Merge pull request #140 from RogueException/khio-enumpatch

Enum TypeReader

src/Discord.Net.Commands/Command.cs

@@ -77,11 +77,22 @@ namespace Discord.Commands
 
                 var typeInfo = type.GetTypeInfo();
                 if (typeInfo.IsEnum)
-                    type = Enum.GetUnderlyingType(type);
+                    Module.Service.AddTypeReader(type, new EnumTypeReader(type));
 
                 var reader = Module.Service.GetTypeReader(type);
+
                 if (reader == null)
-                    throw new InvalidOperationException($"{type.FullName} is not supported as a command parameter, are you missing a TypeReader?");
+                {
+                    if (typeInfo.IsEnum)
+                    {
+                        type = Enum.GetUnderlyingType(type);
+
+                        reader = Module.Service.GetTypeReader(type);
+                    }
+
+                    if (reader == null)
+                        throw new InvalidOperationException($"{type.FullName} is not supported as a command parameter, are you missing a TypeReader?");
+                }
 
                 bool isUnparsed = parameter.GetCustomAttribute<UnparsedAttribute>() != null;
                 if (isUnparsed)

src/Discord.Net.Commands/Readers/EnumTypeReader.cs

@@ -0,0 +1,54 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+
+namespace Discord.Commands
+{
+    internal class EnumTypeReader : TypeReader
+    {
+        private readonly Dictionary<string, object> stringValues;
+        private readonly Dictionary<int, object> intValues;
+        private readonly Type enumType;
+
+        public override Task<TypeReaderResult> Read(IMessage context, string input)
+        {
+            int inputAsInt;
+            object enumValue;
+
+            if (int.TryParse(input, out inputAsInt))
+            {
+                if (intValues.TryGetValue(inputAsInt, out enumValue))
+                    return Task.FromResult(TypeReaderResult.FromSuccess(enumValue));
+                else
+                    return Task.FromResult(TypeReaderResult.FromError(CommandError.CastFailed, $"Value is not a {enumType.Name}"));
+            }
+            else
+            {
+                if (stringValues.TryGetValue(input.ToLower(), out enumValue))
+                    return Task.FromResult(TypeReaderResult.FromSuccess(enumValue));
+                else
+                    return Task.FromResult(TypeReaderResult.FromError(CommandError.CastFailed, $"Value is not a {enumType.Name}"));
+            }
+        }
+
+        public EnumTypeReader(Type type)
+        {
+            enumType = type;
+
+            var stringValuesBuilder = new Dictionary<string, object>();
+            var intValuesBuilder = new Dictionary<int, object>();
+
+            var values = Enum.GetValues(enumType);
+
+            foreach (var v in values)
+            {
+                stringValuesBuilder.Add(v.ToString().ToLower(), v);
+                intValuesBuilder.Add((int)v, v);
+            }
+
+            stringValues = stringValuesBuilder;
+            intValues = intValuesBuilder;
+        }
+    }
+}