Strider-CD/strider

/*
 * Javascript Humane Dates
 * Copyright (c) 2008 Dean Landolt (deanlandolt.com)
 * Re-write by Zach Leatherman (zachleat.com)
 *
 * Adopted from the John Resig's pretty.js
 * at http://ejohn.org/blog/javascript-pretty-date
 * and henrah's proposed modification
 * at http://ejohn.org/blog/javascript-pretty-date/#comment-297458
 *
 * Licensed under the MIT license.
 */

exports.humaneDate = function humaneDate(date, compareTo) {
  if (!date) {
    return;
  }

  const lang = {
    ago: 'Ago',
    from: '',
    now: 'Just Now',
    minute: 'Minute',
    minutes: 'Minutes',
    hour: 'Hour',
    hours: 'Hours',
    day: 'Day',
    days: 'Days',
    week: 'Week',
    weeks: 'Weeks',
    month: 'Month',
    months: 'Months',
    year: 'Year',
    years: 'Years',
  };
  const formats = [
    [60, lang.now],
    [3600, lang.minute, lang.minutes, 60], // 60 minutes, 1 minute
    [86400, lang.hour, lang.hours, 3600], // 24 hours, 1 hour
    [604800, lang.day, lang.days, 86400], // 7 days, 1 day
    [2628000, lang.week, lang.weeks, 604800], // ~1 month, 1 week
    [31536000, lang.month, lang.months, 2628000], // 1 year, ~1 month
    [Infinity, lang.year, lang.years, 31536000], // Infinity, 1 year
  ];
  const isString = typeof date == 'string';
  date = isString
    ? new Date(date.replace(/-/g, '/').replace(/[TZ]/g, ' '))
    : date;

  compareTo = compareTo || new Date();
  let seconds =
    (compareTo -
      date +
      (compareTo.getTimezoneOffset() -
        // if we received a GMT time from a string, doesn't include time zone bias
        // if we got a date object, the time zone is built in, we need to remove it.
        (isString ? 0 : date.getTimezoneOffset())) *
        60000) /
    1000;

  let token;
  if (seconds < 0) {
    seconds = Math.abs(seconds);
    token = lang.from ? ` ${lang.from}` : '';
  } else {
    token = lang.ago ? ` ${lang.ago}` : '';
  }

  /*
   * 0 seconds && < 60 seconds        Now
   * 60 seconds                       1 Minute
   * > 60 seconds && < 60 minutes     X Minutes
   * 60 minutes                       1 Hour
   * > 60 minutes && < 24 hours       X Hours
   * 24 hours                         1 Day
   * > 24 hours && < 7 days           X Days
   * 7 days                           1 Week
   * > 7 days && < ~ 1 Month          X Weeks
   * ~ 1 Month                        1 Month
   * > ~ 1 Month && < 1 Year          X Months
   * 1 Year                           1 Year
   * > 1 Year                         X Years
   *
   * Single units are +10%. 1 Year shows first at 1 Year + 10%
   */

  function normalize(val, single) {
    const margin = 0.1;
    if (val >= single && val <= single * (1 + margin)) {
      return single;
    }
    return val;
  }

  for (let i = 0, format = formats[0]; formats[i]; format = formats[++i]) {
    if (seconds < format[0]) {
      if (i === 0) {
        // Now
        return format[1];
      }

      const val = Math.ceil(normalize(seconds, format[3]) / format[3]);
      return `${val} ${val != 1 ? format[2] : format[1]}${i > 0 ? token : ''}`;
    }
  }
};