// ==UserScript==
// @name         YouTube Restore Dislike Counters
// @version      1.0.1
// @description  A userscript to restore the dislike counts on YouTube. Not 100% accurate all the time, but stil pretty accurate.
// @author       syndiate
// @match        *://www.youtube.com/*
// @run_at       document_start
// ==/UserScript==

// Turns a number like 1234567 into 1,234,567
function numberWithCommas(x) {
    return x.toString().replace(/\B(?=(\d{3})+(?!\d))/g, ",");
}

// Wait for the webpage to load before doing anything.
async function waitForElements(s) {
    while (!document.querySelector(s)) {
        await new Promise(r => requestAnimationFrame(r));
    }
}

async function init() {
    try {
        //Dig into the Webpage to find the Video-Rating element.
        const data = document.querySelector("ytd-app").data;
        const dataContents = data.response.contents.twoColumnWatchNextResults.results.results.contents;
        let like_button = null;
        let likes = 0;

        for(let i = 0; i < dataContents.length; i++) {
            if (typeof dataContents[i].videoPrimaryInfoRenderer != 'undefined') {
                like_button = dataContents[i].videoPrimaryInfoRenderer.videoActions.menuRenderer.topLevelButtons[0].toggleButtonRenderer;
                break;
            }
        }

        // If you liked the video, take the toggledText-Element. If not, take the defaultText-Element.
        const like_count_text = like_button.isToggled ? like_button.toggledText : like_button.defaultText;
        likes = parseInt(like_count_text.simpleText.replace(/(\.|,)/g, ""));

        // YouTube / Google will most likely remove averageRating too!
        // The ratio goes from 0 to 5 stars.
        let ratio = data.playerResponse.videoDetails.averageRating;

        // Calculate the dislikes using the star-ratio and the likes.
        let dislikes = ratio != 0 ? Math.round(likes*((5-ratio)/(ratio-1))) : 0;

        let dislikesfin = numberWithCommas(dislikes);
        let likesfin = numberWithCommas(likes);

        // Apply the calculated numbers to the text.
        document.querySelector("yt-formatted-string#text.ytd-toggle-button-renderer").innerHTML = ratio != 0 ? likesfin : "0";
        document.querySelectorAll("yt-formatted-string#text.ytd-toggle-button-renderer")[1].innerHTML = dislikesfin;

        // Display the ratingbar
        document.querySelector("ytd-sentiment-bar-renderer").removeAttribute("hidden");
        document.getElementById("like-bar").setAttribute("style", "width: " + (100/(1+(5-ratio)/(ratio-1))) + "%;");
    } catch(e) {}
}

waitForElements("yt-formatted-string#text.ytd-toggle-button-renderer").then(() => init());
window.addEventListener('yt-page-data-updated', init, false);