booth-download-all.user.js

// ==UserScript==
// @name         Booth.pm Download All
// @namespace    http://tampermonkey.net/
// @author       a1678991
// @version      1.0
// @description  Add a "Download All" button to purchased items on Booth.pm
// @match        https://accounts.booth.pm/library*
// @grant        none
// ==/UserScript==

(function() {
    'use strict';

    function addDownloadAllButton() {
        const itemContainers = document.querySelectorAll('.mb-16.bg-white');

        itemContainers.forEach((container, index) => {
            const downloadLinks = container.querySelectorAll('a[href^="https://booth.pm/downloadables/"]');

            if (downloadLinks.length >= 1) {
                const downloadAllBtnDiv = document.createElement('div');
                downloadAllBtnDiv.style.flexGrow = '1';
                downloadAllBtnDiv.style.flexBasis = '0';
                downloadAllBtnDiv.style.minWidth = '100px';
                downloadAllBtnDiv.style.display = 'flex';
                downloadAllBtnDiv.style.justifyContent = 'flex-end';

                const downloadAllBtn = document.createElement('button');
                downloadAllBtn.textContent = 'Download ' + downloadLinks.length + (downloadLinks.length > 1 ? ' items' : ' item');
                downloadAllBtn.style.color = '#1b7f8c';
                downloadAllBtn.style.width = '100px';
                downloadAllBtn.addEventListener('click', () => downloadAll(downloadLinks));

                const appendTarget = container.querySelector('.gap-8.border-b.pb-16');
                appendTarget.appendChild(downloadAllBtnDiv);
                downloadAllBtnDiv.appendChild(downloadAllBtn);
            }
        });
    }

    function downloadAll(links) {
        const waitMs = 5000;
        const jitterMs = 300;
        links.forEach((link, index) => {
            setTimeout(() => {
                link.dispatchEvent(new MouseEvent('click', {
                    view: window,
                    bubbles: true,
                    cancelable: false
                }));
            }, waitMs * index + Math.floor((Math.random() * jitterMs) - jitterMs/2))
        });
    }

    addDownloadAllButton();
})();