✨ feat: add Datetime

✅ test: add `Datetime` test case

datetime.go

@@ -6,13 +6,15 @@ import (
 )
 
 type FormatTemplate string
+type AddUnits string
 
 const (
 	FormatYear        FormatTemplate = "YYYY"
 	FormatShortYear   FormatTemplate = "YY"
 	FormatMonth       FormatTemplate = "MM"
 	FormatShortMonth  FormatTemplate = "M"
 	FormatDay         FormatTemplate = "dd"
+	FormatUpperDay    FormatTemplate = "DD"
 	FormatShortDay    FormatTemplate = "d"
 	FormatHour        FormatTemplate = "HH"
 	FormatShortHour   FormatTemplate = "H"
@@ -25,6 +27,14 @@ const (
 	FormatShortWeek   FormatTemplate = "WW"
 )
 
+const (
+	AddYearUnit           AddUnits = "year"
+	AddShortUnit          AddUnits = "Y"
+	AddDaysUnit           AddUnits = "day"
+	AddDaysShortUnit      AddUnits = "D"
+	AddDaysShortLowerUnit AddUnits = "d"
+)
+
 func DateTimeFormat(date time.Time, format string) string {
 	formatted := format
 	formatMap := map[FormatTemplate]int{
@@ -34,6 +44,7 @@ func DateTimeFormat(date time.Time, format string) string {
 		FormatShortMonth:  int(date.Month()),
 		FormatDay:         date.Day(),
 		FormatShortDay:    date.Day(),
+		FormatUpperDay:    date.Day(),
 		FormatHour:        date.Hour(),
 		FormatShortHour:   date.Hour() % 12,
 		FormatSecond:      date.Second(),
@@ -45,7 +56,7 @@ func DateTimeFormat(date time.Time, format string) string {
 		FormatShortWeek:   int(date.Weekday()),
 	}
 
-	for _, key := range []FormatTemplate{FormatYear, FormatMonth, FormatShortYear, FormatShortMonth, FormatDay, FormatShortDay, FormatHour, FormatShortHour, FormatSecond, FormatShortSecond, FormatMinute, FormatShortMinute, FormatMillisecond, FormatWeek, FormatShortWeek} {
+	for _, key := range []FormatTemplate{FormatYear, FormatMonth, FormatShortYear, FormatShortMonth, FormatDay, FormatUpperDay, FormatShortDay, FormatHour, FormatShortHour, FormatSecond, FormatShortSecond, FormatMinute, FormatShortMinute, FormatMillisecond, FormatWeek, FormatShortWeek} {
 		formatted = strings.Replace(
 			formatted,
 			string(key),
@@ -63,3 +74,283 @@ func DateTimeFormat(date time.Time, format string) string {
 
