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

const errorRate = new Rate('errors');
const responseTime = new Trend('response_time');

export const options = {
  stages: [
    { duration: '2m', target: 100 },  // 2分钟内逐步增加到100用户
    { duration: '5m', target: 100 },  // 保持100用户5分钟
    { duration: '2m', target: 200 },  // 2分钟内增加到200用户
    { duration: '5m', target: 200 },  // 保持200用户5分钟
    { duration: '2m', target: 0 },    // 2分钟内减少到0
  ],
  thresholds: {
    http_req_duration: ['p(95)<500', 'p(99)<1000'],  // 95%请求<500ms, 99%请求<1s
    http_req_failed: ['rate<0.01'],  // 错误率<1%
    errors: ['rate<0.01'],
  },
};

const BASE_URL = __ENV.BASE_URL || 'http://localhost:3000';

export default function () {
  const pages = [
    '/',
    '/about',
    '/services',
    '/products',
    '/news',
    '/contact',
  ];

  const page = pages[Math.floor(Math.random() * pages.length)];
  const res = http.get(`${BASE_URL}${page}`, {
    tags: { name: page },
  });

  const success = check(res, {
    'status is 200': (r) => r.status === 200,
    'response time < 500ms': (r) => r.timings.duration < 500,
  });

  errorRate.add(!success);
  responseTime.add(res.timings.duration);

  sleep(Math.random() * 3 + 1);  // 1-4秒随机等待
}

export function handleSummary(data) {
  return {
    'performance/load-test-summary.json': JSON.stringify(data, null, 2),
  };
}