/**
 * Load test: HLS streaming - master playlist and segments
 * Usage: k6 run loadtests/stream/hls.js
 * Requires: Stream server running, AUTH_TOKEN (JWT), TRACK_ID (UUID of track with HLS)
 *
 * Env: STREAM_ORIGIN, AUTH_TOKEN, TRACK_ID
 * Example: AUTH_TOKEN=xxx TRACK_ID=550e8400-e29b-41d4-a716-446655440000 k6 run loadtests/stream/hls.js
 */
import http from 'k6/http';
import { check, sleep } from 'k6';
import { Rate, Trend } from 'k6/metrics';

const errorRate = new Rate('hls_errors');
const manifestDuration = new Trend('hls_manifest_duration');
const segmentDuration = new Trend('hls_segment_duration');

const STREAM_ORIGIN = __ENV.STREAM_ORIGIN || 'http://localhost:8082';
const AUTH_TOKEN = __ENV.AUTH_TOKEN || '';
const TRACK_ID = __ENV.TRACK_ID || '';

export const options = {
  scenarios: {
    hls_streaming: {
      executor: 'constant-arrival-rate',
      rate: 5,
      timeUnit: '1s',
      duration: '2m',
      preAllocatedVUs: 10,
      maxVUs: 50,
    },
  },
  thresholds: {
    http_req_duration: ['p(95)<2000', 'p(99)<5000'],
    hls_errors: ['rate<0.01'],
    hls_manifest_duration: ['p(95)<500', 'p(99)<1000'],
    hls_segment_duration: ['p(95)<2000', 'p(99)<5000'],
  },
};

function getHeaders() {
  const h = { Accept: 'application/vnd.apple.mpegurl,*/*' };
  if (AUTH_TOKEN) {
    h['Authorization'] = `Bearer ${AUTH_TOKEN}`;
  }
  return h;
}

export function setup() {
  if (!TRACK_ID) {
    console.warn('TRACK_ID not set - HLS tests will 404. Set TRACK_ID and AUTH_TOKEN for real streaming load.');
  }
  if (!AUTH_TOKEN) {
    console.warn('AUTH_TOKEN not set - HLS routes require JWT. Requests may return 401.');
  }
  return { trackId: TRACK_ID || '00000000-0000-0000-0000-000000000000' };
}

export default function (data) {
  const { trackId } = data;
  if (!trackId || trackId === '00000000-0000-0000-0000-000000000000') {
    // Still hit the endpoint to exercise the auth path
    const url = `${STREAM_ORIGIN}/hls/${trackId}/master.m3u8`;
    const res = http.get(url, { headers: getHeaders() });
    errorRate.add(res.status !== 200 && res.status !== 404);
    sleep(1);
    return;
  }

  // 1. Fetch master playlist
  const manifestUrl = `${STREAM_ORIGIN}/hls/${trackId}/master.m3u8`;
  const manifestStart = Date.now();
  const manifestRes = http.get(manifestUrl, { headers: getHeaders() });
  manifestDuration.add(Date.now() - manifestStart);

  const manifestOk = check(manifestRes, {
    'master.m3u8 returns 200': (r) => r.status === 200,
  });
  errorRate.add(!manifestOk);
  if (!manifestOk) {
    sleep(1);
    return;
  }

  // 2. Parse playlist for segment URLs (simplified: extract quality playlists or segments)
  const body = manifestRes.body;
  const qualityMatch = body.match(/\/hls\/[^/]+\/([^/\s]+)\/playlist\.m3u8/);
  const quality = qualityMatch ? qualityMatch[1] : 'high';

  sleep(0.2);

  // 3. Fetch quality playlist
  const qualityUrl = `${STREAM_ORIGIN}/hls/${trackId}/${quality}/playlist.m3u8`;
  const qualityRes = http.get(qualityUrl, { headers: getHeaders() });
  errorRate.add(qualityRes.status !== 200);
  if (qualityRes.status !== 200) {
    sleep(1);
    return;
  }

  // 4. Fetch first segment (if present)
  const segmentMatch = qualityRes.body.match(/(segment_\d+\.ts)/);
  if (segmentMatch) {
    const segmentName = segmentMatch[1];
    const segmentUrl = `${STREAM_ORIGIN}/hls/${trackId}/${quality}/${segmentName}`;
    const segmentStart = Date.now();
    const segmentRes = http.get(segmentUrl, { headers: getHeaders() });
    segmentDuration.add(Date.now() - segmentStart);
    errorRate.add(segmentRes.status !== 200);
  }

  sleep(1);
}