Dapper and STJson

Co-Authored-By: ta264 <ta264@users.noreply.github.com>

src/NzbDrone.Common/Serializer/Newtonsoft.Json/UnderscoreStringEnumConverter.cs

@@ -0,0 +1,60 @@
+using System;
+using System.Text;
+using Newtonsoft.Json;
+
+namespace NzbDrone.Common.Serializer
+{
+    public class UnderscoreStringEnumConverter : JsonConverter
+    {
+        public object UnknownValue { get; set; }
+
+        public UnderscoreStringEnumConverter(object unknownValue)
+        {
+            UnknownValue = unknownValue;
+        }
+
+        public override bool CanConvert(Type objectType)
+        {
+            return objectType.IsEnum;
+        }
+
+        public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
+        {
+            var enumString = reader.Value.ToString().Replace("_", string.Empty);
+
+            try
+            {
+                return Enum.Parse(objectType, enumString, true);
+            }
+            catch
+            {
+                if (UnknownValue == null)
+                {
+                    throw;
+                }
+
+                return UnknownValue;
+            }
+        }
+
+        public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
+        {
+            var enumText = value.ToString();
+            var builder = new StringBuilder(enumText.Length + 4);
+            builder.Append(char.ToLower(enumText[0]));
+            for (int i = 1; i < enumText.Length; i++)
+            {
+                if (char.IsUpper(enumText[i]))
+                {
+                    builder.Append('_');
+                }
+
+                builder.Append(char.ToLower(enumText[i]));
+            }
+
+            enumText = builder.ToString();
+
+            writer.WriteValue(enumText);
+        }
+    }
+}