import HolyTime from 'holy-time'

const past = new HolyTime('2023-01-01T00:00:00.000Z')
const future = new HolyTime('2023-01-01T02:30:00.000Z')

HolyTime.relativeFromTo(past, future)
// Returns: "in 2 hours"

HolyTime.relativeFromTo(future, past)
// Returns: "2 hours ago"

const date = new HolyTime('2023-01-01T00:00:00.000Z')
const other = new HolyTime('2023-01-01T05:00:00.000Z')

date.getRelativeTo(other)
// Returns: "in 5 hours"

HolyTime.relativeFromTo(date, other)

const date = new HolyTime('2023-01-01T05:00:00.000Z')
const other = new HolyTime('2023-01-01T00:00:00.000Z')

date.getRelativeFrom(other)
// Returns: "in 5 hours"

HolyTime.relativeFromTo(other, date)

const date = new HolyTime('2023-01-01T01:02:03.000Z')

const duration = HolyTime.since(date)
duration.in('seconds')  // Time in seconds since the date
duration.in('hours')    // Time in hours since the date
duration.in('days')     // Time in days since the date

const date = new HolyTime('2023-01-01')
const duration = HolyTime.since(date)

duration.format('short')  // e.g., "5d 3h 20m"
duration.format('long')   // e.g., "5 days, 3 hours and 20 minutes"

export const RELATIVE_MAP: Record<
  number,
  string | ((milliseconds: number) => string)
> = {
  [TimeUnits.SECOND * 0]: 'a few seconds',
  [TimeUnits.SECOND * 5]: (ms) =>
    `${Math.floor(ms / TimeUnits.SECOND)} seconds`,
  [TimeUnits.MINUTE]: 'a minute',
  [TimeUnits.MINUTE * 2]: (ms) =>
    `${Math.floor(ms / TimeUnits.MINUTE)} minutes`,
  [TimeUnits.HOUR]: 'an hour',
  [TimeUnits.HOUR * 2]: (ms) =>
    `${Math.floor(ms / TimeUnits.HOUR)} hours`,
  [TimeUnits.DAY]: 'a day',
  [TimeUnits.DAY * 2]: (ms) =>
    `${Math.floor(ms / TimeUnits.DAY)} days`,
  [TimeUnits.WEEK]: 'a week',
  [TimeUnits.WEEK * 2]: (ms) =>
    `${Math.floor(ms / TimeUnits.WEEK)} weeks`,
  [TimeUnits.MONTH]: 'a month',
  [TimeUnits.MONTH * 2]: (ms) =>
    `${Math.floor(ms / TimeUnits.MONTH)} months`,
  [TimeUnits.YEAR]: 'a year',
  [TimeUnits.YEAR * 2]: (ms) =>
    `${Math.floor(ms / TimeUnits.YEAR)} years`,
}

function formatPostTime(postDate: Date): string {
  const post = new HolyTime(postDate)
  const now = HolyTime.now()
  
  return post.getRelativeTo(now)
}

formatPostTime(new Date('2023-06-15T10:00:00.000Z'))
// Returns: "5 hours ago" (if current time is 3pm same day)

function getLastUpdated(updatedAt: Date): string {
  return `Last updated ${new HolyTime(updatedAt).getRelativeTo(HolyTime.now())}`
}

getLastUpdated(new Date('2023-06-14'))
// Returns: "Last updated a day ago"

function eventCountdown(eventDate: Date): string {
  const event = new HolyTime(eventDate)
  const now = HolyTime.now()
  
  if (event.isFuture()) {
    return `Event starts ${now.getRelativeTo(event)}`
  } else {
    return `Event started ${event.getRelativeTo(now)}`
  }
}

eventCountdown(new Date('2024-12-25'))
// Returns: "Event starts in 6 months"

function timeSinceLastLogin(lastLogin: Date): {
  text: string
  duration: HolyDuration
} {
  const duration = HolyTime.since(lastLogin)
  const text = new HolyTime(lastLogin).getRelativeTo(HolyTime.now())
  
  return { text, duration }
}

const result = timeSinceLastLogin(new Date('2023-06-10'))
// result.text: "5 days ago"
// result.duration.in('hours'): 120

function getTimeStatus(date: Date): string {
  const time = new HolyTime(date)
  
  if (time.isFuture()) {
    return `Coming ${HolyTime.now().getRelativeTo(time)}`
  } else if (time.isPast()) {
    return `Happened ${time.getRelativeTo(HolyTime.now())}`
  } else {
    return "Happening now"
  }
}

function smartRelativeTime(date: Date): string {
  const time = new HolyTime(date)
  const duration = HolyTime.since(date)
  
  // For very recent times, show exact time
  if (duration.in('minutes') < 5) {
    return time.format('HH:mm')
  }
  
  // For same day, show relative
  if (time.isSame(HolyTime.now(), 'day')) {
    return time.getRelativeTo(HolyTime.now())
  }
  
  // For older dates, show full date
  return time.format('YYYY-MM-DD')
}

// Singular forms (1 unit)
"a minute ago"    // Not "1 minute ago"
"an hour ago"     // Not "1 hour ago"
"a day ago"       // Not "1 day ago"

// Plural forms (2+ units)
"2 minutes ago"
"5 hours ago"
"3 days ago"