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

namespace Znyc.Cloudcar.Admin.Commons.Extensions
{
    /// <summary>
    ///     枚举类型的扩展
    /// </summary>
    public static class EnumExtensions
    {
        /// <summary>
        /// </summary>
        /// <param name="item"></param>
        /// <returns></returns>
        public static string ToDescription(this Enum item)
        {
            string name = item.ToString();
            DescriptionAttribute desc = item.GetType().GetField(name)?.GetCustomAttribute<DescriptionAttribute>();
            return desc?.Description ?? name;
        }

        /// <summary>
        /// </summary>
        /// <param name="item"></param>
        /// <returns></returns>
        public static long ToInt64(this Enum item)
        {
            return Convert.ToInt64(item);
        }

        /// <summary>
        ///     根据枚举的value获取枚举
        /// </summary>
        /// <param name="enumType">枚举的类型,示例:typeof(enum1)</param>
        /// <param name="value">可能的枚举值</param>
        /// <returns>枚举,示例：enum1.en1</returns>
        public static Enum ParseEnum(Type enumType, string value)
        {
            return Enum.Parse(enumType, value) as Enum;
        }


        /// <summary>
        ///     根据 value 值获取Description
        /// </summary>
        /// <param name="enumType"></param>
        /// <param name="value"></param>
        /// <returns></returns>
        public static string GetDescription(this Type enumType, int value)
        {
            object Key = GetNameAndValue(enumType).FirstOrDefault(p => p.Value.Equals(value)).Key;
            if (Key==null)
            {
                return null;
            }

            return Key.ToString();
        }
        /// <summary>
        ///     获取枚举名以及对应的Value
        /// </summary>
        /// <param name="type">枚举类型typeof(T)</param>
        /// <returns>返回Dictionary  ,Key为描述名，  Value为枚举对应的值</returns>
        public static Dictionary<object, object> GetNameAndValue(this Type type)
        {
            if (type.IsEnum)
            {
                Dictionary<object, object> dic = new Dictionary<object, object>();
                Array enumValues = Enum.GetValues(type);
                foreach (Enum value in enumValues)
                {
                    dic.Add(GetDescription(value), value.GetHashCode());
                }

                return dic;
            }

            return null;
        }

        /// <summary>
        ///     从枚举中获取Description
        /// </summary>
        /// <param name="enumName">需要获取枚举描述的枚举</param>
        /// <returns>描述内容</returns>
        public static string GetDescription(this Enum enumName)
        {
            string description = string.Empty;
            FieldInfo fieldInfo = enumName.GetType().GetField(enumName.ToString());
            DescriptionAttribute[] attributes = GetDescriptAttr(fieldInfo);
            if (attributes != null && attributes.Length > 0)
            {
                description = attributes[0].Description;
            }
            else
            {
                description = enumName.ToString();
            }

            return description;
        }
        /// <summary>
        ///     获取字段Description
        /// </summary>
        /// <param name="fieldInfo">FieldInfo</param>
        /// <returns>DescriptionAttribute[] </returns>
        private static DescriptionAttribute[] GetDescriptAttr(FieldInfo fieldInfo)
        {
            if (fieldInfo != null)
            {
                return (DescriptionAttribute[])fieldInfo.GetCustomAttributes(typeof(DescriptionAttribute), false);
            }

            return null;
        }
    }
}