/**
 * Load test: GET playlists, GET playlists/:id, POST playlists, search
 * Usage: k6 run loadtests/backend/playlists.js
 * Requires: setup creates auth users
 */
import http from 'k6/http';
import { check, sleep } from 'k6';
import { Rate } from 'k6/metrics';
import { randomString } from 'https://jslib.k6.io/k6-utils/1.2.0/index.js';

const errorRate = new Rate('errors');
const API_ORIGIN = __ENV.API_ORIGIN || __ENV.BASE_URL || 'http://localhost:8080';
const TEST_EMAIL_PREFIX = __ENV.TEST_EMAIL_PREFIX || 'user+playlist';
const TEST_EMAIL_DOMAIN = __ENV.TEST_EMAIL_DOMAIN || 'example.com';
const TEST_PASSWORD_PREFIX = __ENV.TEST_PASSWORD_PREFIX || 'V3za!playlist-';

function generateTestUser() {
  const rand = randomString(8);
  const pwd = `${TEST_PASSWORD_PREFIX}${rand}`;
  return {
    email: `${TEST_EMAIL_PREFIX}${rand}@${TEST_EMAIL_DOMAIN}`,
    password: pwd,
    password_confirmation: pwd,
    username: `pl${rand}`,
  };
}

export const options = {
  scenarios: {
    playlists: {
      executor: 'ramping-vus',
      stages: [
        { duration: '30s', target: 5 },
        { duration: '1m', target: 5 },
        { duration: '30s', target: 0 },
      ],
    },
  },
  thresholds: {
    http_req_duration: ['p(95)<500', 'p(99)<1000'],
    errors: ['rate<0.1'],
  },
};

export function setup() {
  const users = [];
  const baseURL = `${API_ORIGIN}/api/v1/auth`;
  for (let i = 0; i < 15; i++) {
    const user = generateTestUser();
    const registerRes = http.post(`${baseURL}/register`, JSON.stringify(user), {
      headers: { 'Content-Type': 'application/json' },
    });
    if (registerRes.status === 201) {
      const loginRes = http.post(`${baseURL}/login`, JSON.stringify({ email: user.email, password: user.password }), {
        headers: { 'Content-Type': 'application/json' },
      });
      if (loginRes.status === 200) {
        try {
          const body = JSON.parse(loginRes.body);
          const token = body.data?.token?.access_token;
          if (token) users.push({ ...user, token });
        } catch (e) {}
      }
    }
  }
  return { users };
}

export default function (data) {
  const { users } = data;
  if (users.length === 0) return;
  const user = users[Math.floor(Math.random() * users.length)];
  const headers = { Authorization: `Bearer ${user.token}` };

  const listRes = http.get(`${API_ORIGIN}/api/v1/playlists`, { headers });
  const listOk = check(listRes, {
    'playlists list returns 200': (r) => r.status === 200,
  });
  errorRate.add(!listOk);
  sleep(0.5);

  if (listRes.status === 200) {
    try {
      const body = JSON.parse(listRes.body);
      const playlists = body.data?.playlists || body.data || body.playlists || [];
      if (Array.isArray(playlists) && playlists.length > 0) {
        const pl = playlists[0];
        const plId = pl.id || pl.ID;
        if (plId) {
          const detailRes = http.get(`${API_ORIGIN}/api/v1/playlists/${plId}`, { headers });
          check(detailRes, { 'playlist detail returns 200': (r) => r.status === 200 });
        }
      }
    } catch (e) {}
  }

  if (Math.random() < 0.3) {
    const createRes = http.post(
      `${API_ORIGIN}/api/v1/playlists`,
      JSON.stringify({ name: `LoadTest ${Date.now()}`, description: 'k6 load test' }),
      { headers: { ...headers, 'Content-Type': 'application/json' } }
    );
    check(createRes, { 'create playlist returns 201 or 200': (r) => r.status === 201 || r.status === 200 });
  }

  const searchRes = http.get(`${API_ORIGIN}/api/v1/playlists/search?q=test`, { headers });
  check(searchRes, { 'playlists search returns 200': (r) => r.status === 200 });
  sleep(1);
}