using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace Nirvana.Common
{
    public class EnumHelper
    {
        /// <summary>
        /// 转换如："enum1,enum2,enum3"字符串到枚举值
        /// </summary>
        /// <typeparam name="T">枚举类型</typeparam>
        /// <param name="obj">枚举字符串</param>
        /// <returns></returns>
        public static T Parse<T>(string obj)
        {
            if (string.IsNullOrEmpty(obj))
                return default(T);
            else
                return (T)Enum.Parse(typeof(T), obj);
        }

        public static T TryParse<T>(string obj, T defT = default(T))
        {
            try
            {
                return Parse<T>(obj);
            }
            catch
            {
                return defT;
            }
        }

        public static readonly string ENUM_TITLE_SEPARATOR = ",";

        /// <summary>
        /// 根据枚举值，返回描述字符串
        /// 如果多选枚举，返回以","分割的字符串
        /// </summary>
        /// <param name="e"></param>
        /// <returns></returns>
        public static string GetEnumTitle(Enum e)
        {
            if (e == null)
            {
                return "";
            }
            string[] valueArray = e.ToString().Split(ENUM_TITLE_SEPARATOR.ToArray(), StringSplitOptions.RemoveEmptyEntries);
            Type type = e.GetType();
            string ret = "";
            foreach (string enumValue in valueArray)
            {
                System.Reflection.FieldInfo fi = type.GetField(enumValue.Trim());
                if (fi == null)
                    continue;
                EnumTitleAttribute[] attrs = fi.GetCustomAttributes(typeof(EnumTitleAttribute), false) as EnumTitleAttribute[];
                if (attrs != null && attrs.Length > 0 && attrs[0].IsDisplay)
                {
                    ret += attrs[0].Title + ENUM_TITLE_SEPARATOR;
                }
            }
            return ret.TrimEnd(ENUM_TITLE_SEPARATOR.ToArray());
        }

        /// <summary>
        /// 根据枚举值，返回描述字符串
        /// 如果多选枚举，返回以","分割的字符串
        /// </summary>
        /// <param name="e"></param>
        /// <returns></returns>
        public static string GetAllEnumTitle(Enum e)
        {
            if (e == null)
            {
                return "";
            }
            string[] valueArray = e.ToString().Split(ENUM_TITLE_SEPARATOR.ToArray(), StringSplitOptions.RemoveEmptyEntries);
            Type type = e.GetType();
            string ret = "";
            foreach (string enumValue in valueArray)
            {
                System.Reflection.FieldInfo fi = type.GetField(enumValue.Trim());
                if (fi == null)
                    continue;
                EnumTitleAttribute[] attrs = fi.GetCustomAttributes(typeof(EnumTitleAttribute), false) as EnumTitleAttribute[];
                if (attrs != null && attrs.Length > 0)
                {
                    ret += attrs[0].Title + ENUM_TITLE_SEPARATOR;
                }
            }
            return ret.TrimEnd(ENUM_TITLE_SEPARATOR.ToArray());
        }

        public static EnumTitleAttribute GetEnumTitleAttribute(Enum e)
        {
            if (e == null)
            {
                return null;
            }
            string[] valueArray = e.ToString().Split(ENUM_TITLE_SEPARATOR.ToArray(), StringSplitOptions.RemoveEmptyEntries);
            Type type = e.GetType();
            EnumTitleAttribute ret = null;
            foreach (string enumValue in valueArray)
            {
                System.Reflection.FieldInfo fi = type.GetField(enumValue.Trim());
                if (fi == null)
                    continue;
                EnumTitleAttribute[] attrs = fi.GetCustomAttributes(typeof(EnumTitleAttribute), false) as EnumTitleAttribute[];
                if (attrs != null && attrs.Length > 0)
                {
                    ret = attrs[0];
                    break;
                }
            }
            return ret;
        }

        public static string GetDayOfWeekTitle(DayOfWeek day)
        {
            switch (day)
            {
                case DayOfWeek.Monday:
                    return "周一";
                case DayOfWeek.Tuesday:
                    return "周二";
                case DayOfWeek.Wednesday:
                    return "周三";
                case DayOfWeek.Thursday:
                    return "周四";
                case DayOfWeek.Friday:
                    return "周五";
                case DayOfWeek.Saturday:
                    return "周六";
                case DayOfWeek.Sunday:
                    return "周日";
                default:
                    return "";
            }
        }


        /// <summary>
        /// 返回键值对，建为枚举的EnumTitle中指定的名称和近义词名称，值为枚举项
        /// </summary>
        /// <typeparam name="T">枚举类型</typeparam>
        /// <param name="language"></param>
        /// <returns></returns>
        public static Dictionary<string, T> GetTitleAndSynonyms<T>() where T : struct
        {
            Dictionary<string, T> ret = new Dictionary<string, T>();
            //枚举值
            Array arrEnumValue = typeof(T).GetEnumValues();
            foreach (object enumValue in arrEnumValue)
            {
                System.Reflection.FieldInfo fi = typeof(T).GetField(enumValue.ToString());
                if (fi == null)
                {
                    continue;
                }

