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

const router = express.Router();

// Basic health check
router.get('/', (req, res) => {
  res.json({
    status: 'healthy',
    timestamp: new Date().toISOString(),
    uptime: process.uptime(),
    service: 'harbor-ci-cd-demo'
  });
});

// Detailed health check
router.get('/detailed', (req, res) => {
  const memoryUsage = process.memoryUsage();
  const totalMem = os.totalmem();
  const freeMem = os.freemem();
  
  // Check memory usage (warn if over 80%)
  const memoryPercentage = ((totalMem - freeMem) / totalMem) * 100;
  const memoryStatus = memoryPercentage > 80 ? 'warning' : 'healthy';
  
  // Check process memory (warn if heap over 100MB)
  const heapUsedMB = memoryUsage.heapUsed / 1024 / 1024;
  const processMemoryStatus = heapUsedMB > 100 ? 'warning' : 'healthy';
  
  // Overall status
  const overallStatus = (memoryStatus === 'warning' || processMemoryStatus === 'warning') 
    ? 'warning' 
    : 'healthy';

  res.json({
    status: overallStatus,
    timestamp: new Date().toISOString(),
    service: 'harbor-ci-cd-demo',
    version: process.env.npm_package_version || '1.0.0',
    uptime: {
      process: Math.round(process.uptime()),
      system: Math.round(os.uptime())
    },
    memory: {
      status: memoryStatus,
      system: {
        total: Math.round(totalMem / 1024 / 1024 / 1024 * 100) / 100,
        used: Math.round((totalMem - freeMem) / 1024 / 1024 / 1024 * 100) / 100,
        percentage: Math.round(memoryPercentage)
      },
      process: {
        status: processMemoryStatus,
        heapUsed: Math.round(heapUsedMB),
        heapTotal: Math.round(memoryUsage.heapTotal / 1024 / 1024),
        rss: Math.round(memoryUsage.rss / 1024 / 1024)
      }
    },
    loadAverage: os.loadavg().map(load => Math.round(load * 100) / 100),
    environment: process.env.NODE_ENV || 'development'
  });
});

// Readiness probe (for Kubernetes-style deployments)
router.get('/ready', (req, res) => {
  // Check if the application is ready to serve traffic
  // In a real app, you might check database connections, external services, etc.
  
  const isReady = true; // Simplified check
  
  if (isReady) {
    res.json({
      status: 'ready',
      timestamp: new Date().toISOString()
    });
  } else {
    res.status(503).json({
      status: 'not ready',
      timestamp: new Date().toISOString()
    });
  }
});

// Liveness probe (for Kubernetes-style deployments)
router.get('/live', (req, res) => {
  // Check if the application is alive and should not be restarted
  res.json({
    status: 'alive',
    timestamp: new Date().toISOString(),
    uptime: process.uptime()
  });
});

module.exports = router;