From b59ee091e5856cd9dd6240791b873aa1b74d424a Mon Sep 17 00:00:00 2001
From: Ole Michaelis <Ole.Michaelis@googlemail.com>
Date: Tue, 29 Oct 2019 20:50:06 +0100
Subject: [PATCH] on the road to refactor

---
 gilded_rose/lib/gilded_rose.ex        | 125 ++++++++++++++++----------
 gilded_rose/test/gilded_rose_test.exs |  17 +++-
 2 files changed, 94 insertions(+), 48 deletions(-)

diff --git a/gilded_rose/lib/gilded_rose.ex b/gilded_rose/lib/gilded_rose.ex
index 7edd8c8..8e55869 100644
--- a/gilded_rose/lib/gilded_rose.ex
+++ b/gilded_rose/lib/gilded_rose.ex
@@ -7,52 +7,82 @@ defmodule GildedRose do
     Enum.map(items, &update_item/1)
   end
 
+  def decrease_quality(item, n) do
+    %{item | quality: max(0, item.quality - n)}
+  end
+
+  def increase_quality(item, n) do
+    %{item | quality: min(50, item.quality + n)}
+  end
+
   def update_item(item) do
-    item = cond do
-      item.name != "Aged Brie" && item.name != "Backstage passes to a TAFKAL80ETC concert" ->
-        if item.quality > 0 do
+    item =
+      cond do
+        item.name == "some conjured item" ->
           if item.name != "Sulfuras, Hand of Ragnaros" do
-            %{item | quality: item.quality - 1}
+            decrease_quality(item, 2)
           else
             item
           end
-        else
-          item
-        end
-      true ->
-        cond do
-          item.quality < 50 ->
-            item = %{item | quality: item.quality + 1}
-            cond do
-              item.name == "Backstage passes to a TAFKAL80ETC concert" ->
-                item = cond do
-                  item.sell_in < 11 ->
-                    cond do
-                      item.quality < 50 ->
-                        %{item | quality: item.quality + 1}
-                      true -> item
-                    end
-                  true -> item
-                end
+
+        item.name != "Aged Brie" && item.name != "Backstage passes to a TAFKAL80ETC concert" ->
+          if item.name != "Sulfuras, Hand of Ragnaros" do
+            decrease_quality(item, 1)
+          else
+            item
+          end
+
+        true ->
+          item = increase_quality(item, 1)
+
+          cond do
+            item.name == "Backstage passes to a TAFKAL80ETC concert" ->
+              item =
                 cond do
-                  item.sell_in < 6 ->
+                  item.sell_in < 11 ->
                     cond do
                       item.quality < 50 ->
                         %{item | quality: item.quality + 1}
-                      true -> item
+
+                      true ->
+                        item
                     end
-                  true -> item
+
+                  true ->
+                    item
                 end
-              true -> item
-            end
-          true -> item
-        end
-    end
-    item = cond do
-      item.name != "Sulfuras, Hand of Ragnaros" ->
-        %{item | sell_in: item.sell_in - 1}
-      true -> item
-    end
+
+              cond do
+                item.sell_in < 6 ->
+                  cond do
+                    item.quality < 50 ->
+                      %{item | quality: item.quality + 1}
+
+                    true ->
+                      item
+                  end
+
+                true ->
+                  item
+              end
+
+            true ->
+              item
+          end
+
+        true ->
+          item
+      end
+
+    item =
+      cond do
+        item.name != "Sulfuras, Hand of Ragnaros" ->
+          %{item | sell_in: item.sell_in - 1}
+
+        true ->
+          item
+      end
+
     cond do
       item.sell_in < 0 ->
         cond do
@@ -60,24 +90,29 @@ defmodule GildedRose do
             cond do
               item.name != "Backstage passes to a TAFKAL80ETC concert" ->
                 cond do
-                  item.quality > 0 ->
-                    cond do
-                      item.name != "Sulfuras, Hand of Ragnaros" ->
-                        %{item | quality: item.quality - 1}
-                      true -> item
-                    end
-                  true -> item
+                  item.name != "Sulfuras, Hand of Ragnaros" ->
+                    decrease_quality(item, 1)
+
+                  true ->
+                    item
                 end
-              true -> %{item | quality: item.quality - item.quality}
+
+              true ->
+                decrease_quality(item, item.quality)
             end
+
           true ->
             cond do
               item.quality < 50 ->
                 %{item | quality: item.quality + 1}
-              true -> item
+
+              true ->
+                item
             end
         end
-      true -> item
+
+      true ->
+        item
     end
   end
 end
diff --git a/gilded_rose/test/gilded_rose_test.exs b/gilded_rose/test/gilded_rose_test.exs
index d423cef..f026aaa 100644
--- a/gilded_rose/test/gilded_rose_test.exs
+++ b/gilded_rose/test/gilded_rose_test.exs
@@ -21,6 +21,20 @@ defmodule GildedRoseTest do
              ]
     end
 
+    test "some conjured item" do
+      assert GildedRose.update_quality([
+               %Item{name: "some conjured item", quality: 10, sell_in: 9}
+             ]) == [
+               %Item{name: "some conjured item", quality: 8, sell_in: 8}
+             ]
+
+      assert GildedRose.update_quality([
+               %Item{name: "some conjured item", quality: 1, sell_in: 9}
+             ]) == [
+               %Item{name: "some conjured item", quality: 0, sell_in: 8}
+             ]
+    end
+
     test "Backstage passes" do
       assert GildedRose.update_quality([
                %Item{name: "Backstage passes to a TAFKAL80ETC concert", quality: 1, sell_in: 9}
@@ -68,8 +82,5 @@ defmodule GildedRoseTest do
                %Item{name: "Aged Brie", quality: 50, sell_in: 8}
              ]
     end
-
-    test "some conjured item" do
-    end
   end
 end