feat(ddma-eligibility) - v1

apps/Backend/src/socket.ts

@@ -0,0 +1,53 @@
+import { Server as HttpServer } from "http";
+import { Server, Socket } from "socket.io";
+
+let io: Server | null = null;
+
+export function initSocket(server: HttpServer) {
+  const NODE_ENV = (
+    process.env.NODE_ENV ||
+    process.env.ENV ||
+    "development"
+  ).toLowerCase();
+
+  const rawFrontendUrls =
+    process.env.FRONTEND_URLS || process.env.FRONTEND_URL || "";
+  const FRONTEND_URLS = rawFrontendUrls
+    .split(",")
+    .map((s) => s.trim())
+    .filter(Boolean);
+
+  // In dev: allow all origins
+  // In prod: restrict to FRONTEND_URLS if provided
+  const corsOrigin =
+    NODE_ENV !== "production"
+      ? true
+      : FRONTEND_URLS.length > 0
+      ? FRONTEND_URLS
+      : false; // no origins allowed if none configured in prod
+
+  io = new Server(server, {
+    cors: {
+      origin: corsOrigin,
+      methods: ["GET", "POST"],
+      credentials: true,
+    },
+  });
+
+  io.on("connection", (socket: Socket) => {
+    console.log("🔌 Socket connected:", socket.id);
+
+    socket.on("disconnect", () => {
+      console.log("🔌 Socket disconnected:", socket.id);
+    });
+  });
+
+  // Optional: log low-level engine errors for debugging
+  io.engine.on("connection_error", (err) => {
+    console.error("Socket engine connection_error:", err);
+  });
+
+  return io;
+}
+
+export { io };