Greasemonkey: import/export Wordle's game state to migrate playing it from one device to another

wordle-import-export.user.js

// ==UserScript==
// @name        Wordle import/export
// @version     1.3
// @author      Antonio Bueno
// @namespace   userscripts.atnbueno.com
// @match       https://www.powerlanguage.co.uk/wordle/
// @match       https://wordle.danielfrg.com/
// @require     https://cdn.jsdelivr.net/npm/jquery@3/dist/jquery.min.js
// @require     https://cdn.jsdelivr.net/npm/toastify-js
// @resource    toastifyCSS https://cdn.jsdelivr.net/npm/toastify-js/src/toastify.min.css
// @grant       GM.getResourceUrl
// @grant       GM.setClipboard
// ==/UserScript==

(function () {
    "use strict";

    // DOM manipulations courtesy of jQuery

    const strings = JSON.parse(`{
    "en": {
        "label": "Import/export",
        "prompt": "Paste to import, leave empty to export",
        "importOK": "Updated data",
        "importKO": "Data could not be updated",
        "exportOK": "Game state copied to the clipboard",
        "exportKO": "Game state could not be copied"
		},
    "es": {
        "label": "Importar/exportar",
        "prompt": "Pega para importar, deja en blanco para exportar",
        "importOK": "Datos actualizados",
        "importKO": "Los datos no se han podido actualizar",
        "exportOK": "Estado del juego copiado al portapapeles",
        "exportKO": "El estado del juego no se ha podido copiar"
		}}`);
    const lang = location.href.includes("danielfrg") ? "es" : "en";

    // Modificacions are applied once the DOM has been build (images may be still loading)
    $(document).ready(function () {
        $("body").append('<button id="import-export">' + strings[lang].label);
        $("#import-export").on("click", function () {
            let pasted = prompt(strings[lang].prompt);
            if (pasted != "") {
                try {
                    let data = JSON.parse(atob(pasted));
                    Object.keys(data).forEach(key => { window.localStorage.setItem(key, data[key]) });
                    notification(strings[lang].importOK + ":\n" + Object.keys(data).join(", "));
                } catch (error) {
                    notification(strings[lang].importKO + ":\n" + error.message, "error");
                }
            } else {
                let data = {};
                try {
                    Object.keys(window.localStorage).forEach(key => { data[key] = localStorage.getItem(key); });
                    GM.setClipboard(btoa(JSON.stringify(data)));
                    notification(strings[lang].exportOK + ":\n" + Object.keys(data).join(", "));
                } catch (error) {
                    notification(strings[lang].exportKO + ":\n" + error.message, "error");
                }
            }
        });
    });

    // External CSS files
    (async function () {
        // Toastify CSS
        var externalFileURL = await GM.getResourceUrl("toastifyCSS");
        stylesheet = document.createElement("link");
        stylesheet.setAttribute("rel", "stylesheet");
        stylesheet.setAttribute("href", externalFileURL);
        document.documentElement.appendChild(stylesheet);
    })();

    // Inline CSS
    var stylesheet = document.createElement("style");
    stylesheet.textContent = `
    div.toastify { margin: inherit; padding-bottom: 20px; }
    div.toastify, #import-export { font-family: -apple-system,system-ui,BlinkMacSystemFont,"Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif; }
    #import-export { background-color: #E8E8F0; border-radius: 4px; border: 1px solid #888890; color: black; padding: 2px 6px; font-size: 13px; z-index: 50; position: fixed; bottom: 8px; right: 8px; }
    #import-export:hover { background-color: #C8C8D0; border: 1px solid #686870; }
    `;
    document.documentElement.appendChild(stylesheet);

    // Notifications courtesy of Toastify JS (see https://apvarun.github.io/toastify-js/)

    function notification(message, type = "info", timeout = 5) {
        // The "type" parameter accepts four values: "info", "warning", "error" and "hello"
        // The "timeout" parameter is expressed in seconds although Toastify uses milliseconds
        var color, icon;
        switch (type) {
            case "warning":
                color = "rgba(201, 201, 0, 0.8)";
                icon = "⚠";
                break;
            case "error":
                color = "rgba(201, 51, 51, 0.8)";
                icon = "🛑";
                break;
            case "hello":
                color = "rgba(51, 153, 51, 0.8)";
                icon = "👋🏼";
                break;
            default:
                color = "rgba(51, 51, 153, 0.8)";
                icon = "ℹ";
        }
        Toastify({
            text: icon + " " + message,
            duration: timeout * 1000,
            gravity: "bottom",
            style: {
                background: color,
            }
        }).showToast();
    }
})();