/*******************************************************/
/*Project:基础类库
Module   :时间函数库
Description :
Date    : 2008-6-3 15:09:12
Create  : Lxc
Update  : 2015-12-31
TODO    : */
/*******************************************************/

namespace System
{
	/// <summary>
	/// 日期时间操作单元
	/// </summary>
	public partial class DateUnit
	{
		/// <summary>
		/// 1970-1-1
		/// </summary>
		public static DateTime InitDate()
		{
			return new DateTime(1970, 1, 1);
		}

		/// <summary>
		/// 默认当前日期
		/// </summary>
		public static DateTime DefDate()
		{
			return DateTime.Now;
		}

		/// <summary>
		/// 格式化后的当前日期
		/// </summary>
		public static string DefFormatDate()
		{
			return FormatDate(DefDate());
		}

		/// <summary>
		///格式化当前时间
		/// </summary>
		public static string DefFormatDateTime()
		{
			return FormatDateTime(DefDate());
		}

		/// <summary>
		/// 格式化后的 当前月1号  日期格式yyyy-MM-01
		/// </summary>
		public static string DefMonthBegFormat()
		{
			return DefDate().ToString("yyyy-MM-01");
		}

		/// <summary>
		/// 字符串格式->格式化为当前日期
		/// </summary>
		/// <param name="Indate"></param>
		/// <returns></returns>
		public static string FormatDate(string Indate)
		{
			DateTime nowDate = DefDate();

			if (Indate != null && Indate != "")
			{
				nowDate = ToDate(Indate);
			}

			return FormatDate(nowDate);
		}

		/// <summary>
		/// 格式化为 日期格式yyyy-MM-dd
		/// </summary>
		/// <param name="Indate"></param>
		/// <returns></returns>
		public static string FormatDate(DateTime Indate)
		{
			if (!Indate.Equals(null))
			{
				return Indate.ToString("yyyy-MM-dd");
			}
			else
			{
				return DefFormatDate();
			}
		}

		/// <summary>
		/// 格式化为 日期时间格式yyyy-MM-dd HH:mm:ss
		/// </summary>
		/// <param name="Indate"></param>
		/// <returns></returns>
		public static string FormatDateTime(DateTime Indate)
		{
			if (!Indate.Equals(null))
			{
				return Indate.ToString("yyyy-MM-dd HH:mm:ss");
			}
			else
			{
				return DefFormatDate();
			}
		}

		/// <summary>
		/// 格式化时间 毫秒
		/// </summary>
		/// <param name="Indate"></param>
		/// <returns></returns>
		public static string FormatDateTimefff(DateTime Indate)
		{
			if (!Indate.Equals(null))
			{
				return Indate.ToString("yyyy-MM-dd HH:mm:ss fff");
			}
			else
			{
				return DefFormatDate();
			}
		}

		#region 时间函数

		/// <summary>
		/// 是不是时间格式
		/// </summary>
		/// <param name="datetm"></param>
		/// <returns></returns>
		public static bool IsDate(string datetm)
		{
			bool result = false;
			try
			{
				DateTime dateTime = Convert.ToDateTime(datetm);
				result = true;
			}
			catch
			{
				result = false;
			}
			return result;
		}

		/// <summary>
		/// 将字符串转化成日期，如果输入的字符串不是日期时，则返回1970-1-1
		/// </summary>
		/// <param name="str"></param>
		/// <returns></returns>
		public static DateTime ToDate(string str)
		{
			if (str == null || str == "")
				return DefDate();
			else
			{
				DateTime dt = DefDate();
				if (DateTime.TryParse(str, out dt) == false)
					return DefDate();
				else
					return dt;
			}
		}

		/// <summary>
		/// 将对象转化成日期，如果输入的对象不是日期时，则返回1970-1-1
		/// </summary>
		/// <param name="obj"></param>
		/// <returns></returns>
		public static DateTime ToDate(object obj)
		{
			DateTime Result = DefDate();
			if (!obj.Equals(null))
			{
				try
				{
					Result = (DateTime)obj;
				}
				catch (Exception ex)
				{
					return DefDate();
				}
				//if (DateTime.TryParse(obj.ToString(), out Result) == false)
				//    return DefDate;
			}
			return Result;
		}

		/// <summary>
		/// 将对象转化成日期，如果输入的对象不是日期时，则返回1900-1-1
		/// </summary>
		/// <param name="obj"></param>
		/// <returns></returns>
		public static DateTime ToDate(System.Nullable<System.DateTime> obj)
		{
			if (!obj.Equals(null))
			{
				return (DateTime)obj;
			}
			else
			{
				return DefDate();
			}
		}

		/// <summary>
		/// 20070101-->2007-01-01
		/// </summary>
		/// <param name="Str"></param>
		/// <returns></returns>
		public static string StrTodate(string Str)
		{
			string stryear, strmon, strday;
			try
			{
				stryear = Str.Remove(4, 4);
				Str = Str.Remove(0, 4);
				strmon = Str.Remove(2, 2);
				strday = Str.Remove(0, 2);
				stryear = stryear + "-" + strmon + "-" + strday;
				return stryear;
			}
			catch
			{
				return DefFormatDate();
			}
		}

