/**
 * Health check HTTP server
 *
 * Provides a simple /health endpoint for Docker healthcheck
 * and monitoring. Returns domain list and feature flags.
 */

import { createServer, type Server } from 'node:http';
import { log } from './logger.js';

export function startHealthServer(
  port: number,
  domains: string[],
  getStats?: () => any,
): Server {
  const server = createServer((_req, res) => {
    const stats = getStats?.() ?? {};

    const payload = {
      status: 'healthy',
      worker: 'unified-email-worker-ts',
      version: '2.0.0',
      domains,
      domainCount: domains.length,
      features: {
        bounce_handling: true,
        ooo_replies: true,
        forwarding: true,
        blocklist: true,
        prometheus_metrics: true,
        lmtp: false,
        legacy_smtp_forward: false,
      },
      stats,
      uptime: process.uptime(),
      timestamp: new Date().toISOString(),
    };

    res.writeHead(200, { 'Content-Type': 'application/json' });
    res.end(JSON.stringify(payload, null, 2));
  });

  server.listen(port, () => {
    log(`Health check on port ${port}`);
  });

  return server;
}