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(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"] = gmdate("%H:%M:%S");
	return(event);
}

RENDER()
{
	String ws_url = context->params["DOCUMENT_URI"];
	u64 online = ws_connection_count();
	<>
		<link rel="stylesheet" href='style.css?v=<?= time() ?>'></link>
		<style>
			.chat-shell { max-width: 960px; margin: 1.5rem auto; display: grid; gap: 1rem; }
			.chat-meta { display: flex; gap: 1rem; flex-wrap: wrap; color: #445; }
			.chat-panel { background: #fff; border: 1px solid #d7dde7; border-radius: 14px; padding: 1rem; box-shadow: 0 10px 30px rgba(38,55,77,0.08); }
			.chat-log { min-height: 24rem; max-height: 55vh; overflow: auto; display: grid; gap: 0.75rem; }
			.chat-line { border-left: 4px solid #2f7ad8; padding-left: 0.75rem; }
			.chat-line.system { border-left-color: #8794a7; color: #556; }
			.chat-line .meta { font-size: 0.8rem; color: #667; margin-bottom: 0.2rem; }
			.chat-composer { display: grid; gap: 0.75rem; }
			.chat-row { display: grid; gap: 0.5rem; }
			.chat-row.dual { grid-template-columns: minmax(0, 220px) minmax(0, 1fr); }
			input, textarea, button { font: inherit; border-radius: 10px; border: 1px solid #c5cedb; padding: 0.8rem 0.9rem; }
			textarea { min-height: 6rem; resize: vertical; }
			button { background: #1b5fc9; border-color: #1b5fc9; color: #fff; cursor: pointer; font-weight: 600; }
			button:disabled { opacity: 0.55; cursor: wait; }
			.status { font-weight: 600; }
		</style>
		<div class="chat-shell">
			<h1>
				<a href="index.uce">UCE Test</a>:
				WebSocket Chat
			</h1>
			<div class="chat-meta">
				<div>Page scope: <code><?= ws_url ?></code></div>
				<div>Connected right now: <strong id="online-count"><?= online ?></strong></div>
				<div class="status" id="status">Connecting...</div>
			</div>
			<div class="chat-panel">
				<div class="chat-log" id="chat-log"></div>
			</div>
			<form class="chat-panel chat-composer" id="chat-form">
				<div class="chat-row dual">
					<input id="chat-name" maxlength="32" placeholder="Display name" value="guest-<?= draw_int(1000, 9999) ?>"/>
					<button id="send-button" type="submit">Send Message</button>
				</div>
				<div class="chat-row">
					<textarea id="chat-message" maxlength="500" placeholder="Say something to everyone connected to this same .ws.uce page"></textarea>
				</div>
			</form>
		</div>
		<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 wrapper = document.createElement('div');
				wrapper.className = `chat-line ${kind}`;
				const metaEl = document.createElement('div');
				metaEl.className = 'meta';
				metaEl.textContent = meta;
				const bodyEl = document.createElement('div');
				const titleEl = document.createElement('strong');
				titleEl.textContent = title;
				bodyEl.append(titleEl, document.createTextNode(` ${body}`));
				wrapper.append(metaEl, bodyEl);
				logEl.append(wrapper);
				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()
{
	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);

	if(name == "")
		name = "guest";

	if(type == "join")
	{
		ws_send(json_encode(chat_event("join", name + " joined the room")));
		return;
	}

	if(type == "message" && body != "")
	{
		DTree event = chat_event("message", body);
		event["name"] = name;
		ws_send(json_encode(event));
		return;
	}

	if(type != "")
	{
		ws_send_to(ws_connection_id(), json_encode(chat_event("notice", "Unknown message type: " + type)));
	}
}