Endchan TT Sauce

// ==UserScript==
// @name         Endchan TT Sauce
// @namespace    https://endchan.org/
// @version      1.3
// @description  Add TikTok sauce button next to filenames
// @author       Anonymous (You)
// @match        http://endchan.org/*
// @match        https://endchan.org/*
// @match        http://endchan.net/*
// @match        https://endchan.net/*
// @match        http://magrathea.endchan.net/*
// @match        https://magrathea.endchan.net/*
// @grant        none
// @downloadURL  https://pastebin.com/raw/rA2CWZKP
// @updateURL    https://pastebin.com/raw/rA2CWZKP
// ==/UserScript==

/*
1.3 - added endchan.net to @match
1.2 - support for magrathea
1.1 - added update urls
*/

// ----- CONFIG -----

const sauceText = "[tiktok]";
const sauceUrl = "https://www.tiktok.com/@share/video/";
const sauceRegex = /(6|7)\d{18}/g;

// ----- MAIN -----

(function() {
    'use strict';

    // parse all pre-existing posts when page loads
    parseNode(document);

    // callback function to execute when mutations are observed
    let callback = function(mutationsList) {
        for(let mutation of mutationsList) {
            for (let node of mutation.addedNodes) {
                // make sure we can get elements by class name on node
                if (typeof node.getElementsByClassName === "function") {
                    parseNode(node);
                }
            }
        }
    };

    // observe page for changes to sauce new posts (all articles/posts should be inside the a tag with the id "divThreads")
    var observer = new MutationObserver(callback);
    let observedNode = document.getElementById("divThreads");
    if (!observedNode) {
        observedNode = document.getElementById("threadsContainer"); // magrathea
    }
    observer.observe(observedNode, { childList: true, subtree:true });
})();

// originalNameLink should contain the filename, find all of those under the given node
function parseNode(node) {
    let links = node.getElementsByClassName("originalNameLink");
    if (!links || links.length == 0) {
        links = node.getElementsByClassName("filename"); // magrathea
    }
    if (links) {
        for (let link of links) {
            // here's the catch: page load can tuncate innerHTML so the value of the 'download' attribute should be used for saucing
            // however, when new posts are added via refresh that doesn't create the element, though it looks like there's no truncation
            // so, 'download' should be used if it's present and otherwise fallback to trying innerHTML
            let sauceLink = null;
            if (sauceLink = parseSauceFromString(link.getAttribute("download"))) {
                // attach the sauce link to the page if you have it
                link.parentElement.insertAdjacentElement("afterend", sauceLink);
            } else if (sauceLink = parseSauceFromString(link.innerHTML)) {
                // attach the sauce link to the page if you have it
                link.parentElement.insertAdjacentElement("afterend", sauceLink);
            }
        }
    }
}

// pass a string that may or may not contain a TT id, returns an <a> element that links to sauce if it found an id, null otherwise
function parseSauceFromString(string) {
    if (string == null) return null;

    const found = string.match(sauceRegex);
    if (found != null) {
        var a = document.createElement("a");
        a.setAttribute("href", sauceUrl + found);
        a.setAttribute("target", "_blank"); // new window or tab
        a.innerHTML = sauceText;
        return a;
    }
    return null;
}