Refactoring and adding conjured item

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

@@ -1,62 +1,26 @@
 package com.gildedrose;
 
+import java.util.Arrays;
+import java.util.List;
+import java.util.Collections;
+
+import com.gildedrose.item.quality.QualityUpdater;
+import com.gildedrose.item.quality.QualityUpdaterMapper;
+
 class GildedRose {
-    Item[] items;
+    private final List<Item> items;
+    private final QualityUpdaterMapper qualityUpdaterMapper = new QualityUpdaterMapper();
 
     public GildedRose(Item[] items) {
-        this.items = items;
+        this.items = items != null ? Arrays.asList(items) : Collections.EMPTY_LIST;
     }
 
     public void updateQuality() {
-        for (int i = 0; i < items.length; i++) {
+        for (final Item item : items) {
-            if (!items[i].name.equals("Aged Brie")
+            if (item != null) {
-                    && !items[i].name.equals("Backstage passes to a TAFKAL80ETC concert")) {
+                final QualityUpdater updater = qualityUpdaterMapper.getQualityUpdater(item.name);
-                if (items[i].quality > 0) {
+                updater.updateQuality(item);
-                    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/item/quality/QualityUpdater.java

@@ -0,0 +1,11 @@
+package com.gildedrose.item.quality;
+
+import com.gildedrose.Item;
+
+public interface QualityUpdater {
+    int MAX_LIMIT_QUALITY = 50;
+    int MIM_LIMIT_QUALITY = 0;
+    int MIM_LIMIT_SELL_IN = 0;
+    void updateQuality(final Item item);
+}
+

Java/src/main/java/com/gildedrose/item/quality/QualityUpdaterMapper.java

@@ -0,0 +1,23 @@
+package com.gildedrose.item.quality;
+
+import com.gildedrose.item.quality.type.QualifyUpdaterType;
+import com.gildedrose.item.quality.updater.*;
+
+import java.util.HashMap;
+import java.util.Map;
+
+public class QualityUpdaterMapper {
+    private final Map<String, QualityUpdater> qualityUpdaters = new HashMap<>();
+    private final static QualityUpdater DEFAULT_UPDATER = new QualityUpdaterDefault();
+
+    public QualityUpdaterMapper() {
+        qualityUpdaters.put(QualifyUpdaterType.AGED_BRIE.getValue().toUpperCase(), new QualityUpdaterAgedBrie());
+        qualityUpdaters.put(QualifyUpdaterType.BACKSTAGE_PASSES.getValue().toUpperCase(), new QualityUpdaterBackstagePasses());
+        qualityUpdaters.put(QualifyUpdaterType.CONJURED.getValue().toUpperCase(), new QualityUpdaterConjured());
+        qualityUpdaters.put(QualifyUpdaterType.SULFURAS.getValue().toUpperCase(), new QualityUpdaterSulfuras());
+    }
+
+    public QualityUpdater getQualityUpdater(final String itemName) {
+        return qualityUpdaters.getOrDefault(itemName.toUpperCase(), DEFAULT_UPDATER);
+    }
+}

Java/src/main/java/com/gildedrose/item/quality/type/QualifyUpdaterType.java

@@ -0,0 +1,19 @@
+package com.gildedrose.item.quality.type;
+
+public enum QualifyUpdaterType {
+
+    AGED_BRIE("Aged Brie"),
+    BACKSTAGE_PASSES("Backstage passes to a TAFKAL80ETC concert"),
+    CONJURED("Conjured"),
+    SULFURAS("Sulfuras");
+
+
+    QualifyUpdaterType(final String name) {
+        this.value = name;
+    }
+    private final String value;
+
+    public String getValue() {
+        return value;
+    }
+}

Java/src/main/java/com/gildedrose/item/quality/updater/QualityUpdaterAgedBrie.java

