support natural sorting

1 files changed, 113 insertions, 0 deletions

diff --git a/MediaBrowser.Server.Implementations/Sorting/AlphanumComparator.cs b/MediaBrowser.Server.Implementations/Sorting/AlphanumComparator.cs
new file mode 100644
index 000000000..2ced9a566
--- /dev/null
+++ b/MediaBrowser.Server.Implementations/Sorting/AlphanumComparator.cs
@@ -0,0 +1,113 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace MediaBrowser.Server.Implementations.Sorting
+{
+    public class AlphanumComparator : IComparer<string>
+    {
+        private enum ChunkType { Alphanumeric, Numeric };
+
+        private static bool InChunk(char ch, char otherCh)
+        {
+            var type = ChunkType.Alphanumeric;
+
+            if (char.IsDigit(otherCh))
+            {
+                type = ChunkType.Numeric;
+            }
+
+            if ((type == ChunkType.Alphanumeric && char.IsDigit(ch))
+                || (type == ChunkType.Numeric && !char.IsDigit(ch)))
+            {
+                return false;
+            }
+
+            return true;
+        }
+
+        public static int CompareValues(string s1, string s2)
+        {
+            if (s1 == null || s2 == null)
+            {
+                return 0;
+            }
+
+            var thisMarker = 0;
+            var thatMarker = 0;
+
+            while ((thisMarker < s1.Length) || (thatMarker < s2.Length))
+            {
+                if (thisMarker >= s1.Length)
+                {
+                    return -1;
+                }
+                if (thatMarker >= s2.Length)
+                {
+                    return 1;
+                }
+                var thisCh = s1[thisMarker];
+                var thatCh = s2[thatMarker];
+
+                var thisChunk = new StringBuilder();
+                var thatChunk = new StringBuilder();
+
+                while ((thisMarker < s1.Length) && (thisChunk.Length == 0 || InChunk(thisCh, thisChunk[0])))
+                {
+                    thisChunk.Append(thisCh);
+                    thisMarker++;
+
+                    if (thisMarker < s1.Length)
+                    {
+                        thisCh = s1[thisMarker];
+                    }
+                }
+
+                while ((thatMarker < s2.Length) && (thatChunk.Length == 0 || InChunk(thatCh, thatChunk[0])))
+                {
+                    thatChunk.Append(thatCh);
+                    thatMarker++;
+
+                    if (thatMarker < s2.Length)
+                    {
+                        thatCh = s2[thatMarker];
+                    }
+                }
+
+                int result = 0;
+                // If both chunks contain numeric characters, sort them numerically
+                if (char.IsDigit(thisChunk[0]) && char.IsDigit(thatChunk[0]))
+                {
+                    var thisNumericChunk = Convert.ToInt32(thisChunk.ToString());
+                    var thatNumericChunk = Convert.ToInt32(thatChunk.ToString());
+
+                    if (thisNumericChunk < thatNumericChunk)
+                    {
+                        result = -1;
+                    }
+
+                    if (thisNumericChunk > thatNumericChunk)
+                    {
+                        result = 1;
+                    }
+                }
+                else
+                {
+                    return string.Compare(thisChunk.ToString(), thatChunk.ToString(), StringComparison.CurrentCultureIgnoreCase);
+                }
+
+                if (result != 0)
+                {
+                    return result;
+                }
+            }
+
+            return 0;
+        }
+
+        public int Compare(string x, string y)
+        {
+            return CompareValues(x, y);
+        }
+    }
+}