// ==UserScript==
// @name            Youtube download button - yt1s.com (revised SuchtiOnTour Edit)
// @name:de         Youtube download button - yt1s.com (revised SuchtiOnTour Edit)
// @namespace       Violentmonkey Scripts
// @match           https://www.youtube.com/watch
// @match           https://*.youtube.com/*
// @grant           GM_addStyle
// @run-at          document-start
// @version         1.0
// @author          SuchtiOnTour
// @license         MIT
// @description     Adds a youtube download Button
// @description:de  Fügt einen YouTube-Download-Button hinzu
// @downloadURL none
// ==/UserScript==

(function() {
    const API = "https://yt1s.com/en/youtube-to-mp3?q=";
    const BUTTON_ID = "dwnldBtn";
    const TARGET_BUTTON = "#analytics-button";

    const buttonStyle = `
        #${BUTTON_ID} {
            background-color: #0F0F0F;
            color: #FFFFFF;
            border: 1px solid #3F3F3F;
            border-color: rgba(255,255,255,0.2);
            margin: 0px 4px;
            border-radius: 18px;
            width: 94.56px;
            height: 36px;
            line-height: 37px;
            text-align: center;
            font-style: normal;
            font-size: 14px;
            font-family: Roboto, Noto, sans-serif;
            font-weight: 500;
            text-decoration: none;
        }
        #${BUTTON_ID}:hover {
            background-color: #3F3F3F;
            color: #ffffff;
            border-color: #3F3F3F;
        }
    `;

    GM_addStyle(buttonStyle);

    function waitForElement(selector) {
        return new Promise(resolve => {
            if (document.querySelector(selector)) {
                return resolve(document.querySelector(selector));
            }
            const observer = new MutationObserver(mutations => {
                if (document.querySelector(selector)) {
                    resolve(document.querySelector(selector));
                    observer.disconnect();
                }
            });
            observer.observe(document.body, { childList: true, subtree: true });
        });
    }

    function addButton() {
        waitForElement(TARGET_BUTTON).then((btn) => {
            btn.innerHTML += `<a href="${API + encodeURIComponent(window.location.href)}" target="_blank" id="${BUTTON_ID}">Download</a>`;
        });
    }

    function updateButton() {
        waitForElement(`#${BUTTON_ID}`).then((btn) => {
            btn.href = API + encodeURIComponent(window.location.href);
        });
    }

    window.onload = addButton;
    window.addEventListener("yt-navigate-start", updateButton, true);
})();