Date Formatting

DForm.js

const SECONDS = {
	MINUTE: 60,
	HOUR: 3600,
	DAY: 86400,
	WEEK: 604800,
	MONTH: 2630016, //30.44 day month average
	YEAR: 31557600, //based on 365.25 days per year
}

class DForm {
	/**
	 * 
	 * @param {Date} date 
	 */
	constructor(date) {
		if (date instanceof DForm) return date
		this.Year = date.getFullYear()
		this.Month = date.getMonth() + 1
		this.Day = date.getDate()
		this.Hour = date.getHours()
		this.Minute = date.getMinutes()
		this.Second = date.getSeconds()
		this.Millisecond = date.getMilliseconds()
		this.Weekday = date.getDay()
	}
	get DayOrd () {
		let v = this.Day % 100;
		let s = ["th", "st", "nd", "rd"]
		return `${this.Day}${s[(v - 20) % 10] || s[v] || s[0]}` //stole this
	}
	get MonthPad () { return `${this.Month}`.padStart(2, '0') }
	get DayPad () { return `${this.Day}`.padStart(2, '0') }
	get HourPad () { return `${this.Hour}`.padStart(2, '0') }
	get MinutePad () { return `${this.Minute}`.padStart(2, '0') }
	get SecondPad () { return `${this.Second}`.padStart(2, '0') }
	get Hour12 () { return `${this.Hour > 12 ? this.Hour % 12 : this.Hour}` }
	get Hour12Pad () { return this.Hour12.padStart(2, '0') }
	get AMPM () { return this.Hour >= 12 ? 'PM' : 'AM' }
	get ampm () { return this.AMPM.toLowerCase() }
	get MonthLong () { return ["January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"][this.Month - 1] }
	get MonthShort () { return ["Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"][this.Month - 1] }
	get DayLong () { return ["Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"][this.Weekday] }
	get DayShort () { return ["Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"][this.Weekday] }


	static parse (anyDate) {
		if (!(anyDate instanceof Date)) anyDate = Date.parse(anyDate)
		if (!anyDate) anyDate = new Date()
		return new DForm(anyDate)
	}

	format (formatString) {
		let formatted = `${formatString}`
		let self = this
		let matches = formatString.match(/\{([^\}]*)\}/g) || []
		matches.forEach(function(attr) {
			let prop = `${attr}`.trim().split('').slice(1, attr.length - 1).join('')
			if (prop in self) {
				formatted = formatted.replace(attr, self[prop])
			}
		})
		return formatted;
	}

	/**
	 * 
	 * @param {Object} adjustment The required adjustment config eg {year:1, minute:-5}
	 */
	adjust (adjustment = {}) {
		adjustment = Object.assign({ years: 0, months: 0, days: 0, hours: 0, minutes: 0, seconds: 0, milliseconds: 0 }, adjustment || {})
		let d = this.date
		d.setFullYear(d.getFullYear() + adjustment.years)
		d.setMonth(d.getMonth() + adjustment.months)
		d.setDate(d.getDate() + adjustment.days)
		d.setHours(d.getHours() + adjustment.hours)
		d.setMinutes(d.getMinutes() + adjustment.minutes)
		d.setSeconds(d.getSeconds() + adjustment.seconds)
		d.setMilliseconds(d.getMilliseconds() + adjustment.milliseconds)
		return new DForm(d)
	}

	get date () {
		return new Date(this.Year, this.Month - 1, this.Day, this.Hour, this.Minute, this.Second, this.Millisecond)
	}

	elapsed (date) {
		if (date instanceof DForm) date = date.date
		return Math.round((date.getTime() - this.date.getTime()) / 1000)
	}

	humanElapsed (date, max_seconds = 31557600, alt_format = null) {
		let elapsed = this.elapsed(date)
		let dir = elapsed < 0 ? ' ago' : ' from now'
		elapsed = Math.abs(elapsed)
		if (elapsed > max_seconds) return alt_format ? new DForm(date).format(alt_format) : null
		let y = Math.floor(elapsed / SECONDS.YEAR)
		let M = Math.floor(elapsed % SECONDS.YEAR / SECONDS.MONTH)
		let d = Math.floor(elapsed % SECONDS.YEAR % SECONDS.MONTH / SECONDS.DAY)
		let h = Math.floor(elapsed % SECONDS.YEAR % SECONDS.MONTH % SECONDS.DAY / SECONDS.DAY)
		let m = Math.floor(elapsed % SECONDS.YEAR % SECONDS.MONTH % SECONDS.DAY % SECONDS.DAY / SECONDS.MINUTE)
		let s = Math.floor(elapsed % SECONDS.YEAR % SECONDS.MONTH % SECONDS.DAY % SECONDS.DAY % SECONDS.MINUTE)

