Ombi/PlexRequests.Helpers/EnumHelper.cs

#region Copyright
// /************************************************************************
//    Copyright (c) 2016 Jamie Rees
//    File: EnumHelper.cs
//    Created By: Jamie Rees
//   
//    Permission is hereby granted, free of charge, to any person obtaining
//    a copy of this software and associated documentation files (the
//    "Software"), to deal in the Software without restriction, including
//    without limitation the rights to use, copy, modify, merge, publish,
//    distribute, sublicense, and/or sell copies of the Software, and to
//    permit persons to whom the Software is furnished to do so, subject to
//    the following conditions:
//   
//    The above copyright notice and this permission notice shall be
//    included in all copies or substantial portions of the Software.
//   
//    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
//    EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
//    MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
//    NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
//    LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
//    OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
//    WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//  ************************************************************************/
#endregion

using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Linq;
using System.Reflection;

namespace PlexRequests.Helpers
{
    public static class EnumHelper<T>
    {
        public static IList<T> GetValues(Enum value)
        {
            return value.GetType().GetFields(BindingFlags.Static | BindingFlags.Public).Select(fi => (T) Enum.Parse(value.GetType(), fi.Name, false)).ToList();
        }

        public static T Parse(string value)
        {
            return (T)Enum.Parse(typeof(T), value, true);
        }

        public static IList<string> GetNames(Enum value)
        {
            return value.GetType().GetFields(BindingFlags.Static | BindingFlags.Public).Select(fi => fi.Name).ToList();
        }

        public static IList<string> GetDisplayValues(Enum value)
        {
            return GetNames(value).Select(obj => GetDisplayValue(Parse(obj))).ToList();
        }

        private static string LookupResource(Type resourceManagerProvider, string resourceKey)
        {
            foreach (var staticProperty in resourceManagerProvider.GetProperties(BindingFlags.Static | BindingFlags.NonPublic | BindingFlags.Public))
            {
                if (staticProperty.PropertyType == typeof(System.Resources.ResourceManager))
                {
                    System.Resources.ResourceManager resourceManager = (System.Resources.ResourceManager)staticProperty.GetValue(null, null);
                    return resourceManager.GetString(resourceKey);
                }
            }

            return resourceKey; // Fallback with the key name
        }

        public static string GetDisplayValue(T value)
        {
            var fieldInfo = value.GetType().GetField(value.ToString());

            var descriptionAttributes = fieldInfo.GetCustomAttributes(
                typeof(DisplayAttribute), false) as DisplayAttribute[];

            if (descriptionAttributes[0].ResourceType != null)
                return LookupResource(descriptionAttributes[0].ResourceType, descriptionAttributes[0].Name);

            if (descriptionAttributes == null) return string.Empty;
            return (descriptionAttributes.Length > 0) ? descriptionAttributes[0].Name : value.ToString();
        }

        public static T GetValueFromName(string name)
        {
            var type = typeof(T);
            if (!type.IsEnum) throw new InvalidOperationException();

            foreach (var field in type.GetFields())
            {
                var attribute = Attribute.GetCustomAttribute(field,
                    typeof(DisplayAttribute)) as DisplayAttribute;
                if (attribute != null)
                {
                    if (attribute.Name == name)
                    {
                        return (T)field.GetValue(null);
                    }
                }
                else
                {
                    if (field.Name == name)
                        return (T)field.GetValue(null);
                }
            }

            throw new ArgumentOutOfRangeException(nameof(name));
        }
    }
}