inital

backend/Dockerfile

@@ -0,0 +1,12 @@
+FROM node:20-alpine
+
+WORKDIR /app
+
+COPY package.json .
+RUN npm install --omit=dev
+
+COPY server.js .
+
+EXPOSE 3000
+
+CMD ["node", "server.js"]

backend/package.json

@@ -0,0 +1,12 @@
+{
+  "name": "pulsar-signalling-server",
+  "version": "1.0.0",
+  "description": "WebRTC signalling server for Pulsar remote desktop",
+  "main": "server.js",
+  "scripts": {
+    "start": "node server.js"
+  },
+  "dependencies": {
+    "ws": "^8.16.0"
+  }
+}

backend/server.js

@@ -0,0 +1,104 @@
+const { WebSocketServer } = require("ws");
+
+const PORT = 3000;
+const wss = new WebSocketServer({ port: PORT });
+
+// rooms: { roomId: { host: WebSocket, viewer: WebSocket } }
+const rooms = {};
+
+console.log(`Pulsar signalling server listening on ws://localhost:${PORT}`);
+
+wss.on("connection", (ws) => {
+  ws.roomId = null;
+  ws.role = null; // "host" or "viewer"
+
+  ws.on("message", (raw) => {
+    let msg;
+    try {
+      msg = JSON.parse(raw);
+    } catch {
+      return;
+    }
+
+    const { type, roomId, data } = msg;
+
+    switch (type) {
+      case "create": {
+        if (!roomId) return;
+        if (rooms[roomId]) {
+          ws.send(JSON.stringify({ type: "error", message: "Room already exists" }));
+          return;
+        }
+        rooms[roomId] = { host: ws, viewer: null };
+        ws.roomId = roomId;
+        ws.role = "host";
+        ws.send(JSON.stringify({ type: "created", roomId }));
+        console.log(`Room created: ${roomId}`);
+        break;
+      }
+
+      case "join": {
+        if (!roomId || !rooms[roomId]) {
+          ws.send(JSON.stringify({ type: "error", message: "Room not found" }));
+          return;
+        }
+
+        const room = rooms[roomId];
+
+        if (room.viewer) {
+          ws.send(JSON.stringify({ type: "error", message: "Room full" }));
+          return;
+        }
+
+        room.viewer = ws;
+        ws.roomId = roomId;
+        ws.role = "viewer";
+
+        ws.send(JSON.stringify({ type: "joined", roomId }));
+        room.host.send(JSON.stringify({ type: "peer_joined" }));
+        console.log(`Viewer joined room: ${roomId}`);
+        break;
+      }
+
+      case "signal": {
+        if (!ws.roomId || !rooms[ws.roomId]) return;
+
+        const room = rooms[ws.roomId];
+        const target = ws.role === "host" ? room.viewer : room.host;
+
+        if (target && target.readyState === 1) {
+          target.send(JSON.stringify({ type: "signal", data }));
+        }
+        break;
+      }
+
+      default:
+        break;
+    }
+  });
+
+  ws.on("close", () => {
+    if (!ws.roomId || !rooms[ws.roomId]) return;
+
+    const room = rooms[ws.roomId];
+
+    if (ws.role === "host") {
+      // notify viewer if connected
+      if (room.viewer && room.viewer.readyState === 1) {
+        room.viewer.send(JSON.stringify({ type: "host_disconnected" }));
+      }
+      delete rooms[ws.roomId];
+      console.log(`Room closed: ${ws.roomId}`);
+    } else if (ws.role === "viewer") {
+      room.viewer = null;
+      if (room.host && room.host.readyState === 1) {
+        room.host.send(JSON.stringify({ type: "peer_disconnected" }));
+      }
+      console.log(`Viewer left room: ${ws.roomId}`);
+    }
+  });
+
+  ws.on("error", (err) => {
+    console.error("WebSocket error:", err.message);
+  });
+});