@@ -0,0 +1,22 @@
+package com.gildedrose.item.quality.updater;
+
+import com.gildedrose.Item;
+import com.gildedrose.item.quality.QualityUpdater;
+
+public class QualityUpdaterAgedBrie implements QualityUpdater {
+    public void updateQuality(final Item item) {
+        if (item.quality < MAX_LIMIT_QUALITY) {
+            increaseQuality(item);
+        }
+        item.sellIn--;
+        if (item.sellIn < MIM_LIMIT_SELL_IN) {
+            increaseQuality(item);
+        }
+    }
+
+    private void increaseQuality(final Item item) {
+        if (item.quality < MAX_LIMIT_QUALITY) {
+            item.quality++;
+        }
+    }
+}

Java/src/main/java/com/gildedrose/item/quality/updater/QualityUpdaterBackstagePasses.java

@@ -0,0 +1,30 @@
+package com.gildedrose.item.quality.updater;
+
+import com.gildedrose.Item;
+import com.gildedrose.item.quality.QualityUpdater;
+
+public class QualityUpdaterBackstagePasses implements QualityUpdater {
+
+    private static final int FIRST_SELL_IN_LIMIT = 6;
+    private static final int SECOND_SELL_IN_LIMIT = 11;
+
+    public void updateQuality(final Item item) {
+        increaseQuality(item);
+        if (item.sellIn < FIRST_SELL_IN_LIMIT) {
+            increaseQuality(item);
+        }
+        if (item.sellIn < SECOND_SELL_IN_LIMIT) {
+            increaseQuality(item);
+        }
+        item.sellIn--;
+        if (item.sellIn < MIM_LIMIT_SELL_IN) {
+            item.quality = MIM_LIMIT_QUALITY;
+        }
+    }
+
+    private void increaseQuality(final Item item) {
+        if (item.quality < MAX_LIMIT_QUALITY) {
+            item.quality++;
+        }
+    }
+}

Java/src/main/java/com/gildedrose/item/quality/updater/QualityUpdaterConjured.java

@@ -0,0 +1,24 @@
+package com.gildedrose.item.quality.updater;
+
+import com.gildedrose.Item;
+import com.gildedrose.item.quality.QualityUpdater;
+
+public class QualityUpdaterConjured implements QualityUpdater {
+
+    private static final int AMOUNT_OF_QUALITY_TO_DECREASE = 2;
+
+    public void updateQuality(final Item item) {
+        decreaseQuality(item);
+        updateSellIn(item);
+    }
+
+    private void decreaseQuality(final Item item) {
+        if (item.quality > MIM_LIMIT_SELL_IN) {
+            item.quality -= AMOUNT_OF_QUALITY_TO_DECREASE;
+        }
+    }
+
+    private void updateSellIn(final Item item) {
+        item.sellIn--;
+    }
+}

Java/src/main/java/com/gildedrose/item/quality/updater/QualityUpdaterDefault.java

@@ -0,0 +1,24 @@
+package com.gildedrose.item.quality.updater;
+
+import com.gildedrose.Item;
+import com.gildedrose.item.quality.QualityUpdater;
+
+public class QualityUpdaterDefault implements QualityUpdater {
+    public void updateQuality(final Item item) {
+        decreaseQuality(item);
+        updateSellIn(item);
+        if (item.sellIn < MIM_LIMIT_SELL_IN) {
+            decreaseQuality(item);
+        }
+    }
+
+    private void decreaseQuality(final Item item) {
+        if (item.quality > MIM_LIMIT_QUALITY) {
+            item.quality--;
+        }
+    }
+
+    private void updateSellIn(final Item item) {
+        item.sellIn--;
+    }
+}

Java/src/main/java/com/gildedrose/item/quality/updater/QualityUpdaterSulfuras.java

@@ -0,0 +1,11 @@
+package com.gildedrose.item.quality.updater;
+
+import com.gildedrose.Item;
+import com.gildedrose.item.quality.QualityUpdater;
+
+public class QualityUpdaterSulfuras implements QualityUpdater {
+
+    public void updateQuality(final Item item) {
+        item.sellIn--;
+    }
+}

