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

namespace DSWeb.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>
            /// 获取一个月的结束时间
            /// </summary>
            /// <param name="dateTime"></param>
            /// <returns></returns>
            public static DateTime GetMonthEndTime(this DateTime dateTime)
            {
                return dateTime.GetMonthStartTime().AddMonths(1).AddDays(-1);

            }
        }
    
}