server.js

'use strict';

const express = require('express');
const app = express();


const PORT = process.env.PORT || 3000;
const HOST = process.env.HOST || '0.0.0.0';

app.use(express.json());

// Health endpoint
app.get('/health', (req, res) => {
  res.status(200).json({
    status: 'ok',
    message: 'Service is healthy',
    uptime: process.uptime(),
    timestamp: new Date().toISOString(),
    version: process.env.npm_package_version || '1.0.0',
  });
});

// 404 handler
app.use((req, res) => {
  res.status(404).json({ error: 'Not Found', path: req.path });
});

// 500 error handler
app.use((err, req, res, next) => {
  console.error(err.stack);
  res.status(500).json({ error: 'Internal Server Error' });
});

// Start server only if run directly
if (require.main === module) {
  app.listen(PORT, HOST, () => {
    console.log(`Server running at http://${HOST}:${PORT}`);
    console.log(`Health endpoint: http://${HOST}:${PORT}/health`);
  });
}

module.exports = app;