// ============================================================
//  HF-VPS — Node.js Server (optional layer)
//
//  This server is DISABLED BY DEFAULT.
//  To enable: set autostart=true in config/supervisord.conf
//
//  When enabled:
//    - Runs internally on port 3000
//    - Accessible externally at /node/ via Nginx reverse proxy
//    - Nginx strips the /node/ prefix before forwarding to this server
//
//  HOW TO USE:
//    1. Edit this file with your Node.js app logic
//    2. Set autostart=true in config/supervisord.conf
//    3. Rebuild and push to HF
//
//  Environment variables:
//    NODE_PORT — port to listen on (default: 3000, must match supervisord/nginx)
// ============================================================

const http = require("http");

const PORT = process.env.NODE_PORT || 3000;

const server = http.createServer((req, res) => {
  // Health check — used by Nginx and monitoring
  if (req.url === "/health") {
    res.writeHead(200, { "Content-Type": "application/json" });
    res.end(JSON.stringify({
      status: "ok",
      runtime: "node",
      uptime: process.uptime(),
    }));
    return;
  }

  // Default handler — replace with your application logic
  // Examples:
  //   - Express/Fastify app
  //   - WebSocket server
  //   - Puppeteer/Playwright automation
  //   - Serve a Next.js/React build
  res.writeHead(200, { "Content-Type": "application/json" });
  res.end(JSON.stringify({
    message: "Node.js layer is running",
    hint: "Edit app/node/server.js to add your logic. Enable in config/supervisord.conf.",
  }));
});

server.listen(PORT, "0.0.0.0", () => {
  console.log(`[node] server running on port ${PORT}`);
});

// Graceful shutdown — supervisord sends SIGTERM before stopping the process
process.on("SIGTERM", () => {
  server.close(() => {
    console.log("[node] server stopped cleanly");
    process.exit(0);
  });
});