using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Threading.Tasks;

namespace NX_CommonClassLibrary
{
    public static class EnumExtensionHelper
    {
        #region 根据枚举值返回枚举对象
        /// <summary>
        /// 根据枚举值返回枚举对象
        /// </summary>
        /// <typeparam name="T">枚举类型</typeparam>
        /// <param name="val">枚举值</param>
        /// <returns>返回指定的枚举类型对象</returns>
        public static T GetEnumObj<T>(object val) where T : Enum
        {
            FieldInfo[] fields = typeof(T).GetFields(BindingFlags.Static | BindingFlags.Public);
            bool isGet = false;
            foreach (var fi in fields)
            {
                int enumVal = ((int)fi.GetValue(null));
                int tmpVal = Convert.ToInt32(val);
                if (enumVal == tmpVal)
                {
                    isGet = true;
                    break;
                }
            }
            if (isGet)
            {
                val = Convert.ToInt32(val);
                return (T)val;
            }
            else
            {
                return (T)fields[0].GetValue(null);
            }
        }
        public static object GetEnumObj1(object val,Type t)
        {
            FieldInfo[] fields = t.GetFields(BindingFlags.Static | BindingFlags.Public);
            bool isGet = false;
            foreach (var fi in fields)
            {
                int enumVal = ((int)fi.GetValue(null));
                int tmpVal = Convert.ToInt32(val);
                if (enumVal == tmpVal)
                {
                    isGet = true;
                    break;
                }
            }
            if (isGet)
            {
                val = Convert.ToInt32(val);
                return val;
            }
            else
            {
                return fields[0].GetValue(null);
            }
        }
        #endregion
        public static IEnumerable<KeyValuePair<int, string>> GetEnumDescription(Type type)
        {
            List<KeyValuePair<int, string>> result = new List<KeyValuePair<int, string>>();
            if (!type.IsEnum) return result;
            var fields = type.GetFields();
            foreach (var field in fields)
            {
                object[] attrs = field.GetCustomAttributes(typeof(DescriptionAttribute), false);
                if (null != attrs && attrs.Length > 0)
                {
                    result.Add(new KeyValuePair<int, string>((int)field.GetRawConstantValue(), ((DescriptionAttribute)attrs[0]).Description));

                }
            }
            return result;
        }
    }
}