using System;
using System.Globalization;

namespace Masuit.Tools.DateTimeExt
{
    /// <summary>
    /// 时间相关操作帮助类
    /// </summary>
    public static class TimeHelper
    {
        #region 返回每月的第一天和最后一天

        /// <summary>
        ///  返回每月的第一天和最后一天
        /// </summary>
        /// <param name="_"></param>
        /// <param name="month">月份</param>
        /// <param name="firstDay">第一天</param>
        /// <param name="lastDay">最后一天</param>
        public static void ReturnDateFormat(this DateTime _, int month, out string firstDay, out string lastDay)
        {
            int year = DateTime.Now.Year + month / 12;
            if (month != 12)
            {
                month %= 12;
            }

            switch (month)
            {
                case 1:
                    firstDay = DateTime.Now.ToString($"{year}-0{month}-01");
                    lastDay = DateTime.Now.ToString($"{year}-0{month}-31");
                    break;
                case 2:
                    firstDay = DateTime.Now.ToString(year + "-0" + month + "-01");
                    lastDay = DateTime.IsLeapYear(DateTime.Now.Year) ? DateTime.Now.ToString(year + "-0" + month + "-29") : DateTime.Now.ToString(year + "-0" + month + "-28");
                    break;
                case 3:
                    firstDay = DateTime.Now.ToString(year + "-0" + month + "-01");
                    lastDay = DateTime.Now.ToString("yyyy-0" + month + "-31");
                    break;
                case 4:
                    firstDay = DateTime.Now.ToString(year + "-0" + month + "-01");
                    lastDay = DateTime.Now.ToString(year + "-0" + month + "-30");
                    break;
                case 5:
                    firstDay = DateTime.Now.ToString(year + "-0" + month + "-01");
                    lastDay = DateTime.Now.ToString(year + "-0" + month + "-31");
                    break;
                case 6:
                    firstDay = DateTime.Now.ToString(year + "-0" + month + "-01");
                    lastDay = DateTime.Now.ToString(year + "-0" + month + "-30");
                    break;
                case 7:
                    firstDay = DateTime.Now.ToString(year + "-0" + month + "-01");
                    lastDay = DateTime.Now.ToString(year + "-0" + month + "-31");
                    break;
                case 8:
                    firstDay = DateTime.Now.ToString(year + "-0" + month + "-01");
                    lastDay = DateTime.Now.ToString(year + "-0" + month + "-31");
                    break;
                case 9:
                    firstDay = DateTime.Now.ToString(year + "-0" + month + "-01");
                    lastDay = DateTime.Now.ToString(year + "-0" + month + "-30");
                    break;
                case 10:
                    firstDay = DateTime.Now.ToString(year + "-" + month + "-01");
                    lastDay = DateTime.Now.ToString(year + "-" + month + "-31");
                    break;
                case 11:
                    firstDay = DateTime.Now.ToString(year + "-" + month + "-01");
                    lastDay = DateTime.Now.ToString(year + "-" + month + "-30");
                    break;
                default:
                    firstDay = DateTime.Now.ToString(year + "-" + month + "-01");
                    lastDay = DateTime.Now.ToString(year + "-" + month + "-31");
                    break;
            }
        }

        #endregion

        #region  将时间格式化成 年月日 的形式,如果时间为null，返回当前系统时间

        /// <summary>
        /// 将时间格式化成 年月日 的形式,如果时间为null，返回当前系统时间
        /// </summary>
        /// <param name="dt">年月日分隔符</param>
        /// <param name="separator">分隔符</param>
        /// <returns>xxxx年xx月xx日</returns>
        public static string GetFormatDate(this DateTime dt, char separator)
        {
            if (dt.Equals(DBNull.Value))
            {
                return GetFormatDate(DateTime.Now, separator);
            }

            string tem = $"yyyy{separator}MM{separator}dd";
            return dt.ToString(tem);

        }

        #endregion

        #region 将时间格式化成 时分秒 的形式,如果时间为null，返回当前系统时间

        /// <summary>
        /// 将时间格式化成 时分秒 的形式,如果时间为null，返回当前系统时间
        /// </summary>
        /// <param name="dt">当前日期时间对象</param>
        /// <param name="separator">分隔符</param>
        /// <returns> xx时xx分xx秒 </returns>
        public static string GetFormatTime(this DateTime dt, char separator)
        {
            if (dt.Equals(DBNull.Value))
            {
                return GetFormatDate(DateTime.Now, separator);
            }

            string tem = $"hh{separator}mm{separator}ss";
            return dt.ToString(tem);

