Midpass calendar notify has available record

midpass.js

const beep = (date) => {
  const context = new AudioContext();
  const oscillator = context.createOscillator();
  oscillator.type = "sawtooth";
  oscillator.frequency.value = 1200;
  oscillator.connect(context.destination);
  oscillator.start();
  if (confirm("Появилась запись")) {
    oscillator.stop();
    document.location.href = 'https://q.midpass.ru/ru/Booking/Date?serviceId=54030d6a-e145-08e2-60fb-33344fac2455&date=' + date;
  }
};

const getDate = (month, year) => [
  (month > 11 ? month - 12 : month) + 1,
  month > 11 ? year + Math.floor(month / 11) : year
];

const randSeconds = (n, x) => {
  return Math.floor(Math.random() * (x * 1000 - n * 1000 + 1) + n * 1000);
};

const fetchSlots = async (month, year) => {
  const res = await fetch("https://q.midpass.ru/ru/Booking/GetMonthSchedule", {
    headers: {
      accept: "application/json, text/javascript, */*; q=0.01",
      "accept-language": "ru,en;q=0.9",
      "content-type": "application/x-www-form-urlencoded; charset=UTF-8",
      "sec-ch-ua":
        '"Chromium";v="106", "Google Chrome";v="106", "Not;A=Brand";v="99"',
      "sec-ch-ua-mobile": "?0",
      "sec-ch-ua-platform": '"macOS"',
      "sec-fetch-dest": "empty",
      "sec-fetch-mode": "cors",
      "sec-fetch-site": "same-origin",
      "x-requested-with": "XMLHttpRequest"
    },
    referrer:
      "https://q.midpass.ru/ru/Booking?serviceId=54030d6a-e145-08e2-60fb-33344fac2455",
    referrerPolicy: "strict-origin-when-cross-origin",
    body: `serviceId=54030d6a-e145-08e2-60fb-33344fac2455&month=${month}&year=${year}&day=1&k=7431`,
    method: "POST",
    mode: "cors",
    credentials: "include"
  });

  if (res.ok) {
    return await res.json();
  }

  return null;
};

const start = async () => {
  if (!started) {
    return;
  }

  const date = new Date();
  const month = date.getMonth();
  const year = date.getFullYear();
  const dates = [getDate(month, year), getDate(month + 1, year)];
  const slots = await Promise.all(dates.map(async (date) => await fetchSlots(...date)));
  const totalAvailableSlots = slots.reduce((res, cur) => res + cur.AvailableSlots, 0);

  if (totalAvailableSlots > 0) {
    const days = slots.flatMap(slot => slot.Month.Days.filter(day => day.AvailableAppointmentsCount > 0));
    const selected = days.sort((a, b) => b.AvailableAppointmentsCount - a.AvailableAppointmentsCount)[0];
    const date = new Date(+selected.Date.replaceAll(/[^0-9]/g, '')).toISOString().replace(/T.*$/, '');

    beep(date);
  } else {
    setTimeout(start, randSeconds(30, 90));
  }
};

let started = false;
const buttonText = ['▶ запустить скрипт️', '⏸ остановить скрипт'];

const Button = document.createElement('button');
Button.style.cssText = 'position: fixed; top: 20px; left: 20px; font-size: 1.5rem';
Button.textContent = buttonText[0];
document.documentElement.appendChild(Button)

Button.addEventListener('click', () => {
  started = !started;
  Button.textContent = buttonText[Number(started)];
  start();
})