package util

import (
	"strconv"
)

func FormatTime(seconds int64) string {
	listedTime := make([]string, 0, 5)
	if seconds > 365*24*60*60 {
		listedTime = append(listedTime, FormatPlural(seconds/365/24/60/60, "year", "years"))
		seconds %= 365 * 24 * 60 * 60
	}
	if seconds > 24*60*60 {
		listedTime = append(listedTime, FormatPlural(seconds/24/60/60, "day", "days"))
		seconds %= 24 * 60 * 60
	}
	if seconds > 60*60 {
		listedTime = append(listedTime, FormatPlural(seconds/60/60, "hour", "hours"))
		seconds %= 60 * 60
	}
	if seconds > 60 {
		listedTime = append(listedTime, FormatPlural(seconds/60, "minute", "minutes"))
		seconds %= 60
	}
	listedTime = append(listedTime, FormatPlural(seconds, "second", "seconds"))
	switch len(listedTime) {
	case 1:
		return listedTime[0]
	case 2:
		return listedTime[0] + " and " + listedTime[1]
	}
	time := ""
	for i := 0; i < len(listedTime)-2; i++ {
		time += listedTime[i] + ", "
	}
	time += listedTime[len(listedTime)-2] + ", and "
	time += listedTime[len(listedTime)-1]
	return time
}

func FormatPlural(count int64, singular string, plural string) string {
	if count == 0 || count == 1 {
		return strconv.FormatInt(count, 10) + " " + singular
	}
	return strconv.FormatInt(count, 10) + " " + plural
}

func FormatRomanNumeral(number int) string {
	if number < 1 || number > 3999 {
		return strconv.Itoa(number)
	}
	conversions := []struct {
		value int
		digit string
	}{
		{1000, "M"},
		{900, "CM"},
		{500, "D"},
		{400, "CD"},
		{100, "C"},
		{90, "XC"},
		{50, "L"},
		{40, "XL"},
		{10, "X"},
		{9, "IX"},
		{5, "V"},
		{4, "IV"},
		{1, "I"},
	}
	roman := ""
	for _, conversion := range conversions {
		for number >= conversion.value {
			roman += conversion.digit
			number -= conversion.value
		}
	}
	return roman
}