package trading

import (
	"gitee.com/quant1x/gotdx/proto"
	"gitee.com/quant1x/gox/api"
	"golang.org/x/exp/slices"
	"sort"
	"time"
)

const (
	kIndexDate = "2006-01-02"  // 索引日期格式
	TimeOnly   = time.TimeOnly // 时分秒的格式
)

// FixTradeDate 强制修正交易日字符串
//
//	默认格式 YYYY-MM-DD, 支持其它格式
func FixTradeDate(datetime string, format ...string) string {
	dt, err := api.ParseTime(datetime)
	if err != nil {
		panic(err)
	}
	defaultDateFormat := TradingDayDateFormat
	if len(format) > 0 {
		defaultDateFormat = format[0]
	}
	return dt.Format(defaultDateFormat)
}

// Today 当日, 区别于IndexToday, IndexToday可能存在调整
func Today() string {
	now := time.Now()
	return now.Format(TradingDayDateFormat)
}

// IndexToday 当天
func IndexToday() string {
	now := time.Now()
	return now.Format(kIndexDate)
}

// TradeRange 输出交易日范围
func TradeRange(start, end string) []string {
	start = FixTradeDate(start)
	end = FixTradeDate(end)

	is := sort.SearchStrings(__global_trade_dates, start)
	ie := sort.SearchStrings(__global_trade_dates, end)
	today := IndexToday()
	lastDay := __global_trade_dates[ie]
	if lastDay > today {
		ie = ie - 1
	}
	return slices.Clone(__global_trade_dates[is : ie+1])
}

// LastTradeDate 获得最后一个交易日
func LastTradeDate() string {
	today := IndexToday()
	end := sort.SearchStrings(__global_trade_dates, today)
	lastDay := __global_trade_dates[end]
	if lastDay > today {
		end = end - 1
	}
	return __global_trade_dates[end]
}

// LastNDate 获得指定日期前的N个交易日期数组
func LastNDate(date string, n ...int) []string {
	__opt_end := 0
	if len(n) > 0 {
		__opt_end = n[0]
	}
	r := api.RangeFinite(-__opt_end)
	date = FixTradeDate(date)
	end := sort.SearchStrings(__global_trade_dates, date)
	lastDay := __global_trade_dates[end]
	if lastDay > date {
		end = end - 1
	}
	date_length := len(__global_trade_dates[0:end])
	s, e, err := r.Limits(date_length)
	if err != nil {
		return nil
	}
	return slices.Clone(__global_trade_dates[s : e+1])
}

// GetFrontTradeDay 获取上一个交易日
func GetFrontTradeDay() string {
	//today := LastTradeDate()
	today := GetCurrentlyDay()
	array := LastNDate(today, 1)
	return array[0]
}

// NextTradeDate 获取指定日期的下一个交易日
func NextTradeDate(date string) string {
	date = FixTradeDate(date)
	end := sort.SearchStrings(__global_trade_dates, date)
	lastDay := __global_trade_dates[end]
	if lastDay == date {
		end = end + 1
	}
	return __global_trade_dates[end]
}

// DateIsTradingDay date是否交易日?默认是今天
func DateIsTradingDay(date ...string) bool {
	theDay := Today()
	if len(date) > 0 {
		theDay = FixTradeDate(date[0])
	}
	lastDay := LastTradeDate()
	if lastDay == theDay {
		return true
	}
	return false
}

// GetLastDayForUpdate 获取可以更新数据的最后一个交易日
func GetLastDayForUpdate() string {
	now := time.Now()
	today := now.Format(TradingDayDateFormat)
	if CanUpdate(now) {
		return today
	}
	today = LastTradeDate()
	array := LastNDate(today, 1)
	return array[0]
}

// GetCurrentlyDay 获取数据有效的最后一个交易日, 以9点整划分
func GetCurrentlyDay() (currentlyDay string) {
	today := IndexToday()
	dates := TradeRange(proto.MARKET_CN_FIRST_DATE, today)
	days := len(dates)
	currentlyDay = dates[days-1]
	if today == currentlyDay {
		now := time.Now()
		nowTime := now.Format(CN_SERVERTIME_FORMAT)
		if nowTime < CN_TradingStartTime {
			currentlyDay = dates[days-2]
		}
	}
	return currentlyDay
}