EGN Abfallkalender to ICS format

egn.zx

/* -*- js -*- */
let URL = 'https://www.egn-abfallkalender.de/'

function makeForm (obj) {
  let params = new URLSearchParams()
  for (let o in obj) params.append(o, obj[o])
  return params
}

function formatDate (day, month, year) {
  if (day.length < 2) day = '0' + day
  if (month.length < 2) month = '0' + month
  return year + month + day
}

async function getSessionHeaders () {
  let res = await fetch(URL)
  let data = await res.text()
  let cookies = res.headers.get('set-cookie')
  return {
    cookie: cookies.split(' ').filter((x, i) => i % 7 === 0).slice(0, -1).join(' '),
    'x-csrf-token': data.match(/csrf-token.*?content="(.*?)"/)[1]
  }
}

async function makeRequest (path, params) {
  let session = await getSessionHeaders()

  params = makeForm(params)

  let res = await fetch(URL + path, {
    method: 'POST',
    body: params,
    headers: session
  })

  let data = await res.json()

  return data
}

function createICS (dates, name, text) {
  let out = []
  for (let date of dates) {
    out.push([
      'BEGIN:VEVENT',
      'STATUS:CONFIRMED',
      `DTSTART;TZID=Europe/Berlin:${date + OPTS.time[0]}`,
      `DTEND;TZID=Europe/Berlin:${date + OPTS.time[1]}`,
      `SUMMARY:${text}`,
      'TRANSP:OPAQUE',
      'BEGIN:VALARM',
      'ACTION:DISPLAY',
      'DESCRIPTION:This is an event reminder',
      `TRIGGER:${OPTS.reminder}`,
      'END:VALARM',
      'END:VEVENT'
    ].join('\n'))
  }
  return [
    'BEGIN:VCALENDAR',
    `PRODID:-//${name}`,
    'VERSION:2.0',
    'METHOD:PUBLISH',
    'BEGIN:VTIMEZONE',
    'TZID:Europe/Berlin',
    'X-LIC-LOCATION:Europe/Berlin',
    'BEGIN:DAYLIGHT',
    'TZOFFSETFROM:+0100',
    'TZOFFSETTO:+0200',
    'TZNAME:CEST',
    'DTSTART:19700329T020000',
    'RRULE:FREQ=YEARLY;INTERVAL=1;BYDAY=-1SU;BYMONTH=3',
    'END:DAYLIGHT',
    'BEGIN:STANDARD',
    'TZOFFSETFROM:+0200',
    'TZOFFSETTO:+0100',
    'TZNAME:CET',
    'DTSTART:19701025T030000',
    'RRULE:FREQ=YEARLY;INTERVAL=1;BYDAY=-1SU;BYMONTH=10',
    'END:STANDARD',
    'END:VTIMEZONE',
    ...out,
    'END:VCALENDAR'
  ].join('\n')
}

let OPTS = {
  time: ['T091500Z', 'T093000Z'], // 9:15 > 9:30
  reminder: '-P0DT13H0M0S' // remind 13 hours before
}

let PARAMS = {
  city: await question('City: '),
  district: await question('District: '),
  street: await question('Street: '),
  street_number: await question('Street Number: ')
}

let res = await makeRequest('kalender', PARAMS).catch(() => null)
if (!res) console.error('Invalid location!')
else {
  let colors = res.trash_type_colors
  let dates = res.waste_discharge

  let out = {}

  for (let year in dates) {
    for (let month in dates[year]) {
      for (let day in dates[year][month]) {
        let type = colors[dates[year][month][day][0].toLowerCase()]
        if (!out[type]) out[type] = []
        out[type].push(formatDate(day, month, year))
      }
    }
  }

  let w = (x, y) => fs.writeFileSync(x, y)

  w('grau.ics', createICS(out.grau, 'EGN//Abfallkalender Grau', 'Graue Mülltonne'))
  w('blau.ics', createICS(out.blau, 'EGN//Abfallkalender Blau', 'Blaue Mülltonne'))
  w('gelb.ics', createICS(out.gelb, 'EGN//Abfallkalender Gelb', 'Gelbe Mülltonne'))
  w('braun.ics', createICS(out.braun, 'EGN//Abfallkalender Braun', 'Braune Mülltonne'))
}