 	return formatted
 }
+
+type FormatCallback func(int) string
+
+type DateTime struct {
+	time         time.Time
+	Year         int
+	Month        int
+	Day          int
+	Week         int
+	Hour         int
+	Minute       int
+	Second       int
+	Milliseconds int
+	Nanosecond   int
+	DateFormat   string
+	TimeFormat   string
+	monthFormat  FormatCallback
+	weekFormat   FormatCallback
+}
+
+func NewDateTime() DateTime {
+	d := DateTime{
+		time:       time.Now(),
+		DateFormat: "YYYY-MM-DD",
+		TimeFormat: "HH:mm:ss.ms",
+	}
+	d.Year = d.time.Year()
+	d.Month = int(d.time.Month())
+	d.Day = d.time.Day()
+	d.Hour = d.time.Hour()
+	d.Minute = d.time.Minute()
+	d.Second = d.time.Second()
+	d.Nanosecond = d.time.Nanosecond()
+	return d
+}
+
+func (dt DateTime) SetYear(year int, month int, day int, hour int, minute int, second int, nanosecond int) DateTime {
+	d := DateTime{
+		time:        time.Date(year, time.Month(month), day, hour, minute, second, nanosecond, time.UTC),
+		DateFormat:  dt.DateFormat,
+		TimeFormat:  dt.TimeFormat,
+		monthFormat: dt.monthFormat,
+		weekFormat:  dt.weekFormat,
+	}
+	d.Year = d.time.Year()
+	d.Month = int(d.time.Month())
+	d.Day = d.time.Day()
+	d.Hour = d.time.Hour()
+	d.Minute = d.time.Minute()
+	d.Second = d.time.Second()
+	d.Nanosecond = d.time.Nanosecond()
+	return d
+}
+
+func (dt DateTime) SetMonth(month int, day int, hour int, minute int, second int, nanosecond int) DateTime {
+	return dt.SetYear(dt.Year, month, day, hour, minute, second, nanosecond)
+}
+
+func (dt DateTime) SetDate(day int, hour int, minute int, second int, nanosecond int) DateTime {
+	return dt.SetYear(dt.Year, dt.Month, day, hour, minute, second, nanosecond)
+}
+
+func (dt DateTime) SetHour(hour int, minute int, second int, nanoseconds int) DateTime {
+	return dt.SetYear(dt.Year, dt.Month, dt.Day, hour, minute, second, nanoseconds)
+}
+
+func (dt DateTime) SetMinute(minute int, second int, nanoseconds int) DateTime {
+	return dt.SetHour(dt.Hour, minute, second, nanoseconds)
+}
+
+func (dt DateTime) SetSecond(second int, nanoseconds int) DateTime {
+	return dt.SetMinute(dt.Minute, second, nanoseconds)
+}
+
+func (dt DateTime) SetMilliseconds(milliseconds int, nanosecond int) DateTime {
+	return dt.SetHour(dt.Hour, dt.Minute, 0, milliseconds*int(time.Millisecond)+nanosecond)
+}
+
+func (dt DateTime) SetNanosecond(nanoseconds int) DateTime {
+	return dt.SetSecond(dt.Second, nanoseconds)
+}
+
+func (dt DateTime) Format(format string) string {
+	return DateTimeFormat(dt.time, format)
+}
+
+func (dt DateTime) String() string {
+	return dt.Format("YYYY-MM-DDTHH:mm:ss.msZ")
+}
+
+func (dt DateTime) SetWeekFormatFunc(format func(week int) string) {
+	dt.weekFormat = format
+}
+
+func (dt DateTime) SetMonthFormatFunc(format func(month int) string) {
+	dt.monthFormat = format
+}
+
+func (dt DateTime) MonthToString() string {
+	if dt.weekFormat == nil {
+		return dt.time.Month().String()
+	}
+	return dt.monthFormat(dt.Month)
+}
+
+func (dt DateTime) WeekToString() string {
+	if dt.weekFormat == nil {
+		return dt.time.Weekday().String()
+	}
+	return dt.weekFormat(int(dt.WeekDay()))
+}
+
+func (dt DateTime) TimeToString() string {
+	return dt.Format(dt.TimeFormat)
+}
+
+func (dt DateTime) Today() string {
+	return dt.Format(dt.DateFormat)
+}
+
+func (dt DateTime) Parse(format string) (DateTime, error) {
+	d := DateTime{}
+	parsedTime, err := time.Parse(time.RFC3339, format)
+
+	if err != nil {
+		return d, err
+	}
+
+	d.time = parsedTime
+	d.DateFormat = dt.DateFormat
+	d.TimeFormat = dt.TimeFormat
+	d.monthFormat = dt.monthFormat
