reg.js

const fetch = require("node-fetch");

const SERVICE_ID = "e5e795f2-7f35-4b11-ba7d-d1c45cbec182";
const YEAR = 2020;

const getWeekNumber = (date) => {
  const firstDayOfYear = new Date(date.getFullYear(), 0, 1);
  const pastDaysOfYear = (date - firstDayOfYear) / 86400000;
  return Math.ceil((pastDaysOfYear + firstDayOfYear.getDay() + 1) / 7);
};

process.env.TZ = "Europe/Helsinki";

const obtainSessionId = async () => {
  const session = await fetch(
    "https://migri.vihta.com/public/migri/api/sessions"
  );
  const response = await session.json();
  return response.id;
};

const getLocalities = async (token) => {
  const response = await fetch(
    "https://migri.vihta.com/public/migri/api/services/localities",
    {
      headers: {
        accept: "application/json, text/plain, */*",
        "accept-language": "en,pl-PL;q=0.9,pl;q=0.8,en-US;q=0.7",
        "content-type": "application/json;charset=UTF-8",
        "sec-fetch-dest": "empty",
        "sec-fetch-mode": "cors",
        "sec-fetch-site": "same-origin",
        "vihta-session": token,
      },
      referrer: "https://migri.vihta.com/public/migri/",
      referrerPolicy: "no-referrer-when-downgrade",
      body: JSON.stringify({
        serviceSelections: [{ values: [SERVICE_ID] }],
        extraServices: [],
      }),
      method: "POST",
      mode: "cors",
    }
  );

  return await response.json();
};

const checkSlots = async (token, week, office) => {
  const response = await fetch(
    `https://migri.vihta.com/public/migri/api/scheduling/offices/${office}/${YEAR}/w${week}?end_hours=24&start_hours=0`,
    {
      headers: {
        accept: "application/json, text/plain, */*",
        "accept-language": "en,pl-PL;q=0.9,pl;q=0.8,en-US;q=0.7",
        "content-type": "application/json;charset=UTF-8",
        "sec-fetch-dest": "empty",
        "sec-fetch-mode": "cors",
        "sec-fetch-site": "same-origin",
        "vihta-session": token,
      },
      referrer: "https://migri.vihta.com/public/migri/",
      referrerPolicy: "no-referrer-when-downgrade",
      body: JSON.stringify({
        serviceSelections: [{ values: [SERVICE_ID] }],
        extraServices: [],
      }),
      method: "POST",
      mode: "cors",
      credentials: "include",
    }
  );

  return await response.json();
};

const run = async () => {
  const token = await obtainSessionId();
  const localities = await getLocalities(token);

  const startingWeek = getWeekNumber(new Date());
  const endingWeek = getWeekNumber(new Date("2020-10-01"));

  const offices = localities.localities
    .filter((locality) => locality.name === "Helsinki")
    .map((locality) => locality.offices.map((office) => office.id))
    .flat();

  const requests = [];

  for (let week = startingWeek; week <= endingWeek; week++) {
    for (const office of offices) {
      requests.push(checkSlots(token, week, office));
    }
  }

  const responses = await Promise.all(requests);
  const times = responses.map((result, index) => {
    return {
      week: startingWeek + index,
      name: result.office.name,
      dailyTimes: result.dailyTimesByOffice,
    };
  });

  times.forEach((time) => {
    if (time.dailyTimes.flat().length > 0) {
      console.log(time);
    }
  });
};

run();