SerhiiCho / timeago

import (

	"fmt"

	"log"

	"math"

	"strconv"

	"strings"

	"time"

	"github.com/SerhiiCho/timeago/v3/config"

)

var (

	cachedJsonResults = map[string]*LangSet{}

	options           = []Option{}

	langSet           *LangSet

	conf              = config.New("en", "", []config.Translation{})

)

// Parse coverts given datetime into `x time ago` format.

// First argument can have 3 types:

// 1. int (Unix timestamp)

// 2. time.Time (Type from Go time package)

// 3. string (Datetime string in format 'YYYY-MM-DD HH:MM:SS')

func Parse(datetime interface{}, opts ...Option) string {

	options = []Option{}

	var input time.Time

	switch date := datetime.(type) {

	case int:

		input = parseTimestampIntoTime(date)

	case string:

		input = parseStrIntoTime(date)

	default:

		input = datetime.(time.Time)

	}

	enableOptions(opts)

	return calculateTimeAgo(input)

}

func Configure(c *config.Config) {

	if c.Language != "" {

		conf.Language = c.Language

	}

	if c.Location != "" {

		conf.Location = c.Location

	}

	if len(c.Translations) > 0 {

		conf.Translations = c.Translations

	}

}

func location() *time.Location {

	loc, err := time.LoadLocation(conf.Location)

	if err != nil {

		log.Fatalf("[Timeago]: ERROR: %v", err)

	}

	return loc

}

func calculateTimeAgo(t time.Time) string {

	now := time.Now()

	if conf.LocationIsSet() {

		t = applyLocationToTime(t)

		now = applyLocationToTime(now)

	}

	seconds := now.Sub(t).Seconds()

	if seconds < 0 {

		enableOption(Upcoming)

		seconds = math.Abs(seconds)

	}

	langSet = NewLangSet()

	switch {

	case seconds < 60 && optionIsEnabled("online"):

		return langSet.Online

	case seconds < 0:

		return getWords(langSet.Second, 0)

	}

	timeUnit := generateTimeUnit(int(seconds))

	return timeUnit

}

func generateTimeUnit(seconds int) string {

	minutes, hours, days, weeks, months, years := getTimeCalculations(float64(seconds))

	switch {

	case optionIsEnabled("online") && seconds < 60:

		return langSet.Online

	case optionIsEnabled("justNow") && seconds < 60:

		return langSet.JustNow

	case seconds < 60:

		return getWords(langSet.Second, seconds)

	case minutes < 60:

		return getWords(langSet.Minute, minutes)

	case hours < 24:

		return getWords(langSet.Hour, hours)

	case days < 7:

		return getWords(langSet.Day, days)

	case weeks < 4:

		return getWords(langSet.Week, weeks)

	case months < 12:

		if months == 0 {

			months = 1

		}

		return getWords(langSet.Month, months)

	}

	return getWords(langSet.Year, years)

}

// getWords decides rather the word must be singular or plural,

// and depending on the result it adds the correct word after

// the time number

func getWords(final LangForms, num int) string {

	form := identifyLocaleForm(num)

	result := langSet.Format

	result = strings.Replace(result, "{timeUnit}", final[form], -1)

	result = strings.Replace(result, "{num}", strconv.Itoa(num), -1)

	if optionIsEnabled("noSuffix") || optionIsEnabled("upcoming") {

		result = strings.Replace(result, "{ago}", "", -1)

		return strings.Trim(result, " ")

	}

	return strings.Replace(result, "{ago}", langSet.Ago, -1)

}

func identifyLocaleForm(num int) string {

	rule, err := identifyGrammarRules(num, conf.Language)

	if err != nil {

		fmt.Println(err)

		return "other"

	}

	switch {

	case rule.Zero:

		return "zero"

	case rule.One:

		return "one"

	case rule.Few:

		return "few"

	case rule.Two:

		return "two"

	case rule.Many:

		return "many"

	}

	return "other"

}

func applyLocationToTime(t time.Time) time.Time {

	return t.In(location())

}

func getTimeCalculations(seconds float64) (int, int, int, int, int, int) {

	minutes := math.Round(seconds / 60)

	hours := math.Round(seconds / 3600)

	days := math.Round(seconds / 86400)

	weeks := math.Round(seconds / 604800)

	months := math.Round(seconds / 2629440)

	years := math.Round(seconds / 31553280)

	return int(minutes), int(hours), int(days), int(weeks), int(months), int(years)

}