Merge pull request #38 from rabee-inc/feature/time-formatter

feat: timefmt.TimeFormatter を実装

timefmt/formatter.go

@@ -0,0 +1,88 @@
+package timefmt
+
+import "time"
+
+type TimeFormatter interface {
+	// dayjs like format
+	// REF: https://day.js.org/docs/en/display/format
+	// ISO8601 format example: "YYYY-MM-DDTHH:mm:ss.SSSZ"
+	// escape character: [].
+	// escape example:
+	// - "[Today is] YYYY/MM/DD" = "Today is 2024/01/01"
+	// - not escape "Today is YYYY/MM/DD" = "To1amy i0 2024/01/01"
+	// YYYY: 4 digit year (2024)
+	// YY: 2 digit year (24)
+	// MMMM: full month name (January)
+	// MMM: short month name (Jan)
+	// MM: 2 digit month (01-12)
+	// M: 1 digit month (1-12)
+	// DD: 2 digit day (01-31)
+	// D: 1 digit day (1-31)
+	// HH: 2 digit hour (00-23)
+	// H: 1 digit hour (0-23)
+	// hh: 2 digit hour (00-12)
+	// h: 1 digit hour (0-12)
+	// mm: 2 digit minute (00-59)
+	// m: 1 digit minute (0-59)
+	// ss: 2 digit second (00-59)
+	// s: 1 digit second (0-59)
+	// SSS: 3 digit millisecond (000-999)
+	// A: upper case meridiem (AM/PM)
+	// a: lower case meridiem (am/pm)
+	// Z: time zone offset (+09:00/Z). if time zone is UTC, return "Z".
+	// ZZ: time zone offset (+0900/Z). if time zone is UTC, return "Z".
+	// dddd: full day of the week (Sunday)
+	// ddd: short day of the week (Sun)
+	// dd: min day of the week (Su)
+	// d: 1 digit day of the week (0-6)
+	Format(t time.Time, layout string) string
+
+	// dddd で使用される曜日の full name を設定する。
+	// len(names) != 7 の場合 panic。
+	// ex) []string{"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"}
+	// ex) []string{"日曜日", "月曜日", "火曜日", "水曜日", "木曜日", "金曜日", "土曜日"}
+	SetWeekdayFullNames(names []string)
+
+	// dddd で使用される曜日の short name を取得する
+	WeekdayFullNames() []string
+
+	// ddd で使用される曜日の short name を設定する。
+	// len(names) != 7 の場合 panic。
+	// ex) []string{"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"}
+	// ex) []string{"日", "月", "火", "水", "木", "金", "土"}
+	SetWeekdayShortNames(names []string)
+
+	// ddd で使用される曜日の short name を取得する。
+	WeekdayShortNames() []string
+
+	// dd で使用される曜日の min name を設定する。
+	// len(names) != 7 の場合 panic。
+	// ex) []string{"Su", "Mo", "Tu", "We", "Th", "Fr", "Sa"}
+	// ex) []string{"日", "月", "火", "水", "木", "金", "土"}
+	SetWeekdayMinNames(names []string)
+
+	// dd で使用される曜日の min name を取得する。
+	WeekdayMinNames() []string
+
+	// MMMM で使用される month の name を設定する。
+	// len(names) != 12 の場合 panic。
+	// ex) []string{"January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"}
+	// ex) []string{"1月", "2月", "3月", "4月", "5月", "6月", "7月", "8月", "9月", "10月", "11月", "12月"}
+	SetMonthNames(names []string)
+
+	// MMMM で使用される month の name を取得する
+	MonthNames() []string
+
+	// MMM で使用される month の short name を設定する。
+	// len(names) != 12 の場合 panic。
+	// ex) []string{"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"}
+	// ex) []string{"1月", "2月", "3月", "4月", "5月", "6月", "7月", "8月", "9月", "10月", "11月", "12月"}
+	SetMonthShortNames(names []string)
+
+	// MMM で使用される month の short name を取得する
+	MonthShortNames() []string
+
+	// AM/PM を判定する関数を設定する。
+	// hours には 24 時間表記の時間が入る。(0〜23)
+	SetMeridiem(f func(hours int) string)
+}

