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

namespace FlexJobApi.Core
{
    /// <summary>
    /// 枚举工具
    /// </summary>
    public static class EnumUtils
    {
        /// <summary>
        /// 获取模型
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <returns></returns>
        public static async Task<EnumModel<T>> GetModel<T>()
            where T : struct
        {
            var type = typeof(T);
            var model = new EnumModel<T>();
            var xmlDoc = await XmlDocUtils.GetXmlDocAsync();
            var xmlDocMember = await XmlDocUtils.GetXmlDocMemberAsync(type, xmlDoc);
            model.Name = type.Name;
            model.Description = xmlDocMember?.Summary;

            foreach (var enumValue in Enum.GetValues(type))
            {
                var item = new EnumModelItem<T>();
                item.Name = enumValue.ToString();
                item.Value = (int)enumValue;
                item.Enum = (T)enumValue;
                var enumMember = type.GetMember(enumValue.ToString()).FirstOrDefault();
                var enumXmlDocMember = await XmlDocUtils.GetXmlDocMemberAsync(enumMember, xmlDoc);
                item.Description = enumXmlDocMember?.Summary;
                model.Items.Add(item);
            }
            return model;
        }

        /// <summary>
        /// 获取模型
        /// </summary>
        /// <param name="type"></param>
        /// <returns></returns>
        public static async Task<EnumModel> GetModel(this Type type)
        {
            var model = new EnumModel();
            var xmlDoc = await XmlDocUtils.GetXmlDocAsync();
            var xmlDocMember = await XmlDocUtils.GetXmlDocMemberAsync(type, xmlDoc);
            model.Name = type.Name;
            model.Description = xmlDocMember?.Summary;

            foreach (var enumValue in Enum.GetValues(type))
            {
                var item = new EnumModelItem();
                item.Name = enumValue.ToString();
                item.Value = (int)enumValue;
                var enumMember = type.GetMember(enumValue.ToString()).FirstOrDefault();
                var enumXmlDocMember = await XmlDocUtils.GetXmlDocMemberAsync(enumMember, xmlDoc);
                item.Description = enumXmlDocMember?.Summary;
                model.Items.Add(item);
            }
            return model;
        }

        /// <summary>
        /// 获取描述
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="model"></param>
        /// <param name="t"></param>
        /// <returns></returns>
        public static string GetDescription<T>(this EnumModel<T> model, T t)
            where T : struct
        {
            return model.Items
                .Where(it => it.Enum.Equals(t))
                .Select(it => it.Description)
                .FirstOrDefault();
        }

        /// <summary>
        /// 获取枚举
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="model"></param>
        /// <param name="name"></param>
        /// <returns></returns>
        public static T GetEnum<T>(this EnumModel<T> model, string name)
            where T : struct
        {
            return model.Items
               .Where(it => it.Name.Equals(name, StringComparison.OrdinalIgnoreCase))
               .Select(it => it.Enum)
               .FirstOrDefault();
        }

        /// <summary>
        /// 获取自定义特性
        /// </summary>
        /// <typeparam name="TEnum"></typeparam>
        /// <typeparam name="TAttribute"></typeparam>
        /// <param name="enum"></param>
        /// <returns></returns>
        public static TAttribute GetCustomAttribute<TEnum, TAttribute>(this TEnum @enum)
            where TEnum : struct
            where TAttribute : Attribute
        {

            return typeof(TEnum).GetMember(@enum.ToString())[0].GetCustomAttribute<TAttribute>();
        }
    }
}