplier(
+      int positiveSellInDegradeBy,
+      int negativeSellInDegradeBy,
+      EnumSet<Category> matchingCategories) {
+    super(matchingCategories);
+    this.positiveSellInDegradeBy = positiveSellInDegradeBy;
+    this.negativeSellInDegradeBy = negativeSellInDegradeBy;
+  }
+
+  @Override
+  public int apply(Item item) {
+    int degradeBy = item.sellIn >= 0 ? this.positiveSellInDegradeBy : negativeSellInDegradeBy;
+    int newQuality = item.quality - degradeBy;
+    if (newQuality < 0) {
+      newQuality = 0;
+    }
+    return newQuality;
+  }
+}
+
+class IncreasingQualityApplier extends BaseQualityApplier {
+
+  private final int increaseBy;
+  private final int max;
+
+  IncreasingQualityApplier(int increaseBy, int max, EnumSet<Category> matchingCategories) {
+    super(matchingCategories);
+    this.increaseBy = increaseBy;
+    this.max = max;
+  }
+
+  @Override
+  public int apply(Item item) {
+    int newQuality = item.quality + increaseBy;
+    if (newQuality >= max) {
+      newQuality = max;
+    }
+    return newQuality;
+  }
+}
+
+class BackstagePassQualityApplier extends BaseQualityApplier {
+
+  private final int max;
+
+  BackstagePassQualityApplier(int max, EnumSet<Category> matchingCategories) {
+    super(matchingCategories);
+    this.max = max;
+  }
+
+  @Override
+  public int apply(Item item) {
+    int newQuality;
+
+    if (item.sellIn < 0) {
+      newQuality = 0;
+    } else if (item.sellIn < 5) {
+      newQuality = item.quality + 3;
+    } else if (item.sellIn < 10) {
+      newQuality = item.quality + 2;
+    } else {
+      newQuality = item.quality + 1;
+    }
+    if (newQuality >= max) {
+      newQuality = max;
+    }
+    return newQuality;
+  }
+}

Java/src/main/java/com/gildedrose/QualityApplierFactory.java

@@ -0,0 +1,23 @@
+package com.gildedrose;
+
+import java.util.Arrays;
+import java.util.EnumSet;
+import java.util.List;
+
+class QualityApplierFactory {
+  private static final List<QualityApplier> APPLIERS =
+      Arrays.asList(
+          new DegradingQualityApplier(1, 2, EnumSet.of(Category.OTHER)),
+          new DegradingQualityApplier(2, 2, EnumSet.of(Category.CONJURED)),
+          new IncreasingQualityApplier(1, 50, EnumSet.of(Category.AGED_BRIE)),
+          new BackstagePassQualityApplier(50, EnumSet.of(Category.BACKSTAGE_PASS)));
+
+  private QualityApplierFactory() {
+  }
+
+  static void applyQuality(Item item, Category category) {
+    APPLIERS.stream()
+        .filter(applier -> applier.matches(item, category))
+        .forEach(applier -> item.quality = applier.apply(item));
+  }
+}

Java/src/test/java/com/gildedrose/ItemFixture.java

@@ -0,0 +1,32 @@
+package com.gildedrose;
+
+public class ItemFixture {
+  private static final String DEXTERITY_VEST = "+5 Dexterity Vest";
+  private static final String AGED_BRIE = "Aged Brie";
+  private static final String BACKSTAGE_PASS = "Backstage passes to a TAFKAL80ETC concert";
+  private static final String SULFURAS = "Sulfuras, Hand of Ragnaros";
+  private static final String CONJURED = "Conjured Mana Cake";
+
+  static ItemBuilder standard() {
+    return new ItemBuilder().name(DEXTERITY_VEST);
+  }
+
+  static ItemBuilder agedBrie() {
+    return new ItemBuilder().name(AGED_BRIE);
+  }
+
+  static ItemBuilder backstagePass() {
+    return new ItemBuilder().name(BACKSTAGE_PASS);
+  }
+
+  static ItemBuilder sulfuras() {
+    return new ItemBuilder()
+        .name(SULFURAS)
+        .quality(80);
+  }
+
+  static ItemBuilder conjured() {
+    return new ItemBuilder()
+        .name(CONJURED);
+  }
+}

Java/src/test/java/com/gildedrose/TexttestFixture.java

@@ -1,37 +0,0 @@
-package com.gildedrose;
-
-public class TexttestFixture {
-    public static void main(String[] args) {
-        System.out.println("OMGHAI!");
-
-        Item[] items = new Item[] {
-                new Item("+5 Dexterity Vest", 10, 20), //
-                new Item("Aged Brie", 2, 0), //
-                new Item("Elixir of the Mongoose", 5, 7), //
-                new Item("Sulfuras, Hand of Ragnaros", 0, 80), //
-                new Item("Sulfuras, Hand of Ragnaros", -1, 80),
-                new Item("Backstage passes to a TAFKAL80ETC concert", 15, 20),
-                new Item("Backstage passes to a TAFKAL80ETC concert", 10, 49),
-                new Item("Backstage passes to a TAFKAL80ETC concert", 5, 49),
-                // this conjured item does not work properly yet
-                new Item("Conjured Mana Cake", 3, 6) };
-
-        GildedRose app = new GildedRose(items);
-
-        int days = 2;
-        if (args.length > 0) {
-            days = Integer.parseInt(args[0]) + 1;
-        }
-
-        for (int i = 0; i < days; i++) {
-            System.out.println("-------- day " + i + " --------");
-            System.out.println("name, sellIn, quality");
-            for (Item item : items) {
-                System.out.println(item);
-            }
-            System.out.println();
-            app.updateQuality();
-        }
-    }
-
-}