1 files changed, 131 insertions, 0 deletions
diff --git a/scripts/demo-websocket-server.mjs b/scripts/demo-websocket-server.mjs
new file mode 100644
index 0000000..1bee865
--- /dev/null
+++ b/scripts/demo-websocket-server.mjs
@@ -0,0 +1,131 @@
+import { WebSocketServer } from 'ws';
+
+const port = Number(process.env.PORT || 8080);
+const profile = process.env.TIMEPLOT_PROFILE || 'telemetry';
+const sendIntervalMs = Number(process.env.TIMEPLOT_INTERVAL_MS || 100);
+const logEvery = Number(process.env.TIMEPLOT_LOG_EVERY || 10);
+
+const wss = new WebSocketServer({ port });
+const startedAt = Date.now();
+let sampleIndex = 0;
+let activeClientCount = 0;
+
+function log(message, details = '') {
+    const timestamp = new Date().toISOString();
+    if (details) {
+        console.log(`[timeplot-ws ${timestamp}] ${message} ${details}`);
+        return;
+    }
+
+    console.log(`[timeplot-ws ${timestamp}] ${message}`);
+}
+
+function sampleTelemetry(seconds) {
+    return Math.sin(seconds * 2.2) + 0.35 * Math.cos(seconds * 6.4 + Math.sin(seconds * 0.8)) + 0.15 * Math.sin(seconds * 0.33);
+}
+
+function sampleChirp(seconds) {
+    return 0.7 * Math.sin(seconds * seconds * 1.4) + 0.3 * Math.sin(seconds * 7.5);
+}
+
+function sampleSteps(seconds) {
+    const phase = Math.floor((seconds % 8) / 1.0);
+    return [0, 0.4, 0.9, 1.2, 0.2, -0.6, -1.0, 0.3][phase] ?? 0;
+}
+
+function sampleBurst(seconds) {
+    const burstPhase = (seconds % 6) - 1.5;
+    const burst = Math.sin(seconds * 9.5) * Math.exp(-(burstPhase ** 2) * 0.8);
+    return 0.45 * Math.sin(seconds * 2.1) + burst;
+}
+
+function sampleValue(seconds) {
+    switch (profile) {
+        case 'chirp':
+            return sampleChirp(seconds);
+        case 'steps':
+            return sampleSteps(seconds);
+        case 'burst':
+            return sampleBurst(seconds);
+        case 'telemetry':
+        default:
+            return sampleTelemetry(seconds);
+    }
+}
+
+function buildMessage() {
+    const timestampMs = Date.now() - startedAt;
+    const seconds = timestampMs / 1000;
+    sampleIndex += 1;
+
+    return {
+        timestampMs,
+        value: Number(sampleValue(seconds).toFixed(6)),
+        sequence: sampleIndex,
+        profile,
+    };
+}
+
+const interval = setInterval(() => {
+    const message = buildMessage();
+    const payload = JSON.stringify(message);
+    let sentCount = 0;
+
+    for (const client of wss.clients) {
+        if (client.readyState === client.OPEN) {
+            client.send(payload);
+            sentCount += 1;
+        }
+    }
+
+    if (message.sequence === 1 || (logEvery > 0 && message.sequence % logEvery === 0)) {
+        log(
+            'broadcast',
+            `seq=${message.sequence} clients=${sentCount} timestampMs=${message.timestampMs} value=${message.value}`,
+        );
+    }
+}, sendIntervalMs);
+
+wss.on('connection', (socket, request) => {
+    const clientAddress = request.socket.remoteAddress || 'unknown';
+    activeClientCount += 1;
+    log('client connected', `from=${clientAddress} activeClients=${activeClientCount}`);
+
+    socket.send(JSON.stringify({
+        timestampMs: 0,
+        value: 0,
+        sequence: 0,
+        profile,
+        message: 'connected',
+    }));
+
+    socket.on('error', (error) => {
+        log('client error', `from=${clientAddress} error=${error.message}`);
+    });
+
+    socket.on('close', () => {
+        activeClientCount = Math.max(0, activeClientCount - 1);
+        log('client disconnected', `from=${clientAddress} activeClients=${activeClientCount}`);
+    });
+});
+
+wss.on('error', (error) => {
+    log('server error', error.message);
+});
+
+wss.on('listening', () => {
+    log('listening', `url=ws://localhost:${port}`);
+    log('config', `profile=${profile} intervalMs=${sendIntervalMs} logEvery=${logEvery}`);
+});
+
+function shutdown() {
+    log('shutdown requested', `activeClients=${activeClientCount}`);
+    clearInterval(interval);
+    wss.close(() => {
+        log('server stopped');
+        process.exit(0);
+    });
+}
+
+process.on('SIGINT', shutdown);
+process.on('SIGTERM', shutdown);