                EnumTitleAttribute[] arrEnumTitleAttr = fi.GetCustomAttributes(typeof(EnumTitleAttribute), false) as EnumTitleAttribute[];
                if (arrEnumTitleAttr == null || arrEnumTitleAttr.Length < 1 || !arrEnumTitleAttr[0].IsDisplay)
                {
                    continue;
                }

                if (!ret.ContainsKey(arrEnumTitleAttr[0].Title))
                {
                    ret.Add(arrEnumTitleAttr[0].Title, (T)enumValue);
                }

                if (arrEnumTitleAttr[0].Synonyms == null || arrEnumTitleAttr[0].Synonyms.Length < 1)
                {
                    continue;
                }

                foreach (string s in arrEnumTitleAttr[0].Synonyms)
                {
                    if (!ret.ContainsKey(s))
                    {
                        ret.Add(s, (T)enumValue);
                    }
                }
            }//using
            return ret;
        }

        /// <summary>
        /// 根据枚举获取包含所有所有值和描述的哈希表，其文本是由应用在枚举值上的EnumTitleAttribute设定
        /// </summary>
        /// <returns></returns>
        public static Dictionary<T, string> GetItemList<T>() where T : struct
        {
            return GetItemValueList<T, T>(false);
        }

        /// <summary>
        /// 根据枚举获取包含所有所有值和描述的哈希表，其文本是由应用在枚举值上的EnumTitleAttribute设定
        /// </summary>
        /// <returns></returns>
        public static Dictionary<T, string> GetAllItemList<T>() where T : struct
        {
            return GetItemValueList<T, T>(true);
        }

        /// <summary>
        /// 获取枚举所有项的标题,其文本是由应用在枚举值上的EnumTitleAttribute设定
        /// </summary>
        /// <typeparam name="T">枚举类型</typeparam>
        /// <param name="language">语言</param>
        /// <returns></returns>
        public static Dictionary<int, string> GetItemValueList<T>() where T : struct
        {
            return GetItemValueList<T, int>(false);
        }

        /// <summary>
        /// 获取枚举所有项的标题,其文本是由应用在枚举值上的EnumTitleAttribute设定
        /// </summary>
        /// <typeparam name="T">枚举类型</typeparam>
        /// <param name="isAll">是否生成“全部”项</param>
        /// <param name="language">语言</param>
        /// <returns></returns>
        public static Dictionary<TKey, string> GetItemValueList<T, TKey>(bool isAll) where T : struct
        {
            if (!typeof(T).IsEnum)
            {
                throw new Exception("参数必须是枚举！");
            }
            Dictionary<TKey, string> ret = new Dictionary<TKey, string>();

            var titles = EnumHelper.GetItemAttributeList<T>().OrderBy(t => t.Value.Order);
            foreach (var t in titles)
            {
                if (!isAll && (!t.Value.IsDisplay || t.Key.ToString() == "None"))
                    continue;

                if (t.Key.ToString() == "None" && isAll)
                {
                    ret.Add((TKey)(object)t.Key, "全部");
                }
                else
                {
                    if (!string.IsNullOrEmpty(t.Value.Title))
                        ret.Add((TKey)(object)t.Key, t.Value.Title);
                }
            }

            return ret;
        }

        public static List<T> GetItemKeyList<T>() where T : struct
        {
            List<T> list = new List<T>();
            Array array = typeof(T).GetEnumValues();
            foreach (object t in array)
            {
                list.Add((T)t);
            }
            return list;
        }

        public static Dictionary<T, EnumTitleAttribute> GetItemAttributeList<T>() where T : struct
        {
            if (!typeof(T).IsEnum)
            {
                throw new Exception("参数必须是枚举！");
            }
            Dictionary<T, EnumTitleAttribute> ret = new Dictionary<T, EnumTitleAttribute>();

            Array array = typeof(T).GetEnumValues();
            foreach (object t in array)
            {
                EnumTitleAttribute att = GetEnumTitleAttribute(t as Enum);
                if (att != null)
                    ret.Add((T)t, att);
            }

            return ret;
        }

        /// <summary>
        /// 获取枚举所有项的标题,其文本是由应用在枚举值上的EnumTitleAttribute设定
        /// </summary>
        /// <typeparam name="T">枚举类型</typeparam>
        /// <param name="isAll">是否生成“全部”项</param>
        /// <param name="language">语言</param>
        /// <returns></returns>
        public static Dictionary<TKey, string> GetAllItemValueList<T, TKey>() where T : struct
        {
            return GetItemValueList<T, TKey>(true);
        }


        /// <summary>
        /// 获取一个枚举的键值对形式
        /// </summary>
        /// <typeparam name="TEnum">枚举类型</typeparam>
        /// <param name="exceptTypes">排除的枚举</param>
        /// <returns></returns>
        public static Dictionary<int, string> GetEnumDictionary<TEnum>(IEnumerable<TEnum> exceptTypes = null) where TEnum : struct
        {
            var dic = GetItemList<TEnum>();

            Dictionary<int, string> dicNew = new Dictionary<int, string>();
            foreach (var d in dic)
            {
                if (exceptTypes != null && exceptTypes.Contains(d.Key))
                {
                    continue;
                }
                dicNew.Add(d.Key.GetHashCode(), d.Value);
            }
            return dicNew;
        }
    }


    public class EnumTitleAttribute : Attribute
    {
        private bool _IsDisplay = true;

        public EnumTitleAttribute(string title, params string[] synonyms)
        {
            Title = title;
            Synonyms = synonyms;
            Order = int.MaxValue;
        }
        public bool IsDisplay { get { return _IsDisplay; } set { _IsDisplay = value; } }
        public string Title { get; set; }
        public string Description { get; set; }
        public string Letter { get; set; }
        /// <summary>
        /// 近义词
        /// </summary>
        public string[] Synonyms { get; set; }
        public int Category { get; set; }
        public int Order { get; set; }
    }
}