plmercereau/platyplus

function timeDifference (current, previous) {
  const milliSecondsPerMinute = 60 * 1000
  const milliSecondsPerHour = milliSecondsPerMinute * 60
  const milliSecondsPerDay = milliSecondsPerHour * 24
  const milliSecondsPerMonth = milliSecondsPerDay * 30
  const milliSecondsPerYear = milliSecondsPerDay * 365

  const elapsed = current - previous

  if (elapsed < milliSecondsPerMinute / 3) {
    return 'just now'
  }

  if (elapsed < milliSecondsPerMinute) {
    return 'less than 1 min ago'
  } else if (elapsed < milliSecondsPerHour) {
    return Math.round(elapsed / milliSecondsPerMinute) + ' min ago'
  } else if (elapsed < milliSecondsPerDay) {
    return Math.round(elapsed / milliSecondsPerHour) + ' h ago'
  } else if (elapsed < milliSecondsPerMonth) {
    return Math.round(elapsed / milliSecondsPerDay) + ' days ago'
  } else if (elapsed < milliSecondsPerYear) {
    return Math.round(elapsed / milliSecondsPerMonth) + ' mo ago'
  } else {
    return Math.round(elapsed / milliSecondsPerYear) + ' years ago'
  }
}

export function timeDifferenceForDate (date) {
  const now = new Date().getTime()
  const updated = new Date(date).getTime()
  return timeDifference(now, updated)
}

// returns the first attribute of an object. rank allows to pick the first attribute of the first sub-object recursively
export function firstAttribute (obj, rank = 1) {
  if (rank > 0) {
    return firstAttribute(obj[Object.keys(obj)[0]], rank - 1)
  }
  return obj
}