notify-on-termin.js

// ==UserScript==
// @name         Termin Notifier
// @namespace    http://tampermonkey.net/
// @version      0.1
// @description  try to take over the world!
// @author       You
// @match        https://service.berlin.de/terminvereinbarung/*
// @icon         https://www.google.com/s2/favicons?domain=berlin.de
// @grant        none
// ==/UserScript==

(function () {
  "use strict";

  function addElement(type, value) {
    const element = document.createElement("input");
    element.type = type;
    element.value = value;
    element.name = type;
    element.style = "color: red;"
    element.onclick = function () {
      notifyMe();
    };

    const parent = document.getElementById("layout-grid__area--contentheader");
    parent.appendChild(element);
  }

  function notifyMe() {
    if (!window.Notification) {
      console.log("Browser does not support notifications.");
    } else {
      if (Notification.permission === "granted") {
        const notify = new Notification("Hi there!", {
          body: "Termin available!"
        });
      } else {
        Notification.requestPermission()
          .then(function (p) {
            if (p === "granted") {
              const notify = new Notification("Hi there!", {
                  body: "Termin available!"
              });
            } else {
              console.log("User blocked notifications.");
            }
          })
          .catch(function (err) {
            console.error(err);
          });
      }
    }
  }

  const sleep = t => new Promise(s => setTimeout(s, t));

  async function repeatNotification() {
    for (let i = 0; i <= 15; i++) {
      notifyMe();
      await sleep(1500);
    }
  }

  // Your code here...
  addElement("button", "------ >>>>>>>>  Click here to set notification permission! <<<<<<<<<< ------");

  const nodes = document.querySelectorAll(
    'a[title="An diesem Tag einen Termin buchen"]'
  );

  console.log(new Date(), nodes)
  
  if (nodes.length) {
    for (const node of nodes) {
      const day = node.textContent * 1

      if (day < 15) {
        repeatNotification();
        break;
      } else {
        console.log("Skipping notification for termin on ", day)
      }
    }
  } else {
    console.log('No termin :( :( :(. Refresh the page again sometime later.')
  }
})();