refactor

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

@@ -3,60 +3,65 @@ package com.gildedrose;
 class GildedRose {
     Item[] items;
 
+    private static final String BACKSTAGE_PASSES = "Backstage passes to a TAFKAL80ETC concert";
+    private static final String SULFURAS = "Sulfuras, Hand of Ragnaros";
+    private static final String AGED_BRIE = "Aged Brie";
+
     public GildedRose(Item[] items) {
         this.items = items;
     }
 
     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;
-                            }
-                        }
-                    }
-                }
+        for (Item item : items) {
+            if (item.name.equals(AGED_BRIE)) {
+                updateQualityAgedBrie(item);
+            } else if (item.name.equals(BACKSTAGE_PASSES)) {
+                updateQualityBackstagePasses(item);
+            } else if (!item.name.equals(SULFURAS)) {
+                updateQualityOtherItems(item);
             }
+        }
+    }
 
-            if (!items[i].name.equals("Sulfuras, Hand of Ragnaros")) {
-                items[i].sellIn = items[i].sellIn - 1;
-            }
+    private void updateQualityAgedBrie(Item item) {
+        if (item.quality < 50) {
+            item.quality++;
+        }
+        if (item.sellIn < 0 && item.quality < 50) {
+            item.quality++;
+        }
+        updateSellIn(item);
+    }
 
-            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;
-                    }
-                }
+    private void updateQualityBackstagePasses(Item item) {
+        if (item.quality < 50) {
+            item.quality++;
+            if (item.sellIn < 11 && item.quality < 50) {
+                item.quality++;
+            }
+            if (item.sellIn < 6 && item.quality < 50) {
+                item.quality++;
             }
         }
+        updateSellIn(item);
+        if (item.sellIn < 0) {
+            item.quality = 0;
+        }
+    }
+
+    private void updateQualityOtherItems(Item item) {
+        if (item.quality > 0) {
+            item.quality--;
+        }
+        updateSellIn(item);
+        if (item.sellIn < 0 && item.quality > 0) {
+            item.quality--;
+        }
+    }
+
+    private void updateSellIn(Item item) {
+        if (!item.name.equals(SULFURAS)) {
+            item.sellIn--;
+        }
     }
-}
\ No newline at end of file
+}