package date_utils

import (
	"strconv"
	"time"
)

const TimeZoneString = "Africa/Johannesburg"

func DateLayoutYearMonthDayTimeT() string {
	layout := "2006-01-02T15:04:05"
	return layout
}

func DateLayoutYearMonthDayTimeTZ() string {
	layout := "2006-01-02T15:04:05Z"
	return layout
}

func DateLayoutYearMonthDayTimeMillisecondTZ() string {
	layout := "2006-01-02T15:04:05.000Z"
	return layout
}

func DateLayoutDB() string {
	return "2006-01-02 15:04:05.000000-07"
}

func DateLayoutYearMonthDayTimeTimezone() string {
	layout := "2006-01-02 15:04:05-07:00"
	return layout
}

func DateLayoutForDB() string {
	layout := "2006-01-02 15:04:05-07"
	return layout
}

func DateLayoutYearMonthDayTime() string {
	layout := "2006-01-02 15:04:05"
	return layout
}

func DateLayoutFilenameSafe() string {
	layout := "2006-01-02(15h04s05)"
	return layout
}

func DateLayoutYearMonthDay() string {
	layout := "2006-01-02"
	return layout
}

func DateLayoutTime() string {
	layout := "15:04:05"
	return layout
}

func DateLayoutHumanReadable() string {
	layout := "02 Jan 2006"
	return layout
}

func DateLayoutTrimmed() string {
	layout := "20060102150405"
	return layout
}

func DateDBFormattedString(date time.Time) string {
	return date.Format(DateLayoutDB())
}

func DateDBFormattedStringDateOnly(date time.Time) string {
	return date.Format(DateLayoutYearMonthDay())
}

func CurrentLocation() *time.Location {
	loc, _ := time.LoadLocation(TimeZoneString)
	return loc
}

func DateLocal(date *time.Time) {
	if date == nil {
		return
	}
	*date = (*date).In(CurrentLocation())
}

func CurrentDate() time.Time {
	currentDate := time.Now().In(CurrentLocation())
	return currentDate
}

func DateEqual(date1, date2 time.Time) bool {
	y1, m1, d1 := date1.Date()
	y2, m2, d2 := date2.Date()
	return y1 == y2 && m1 == m2 && d1 == d2
}

// TimeBefore determines whether a (string format HH:mm) is earlier than b (string format HH:mm)
func TimeBefore(a string, b string) bool {
	if len(a) < 5 || len(b) < 5 {
		return false // can't detemrine before/after
	}

	hoursA, _ := strconv.Atoi(a[0:2])
	hoursB, _ := strconv.Atoi(b[0:2])

	minA, _ := strconv.Atoi(a[3:5])
	minB, _ := strconv.Atoi(b[3:5])

	if hoursA == hoursB {
		return minA < minB
	}

	return hoursA < hoursB
}

// ConvertToNoDateTimeString  - Converts a PSQL Time type to Go Time type
func ConvertToNoDateTimeString(timeString *string) (*string, error) {
	parsedTime, err := time.Parse("15:04:05", *timeString)
	if err != nil {
		return nil, err
	}
	formattedTime := parsedTime.Format("15:04")
	return &formattedTime, nil
}

// ParseTimeString attempts to parse the string as the default date-time format, or as a date only format
func ParseTimeString(timeString string) (time.Time, error) {
	// Try using the default format
	parsedTime, err := time.Parse(DateLayoutYearMonthDayTimeMillisecondTZ(), timeString)
	if err != nil {
		// Try using date only format
		parsedTime, err = time.Parse(DateLayoutYearMonthDay(), timeString)
	}
	return parsedTime, err
}