const main = async () => {
  // Import core modules
  const express = require("express");
  const cors = require("cors");
  const bodyParser = require("body-parser");
  const path = require("path");
  const compression = require("compression");
  const cookieParser = require("cookie-parser");
  const http = require("http");
  const { Server } = require("socket.io");
  const { createClient } = require("redis");
  const { createAdapter } = require("@socket.io/redis-adapter");

  // Load environment variables
  require("dotenv").config({
    path: path.resolve(process.cwd(), `.env.${process.env.NODE_ENV || "development"}`)
  });

  // Import custom utilities and handlers
  const logger = require("./server/utils/logger");

  // Express app and server setup
  const app = express();
  const port = process.env.PORT || 5000;
  const server = http.createServer(app);

  // Redis client setup for Pub/Sub and Key-Value Store
  const pubClient = createClient({ url: process.env.REDIS_URL || "redis://localhost:6379" });
  const subClient = pubClient.duplicate();

  // Clean up on exit
  process.on("SIGINT", async () => {
    await Promise.all([pubClient.disconnect(), subClient.disconnect()]);
    process.exit(0);
  });

  // Connect Redis clients
  await Promise.all([pubClient.connect(), subClient.connect()]);

  // Redis Pub/Sub adapter for Socket.IO
  const io = new Server(server, {
    path: "/ws",
    adapter: createAdapter(pubClient, subClient),
    cors: {
      origin: [
        "https://test.imex.online",
        "https://www.test.imex.online",
        "http://localhost"
        // Other allowed origins
      ],
      methods: ["GET", "POST"],
      credentials: true,
      exposedHeaders: ["set-cookie"]
    }
  });

  // Export io and Redis client for external use
  exports.io = io;
  exports.redisClient = pubClient;

  require("./server/web-sockets/web-socket");

  // Middleware
  app.use(compression());
  app.use(cookieParser());
  app.use(bodyParser.json({ limit: "50mb" }));
  app.use(bodyParser.urlencoded({ limit: "50mb", extended: true }));
  app.use(cors({ credentials: true, exposedHeaders: ["set-cookie"] }));

  // Helper middleware
  app.use((req, res, next) => {
    req.logger = logger;
    next();
  });

  // Route groupings
  app.use("/", require("./server/routes/miscellaneousRoutes"));
  // Other routes...

  // Default route for forbidden access
  app.get("/", (req, res) => {
    res.status(200).send("Access Forbidden.");
  });

  try {
    await server.listen(port);
    logger.log(`[${process.env.NODE_ENV || "DEVELOPMENT"}] Server started on port ${port}`, "INFO", "api");
  } catch (error) {
    logger.log(
      `[${process.env.NODE_ENV || "DEVELOPMENT"}] Server failed to start on port ${port}`,
      "ERROR",
      "api",
      error
    );
  }
};

// Start server
main();