		const dYears = () => [y ? `${y} years` : '', M ? `${M} months` : '', d ? `${d} days` : ''].filter(v => !!v).join(', ') + dir
		const dMonths = () => [M ? `${M} months` : '', d ? `${d} days` : ''].filter(v => !!v).join(' and ') + dir
		const dDays = () => [d ? `${d} days` : '', h ? `${h} hours` : ''].filter(v => !!v).join(', ') + dir
		const dHours = () => [h ? `${h} hours` : '', m ? `${m} minutes` : ''].filter(v => !!v).join(' and ') + dir
		const dMinutes = () => (m ? `${m} minutes` : '') + dir
		const dSeconds = () => (s ? `${s} seconds` : '') + dir

		if (y) return dYears()
		if (M) return dMonths()
		if (d) return dDays()
		if (h) return dHours()
		if (m) return dMinutes()
		if (s) return dSeconds()
	}
}


const DateFormats = {
	HumanDate: '{Day} {MonthShort} {Year}',
	HumanDateTime: '{Day} {MonthShort} {Year} at {Hour12}:{MinutePad} {ampm}',
	HumanDateLong: '{DayLong}, {DayOrd} {MonthLong} {Year}',
	HumanDateTimeLong: '{DayLong}, {DayOrd} {MonthLong} {Year} at {HourPad}h{MinutePad}',
	ConciseDate: '{Day}-{Month}-{Year}',
	ConciseDateTime: '{Day}-{Month}-{Year} {Hour}:{MinutePad}:{SecondPad}',
	FormalDate: '{DayPad}/{MonthPad}/{Year}',
	FormalDateTime: '{DayPad}/{MonthPad}/{Year} {HourPad}:{MinutePad}:{SecondPad}',
}


const rand = (min, max) => Math.trunc((Math.random() * (max - min + 1)) + min)

/**
 * Testing
 */
const date1 = new DForm(new Date())
const date2 = date1.adjust({ days: -130, months: 0 })
const date3 = date1.adjust({ months: rand(0, 2), days: rand(0, 40), hours: rand(0, 15) })

/**************************************************
 * DateFormats Test --- START
 *************************Toggle with this space->* /
Object.keys(DateFormats).forEach(name => {
	console.log(`${name}: `, date1.format(DateFormats[name]))
})
/**************************************************
 * DateFormats Test --- END
 **************************************************/


console.log('date1: ',date1.format(DateFormats.FormalDateTime))
console.log('date2: ',date2.format(DateFormats.FormalDateTime))
console.log('date3: ',date3.format(DateFormats.FormalDateTime))
console.log()

console.log('date 2 elapsed seconds', date1.elapsed(date2))
console.log('date 2 elapsed', date1.humanElapsed(date2))
console.log('date 2 elapsed with short ttl:', date1.humanElapsed(date2, SECONDS.DAY * 5))
console.log('date 2 elapsed with short ttl and alt format:', date1.humanElapsed(date2, SECONDS.DAY * 5, DateFormats.HumanDateTimeLong))
console.log()

console.log('date 3 elapsed seconds', date1.elapsed(date3))
console.log('date 3 elapsed', date1.humanElapsed(date3, SECONDS.YEAR * 3))
console.log('date 3 elapsed with short ttl:', date1.humanElapsed(date3, SECONDS.DAY * 5))
console.log('date 3 elapsed with short ttl and alt format:', date1.humanElapsed(date3, SECONDS.DAY * 5, DateFormats.HumanDateTimeLong))


/**************************************************
 * Export Section --- START
 *************************Toggle with this space->* /
module.exports = {
	DateFormats,
	DForm,
	SECONDS
}
/**************************************************
 * Export Section --- END
 **************************************************/