Moved Extension methods in common to subfolder

src/NzbDrone.Common/Extensions/LevenstheinExtensions.cs

@@ -0,0 +1,50 @@
+using System;
+
+namespace NzbDrone.Common.Extensions
+{
+    public static class LevenstheinExtensions
+    {
+        public static Int32 LevenshteinDistance(this String text, String other, Int32 costInsert = 1, Int32 costDelete = 1, Int32 costSubstitute = 1)
+        {
+            if (text == other) return 0;
+            if (text.Length == 0) return other.Length * costInsert;
+            if (other.Length == 0) return text.Length * costDelete;
+
+            Int32[] matrix = new Int32[other.Length + 1];
+
+            for (var i = 1; i < matrix.Length; i++)
+            {
+                matrix[i] = i * costInsert;
+            }
+
+            for (var i = 0; i < text.Length; i++)
+            {
+                Int32 topLeft = matrix[0];
+                matrix[0] = matrix[0] + costDelete;
+
+                for (var j = 0; j < other.Length; j++)
+                {
+                    Int32 top = matrix[j];
+                    Int32 left = matrix[j + 1];
+
+                    var sumIns = top + costInsert;
+                    var sumDel = left + costDelete;
+                    var sumSub = topLeft + (text[i] == other[j] ? 0 : costSubstitute);
+
+                    topLeft = matrix[j + 1];
+                    matrix[j + 1] = Math.Min(Math.Min(sumIns, sumDel), sumSub);
+                }
+            }
+
+            return matrix[other.Length];
+        }
+
+        public static Int32 LevenshteinDistanceClean(this String expected, String other)
+        {
+            expected = expected.ToLower().Replace(".", "");
+            other = other.ToLower().Replace(".", "");
+
+            return expected.LevenshteinDistance(other, 1, 3, 3);
+        }
+    }
+}