(() => {
	let cache = {timepoints: {}, banned:load_banned()};

	function load_banned() {
		return JSON.parse(localStorage.getItem('bannedChannels')) || [];
	}

	function save_banned(banned) {
		localStorage.setItem('bannedChannels', JSON.stringify(banned));
	}

	function edit_page() {
		for (const element of document.getElementById("related").querySelectorAll('ytd-compact-video-renderer')) {
			if (element.getAttribute('scanned')) continue;
			element.setAttribute('scanned', 'true');

			const channel = extract_channel_id(element);
			if (is_banned(channel)) element.remove();
			else add_button(element, channel);
		}
	}

	function add_button(element, channel) {
		const button = document.createElement('button');
		button.textContent = 'Ban This Channel';
		button.addEventListener('click', () => {
			ban(channel);
			element.parentNode.removeChild(element);
		});
		element.appendChild(button);
	}

	function extract_channel_id(element) {
		return element.querySelector('.ytd-channel-name').innerText;
	}

	function last_ran(checkpoint) {
		if (!cache.timepoints[checkpoint]) {
			cache.timepoints[checkpoint] = Date.now();
			return 0;
		}
		let difference = Date.now() - cache.timepoints[checkpoint];
		cache.timepoints[checkpoint] = Date.now();
		return difference;
	}

	function is_banned(channel) {
		if(last_ran("loading banned channels") > 1000) cache.banned  = load_banned();
		return cache.banned.includes(channel);
	}

	function ban(channel) {
		cache.banned.push(channel);
		save_banned(cache.banned);
	}

	setInterval(edit_page, 50);
})();