using Qdp.Foundation.Implementations;
using Qdp.Pricing.Base.Enums;
using Qdp.Pricing.Base.Implementations;
using Qdp.Pricing.Base.Utilities;

namespace YLErp.QdpModule
{
    /// <summary>
    /// QDP日历帮助类
    /// </summary>
    public static class QdpCalendarHelper
    {
        /// <summary>
        /// 给定任一日期，按特定交易日历和偏移量，给出交易日。
        /// 例如：
        /// 2018-06-16,2018-06-17,2018-06-18三天是chn假期
        /// 
        /// BizDayShift("2018-06-15", "chn", 0); //2018-06-15
        /// BizDayShift("2018-06-15", "chn", 1); //2018-06-19
        /// BizDayShift("2018-06-16", "chn", 0); //2018-06-19
        /// BizDayShift("2018-06-17", "chn", 0); //2018-06-19
        /// BizDayShift("2018-06-18", "chn", 0); //2018-06-19
        /// BizDayShift("2018-06-19", "chn", 0); //2018-06-19
        /// BizDayShift("2018-06-16", "chn", 1); //2018-06-20
        /// BizDayShift("2018-06-17", "chn", 1); //2018-06-20
        /// BizDayShift("2018-06-18", "chn", 1); //2018-06-20
        /// BizDayShift("2018-06-19", "chn", 1); //2018-06-20
        /// BizDayShift("2018-06-16", "chn", -1); //2018-06-15
        /// BizDayShift("2018-06-17", "chn", -1); //2018-06-15
        /// BizDayShift("2018-06-18", "chn", -1); //2018-06-15
        /// BizDayShift("2018-06-19", "chn", -1); //2018-06-15
        /// </summary>
        /// <param name="date">日期</param>
        /// <param name="calendarName">交易日历名称</param>
        /// <param name="offset">偏移天数</param>
        /// <returns></returns>
        public static DateTime BizDayShift(DateTime date, int offset = 0, string calendarName = "chn")
        {
            return BizDayShift2(date, offset, calendarName).DateTime;
        }

        public static Date BizDayShift2(DateTime date, int offset = 0, string calendarName = "chn")
        {
            if (string.IsNullOrEmpty(calendarName))
            {
                calendarName = "chn";
            }

            var calendar = CalendarImpl.Get(calendarName);
            if (calendar == null)
            {
                return new Date(date);
            }

            var qdpDate = new Date(date);
            var bizDay = calendar.IsBizDay(qdpDate) ? qdpDate : calendar.NextBizDay(qdpDate);
            return calendar.AddBizDays(bizDay, offset);
        }

        public static DateTime PrevBizDayShift(DateTime date, int offset = 0, string calendarName = "chn")
        {
            if (string.IsNullOrEmpty(calendarName))
            {
                calendarName = "chn";
            }

            var calendar = CalendarImpl.Get(calendarName);
            if (calendar == null)
            {
                return date;
            }

            var qdpDate = new Date(date);
            var bizDay = calendar.IsBizDay(qdpDate) ? qdpDate : calendar.PrevBizDay(qdpDate);
            return calendar.AddBizDays(bizDay, offset).DateTime;
        }

        /// <summary>
        /// 返回一个日期区间内的所有交易日
        /// AllBizDays(2022-04-26,2022-04-26)  null
        /// AllBizDays(2022-04-26,2022-04-27)  2022-04-26
        /// </summary>
        /// <param name="startDate"></param>
        /// <param name="endDate"></param>
        /// <param name="calendarName"></param>
        /// <returns></returns>
        public static List<DateTime> AllBizDays(DateTime startDate, DateTime endDate, string calendarName = "chn")
        {
            if (string.IsNullOrEmpty(calendarName))
            {
                calendarName = "chn";
            }

            var calendar = CalendarImpl.Get(calendarName);
            if (calendar == null)
            {
                return null;
            }

            var qdpStartDate = new Date(startDate);
            var qdpEndDate = new Date(endDate);
            var holidays = calendar.BizDaysBetweenDates(qdpStartDate, qdpEndDate);
            return holidays.Select(x => x.DateTime).ToList();
        }

        /// <summary>
        /// 从到期日天数转换成以年为单位的时间
        /// </summary>
        /// <param name="timeToMaturityDays">天数，可以是小数</param>
        /// <param name="optionDayCount">DayCount规则名称</param>
        /// <param name="referenceDate">参考日期，对于某些DayCount有效</param>
        /// <returns></returns>
        public static double CalculateTFromDays(double timeToMaturityDays, string optionDayCount, DateTime referenceDate)
        {
            if (double.IsNaN(timeToMaturityDays))
            {
                return double.NaN;
            }

            var dayCount = optionDayCount.ToDayCountImpl();
            return timeToMaturityDays / dayCount.DaysInYear(new Date(referenceDate));
        }

