// @ts-nocheck
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: '1m', target: 50 },   // 1分钟内增加到50用户
    { duration: '2m', target: 100 },  // 2分钟内增加到100用户
    { duration: '3m', target: 200 },  // 3分钟内增加到200用户
    { duration: '5m', target: 300 },  // 5分钟内增加到300用户（压力峰值）
    { duration: '2m', target: 100 },  // 2分钟内减少到100用户
    { duration: '1m', target: 0 },    // 1分钟内减少到0
  ],
  thresholds: {
    // 压力测试允许比负载测试更高的延迟；峰值 300 并发下 p95<2s、p99<3s 视为可接受
    http_req_duration: ['p(95)<2000', 'p(99)<3000'],
    http_req_failed: ['rate<0.05'],  // 错误率<5%
    errors: ['rate<0.05'],
  },
};

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

const pages = [
  '/',
  '/about',
  '/services',
  '/products',
  '/news',
  '/contact',
];

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

  // 记录非200响应的详细信息以便诊断混合渲染模式下的异常
  if (res.status !== 200) {
    const bodyLength = res.body ? res.body.length : 0;
    console.warn(`[WARN] ${page} returned status ${res.status} (body length: ${bodyLength})`);
  }

  const success = check(res, {
    'status is 200': (r) => r.status === 200,
    'response time < 2000ms': (r) => r.timings.duration < 2000,
    'body is not empty': (r) => r.body && r.body.length > 0,
  });

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

  sleep(Math.random() * 2 + 0.5);  // 0.5-2.5秒随机等待
}

export function handleSummary(data) {
  const metrics = data.metrics;
  const httpReqs = metrics?.http_reqs?.values || {};
  const httpDuration = metrics?.http_req_duration?.values || {};
  const httpFailed = metrics?.http_req_failed?.values || {};

  // 构建按页面分组的统计（利用 k6 按 name 标签自动聚合的子指标）
  const perPage = {};
  for (const page of pages) {
    const pageDur = metrics?.[`http_req_duration{name:${page}}`]?.values;
    const pageFail = metrics?.[`http_req_failed{name:${page}}`]?.values;
    perPage[page] = {
      avg_response_time: pageDur?.avg ?? null,
      p95_response_time: pageDur?.['p(95)'] ?? null,
      p99_response_time: pageDur?.['p(99)'] ?? null,
      max_response_time: pageDur?.max ?? null,
      error_rate: pageFail?.rate ?? null,
      total_requests: pageFail ? (pageFail.fails + pageFail.passes) : null,
      error_count: pageFail?.fails ?? null,
    };
  }

  const summary = {
    type: 'stress-test',
    stages: [
      { duration: '1m', target: 50, desc: 'Ramp up to 50 users' },
      { duration: '2m', target: 100, desc: 'Ramp up to 100 users' },
      { duration: '3m', target: 200, desc: 'Ramp up to 200 users' },
      { duration: '5m', target: 300, desc: 'Peak load at 300 users' },
      { duration: '2m', target: 100, desc: 'Scale down to 100 users' },
      { duration: '1m', target: 0, desc: 'Scale down to 0' },
    ],
    thresholds: {
      http_req_duration: ['p(95)<2000ms', 'p(99)<3000ms'],
      http_req_failed: ['rate<0.05'],
      errors: ['rate<0.05'],
    },
    results: {
      overall: {
        total_requests: httpReqs.count || 0,
        error_rate: httpFailed.rate || 0,
        avg_response_time: httpDuration.avg || 0,
        p95_response_time: httpDuration['p(95)'] || 0,
        p99_response_time: httpDuration['p(99)'] || 0,
        max_response_time: httpDuration.max || 0,
      },
      per_page: perPage,
      pages_tested: pages,
    },
    checks_passed: data.root_group?.checks?.map((c) => ({
      name: c.name,
      passes: c.passes,
      fails: c.fails,
    })),
  };

  return {
    'performance/stress-test-summary.json': JSON.stringify(summary, null, 2),
  };
}