String clean_chat_field(String raw, u32 max_length)
{
	String value = trim(raw);
	value = replace(value, "\r", " ");
	value = replace(value, "\n", " ");
	if(value.length() > max_length)
		value.resize(max_length);
	return(value);
}

DTree chat_event(Request& context, String type, String body)
{
	DTree event;
	event["type"] = type;
	event["body"] = body;
	event["connection_id"] = ws_connection_id();
	event["scope"] = first(context.params["DOCUMENT_URI"], ws_scope());
	event["online"] = (f64)ws_connection_count();
	event["at"] = time_format_utc("%H:%M:%S");
	event["name"] = context.connection["name"].to_string();
	event["message_count"] = context.connection["message_count"];
	return(event);
}

RENDER(Request& context)
{
	String ws_url = context.params["DOCUMENT_URI"];
	u64 online = ws_connection_count();
	<>
		<link rel="stylesheet" href='style.css?v=<?= time() ?>'></link>
		<h1>
			<a href="index.uce">UCE Test</a>:
			WebSocket Chat
		</h1>

		<label>Chat Info</label>
		<pre>Page scope: <?= ws_url ?>
Connected right now: <span id="online-count"><?= online ?></span>
Status: <span id="status">Connecting...</span></pre>

		<form id="chat-form" action="?" method="post">
			<div>
				<label>Display name:</label>
				<input id="chat-name" type="text" maxlength="32" value="guest-<?= draw_int(1000, 9999) ?>"/>
			</div>
			<div>
				<label>Message:</label>
				<textarea id="chat-message" maxlength="500" placeholder="Say something to everyone connected to this same .ws.uce page"></textarea>
			</div>
			<div>
				<input id="send-button" type="submit" value="Send Message"/>
			</div>
		</form>

		<label>Chat Log</label>
		<pre id="chat-log"></pre>

		<script>
			const wsUrl = `${window.location.protocol === 'https:' ? 'wss' : 'ws'}://${window.location.host}<?= ws_url ?>`;
			const statusEl = document.getElementById('status');
			const onlineEl = document.getElementById('online-count');
			const logEl = document.getElementById('chat-log');
			const formEl = document.getElementById('chat-form');
			const nameEl = document.getElementById('chat-name');
			const messageEl = document.getElementById('chat-message');
			const sendButtonEl = document.getElementById('send-button');
			const savedName = window.localStorage.getItem('uce-chat-name');
			if (savedName) nameEl.value = savedName;

			let ws;
			let reconnectDelay = 1000;

			function addLine(kind, title, body, meta = '') {
				const prefix = kind === 'system' ? '[system]' : `[${title}]`;
				const metaText = meta ? ` ${meta}` : '';
				logEl.append(`${prefix} ${body}${metaText}\n`);
				logEl.scrollTop = logEl.scrollHeight;
			}

			function setStatus(text, online) {
				statusEl.textContent = text;
				if (typeof online === 'number') onlineEl.textContent = String(online);
			}

			function sendPayload(payload) {
				if (!ws || ws.readyState !== WebSocket.OPEN) return false;
				payload.name = (nameEl.value || '').trim().slice(0, 32) || 'guest';
				window.localStorage.setItem('uce-chat-name', payload.name);
				ws.send(JSON.stringify(payload));
				return true;
			}

			function connect() {
				ws = new WebSocket(wsUrl);
				setStatus(`Connecting to ${wsUrl}...`);
				sendButtonEl.disabled = true;

				ws.addEventListener('open', () => {
					reconnectDelay = 1000;
					sendButtonEl.disabled = false;
					setStatus('Connected');
					addLine('system', 'system', 'socket connected', new Date().toLocaleTimeString());
					sendPayload({ type: 'join' });
				});

				ws.addEventListener('message', (event) => {
					let payload;
					try {
						payload = JSON.parse(event.data);
					} catch (error) {
						addLine('system', 'decode error', String(error), new Date().toLocaleTimeString());
						return;
					}
					if (typeof payload.online === 'number') onlineEl.textContent = String(payload.online);
					if (payload.type === 'message') {
						addLine('', payload.name || 'guest', payload.body || '', `${payload.at || ''} ${payload.connection_id || ''}`);
					} else {
						addLine('system', payload.type || 'system', payload.body || '', `${payload.at || ''} ${payload.connection_id || ''}`);
					}
				});

				ws.addEventListener('close', () => {
					sendButtonEl.disabled = true;
					setStatus(`Disconnected, retrying in ${reconnectDelay / 1000}s`);
					addLine('system', 'system', 'socket closed', new Date().toLocaleTimeString());
					window.setTimeout(connect, reconnectDelay);
					reconnectDelay = Math.min(reconnectDelay * 2, 10000);
				});

				ws.addEventListener('error', () => {
					setStatus('WebSocket error');
				});
			}

			formEl.addEventListener('submit', (event) => {
				event.preventDefault();
				const body = (messageEl.value || '').trim();
				if (!body) return;
				if (sendPayload({ type: 'message', body })) {
					messageEl.value = '';
					messageEl.focus();
				}
			});

			connect();
		</script>
	</>
}

WS(Request& context)
{
	if(ws_is_binary())
	{
		ws_send_to(
			ws_connection_id(),
			json_encode(chat_event(context, "notice", "Binary messages are not handled by this demo"))
		);
		return;
	}

	DTree payload = json_decode(ws_message());
	String type = clean_chat_field(payload["type"].to_string(), 24);
	String name = clean_chat_field(payload["name"].to_string(), 32);
	String body = clean_chat_field(payload["body"].to_string(), 500);
	u64 message_count = int_val(context.connection["message_count"].to_string());

	if(name == "")
		name = first(context.connection["name"].to_string(), "guest");

	context.connection["name"] = name;

	if(type == "join")
	{
		context.connection["joined_at"] = time_format_utc("%Y-%m-%d %H:%M:%S");
		context.connection["last_type"] = type;
		ws_send(json_encode(chat_event(context, "join", name + " joined the room")));
		return;
	}

	if(type == "message" && body != "")
	{
		context.connection["last_type"] = type;
		context.connection["last_body"] = body;
		context.connection["message_count"] = (f64)(message_count + 1);
		DTree event = chat_event(context, "message", body);
		ws_send(json_encode(event));
		return;
	}

	if(type != "")
	{
		context.connection["last_type"] = type;
		ws_send_to(ws_connection_id(), json_encode(chat_event(context, "notice", "Unknown message type: " + type)));
	}
}