itch-random-bundle-game.user.js

// ==UserScript==
// @name         itch.io play a random bundle game
// @namespace    https://twitter.com/tomasduda
// @version      1.0
// @description  Shows which game to play next from an itch.io bundle download page.
// @author       Tomáš Duda
// @match        https://itch.io/bundle/download/*
// @grant        GM.setValue
// @grant        GM.getValue
// @grant        GM.deleteValue
// ==/UserScript==

(async () => {
    'use strict';

    const VAL_REDIRECTED = 'redirected';

    const filterOptions = document.querySelector('.filter_options');
    const pager = filterOptions.querySelector('.pager');

    if (await GM.getValue(VAL_REDIRECTED) === true) {
        selectRandomItem();
    }

    addRandomButton();

    function addRandomButton() {
        // Add a button next to the search box

        const randomButton = document.createElement('a');
        randomButton.classList.add('button');
        randomButton.innerText = 'Random';
        filterOptions.appendChild(randomButton);

        randomButton.addEventListener('click', randomButtonClick);
    }

    async function randomButtonClick() {
        if (await GM.getValue(VAL_REDIRECTED) !== true) {
            if (pager) {
                goToRandomPage();
                return;
            }
        }

        selectRandomItem();
    }

    function goToRandomPage() {
        const numPages = Number(pager.querySelector('.pager_label a').innerText);
        const randPage = Math.ceil(Math.random() * numPages);
        GM.setValue(VAL_REDIRECTED, true);
        window.location.search = "?page=" + randPage;
    }

    function selectRandomItem() {
        GM.deleteValue(VAL_REDIRECTED);

        const gameList = document.querySelector('.game_list');

        // Reset styles just in case
        gameList.querySelectorAll('.game_row').forEach(e => { e.style = '' });

        const randomGame = gameList.children[Math.floor(Math.random() * gameList.childElementCount)];
        randomGame.style = 'border: 5px solid var(--itchio_button_color, #FF2449);';
        randomGame.scrollIntoView({behavior: 'smooth', block: 'end', inline: 'nearest'});
    }
})();