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

@@ -8,10 +8,109 @@ class GildedRoseTest {
 
     @Test
     void foo() {
-        Item[] items = new Item[] { new Item("foo", 0, 0) };
+        final String itemName = "foo";
-        GildedRose app = new GildedRose(items);
+        final Item[] items = new Item[]{createItem("foo", 0, 0)};
+        final GildedRose app = new GildedRose(items);
         app.updateQuality();
-        assertEquals("fixme", app.items[0].name);
+
+        validateItem(items[0], itemName, -1, 0);
     }
 
+    @Test
+    public void testUpdateQualityConjuredItem() {
+        final String itemName = "Conjured";
+        final Item[] items = new Item[]{createItem(itemName, 4, 8)};
+        final GildedRose gildedRose = new GildedRose(items);
+
+        gildedRose.updateQuality();
+        validateItem(items[0], itemName, 3, 6);
+    }
+
+    @Test
+    public void testUpdateQualitySulfuras() {
+        final String itemName = "Sulfuras";
+        final Item[] items = new Item[]{new Item(itemName, 0, 80)};
+        final GildedRose gildedRose = new GildedRose(items);
+
+        gildedRose.updateQuality();
+
+        validateItem(items[0], itemName, -1, 80);
+    }
+
+    @Test
+    public void testUpdateQualityBackstagePassesSelinDayLessThanZero() {
+        final String itemName = "Backstage passes to a TAFKAL80ETC concert";
+        final Item[] items = new Item[]{new Item(itemName, 0, 50)};
+        final GildedRose gildedRose = new GildedRose(items);
+
+        gildedRose.updateQuality();
+
+        validateItem(items[0], itemName, -1, 0);
+    }
+
+    @Test
+    public void testUpdateQualityBackstagePassesLessThanSixDays() {
+        final String itemName = "Backstage passes to a TAFKAL80ETC concert";
+        final Item[] items = new Item[]{new Item(itemName, 5, 40)};
+        final GildedRose gildedRose = new GildedRose(items);
+
+        gildedRose.updateQuality();
+
+        validateItem(items[0], itemName, 4, 43);
+    }
+
+    @Test
+    public void testUpdateQualityBackstagePassesGreaterThanElevenDays() {
+        final String itemName = "Backstage passes to a TAFKAL80ETC concert";
+        final Item[] items = new Item[]{new Item(itemName, 12, 40)};
+        final GildedRose gildedRose = new GildedRose(items);
+
+        gildedRose.updateQuality();
+
+        validateItem(items[0], itemName, 11, 41);
+    }
+
+    @Test
+    public void testUpdateQualityAgedBrieSelinGreaterThanZero() {
+        final String itemName = "Backstage passes to a TAFKAL80ETC concert";
+        final Item[] items = new Item[]{new Item(itemName, 12, 39)};
+        final GildedRose gildedRose = new GildedRose(items);
+
+        gildedRose.updateQuality();
+
+        validateItem(items[0], itemName, 11, 40);
+    }
+
+    @Test
+    public void testUpdateQualityAgedBrieSelinEqualToZero() {
+        final String itemName = "Aged Brie";
+        final Item[] items = new Item[]{new Item(itemName, 0, 39)};
+        final GildedRose gildedRose = new GildedRose(items);
+
+        gildedRose.updateQuality();
+
+        validateItem(items[0], itemName, -1, 41);
+    }
+
+    @Test
+    public void testUpdateQualityDefaultSelinEqualToZero() {
+        final String itemName = "Another foo";
+        final Item[] items = new Item[]{new Item(itemName, 0, 40)};
+        final GildedRose gildedRose = new GildedRose(items);
+
+        gildedRose.updateQuality();
+
+        validateItem(items[0], itemName, -1, 38);
+    }
+
+    private Item createItem(final String name, final int sellIn, final int quality) {
+        return new Item(name, sellIn, quality);
+    }
+
+    private void validateItem(final Item item, final String expectedName, final int expectedSellIn,
+                              final int expectedQuality) {
+        assertEquals(expectedName, item.name, "The name must be " + expectedName);
+        assertEquals(expectedSellIn, item.sellIn, "The sellIn must be " + expectedSellIn);
+        assertEquals(expectedQuality, item.quality, "The quality must be " + expectedQuality);
+    }
 }