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

namespace VOL.Model
{
    public static class EnumExtensions
    {
        // 获取 Display Name
        public static string GetDisplayName(this Enum value)
        {
            if (value == null)
            {
                return "";
            }

            FieldInfo fi = value.GetType().GetField(value.ToString());

            if (fi == null)
            {
                return value.ToString();
            }

            DisplayAttribute attribute = fi.GetCustomAttribute<DisplayAttribute>();

            if (attribute != null && !string.IsNullOrEmpty(attribute.Name))
            {
                return attribute.Name;
            }
            return value.ToString();
        }

        public static string GetDisplayDescription(this Enum value)
        {
            if (value == null)
            {
                return "";
            }

            FieldInfo fi = value.GetType().GetField(value.ToString());

            if (fi == null)
            {
                return value.ToString();
            }

            DisplayAttribute attribute = fi.GetCustomAttribute<DisplayAttribute>();

            if (attribute != null && !string.IsNullOrEmpty(attribute.Description))
            {
                return attribute.Description;
            }
            return "";
        }
        public static string Description(this Enum value)
        {
            if (value == null)
            {
                throw new ArgumentNullException(nameof(value), "Enum value cannot be null");
            }

            // 获取字段信息
            FieldInfo field = value.GetType().GetField(value.ToString());

            if (field == null)
            {
                // 如果字段信息为空，返回默认的描述
                return "";
            }

            // 获取 DescriptionAttribute 特性
            var attributes = field.GetCustomAttributes(typeof(DescriptionAttribute), false);
            var attribute = attributes.FirstOrDefault() as DescriptionAttribute;

            // 如果特性为空，返回空字符串
            return attribute?.Description ?? "";
        }
    }
}