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

namespace Common
{
    /// <summary>
    /// datetime数据类型拓展
    /// </summary>
  public static class  DateTimeExtension
    {

        /// <summary>
        ///将一个时间转换为秒级时间戳
        /// </summary>
        /// <param name="datetime">时间</param>
        /// <returns></returns>
        public static long ToTimeStampSeconds(this DateTime datetime)
        {
            return (long)Math.Round((datetime.ToUniversalTime() - new DateTimeOffset(1970, 1, 1, 0, 0, 0, TimeSpan.Zero)).TotalSeconds);
        }

        /// <summary>
        ///将一个时间转换为毫秒级时间戳
        /// </summary>
        /// <param name="datetime"></param>
        /// <returns></returns>
        public static long ToTimeStampMilliSeconds(this DateTime datetime)
        {
           
            return (long)Math.Round((datetime.ToUniversalTime() - new DateTimeOffset(1970, 1, 1, 0, 0, 0, TimeSpan.Zero)).TotalMilliseconds);
        }

        /// <summary>
        /// 获取标准时间戳 秒级
        /// </summary>
        /// <param name="datetime"></param>
        /// <returns></returns>
        public static long ToTimeStamp(this DateTime datetime)
        { return ToTimeStampSeconds(datetime); }

        /// <summary>
        /// 将时间转换为时间字符串编码 yyyyMMddHHmmssffff
        /// </summary>
        /// <param name="datetime"></param>
        /// <returns></returns>
        public static string ToTimeStr(this DateTime datetime)
        {
            return datetime.ToString("yyyyMMddHHmmssffff");
        }

        /// <summary>
        /// 判断时间是否大于1970年的有效时间
        /// </summary>
        /// <param name="dateTime"></param>
        /// <returns></returns>
        public static bool IsValidTime(this DateTime dateTime) {
            if (dateTime.Date >= DateTime.Parse("1970-1-1"))
                return true;
            else return false;
        }
        /// <summary>
        /// 获时间一天中的开始时间
        /// </summary>
        /// <param name="dateTime"></param>
        public static DateTime GetDayStartTime(this DateTime dateTime) {
            return dateTime.Date;
        }
        /// <summary>
        /// 获取时间一天的结束时间
        /// </summary>
        /// <param name="dateTime"></param>
        /// <returns></returns>

        public static DateTime GetDateEndTime(this DateTime dateTime) {
            return dateTime.Date.AddDays(1).AddSeconds(-1);
        }

        /// <summary>
        /// 获取时间周的星期一的时间
        /// </summary>
        /// <param name="dateTime"></param>
        /// <returns></returns>
        public static DateTime GetWeekStartTime(this DateTime dateTime) {
          return  dateTime.GetWeekOfDayTime(1);
        }

        /// <summary>
        /// 获取时间周的周日
        /// </summary>
        /// <param name="dateTime"></param>
        /// <returns></returns>
        public static DateTime GetWeekEndTime(this DateTime dateTime) {
            return dateTime.GetWeekOfDayTime(7);
        }

        /// <summary>
        /// 获取时间周的指定周几时间
        /// </summary>
        /// <param name="dateTime"></param>
        /// <param name="Day">周几 1 2 3 4 5 6 7</param>
        /// <returns></returns>
        public static DateTime GetWeekOfDayTime(this DateTime dateTime, int Day) {
            if (Day < 1)
                Day = 1;
            if (Day > 7)
                Day = (int)dateTime.DayOfWeek; 
            return dateTime.Subtract(new TimeSpan(dateTime.DayOfWeek - (DayOfWeek)Day, 0, 0, 0)).Date;
        }

        /// <summary>
        /// 获取时间月度开始时间
        /// </summary>
        /// <param name="dateTime"></param>
        /// <returns></returns>
        public static DateTime GetMonthStartTime(this DateTime dateTime) {
            return new DateTime(dateTime.Year,dateTime.Month,1).Date;
        }
        /// <summary>
        /// 获取一个月度的结束时间
        /// </summary>
        /// <param name="dateTime"></param>
        /// <returns></returns>
        public static DateTime GetMonthEndTime(this DateTime dateTime) {
            return dateTime.GetMonthStartTime().AddMonths(1).AddSeconds(-1);

        }

        /// <summary>
        /// 获取时间年度度开始时间
        /// </summary>
        /// <param name="dateTime"></param>
        /// <returns></returns>
        public static DateTime GetYearStartTime(this DateTime dateTime)
        {
            return new DateTime(dateTime.Year,1, 1).Date;
        }
        /// <summary>
        /// 获取一个年度的结束时间
        /// </summary>
        /// <param name="dateTime"></param>
        /// <returns></returns>
        public static DateTime GetYearEndTime(this DateTime dateTime)
        {
            return dateTime.GetYearStartTime().AddYears(1).AddSeconds(-1);

        }
        /// <summary>
        /// 获取零时区时间
        /// </summary>
        /// <returns>返回服务器零时区时间</returns>
        public static DateTime GetUtcDateTime()
        {
            DateTime serverTime2 = TimeZoneInfo.ConvertTimeToUtc(DateTime.Now, TimeZoneInfo.Local);
            return serverTime2;
        }
        private static DateTime dtMin = DateTime.Parse("1970-01-01");
        /// <summary>
        /// 获取yyyy-MM-dd HH:mm:ss 时间格式
        /// </summary>
        /// <param name="dt"></param>
        /// <returns></returns>
        public static string ToSqlServerTimeString(this DateTime dt)
        {
            if (dt == dtMin)
            {
                return string.Empty;
            }

            return dt.ToString("yyyy-MM-dd HH:mm:ss");
        }
    }
}