tampermonkey script to calculate video bitrate on rarbg.to

rarbgBitrateCalculator.js

// ==UserScript==
// @name         rarbg.to bitrate calculator
// @namespace    http://tampermonkey.net/
// @version      0.2
// @description  does a rough estimation of video bitrate based on filesize and runtime, and appends it to the "Size" element
// @author       https://github.com/A1ex-N
// @match        https://rarbg.to/torrent/*
// @icon         https://www.google.com/s2/favicons?sz=64&domain=rarbg.to
// @grant        none
// ==/UserScript==

function findElements() {
    const infoTableSelector = '.lista-rounded > tbody:nth-child(1) > tr:nth-child(2) > td:nth-child(1) > div:nth-child(1) > table:nth-child(1) > tbody:nth-child(1)';
    const torrentDescriptionTable = document.querySelector(infoTableSelector).children;
    let elements = {
        sizeElement: {
            headerEl: null,
            textEl: null,
            strippedText: null, // size text without MB/GB
            // if isGigabytes is false we assume it's megabytes, even though it could be KB or even TB
            isGigabytes: false,
        },
        runtimeElement: {
            headerEl: null,
            textEl: null,
        },
    };

    for (const tableRow of torrentDescriptionTable) {
        if (tableRow.children.length != 0) {
            let headerElement = tableRow.children[0];
            let textElement = tableRow.children[1];
            switch (headerElement.innerText) {
                case "Size:":
                    elements.sizeElement.headerEl = headerElement;
                    elements.sizeElement.textEl = textElement;
                    elements.sizeElement.strippedText = textElement.innerText.replace(RegExp(" (MB)|(GB)"), "");
                    if (textElement.innerText.includes("GB")) { elements.sizeElement.isGigabytes = true }
                    break;
                case "IMDB Runtime:":
                    elements.runtimeElement.headerEl = headerElement;
                    elements.runtimeElement.textEl = textElement;
                    break;
            }
        }
    }
    return elements;
}

(function () {
    'use strict';

    let elements = findElements();
    let rawSize = elements.sizeElement.strippedText;
    var sizeInMegabytes;
    if (elements.sizeElement.isGigabytes) {
        sizeInMegabytes = parseFloat(rawSize) * 1024;
    } else {
        sizeInMegabytes = parseFloat(rawSize);
    }

    if (elements.runtimeElement.headerEl === null) {
        console.error("[rarbg.to bitrate calculator] Cannot find runtime, therefore the bitrate cannot be calculated");
        elements.sizeElement.textEl.innerText += " [Unable to calculate bitrate]";
        return;
    }
    let runtimeInMinutes = elements.runtimeElement.textEl.innerText;
    let runtimeInSeconds = parseInt(runtimeInMinutes * 60);
    let bitrateInMegabytes = (sizeInMegabytes / runtimeInSeconds).toFixed(2);
    let bitrateInMegabits = bitrateInMegabytes * 8;
    elements.sizeElement.textEl.innerText += ` [Bitrate: ~${bitrateInMegabits}Mb/s (probably a bit less than reported)]`;
})();