Merge pull request #2474 from JustAMan/simplify-sorting

Simplify AlphanumericComparer, reduce code duplication

1 files changed, 97 insertions, 0 deletions

diff --git a/MediaBrowser.Controller/Sorting/AlphanumComparator.cs b/MediaBrowser.Controller/Sorting/AlphanumComparator.cs
new file mode 100644
index 000000000..65dc120ca
--- /dev/null
+++ b/MediaBrowser.Controller/Sorting/AlphanumComparator.cs
@@ -0,0 +1,97 @@
+using System.Collections.Generic;
+using System.Text;
+using MediaBrowser.Controller.Sorting;
+
+namespace MediaBrowser.Controller.Sorting
+{
+    public class AlphanumComparator : IComparer<string>
+    {
+        public static int CompareValues(string s1, string s2)
+        {
+            if (s1 == null || s2 == null)
+            {
+                return 0;
+            }
+
+            int thisMarker = 0, thisNumericChunk = 0;
+            int thatMarker = 0, thatNumericChunk = 0;
+
+            while ((thisMarker < s1.Length) || (thatMarker < s2.Length))
+            {
+                if (thisMarker >= s1.Length)
+                {
+                    return -1;
+                }
+                else if (thatMarker >= s2.Length)
+                {
+                    return 1;
+                }
+                char thisCh = s1[thisMarker];
+                char thatCh = s2[thatMarker];
+
+                var thisChunk = new StringBuilder();
+                var thatChunk = new StringBuilder();
+                bool thisNumeric = char.IsDigit(thisCh), thatNumeric = char.IsDigit(thatCh);
+
+                while (thisMarker < s1.Length && char.IsDigit(thisCh) == thisNumeric)
+                {
+                    thisChunk.Append(thisCh);
+                    thisMarker++;
+
+                    if (thisMarker < s1.Length)
+                    {
+                        thisCh = s1[thisMarker];
+                    }
+                }
+
+                while (thatMarker < s2.Length && char.IsDigit(thatCh) == thatNumeric)
+                {
+                    thatChunk.Append(thatCh);
+                    thatMarker++;
+
+                    if (thatMarker < s2.Length)
+                    {
+                        thatCh = s2[thatMarker];
+                    }
+                }
+
+
+                // If both chunks contain numeric characters, sort them numerically
+                if (thisNumeric && thatNumeric)
+                {
+                    if (!int.TryParse(thisChunk.ToString(), out thisNumericChunk)
+                        || !int.TryParse(thatChunk.ToString(), out thatNumericChunk))
+                    {
+                        return 0;
+                    }
+
+                    if (thisNumericChunk < thatNumericChunk)
+                    {
+                        return -1;
+                    }
+
+                    if (thisNumericChunk > thatNumericChunk)
+                    {
+                        return 1;
+                    }
+                }
+                else
+                {
+                    int result = thisChunk.ToString().CompareTo(thatChunk.ToString());
+                    if (result != 0)
+                    {
+                        return result;
+                    }
+                }
+
+            }
+
+            return 0;
+        }
+
+        public int Compare(string x, string y)
+        {
+            return CompareValues(x, y);
+        }
+    }
+}