import http from 'k6/http';
import { check, sleep } from 'k6';
import { Rate, Trend, Counter, Gauge } from 'k6/metrics';

// Custom metrics
const errorRate = new Rate('errors');
const requestDuration = new Trend('request_duration');
const requestCount = new Counter('requests');
const activeConnections = new Gauge('active_connections');

// Test configuration
export const options = {
  vus: 10,           // Virtual users
  duration: '5m',    // Test duration
  thresholds: {
    'http_req_duration': ['p(95)<200', 'p(99)<500'],  // p95 <200ms, p99 <500ms
    'http_req_failed': ['rate<0.1'],                   // <0.1% error rate
    'errors': ['rate<0.01'],                           // <1% custom errors
  },
};

// Test target (update with production domain)
const BASE_URL = __ENV.GRAVL_API_URL || 'https://gravl.example.com';

export default function () {
  // Simulate active connection count
  activeConnections.add(1);

  // Test 1: Health check
  {
    let response = http.get(`${BASE_URL}/api/health`);
    check(response, {
      'health check status is 200': (r) => r.status === 200,
      'health check has status field': (r) => r.body.includes('status'),
    });
    errorRate.add(response.status !== 200);
    requestDuration.add(response.timings.duration);
    requestCount.add(1);
  }

  sleep(1);

  // Test 2: List exercises (unauthenticated or with test token)
  {
    let response = http.get(`${BASE_URL}/api/exercises`);
    check(response, {
      'exercises endpoint status is 200': (r) => r.status === 200,
      'exercises returns array': (r) => r.body.includes('['),
    });
    errorRate.add(response.status !== 200);
    requestDuration.add(response.timings.duration);
    requestCount.add(1);
  }

  sleep(1);

  // Test 3: Metrics endpoint (for monitoring)
  {
    let response = http.get(`${BASE_URL}:3001/metrics`);
    check(response, {
      'metrics endpoint status is 200': (r) => r.status === 200 || r.status === 404, // Optional endpoint
    });
    requestDuration.add(response.timings.duration);
    requestCount.add(1);
  }

  sleep(1);

  activeConnections.add(-1);
}

export function teardown(data) {
  console.log(`\n=== Load Test Summary ===`);
  console.log(`Total requests: ${requestCount.value}`);
  console.log(`Error rate: ${(errorRate.value * 100).toFixed(2)}%`);
}