import { NextRequest, NextResponse } from 'next/server';

/**
 * Health check endpoint for network status detection and monitoring
 * Returns 200 OK when the app is healthy
 * Supports detailed health checks with ?detailed=true
 */
export async function GET(request: NextRequest) {
  const startTime = Date.now();

  // Basic health check response
  const basicHealth = {
    status: 'healthy',
    timestamp: new Date().toISOString(),
    version: process.env.APP_VERSION || process.env.NEXT_PUBLIC_APP_VERSION || 'unknown',
    environment: process.env.NODE_ENV || 'unknown',
  };

  // Check for detailed health check
  const isDetailed = request.nextUrl.searchParams.get('detailed') === 'true';

  if (!isDetailed) {
    return NextResponse.json(basicHealth, { status: 200 });
  }

  // Detailed health check
  const checks: Record<string, any> = {};

  // Check memory usage
  const memUsage = process.memoryUsage();
  const memoryHealthy = memUsage.heapUsed < 150 * 1024 * 1024; // 150MB threshold
  checks.memory = {
    status: memoryHealthy ? 'healthy' : 'warning',
    heapUsed: Math.round(memUsage.heapUsed / 1024 / 1024) + 'MB',
    heapTotal: Math.round(memUsage.heapTotal / 1024 / 1024) + 'MB',
    rss: Math.round(memUsage.rss / 1024 / 1024) + 'MB',
  };

  // Check API connectivity
  try {
    const apiUrl = process.env.NEXT_PUBLIC_API_URL || 'https://api.parentflowapp.com';
    const controller = new AbortController();
    const timeoutId = setTimeout(() => controller.abort(), 5000);

    const apiStart = Date.now();
    const apiResponse = await fetch(`${apiUrl}/health`, {
      signal: controller.signal,
      cache: 'no-cache',
    });

    clearTimeout(timeoutId);

    checks.api = {
      status: apiResponse.ok ? 'healthy' : 'unhealthy',
      statusCode: apiResponse.status,
      responseTime: `${Date.now() - apiStart}ms`,
      url: apiUrl,
    };
  } catch (error) {
    checks.api = {
      status: 'unhealthy',
      error: error instanceof Error ? error.message : 'Unknown error',
    };
  }

  // Check build info
  checks.build = {
    version: process.env.APP_VERSION || process.env.NEXT_PUBLIC_APP_VERSION || 'unknown',
    nodeVersion: process.version,
    uptime: Math.round(process.uptime()) + 's',
  };

  // Overall health status
  const overallHealthy = memoryHealthy && checks.api?.status === 'healthy';

  return NextResponse.json(
    {
      ...basicHealth,
      status: overallHealthy ? 'healthy' : 'degraded',
      checks,
      responseTime: `${Date.now() - startTime}ms`,
    },
    { status: overallHealthy ? 200 : 503 }
  );
}

// Kubernetes liveness probe
export async function HEAD() {
  return new NextResponse(null, { status: 200 });
}