Feat: flesh out

web/server.js

@@ -0,0 +1,168 @@
+import { createServer } from "node:http";
+import { readFileSync } from "node:fs";
+import { Socket } from "node:net";
+import { encode, decode } from "@msgpack/msgpack";
+import CRC32 from "crc-32";
+import { WebSocketServer } from "ws";
+
+const SOVA_HOST = process.env.SOVA_HOST || "localhost";
+const SOVA_PORT = parseInt(process.env.SOVA_PORT || "8080");
+const SOVA_PASSWORD = process.env.SOVA_PASSWORD || null;
+const WEB_PORT = parseInt(process.env.WEB_PORT || "3000");
+const PROTOCOL_VERSION = 0x02;
+
+const indexHtml = readFileSync(new URL("./index.html", import.meta.url));
+
+let state = {
+  peers: [],
+  tempo: 120,
+  isPlaying: false,
+  connected: false,
+};
+
+// --- Wire protocol ---
+
+function buildFrame(msg) {
+  const payload = encode(msg);
+  const crc = CRC32.buf(payload) >>> 0;
+  const len = payload.length;
+  const frame = Buffer.alloc(8 + len);
+  frame[0] = PROTOCOL_VERSION;
+  frame[1] = (len >> 16) & 0xff;
+  frame[2] = (len >> 8) & 0xff;
+  frame[3] = len & 0xff;
+  frame.writeUInt32BE(crc, 4);
+  Buffer.from(payload).copy(frame, 8);
+  return frame;
+}
+
+function parseFrames(buffer) {
+  const messages = [];
+  let offset = 0;
+  while (offset + 8 <= buffer.length) {
+    if (buffer[offset] !== PROTOCOL_VERSION) {
+      offset++;
+      continue;
+    }
+    const len = (buffer[offset + 1] << 16) | (buffer[offset + 2] << 8) | buffer[offset + 3];
+    if (len > 10 * 1024 * 1024) {
+      offset++;
+      continue;
+    }
+    if (offset + 8 + len > buffer.length) break;
+    const payload = buffer.subarray(offset + 8, offset + 8 + len);
+    const expectedCrc = buffer.readUInt32BE(offset + 4);
+    const actualCrc = CRC32.buf(payload) >>> 0;
+    if (expectedCrc !== actualCrc) {
+      offset++;
+      continue;
+    }
+    try {
+      messages.push(decode(payload));
+    } catch {
+      // skip malformed msgpack
+    }
+    offset += 8 + len;
+  }
+  return { messages, remaining: buffer.subarray(offset) };
+}
+
+// --- TCP client to sova-server ---
+
+let tcp = null;
+let reconnectTimer = null;
+
+function connectToSova() {
+  if (tcp) return;
+  console.log(`Connecting to sova-server at ${SOVA_HOST}:${SOVA_PORT}`);
+  const sock = new Socket();
+  let recvBuf = Buffer.alloc(0);
+
+  sock.connect(SOVA_PORT, SOVA_HOST, () => {
+    console.log("Connected to sova-server");
+    const handshake = { SetName: { name: "Web Monitor", password: SOVA_PASSWORD } };
+    sock.write(buildFrame(handshake));
+  });
+
+  sock.on("data", (chunk) => {
+    recvBuf = Buffer.concat([recvBuf, chunk]);
+    const { messages, remaining } = parseFrames(recvBuf);
+    recvBuf = remaining;
+    for (const msg of messages) handleMessage(msg);
+  });
+
+  sock.on("close", () => {
+    console.log("Disconnected from sova-server");
+    tcp = null;
+    state.connected = false;
+    broadcast();
+    scheduleReconnect();
+  });
+
+  sock.on("error", (err) => {
+    console.error("TCP error:", err.message);
+    sock.destroy();
+  });
+
+  tcp = sock;
+}
+
+function scheduleReconnect() {
+  if (reconnectTimer) return;
+  reconnectTimer = setTimeout(() => {
+    reconnectTimer = null;
+    connectToSova();
+  }, 3000);
+}
+
+function handleMessage(msg) {
+  if (msg.Hello) {
+    state.connected = true;
+    state.peers = msg.Hello.peers || [];
+    state.isPlaying = msg.Hello.is_playing || false;
+    if (msg.Hello.link_state) state.tempo = msg.Hello.link_state[0];
+    broadcast();
+  } else if (msg.PeersUpdated) {
+    state.peers = msg.PeersUpdated;
+    broadcast();
+  } else if (msg.PlaybackStateChanged != null) {
+    state.isPlaying = !!msg.PlaybackStateChanged;
+    broadcast();
+  } else if (msg.ClockState) {
+    state.tempo = msg.ClockState[0];
+    broadcast();
+  } else if (msg.ConnectionRefused) {
+    console.error("Connection refused:", msg.ConnectionRefused);
+  }
+}
+
+// --- HTTP + WebSocket ---
+
+const server = createServer((req, res) => {
+  if (req.url === "/" || req.url === "/index.html") {
+    res.writeHead(200, { "Content-Type": "text/html" });
+    res.end(indexHtml);
+  } else {
+    res.writeHead(404);
+    res.end();
+  }
+});
+
+const wss = new WebSocketServer({ server });
+const clients = new Set();
+
+wss.on("connection", (ws) => {
+  clients.add(ws);
+  ws.send(JSON.stringify(state));
+  ws.on("close", () => clients.delete(ws));
+});
+
+function broadcast() {
+  const data = JSON.stringify(state);
+  for (const ws of clients) ws.send(data);
+}
+
+server.listen(WEB_PORT, () => {
+  console.log(`Web server listening on port ${WEB_PORT}`);
+  connectToSova();
+});