timefmt/formatter_impl.go

@@ -0,0 +1,216 @@
+package timefmt
+
+import (
+	"fmt"
+	"regexp"
+	"strconv"
+	"strings"
+	"time"
+)
+
+type timeFormatter struct {
+	weekdayFullNames  []string
+	weekdayShortNames []string
+	weekdayMinNames   []string
+	monthNames        []string
+	monthShortNames   []string
+	meridiemFunc      func(int) string
+}
+
+var defaultWeekdayFullNames = []string{"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"}
+var defaultWeekdayShortNames = []string{"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"}
+var defaultWeekdayMinNames = []string{"Su", "Mo", "Tu", "We", "Th", "Fr", "Sa"}
+var defaultMonthNames = []string{"January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"}
+var defaultMonthShortNames = []string{"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"}
+var defaultMeridiemFunc = func(hours int) string {
+	if hours < 12 {
+		return "am"
+	}
+	return "pm"
+}
+
+// REF: https://github.com/iamkun/dayjs/blob/dev/src/constant.js#L30C30-L30C112
+var reFormat = regexp.MustCompile(`\[([^\]]+)]|Y{1,4}|M{1,4}|D{1,2}|d{1,4}|H{1,2}|h{1,2}|a|A|m{1,2}|s{1,2}|Z{1,2}|SSS`)
+
+var weekLen = 7
+var monthLen = 12
+
+// New returns a new instance of TimeFormatter.
+func New() TimeFormatter {
+	return &timeFormatter{
+		weekdayFullNames:  defaultWeekdayFullNames,
+		weekdayShortNames: defaultWeekdayShortNames,
+		weekdayMinNames:   defaultWeekdayMinNames,
+		monthNames:        defaultMonthNames,
+		monthShortNames:   defaultMonthShortNames,
+		meridiemFunc:      nil,
+	}
+}
+
+func (t *timeFormatter) Format(tm time.Time, layout string) string {
+	return reFormat.ReplaceAllStringFunc(layout, func(s string) string {
+		// [] で囲まれている場合は、フォーマットせずに[]の中身を返す
+		if s[0] == '[' {
+			return s[1 : len(s)-1]
+		}
+		return t.format(tm, s)
+	})
+}
+
+func (t *timeFormatter) MonthNames() []string {
+	return t.monthNames
+}
+
+func (t *timeFormatter) MonthShortNames() []string {
+	return t.monthShortNames
+}
+
+func (t *timeFormatter) SetMonthNames(names []string) {
+	mustLen(names, monthLen)
+	t.monthNames = names
+}
+
+func (t *timeFormatter) SetMonthShortNames(names []string) {
+	mustLen(names, monthLen)
+	t.monthShortNames = names
+}
+
+func (t *timeFormatter) SetWeekdayFullNames(names []string) {
+	mustLen(names, weekLen)
+	t.weekdayFullNames = names
+}
+
+func (t *timeFormatter) SetWeekdayMinNames(names []string) {
+	mustLen(names, weekLen)
+	t.weekdayMinNames = names
+}
+
+func (t *timeFormatter) SetWeekdayShortNames(names []string) {
+	mustLen(names, weekLen)
+	t.weekdayShortNames = names
+}
+
+func (t *timeFormatter) WeekdayFullNames() []string {
+	return t.weekdayFullNames
+}
+
+func (t *timeFormatter) WeekdayMinNames() []string {
+	return t.weekdayMinNames
+}
+
+func (t *timeFormatter) WeekdayShortNames() []string {
+	return t.weekdayShortNames
+}
+
+func (t *timeFormatter) SetMeridiem(f func(hours int) string) {
+	t.meridiemFunc = f
+}
+
+// mustLen ... names の長さが l でない場合 panic にする
+func mustLen(names []string, l int) {
+	if len(names) != l {
+		panic(fmt.Sprintf("len error: names length must be %d but %d", l, len(names)))
+	}
+}
+
+// chunk に応じたフォーマットを行う
+func (t *timeFormatter) format(tm time.Time, chunk string) string {
+	switch chunk {
+	// year
+	case "YYYY":
+		return strconv.Itoa(tm.Year())
+	case "YY":
+		return fmt.Sprintf("%02d", tm.Year()%100)
+
+	// month
+	case "M":
+		return strconv.Itoa(int(tm.Month()))
+	case "MM":
+		return fmt.Sprintf("%02d", int(tm.Month()))
+	case "MMM":
+		return t.monthShortNames[int(tm.Month())-1]
+	case "MMMM":
+		return t.monthNames[int(tm.Month())-1]
+
+	// day
+	case "D":
+		return strconv.Itoa(tm.Day())
+	case "DD":
+		return fmt.Sprintf("%02d", tm.Day())
+
+	// hours
+	case "H":
+		return strconv.Itoa(tm.Hour())
+	case "HH":
+		return fmt.Sprintf("%02d", tm.Hour())
+	case "h", "hh":
+		h := tm.Hour() % 12
+		if h == 0 {
+			h = 12
+		}
+		if chunk == "h" {
+			return strconv.Itoa(h)
+		}
+		return fmt.Sprintf("%02d", h)
+
+	// minutes
+	case "m":
+		return strconv.Itoa(tm.Minute())
+	case "mm":
+		return fmt.Sprintf("%02d", tm.Minute())
+
+	// seconds
+	case "s":
+		return strconv.Itoa(tm.Second())
+	case "ss":
+		return fmt.Sprintf("%02d", tm.Second())
+
+	// milliseconds
+	case "SSS":
+		return fmt.Sprintf("%03d", tm.Nanosecond()/1e6)
+
+	// AM/PM
+	case "a", "A":
+		meridiemFunc := t.meridiemFunc
+		if meridiemFunc == nil {
+			meridiemFunc = defaultMeridiemFunc
+		}
+		meridiem := meridiemFunc(tm.Hour())
+		if chunk == "a" {
+			return strings.ToLower(meridiem)
+		}
+		return strings.ToUpper(meridiem)
+
+	// weekday
+	case "d":
+		return strconv.Itoa(int(tm.Weekday()))
+	case "dd":
+		return t.weekdayMinNames[int(tm.Weekday())]
+	case "ddd":
+		return t.weekdayShortNames[int(tm.Weekday())]
+	case "dddd":
+		return t.weekdayFullNames[int(tm.Weekday())]
+
+	// timezone
+	case "Z", "ZZ":
+		_, offset := tm.Zone()
+		if offset == 0 {
+			return "Z"
+		}
+		sign := "+"
+		if offset < 0 {
+			sign = "-"
+			offset = -offset
+		}
+		hour := offset / 3600
+		min := (offset % 3600) / 60
+		if chunk == "Z" {
+			return fmt.Sprintf("%s%02d:%02d", sign, hour, min)
+		}
+		return fmt.Sprintf("%s%02d%02d", sign, hour, min)
+
+	// match しない場合はそのまま返す
+	default:
+		return chunk
+	}
+}