using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.ComponentModel.DataAnnotations;
using System.Data;
using System.Reflection;
using System.Text;

namespace HotelPms.Share.Util
{
    public static class ObjectEx
    {
         public enum Days
         {
            [Description("小木ですよ、　－～\"#$%#%$#\"===")]
            Sun,
            [Description("今天星期一 猴子穿新衣")]
            Mon,
            [Description("今天星期二 猴子肚子餓")]
            Tue,
            [Description("今天星期三 猴子去爬山")]
            Wed,
            [Description("今天星期四 猴子去考試")]
            Thu,
            [Description("今天星期五 猴子去跳舞")]
            Fri,
            [Description("今天星期六 猴子去斗六")]
            Sat,
            Inter,
         }

    /// <summary>
    /// 返回枚举类型的注释
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// 例：
    /// public enum Days
    /// {
    ///    [Description("小木ですよ、　－～\"#$%#%$#\"===")]
    ///    Sun,
    ///    [Description("今天星期一 猴子穿新衣")]
    ///    Mon,
    ///    [Description("今天星期二 猴子肚子餓")]
    ///    Tue,
    ///    [Description("今天星期三 猴子去爬山")]
    ///    Wed,
    ///    [Description("今天星期四 猴子去考試")]
    ///    Thu,
    ///    [Description("今天星期五 猴子去跳舞")]
    ///    Fri,
    ///    [Description("今天星期六 猴子去斗六")]
    ///    Sat,
    ///    Inter,
    /// }
    /// <param name="source"></param>
    /// <returns></returns>
    public static string ToDescription<T>(this T source) where T : Enum
    {
            try
            {
                FieldInfo fi = source.GetType().GetField(source.ToString());
                DescriptionAttribute[] attributes = (DescriptionAttribute[])fi.GetCustomAttributes(typeof(DescriptionAttribute), false);
                if (attributes != null && attributes.Length > 0) { return attributes[0].Description; } else { return source.ToString(); }
            }
            catch
            {
                return string.Empty;
            }
        }

        /// <summary>
        /// 任意オブジェクトのAttribute取得
        /// </summary>
        /// <param name="source"></param>
        /// <returns></returns>
        public static string GetDisplayName<T>(this T source, string property) where T : class
        {
            try
            {
                PropertyInfo p = source.GetType().GetProperty(property);
                DisplayAttribute[] attributes = (DisplayAttribute[])p.GetCustomAttributes(typeof(DisplayAttribute), false);
                if (attributes != null && attributes.Length > 0) { return attributes[0].Name; } else { return string.Empty; }
            }
            catch
            {
                return string.Empty;
            }
        }

        /// <summary>
        /// 任意オブジェクトのハンドル取得
        /// </summary>
        /// <param name="source"></param>
        /// <returns></returns>
        public static long ToHandle64<T>(this T source) where T : class
        {
            try
            {
                return source.GetType().TypeHandle.Value.ToInt64();
            }
            catch
            {
                return 0;
            }
        }

        /// <summary>
        /// Null判断
        /// </summary>
        /// <param name="dataReader"></param>
        /// <param name="columnName"></param>
        /// <returns></returns>
        public static bool IsNull(this IDataReader dataReader, string columnName)
        {
            return dataReader[columnName] == DBNull.Value;
        }

        //public static T ToInstance<T>(long handle) where T : class
        //{
        //    try
        //    {
        //        unsafe
        //        {
        //            IntPtr ptr = new IntPtr(handle);
        //            Object obj = Pointer.Box((void*)ptr, typeof(T));
        //            return obj as T;
        //        }
        //    }
        //    catch
        //    {
        //        return default(T);
        //    }
        //}
    }
}