        /// <summary>
        /// 获取date(包括)之前的第一个非假日
        /// </summary>
        public static DateTime GetNonHolidayDefore(DateTime date, string country = "chn")
        {
            var calendar = CalendarImpl.Get(country);
            var qdpDate = new Date(date);
            return calendar.IsBizDay(qdpDate) ? date : calendar.PrevBizDay(qdpDate).DateTime;
        }

        /// <summary>
        /// 获取tuningdays后的工作日信息
        /// </summary>
        public static DateTime GetWorkingDay(DateTime fromdate, int tuningdays)
        {
            var calendar = CalendarImpl.Get("chn");
            return calendar.AddBizDays(new Date(fromdate), tuningdays).DateTime;
        }

        /// <summary>
        /// 获取工作日天数(不包括from,包括to)
        /// </summary>
        public static int GetWorkDayCount(DateTime from, DateTime to)
        {
            var calendar = CalendarImpl.Get("chn");
            return (int)Math.Round(calendar.NumberBizDaysBetweenDate(new Date(from), new Date(to), excludeEndDate: true));
        }

        public static List<DateTime> GetWorkingDatesBeforeDate(DateTime toDate, int days)
        {
            var calendar = CalendarImpl.Get("chn");
            var toQdpDate = new Date(toDate);
            var fromQdpDate = calendar.AddBizDays(toQdpDate, -days + 1);
            return calendar.BizDaysBetweenDatesInclEndDay(fromQdpDate, toQdpDate).Select(x => x.DateTime).Reverse().ToList();
        }


        public static DateTime AddDate(DateTime fromDate,int days)
        {
            var calendar = CalendarImpl.Get("chn");
            var toQdpDate = new Date(fromDate);
            return calendar.AddBizDays(toQdpDate,days);
        }


        /// <summary>
        /// 获取fromDate到toDate天数
        /// </summary>
        public static int GetNonHolidayDaysBetween(DateTime fromDate, DateTime toDate, string country = "chn")
        {
            var calendar = CalendarImpl.Get(country);
            return (int)Math.Round(calendar.NumberBizDaysBetweenDate(new Date(fromDate), new Date(toDate), excludeEndDate: true));
        }

        /// <summary>
        /// 获取date(包括)之后的第一个非假日
        /// </summary>
        public static DateTime GetNonHoliday(DateTime date, string country = "chn")
        {
            var calendar = CalendarImpl.Get(country);
            var qdpDate = new Date(date);
            return calendar.IsBizDay(qdpDate) ? date : calendar.NextBizDay(qdpDate).DateTime;
        }

        public static bool IsHoliday(DateTime date, string country = "chn")
        {
            var calendar = CalendarImpl.Get(country);
            return calendar.IsHoliday(new Date(date));
        }

        /// <summary>
        /// 获取不超过到期日的实行日
        /// 1个月，2周，1周，到日期这样的规则向前计算
        /// </summary>
        public static DateTime GetUnderlyingExerciseDate(DateTime underlyingMaturityDate, DateTime SystemDate)
        {
            //OTC - 6717 组合报价-默认的到期日为交易日后一个月，且算头不算尾
            DateTime exerciseDate = GetNonHoliday(SystemDate.AddMonths(1).AddDays(-1));
            if (underlyingMaturityDate < exerciseDate)
            {
                exerciseDate = GetNonHoliday(SystemDate.AddDays(14));
                if (underlyingMaturityDate < exerciseDate)
                {
                    exerciseDate = GetNonHoliday(SystemDate.AddDays(7));
                    if (underlyingMaturityDate < exerciseDate)
                    {
                        exerciseDate = GetNonHolidayDefore(underlyingMaturityDate);
                    }
                }
            }
            return exerciseDate;
        }

        /// <summary>
        /// 根据DayCount规则和调整天数来调整日期
        /// </summary>
        public static string ShiftDate(string date, string dayCount, int maturityShift)
        {
            return ShiftDate(DateTime.Parse(date), dayCount, maturityShift).ToString();
        }

        /// <summary>
        /// 根据DayCount规则和调整天数来调整日期
        /// </summary>
        public static Date ShiftDate(DateTime date, string dayCount, int maturityShift)
        {
            return ShiftDate(new Date(date), dayCount, maturityShift);
        }

        /// <summary>
        /// 根据DayCount规则和调整天数来调整日期
        /// </summary>
        public static Date ShiftDate(Date qdpDate, string dayCount, int maturityShift)
        {
            if (dayCount == "Act365")
            {
                return CalendarImpl.Get("chn").AddDays(qdpDate, maturityShift);
            }
            else
            {
                return CalendarImpl.Get("chn").AddBizDays(qdpDate, maturityShift, BusinessDayConvention.Following);
            }
        }
    }
}