Adds desktop notifications for Scratch (https://scratch.mit.edu)

scratch-notifications.user.js

// ==UserScript==
// @name        Scratch Notifications
// @namespace   zro617.github.io
// @description Adds desktop notifications for Scratch messages
// @include     https://scratch.mit.edu/*
// @version     1.21
// @grant       none
// ==/UserScript==

if (typeof Scratch.INIT_DATA.LOGGED_IN_USER === "undefined") well_poop_you_need_to_log_in;

class ScratchMessage {
  constructor(e) {
    this.e = e;
    this.id = e.dataset.receiptId;
    this.what = this.who = this.where = this.when = this.link = this.body = this.icon = "";
    
    let links = e.querySelectorAll("a");
    let text = e.textContent.trim();
    
    if (text.match(/ is now following you/)) {
      this.what = "follow";
      this.who = links[0].innerHTML;
      this.link = links[0].href;
    } else if (text.match(/ commented on/)) {
      this.what = "comment";
      this.who = links[0].innerHTML;
      this.where = links[1].innerHTML;
      this.link = links[1].href;
      this.body = e.querySelector("span.comment-snippet").innerHTML;
    } else if (text.match(/ replied to/)) {
      this.what = "reply";
      this.who = links[0].innerHTML;
      this.where = links[1].innerHTML;
      this.link = links[1].href;
      this.body = e.querySelector("span.comment-snippet").innerHTML;
    } else if (text.match(/ loved/)) {
      this.what = "love";
      this.who = links[0].innerHTML;
      this.where = links[1].innerHTML;
      this.link = links[1].href;
    } else if (text.match(/ favorited/)) {
      this.what = "fave";
      this.who = links[0].innerHTML;
      this.where = links[1].innerHTML;
      this.link = links[1].href;
    } else if (text.match(/ remixed/)) {
      this.what = "remix";
      this.who = links[0].innerHTML;
      this.where = links[1].innerHTML;
      this.body = links[2].innerHTML;
      this.link = links[2].href;
    } else if (text.match(/ invited/)) {
      this.what = "invite";
      this.who =  links[0].innerHTML;
      this.where = links[1].innerHTML;
      this.link = links[2].href;
    } else if (text.match(/new activity/)) {
      this.what = "studio activity";
      this.where = links[0].innerHTML;
      this.link = links[0].href;
    } else if (text.match(/new posts/)) {
      this.what = "forum activity";
      this.where = links[0].innerHTML;
      this.link = links[0].href;
    }
    // Beware of missing timestamp for certain messages
    this.when = e.parentElement.firstElementChild.innerHTML;
    let time = e.querySelector("span.time");
    if (time) this.when += " " + time.innerHTML;
    
    // need a better icon
    this.icon = Scratch.INIT_DATA.LOGGED_IN_USER.model.thumbnail_url || "https://cdn.scratch.mit.edu/scratchr2/static/__0c1805349a6fe15c01c668d3f8acd971__/images/nav-notifications.png";
    /*
    if (this.who) {
      let xhr = new XMLHttpRequest();
      xhr.open("GET","https://scratch.mit.edu/users/"+this.who+"/",true);
      xhr.onload = function() {
        if (xhr.status == 200) i = xhr.response.querySelector("div.avatar img").src;
      };
      xhr.send();
    }
    */
    console.log(this);
  }
  get title() {
    switch (this.what) {
      case "follow":          return this.who + " added you";
      case "comment":         return this.who + " commented on "   + this.where;
      case "reply":           return this.who + " replied on "     + this.where;
      case "love":            return this.who + " ❤'d "           + this.where;
      case "fave":            return this.who + " ⭐'d "           + this.where;
      case "remix":           return this.who + " remixed "        + this.where;
      case "invite":          return this.who + " invited you to " + this.where;
      case "studio activity": return "New activity in "            + this.where;
      case "forum activity":  return "New posts in "               + this.where;
      default:                return "Message from Scratch";
    }
  }
  notify() {
    let x = new Notification(this.title,{
      body:this.body + "\n" + this.when,
      icon:this.icon,
      tag:this.id,
      requireInteraction:true
    });
    x.addEventListener("click",(function(e){
     window.open(this.link,"_blank").focus();
    }).bind(this));
  }
}

let read = [];

let purge = () => {
  let body = JSON.stringify(read);
  let xhr = new XMLHttpRequest();
  xhr.open("POST","https://scratch.mit.edu/messages/ajax/messages-clear/",true);
  xhr.setRequestHeader("X-CSRFToken",document.cookie.match(/scratchcsrftoken=([a-zA-Z0-9]+)/)[1]);
  xhr.setRequestHeader("Cookie",document.cookie);
  xhr.setRequestHeader("X-Requested-With","XMLHttpRequest");
  xhr.setRequestHeader("Referer","https://scratch.mit.edu/messages/");
  xhr.setRequestHeader("Content-Length",body.length);
  xhr.send(body);
  
  read = [];
};

let check = () => {
  if (Notification.permission != "granted") return;
  let xhr = new XMLHttpRequest();
  xhr.open("GET","https://scratch.mit.edu/messages/",true);
  xhr.responseType = "document";
  xhr.onload = function() {
    if (xhr.status != 200)  return;
    let messages = xhr.response.querySelectorAll("li.unread");
    if (!messages.length) return;
    for (let m of messages) {
      var message = new ScratchMessage(m);
      message.notify();
      read.push(message.id);
    }
    purge();
  };
  xhr.send();
};

Notification.requestPermission();
window.setInterval(check,10000);