Eh+ add to calendar #GMS

eh-plus.user.js

// ==UserScript==
// @name         Eh+ add link to add to calendar
// @namespace    http://senta.me/
// @version      0.1.1
// @description  try to take over the world!
// @author       You
// @match        https://eh-plus.com/book-online*
// @grant        none
// ==/UserScript==

;(() => {
  const MONTH_MAP = Object.freeze({
    Jan: 0,
    Feb: 1,
    Mar: 2,
    Apr: 3,
    May: 4,
    Jun: 5,
    Jul: 6,
    Aug: 7,
    Sep: 8,
    Oct: 9,
    Nov: 10,
    Dec: 11
  })

  // @ts-ignore
  const $ = jQuery
  // ensure they use jQuery
  const CALENDAR_QUERY = ".fa.fa-fw.fa-calendar"
  if ($(CALENDAR_QUERY).length < 1) {
    return
  }

  $(CALENDAR_QUERY).each(function() {
    const [parent] = $(this).parents(".panel-heading")
    let s = $(parent).text()
    s = s.replace(/^\s*/g, "")
    s = s.replace(/\r?\n/g, " ")

    // Thu, 29 Aug 2019 4:30pm   Approved
    // Tue, 20 Aug 2019 		3:15pm 		 Vocabulary Class
    const m = s.match(
      /(\w{3}), (\d{1,2}) (\w{3}) (\d{4})\s+(\d{1,2}):(\d{1,2})(pm|am)/
    )
    if (!m) {
      return
    }
    const [_, __, day, month, year, hour, minute, period] = m
    const horuPrefix = period == "pm" ? 12 : 0
    const date = new Date(
      year,
      MONTH_MAP[month],
      day,
      parseInt(hour, 10) + horuPrefix,
      minute
    )

    const link = createLink(date)
    $(parent).append(link)
  })

  function createLink(date) {
    const endDate = new Date(date)
    endDate.setHours(endDate.getHours() + 1)

    const start = formatDate(date)
    const end = formatDate(endDate)

    return (
      '<a href="http://www.google.com/calendar/render?\
action=TEMPLATE\
&text=Eh%2B\
&dates=' +
      start +
      "/" +
      end +
      "\
&ctz=Canda/Vancouver\
&location=568+Seymour+St+%233%2C+Vancouver%2C+BC+V6B+3J5" +
      '\
&trp=false\
&sprop=\
&sprop=name:"\
target="_blank" rel="nofollow">Add to my calendar</a>'
    )
  }

  function formatDate(date) {
    const f =
      date.getFullYear().toString() +
      zeropad(date.getMonth() + 1) +
      zeropad(date.getDate()) +
      "T" +
      zeropad(date.getHours()) +
      zeropad(date.getMinutes()) +
      zeropad(date.getSeconds())
    return f
  }

  function zeropad(n, length = 2) {
    const len = n.toString().length
    if (len >= length) {
      return n.toString()
    }
    return "0".repeat(length - len) + n.toString()
  }
})()