CF notification

Send a system notification when your friend solves a problem on codeforces.

You will need to install an extension such as Tampermonkey, Greasemonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey to install this script.

You will need to install an extension such as Tampermonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey or Userscripts to install this script.

You will need to install an extension such as Tampermonkey to install this script.

You will need to install a user script manager extension to install this script.

(I already have a user script manager, let me install it!)

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

(I already have a user style manager, let me install it!)

// ==UserScript==
// @name         CF notification
// @name:zh-CN   CF notification
// @namespace    https://github.com/platelett/script
// @version      0.2.2
// @description  Send a system notification when your friend solves a problem on codeforces.
// @description:zh-CN 看看是谁在卷题
// @author       platelet
// @match        https://codeforces.com/problemset/status?friends=on
// @icon         https://www.google.com/s2/favicons?sz=64&domain=codeforces.com
// @license      MIT
// @source       https://github.com/platelett/script/blob/main/CF%20notification.js
// @grant        none
// ==/UserScript==

// Open the page https://codeforces.com/problemset/status?friends=on script takes effect.

(function() {
    'use strict';
    onload = () => {
        const interval = 1000 * 12;
        var parser = new DOMParser();
        const query = async (url, path) => parser.parseFromString(await (await fetch(url)).text(), "text/html").querySelectorAll(path);
        Notification.requestPermission(() => {
            if(document.querySelector("#header > div.lang-chooser > div:nth-child(2) > a:nth-child(2)").textContent == "Register") {
                alert("You are not logged in and cannot receive notifications.");
                return;
            }
            var last = document.querySelector("#pageContent > div.datatable > div:nth-child(6) > table > tbody > tr > td.id-cell.dark.left > a").textContent;
            var running = new Set();
            var ID = setInterval(async () => {
                try {
                    var now, result = [];
                    await (async () => {
                        for(var page = 1; page <= 5; page++) {
                            var list = await query("https://codeforces.com/problemset/status/page/" + page + "?friends=on",
                                "#pageContent > div.datatable > div:nth-child(6) > table > tbody > tr:not(.first-row)");
                            if(!list.length) throw "Invalid page";
                            if(page == 1) now = list[0].children[0].textContent.trim();
                            for(var submission of list) {
                                var info = [];
                                for(var i of submission.children) {
                                    if(i.children[0]) i = i.children[0];
                                    info.push(i.textContent.trim());
                                }
                                if(info[0] <= last && (!running.size || info[0] < Math.min.apply(null, [...running]))) return;
                                var visited = info[0] <= last;
                                if(running.has(info[0])) running.delete(info[0]), visited = false;
                                if(visited) continue;
                                if(info[5] == "Accepted" || info[5] == "Happy New Year!" ||
                                info[5].startsWith("Pretests passed") || info[5].startsWith("Perfect result")) {
                                    var parts = info[3].split(" ");
                                    result.push({
                                        title: info[2] + " has solved " + parts[0],
                                        user: info[2],
                                        problem: submission.children[3].children[0].href,
                                        name: parts[0].slice(parts[0].match(/[A-Z]/).index) + ". " + parts.slice(2).join("")
                                    });
                                }
                                if(info[5] == "In queue" || info[5].startsWith("Running on test")) running.add(info[0]);
                            }
                        }
                        running.clear();
                    })();
                    last = now;
                    var all = [];
                    for(var i of result) all.push(new Promise(async resolve => {
                        var tmp = i;
                        for(var node of await query(tmp.problem, "span.tag-box")) {
                            var tag = node.textContent.trim();
                            if(tag[0] == '*') tmp.title += " (" + parseInt(tag.slice(1)) + ")";
                        }
                        tmp.title += ".", resolve();
                    }));
                    await Promise.all(all);
                    while(result.length) {
                        var i = result.pop();
                        if(!i.duplicate) new Notification(i.title, { body: i.name }).onclick
                            = () => window.open(i.problem, '_blank');
                    }
                } catch(err) {
                    new Notification("Error happened! Please check the console.");
                    console.log(err), clearInterval(ID);
                }
            }, interval);
        });
    }
})();