        }

        #endregion

        #region  把秒转换成分钟

        /// <summary>
        /// 把秒转换成分钟
        /// </summary>
        /// <param name="_"></param>
        /// <param name="second">秒数</param>
        /// <returns>分钟数</returns>
        public static int SecondToMinute(this DateTime _, int second)
        {
            decimal mm = second / (decimal)60;
            return Convert.ToInt32(Math.Ceiling(mm));
        }

        #endregion

        #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="_"></param>
        /// <param name="year">年份</param>
        /// <param name="month">月份</param>
        /// <returns>日</returns>
        public static int GetMonthLastDate(this DateTime _, int year, int month)
        {
            DateTime lastDay = new DateTime(year, month, new GregorianCalendar().GetDaysInMonth(year, month));
            int day = lastDay.Day;
            return day;
        }

        #endregion

        #region 获得两个日期的间隔

        /// <summary>
        /// 获得两个日期的间隔
        /// </summary>
        /// <param name="dateTime1">日期一。</param>
        /// <param name="dateTime2">日期二。</param>
        /// <returns>日期间隔TimeSpan。</returns>
        /// <exception cref="OverflowException">The return value is less than <see cref="F:System.TimeSpan.MinValue" /> or greater than <see cref="F:System.TimeSpan.MaxValue" />. </exception>
        public static TimeSpan DateDiff2(this DateTime dateTime1, DateTime dateTime2)
        {
            return dateTime1 - dateTime2;
        }

        #endregion

        #region 得到随机日期

        /// <summary>
        /// 得到随机日期
        /// </summary>
        /// <param name="time1">起始日期</param>
        /// <param name="time2">结束日期</param>
        /// <returns>间隔日期之间的 随机日期</returns>
        public static DateTime GetRandomTime(this DateTime time1, DateTime time2)
        {
            var random = new Random();
            DateTime minTime;
            var ts = new TimeSpan(time1.Ticks - time2.Ticks);
            // 获取两个时间相隔的秒数
            double dTotalSecontds = ts.TotalSeconds;
            int iTotalSecontds;
            if (dTotalSecontds > int.MaxValue) iTotalSecontds = int.MaxValue;
            else if (dTotalSecontds < int.MinValue) iTotalSecontds = int.MinValue;
            else iTotalSecontds = (int)dTotalSecontds;
            if (iTotalSecontds > 0)
            {
                minTime = time2;
            }
            else if (iTotalSecontds < 0)
            {
                minTime = time1;
            }
            else
            {
                return time1;
            }

            int maxValue = iTotalSecontds;
            if (iTotalSecontds <= int.MinValue)
            {
                maxValue = int.MinValue + 1;
            }

            int i = random.Next(Math.Abs(maxValue));
            return minTime.AddSeconds(i);
        }

        #endregion

        #region Rss日期时间转换，将时间全部转换为GMT时间

        /// <summary> 
        /// Rss日期时间转换，将时间全部转换为GMT时间 
        /// </summary> 
        /// <param name="strDateTime">Rss中读取的时间</param> 
        /// <returns>处理后的标准时间格式</returns> 
        public static string DateConvert(this string strDateTime)
        {
            strDateTime = strDateTime.Replace("+0000", "GMT");
            strDateTime = strDateTime.Replace("+0100", "GMT");
            strDateTime = strDateTime.Replace("+0200", "GMT");
            strDateTime = strDateTime.Replace("+0300", "GMT");
            strDateTime = strDateTime.Replace("+0400", "GMT");
            strDateTime = strDateTime.Replace("+0500", "GMT");
            strDateTime = strDateTime.Replace("+0600", "GMT");
            strDateTime = strDateTime.Replace("+0700", "GMT");
            strDateTime = strDateTime.Replace("+0800", "GMT");
            strDateTime = strDateTime.Replace("-0000", "GMT");
            strDateTime = strDateTime.Replace("-0100", "GMT");
            strDateTime = strDateTime.Replace("-0200", "GMT");
            strDateTime = strDateTime.Replace("-0300", "GMT");
            strDateTime = strDateTime.Replace("-0400", "GMT");
            strDateTime = strDateTime.Replace("-0500", "GMT");
            strDateTime = strDateTime.Replace("-0600", "GMT");
            strDateTime = strDateTime.Replace("-0700", "GMT");
            strDateTime = strDateTime.Replace("-0800", "GMT");
            DateTime dt = DateTime.Parse(strDateTime, null, DateTimeStyles.AdjustToUniversal);
            return dt.ToString();
        }