+	d.weekFormat = dt.weekFormat
+	d.Year = d.time.Year()
+	d.Month = int(d.time.Month())
+	d.Day = d.time.Day()
+	d.Hour = d.time.Hour()
+	d.Minute = d.time.Minute()
+	d.Second = d.time.Second()
+	d.Nanosecond = d.time.Nanosecond()
+	return d, nil
+}
+
+func (dt DateTime) SetTime(sec int64, ns int64) DateTime {
+	d := DateTime{
+		time:        time.Unix(sec, ns),
+		DateFormat:  dt.DateFormat,
+		TimeFormat:  dt.TimeFormat,
+		monthFormat: dt.monthFormat,
+		weekFormat:  dt.weekFormat,
+	}
+	d.Year = d.time.Year()
+	d.Month = int(d.time.Month())
+	d.Day = d.time.Day()
+	d.Hour = d.time.Hour()
+	d.Minute = d.time.Minute()
+	d.Second = d.time.Second()
+	d.Nanosecond = d.time.Nanosecond()
+	return d
+}
+
+func (dt DateTime) LocaleCallBack(t string, call func(t string) string) string {
+	return dt.Format(call(t))
+}
+
+func (dt DateTime) IsLeapYear() bool {
+	return ((dt.Year%4 == 0) && (dt.Year%100 != 0)) || (dt.Year%400 == 0)
+}
+
+func (dt DateTime) DayOfYear() int {
+	return dt.time.YearDay()
+}
+
+func (dt DateTime) MinuteOfDay() int {
+	return dt.Hour*60 + dt.Minute
+}
+
+func (dt DateTime) CurrentYearDays() int {
+	days := 365
+	if dt.IsLeapYear() {
+		return days + 1
+	}
+	return days
+}
+
+func (dt DateTime) AddDays(days int) DateTime {
+	return dt.Add(days, "day")
+}
+
+func (dt DateTime) AddMonth(month int) DateTime {
+	return dt.Add(month, "month")
+}
+func (dt DateTime) AddWeek(week int) DateTime {
+	return dt.Add(week, "week")
+}
+
+func (d DateTime) SubtractDays(days int) DateTime {
+	return d.AddDays(-days)
+}
+
+func (d DateTime) WeekDay() int {
+	return int(d.time.Weekday())
+}
+
+func (d DateTime) WeekOfYear() int {
+	_, week := d.time.ISOWeek()
+	return week
+}
+
+func (d DateTime) Add(num int, unit AddUnits) DateTime {
+	result := DateTime{}
+	switch unit {
+	case "Year", "year", "Y":
+		result = d.SetYear(d.Year+num, d.Month, d.Day, d.Hour, d.Minute, d.Second, d.Nanosecond)
+	case "month", "M":
+		result = d.SetMonth(d.Month+num, d.Day, d.Hour, d.Minute, d.Second, d.Nanosecond)
+	case "day", "D":
+		result = d.SetDate(d.Day+num, d.Hour, d.Minute, d.Second, d.Nanosecond)
+	case "week", "W":
+		result = d.SetDate(d.Day+(num*7), d.Hour, d.Minute, d.Second, d.Nanosecond)
+	case "hour", "H", "h":
+		result = d.SetHour(d.Hour+num, d.Minute, d.Second, d.Nanosecond)
+	case "minute", "m":
+		result = d.SetMinute(d.Minute+num, d.Second, d.Nanosecond)
+	case "second", "s":
+		result = d.SetSecond(d.Second+num, d.Nanosecond)
+	case "milliseconds", "ms":
+		result = d.SetMilliseconds(d.Milliseconds+num, d.Nanosecond)
+	case "nanosecond", "ns":
+		result = d.SetNanosecond(d.Nanosecond + num)
+	}
+	return result
+}
+
+func (dt DateTime) Time() int64 {
+	return dt.time.UnixNano()
+}
+
+func (dt DateTime) Now() DateTime {
+	now := time.Now()
+	return dt.SetTime(now.Unix(), int64(now.Nanosecond()))
+}
+
+func (dt DateTime) UTCOffset() int64 {
+	localUnix := dt.time.Local().Unix()
+	utcUnix := dt.time.Unix()
+	return localUnix - utcUnix
+}
+
+func (dt DateTime) IsToday(date DateTime) bool {
+	return dt.Year == date.Year && dt.Month == date.Month && dt.Day == date.Day
+}
+
+func (dt DateTime) Max(date ...DateTime) DateTime {
+	var max DateTime
+	for _, v := range date {
+		if max.Time() < v.Time() {
+			max = v
+		}
+	}
+	return max
+}
+
+func (dt DateTime) Min(date ...DateTime) DateTime {
+	min := date[0]
+	for _, v := range date {
+		if v.Time() > min.Time() {
+			min = v
+		}
+	}
+	return min
+}
+
+func (dt DateTime) IsBefore(d DateTime) bool {
+	return d.Time() < dt.Time()
+}
+
+func (dt DateTime) IsAfter(d DateTime) bool {
+	return dt.Time() < d.Time()
+}