		#endregion 时间函数

		#region 周计算

		/// <summary>
		/// 周几
		/// </summary>
		/// <param name="curDay"></param>
		/// <returns></returns>
		public static string DayOfWeek(DateTime curDay)
		{
			string[] weekdays = { "星期日", "星期一", "星期二", "星期三", "星期四", "星期五", "星期六" };
			string week = weekdays[Convert.ToInt32(curDay.DayOfWeek)];

			return week;
		}

		/// <summary>
		/// 第几周
		/// </summary>
		/// <param name="curDay"></param>
		/// <returns></returns>
		public static int WeekOfYear(DateTime curDay)
		{
			int firstdayofweek = Convert.ToInt32(Convert.ToDateTime(curDay.Year.ToString() + "-" + "1-1").DayOfWeek);

			int days = curDay.DayOfYear;
			int daysOutOneWeek = days - (7 - firstdayofweek);

			if (daysOutOneWeek <= 0)
			{
				return 1;
			}
			else
			{
				int weeks = daysOutOneWeek / 7;
				if (daysOutOneWeek % 7 != 0)
					weeks++;

				return weeks + 1;
			}
		}

		#region 返回某年某月最后一天

		/// <summary>
		/// 返回某年某月最后一天
		/// </summary>
		/// <param name="year">年份</param>
		/// <param name="month">月份</param>
		/// <returns>日</returns>
		public static int GetMonthLastDate(int year, int month)
		{
			DateTime lastDay = new DateTime(year, month, new System.Globalization.GregorianCalendar().GetDaysInMonth(year, month));
			int Day = lastDay.Day;
			return Day;
		}

		#endregion 返回某年某月最后一天

		#endregion 周计算

		#region 返回时间差

		/// <summary>
		/// 返回时间差 秒
		/// </summary>
		/// <param name="begDateTime"></param>
		/// <param name="endDateTime"></param>
		/// <returns></returns>
		public static double DateDiffSeconds(DateTime begDateTime, DateTime endDateTime)
		{
			try
			{
				TimeSpan ts = endDateTime - begDateTime;
				return ts.TotalSeconds;
			}
			catch (Exception)
			{
				return 0;
			}
		}

		/// <summary>
		/// 返回时间差 分钟
		/// </summary>
		/// <param name="begDateTime"></param>
		/// <param name="endDateTime"></param>
		/// <returns></returns>
		public static double DateDiffMinutes(DateTime begDateTime, DateTime endDateTime)
		{
			try
			{
				TimeSpan ts = endDateTime - begDateTime;
				return ts.TotalMinutes;
			}
			catch (Exception)
			{
				return 0;
			}
		}

		public static double DateDiffHours(DateTime begDateTime, DateTime endDateTime)
		{
			try
			{
				TimeSpan ts = endDateTime - begDateTime;
				return ts.TotalHours;
			}
			catch (Exception)
			{
				return 0;
			}
		}

		public static double DateDifDays(DateTime begDateTime, DateTime endDateTime)
		{
			try
			{
				TimeSpan ts = endDateTime - begDateTime;
				return ts.TotalDays;
			}
			catch (Exception)
			{
				return 0;
			}
		}

		#endregion 返回时间差

		/// <summary>
		/// Unix时间戳
		/// </summary>
		/// <returns>毫秒</returns>
		public static long UnixTime()
		{
			System.DateTime time = DateTime.Now;
			System.DateTime startTime = TimeZone.CurrentTimeZone.ToLocalTime(new System.DateTime(1970, 1, 1, 0, 0, 0, 0));
			long t = (time.Ticks - startTime.Ticks) / 10000;   //除10000调整为13位
			return t;
		}

		/// <summary>
		/// 将c# DateTime时间格式转换为Unix时间戳格式
		/// </summary>
		/// <param name="time">时间</param>
		/// <returns> 毫秒</returns>
		public static long DateTimeToUnixTime(System.DateTime time)
		{
			System.DateTime startTime = TimeZone.CurrentTimeZone.ToLocalTime(new System.DateTime(1970, 1, 1, 0, 0, 0, 0));
			long t = (time.Ticks - startTime.Ticks) / 10000;   //除10000调整为13位
			return t;
		}

		/// <summary>
		/// 时间戳转为C#格式时间
		/// </summary>
		/// <param name="timeStamp"></param>
		/// <returns></returns>
		public static DateTime UnixTimeToDateTime(long timeStamp)
		{
			DateTime dtStart = TimeZone.CurrentTimeZone.ToLocalTime(new DateTime(1970, 1, 1));
			long lTime = timeStamp * 10000;
			TimeSpan toNow = new TimeSpan(lTime);
			return dtStart.Add(toNow);
		}

		/// <summary>
		/// Unix时间戳 时间格式化 为日期
		/// </summary>
		/// <param name="timeStamp"></param>
		/// <returns></returns>
		public static string FormatDateUnixTime(long timeStamp)
		{
			DateTime dtStart = UnixTimeToDateTime(timeStamp);
			return FormatDate(dtStart);
		}

		/// <summary>
		/// Unix时间戳 时间格式化 为时间
		/// </summary>
		/// <param name="timeStamp"></param>
		/// <returns></returns>
		public static string FormatDateTimeUnixTime(long timeStamp)
		{
			DateTime dtStart = UnixTimeToDateTime(timeStamp);
			return FormatDateTime(dtStart);
		}
	}
}