return-youtube-dislike/Extensions/UserScript/Return Youtube Dislike.user.js

// ==UserScript==
// @name         Return Youtube Dislike
// @namespace    https://www.returnyoutubedislike.com/
// @version      0.1
// @description  Return of the Youtube Dislike, Based off https://www.returnyoutubedislike.com/
// @author       Anarios & JRWR
// @match        *://*.youtube.com/*
// @include      *://*.youtube.com/*
// @compatible chrome
// @compatible firefox
// @compatible opera
// @compatible safari
// @compatible edge
// @downloadURL
// @grant GM_xmlhttpRequest
// ==/UserScript==
function getButtons() {
    return document
        .getElementById("menu-container")
        ?.querySelector("#top-level-buttons-computed");
}

function getLikeButton() {
    return getButtons().children[0];
}

function getDislikeButton() {
    return getButtons().children[1];
}

function isVideoLiked() {
    return getLikeButton().classList.contains("style-default-active");
}

function isVideoDisliked() {
    return getDislikeButton().classList.contains("style-default-active");
}

function isVideoNotLiked() {
    return getLikeButton().classList.contains("style-text");
}

function isVideoNotDisliked() {
    return getDislikeButton().classList.contains("style-text");
}

function getState() {
    if (isVideoLiked()) {
        return "liked";
    }
    if (isVideoDisliked()) {
        return "disliked";
    }
    return "neutral";
}

function setLikes(likesCount) {
    getButtons().children[0].querySelector("#text").innerText = likesCount;
}

function setDislikes(dislikesCount) {
    getButtons().children[1].querySelector("#text").innerText = dislikesCount;
}

function setState() {
    GM_xmlhttpRequest({
        method: "GET",
        responseType: "json",
        url: "https://return-youtube-dislike-api.azurewebsites.net/votes?videoId=" + getVideoId(),
        onload: function(response) {
            if (response != undefined) {
                const formattedDislike = numberFormat(response.response.dislikes);
                console.log(response);
                setDislikes(formattedDislike);
            }
        }
    });
}

function likeClicked() {
    console.log("like" + getState());
    setState();
}

function dislikeClicked() {
    console.log("dislike" + getState());
    setState();
}

function setInitalState() {
    setState();
}

function getVideoId() {
    const urlParams = new URLSearchParams(window.location.search);
    const videoId = urlParams.get("v");
    return videoId;
}

function isVideoLoaded() {
    const videoId = getVideoId();
    return (
        document.querySelector(`ytd-watch-flexy[video-id='${videoId}']`) !== null
    );
}

function numberFormat(numberState) {
    const userLocales = navigator.language;
    const formatter = Intl.NumberFormat(userLocales, { notation: "compact" });
    return formatter.format(numberState);
}

function setEventListeners(evt) {
    function checkForJS_Finish() {
        if (getButtons()?.offsetParent && isVideoLoaded()) {
            clearInterval(jsInitChecktimer);
            const buttons = getButtons();
            if (!window.returnDislikeButtonlistenersSet) {
                buttons.children[0].addEventListener("click", likeClicked);
                buttons.children[1].addEventListener("click", dislikeClicked);
                window.returnDislikeButtonlistenersSet = true;
            }
            setInitalState();
        }
    }

    if (window.location.href.indexOf("watch?") >= 0) {
        var jsInitChecktimer = setInterval(checkForJS_Finish, 111);
    }
}

(function() {
    'use strict';
    setEventListeners();

})();