        #endregion

        #region 时间相关操作类

        /// <summary>
        /// 获得一段时间内有多少小时
        /// </summary>
        /// <param name="dtStar">起始时间</param>
        /// <param name="dtEnd">终止时间</param>
        /// <returns>小时差</returns>
        public static string GetTimeDelay(this DateTime dtStar, DateTime dtEnd)
        {
            long lTicks = (dtEnd.Ticks - dtStar.Ticks) / 10000000;
            string sTemp = (lTicks / 3600).ToString().PadLeft(2, '0') + ":";
            sTemp += (lTicks % 3600 / 60).ToString().PadLeft(2, '0') + ":";
            sTemp += (lTicks % 3600 % 60).ToString().PadLeft(2, '0');
            return sTemp;
        }

        /// <summary>
        /// 获得8位时间整型数字
        /// </summary>
        /// <param name="dt">当前的日期时间对象</param>
        /// <returns>8位时间整型数字</returns>
        public static string GetDateString(this DateTime dt)
        {
            return dt.Year + dt.Month.ToString().PadLeft(2, '0') + dt.Day.ToString().PadLeft(2, '0');
        }

        #endregion

        #region 返回时间差

        /// <summary>
        /// 返回时间差
        /// </summary>
        /// <param name="dateTime1">时间1</param>
        /// <param name="dateTime2">时间2</param>
        /// <returns>时间差</returns>
        public static string DateDiff(this DateTime dateTime1, DateTime dateTime2)
        {
            string dateDiff;
            var ts = dateTime2 - dateTime1;
            if (ts.Days >= 1)
            {
                dateDiff = dateTime1.Month + "月" + dateTime1.Day + "日";
            }
            else
            {
                dateDiff = ts.Hours > 1 ? ts.Hours + "小时前" : ts.Minutes + "分钟前";
            }

            return dateDiff;
        }

        /// <summary>
        /// 计算2个时间差
        /// </summary>
        /// <param name="beginTime">开始时间</param>
        /// <param name="endTime">结束时间</param>
        /// <returns>时间差</returns>
        public static string GetDiffTime(this DateTime beginTime, DateTime endTime)
        {
            string strResout = string.Empty;
            //获得2时间的时间间隔秒计算
            TimeSpan span = endTime.Subtract(beginTime);
            int sec = Convert.ToInt32(span.TotalSeconds);
            int minutes = 1 * 60;
            int hours = minutes * 60;
            int day = hours * 24;
            int month = day * 30;
            int year = month * 12;

            //提醒时间,到了返回1,否则返回0
            if (sec > year)
            {
                strResout += sec / year + "年";
                sec %= year; //剩余
            }

            if (sec > month)
            {
                strResout += sec / month + "月";
                sec %= month;
            }

            if (sec > day)
            {
                strResout += sec / day + "天";
                sec %= day;
            }

            if (sec > hours)
            {
                strResout += sec / hours + "小时";
                sec %= hours;
            }

            if (sec > minutes)
            {
                strResout += sec / minutes + "分";
                sec %= minutes;
            }

            strResout += sec + "秒";
            return strResout;
        }

        #endregion

        #region 时间其他转换静态方法

        /// <summary>
        /// C#的时间到Javascript的时间的转换
        /// </summary>
        /// <param name="theDate">C#的时间</param>
        /// <returns>Javascript的时间</returns>
        public static long CsharpTime2JavascriptTime(this DateTime theDate)
        {
            DateTime d1 = new DateTime(1970, 1, 1);
            DateTime d2 = theDate.ToUniversalTime();
            TimeSpan ts = new TimeSpan(d2.Ticks - d1.Ticks);
            return (long)ts.TotalMilliseconds;
        }

        /// <summary>
        /// PHP的时间转换成C#中的DateTime
        /// </summary>
        /// <param name="_"></param>
        /// <param name="time">php的时间</param>
        /// <returns>C#的时间</returns>
        public static DateTime PhpTime2CsharpTime(this DateTime _, long time)
        {
            DateTime timeStamp = new DateTime(1970, 1, 1); //得到1970年的时间戳
            long t = (time + 8 * 60 * 60) * 10000000 + timeStamp.Ticks;
            return new DateTime(t);
        }

        /// <summary>
        ///  C#中的DateTime转换成PHP的时间
        /// </summary>
        /// <param name="time">C#时间</param>
        /// <returns>php时间</returns>
        public static long CsharpTime2PhpTime(this DateTime time)
        {
            DateTime timeStamp = new DateTime(1970, 1, 1); //得到1970年的时间戳
            //注意这里有时区问题，用now就要减掉8个小时
            return (DateTime.UtcNow.Ticks - timeStamp.Ticks) / 10000000;
        }

        #endregion
    }
}