/**
 * Monitoring & Health Check — aggregates health from all services.
 *
 * Standalone script that polls each service's /health endpoint and
 * reports combined status. Can be run as a cron job, GitHub Action,
 * or standalone HTTP endpoint.
 *
 * Usage:
 *   npx tsx services/monitoring/health-check.ts          # one-shot check
 *   npx tsx services/monitoring/health-check.ts --serve   # HTTP server on :4004
 *
 * Environment:
 *   BACKEND_URL          (default: http://localhost:8000)
 *   PLATFORM_SERVICE_URL (default: http://localhost:4003)
 *   ADMIN_DASHBOARD_URL  (default: http://localhost:3001)
 *   USER_DASHBOARD_URL   (default: http://localhost:3002)
 */

import { DEFAULT_SERVICES, generateHealthReport } from '@bytelyst/monitoring';

// ── CLI / HTTP server mode ──

const args = process.argv.slice(2);

if (args.includes('--serve')) {
  // Run as HTTP server for continuous monitoring
  const { createServer } = await import('http');
  const PORT = Number(process.env.MONITOR_PORT || 4004);

  const server = createServer(async (_req, res) => {
    const report = await generateHealthReport(DEFAULT_SERVICES);
    res.writeHead(report.overall === 'healthy' ? 200 : 503, { 'Content-Type': 'application/json' });
    res.end(JSON.stringify(report, null, 2));
  });

  server.listen(PORT, () => {
    console.log(`🩺 Monitoring dashboard running on http://localhost:${PORT}`);
    console.log(`   Checking ${DEFAULT_SERVICES.length} services every request`);
  });
} else {
  // One-shot check
  const report = await generateHealthReport(DEFAULT_SERVICES);
  const icon = { healthy: '✅', degraded: '⚠️', down: '❌' };
  console.log(`\n${icon[report.overall]} Overall: ${report.overall.toUpperCase()}\n`);

  for (const svc of report.services) {
    const sIcon = { healthy: '✅', unhealthy: '⚠️', unreachable: '❌' };
    console.log(
      `  ${sIcon[svc.status]} ${svc.name.padEnd(20)} ${svc.responseTimeMs}ms${svc.error ? ` — ${svc.error}` : ''}`
    );
  }

  console.log(`\nHealthy: ${report.summary.healthy}/${report.summary.total}`);
  process.exit(report.overall === 'healthy' ? 0 : 1);
}