#!/usr/bin/env node
import assert from 'node:assert/strict';

const [baseUrl, candidateUrl = process.env.RUST_URL || 'http://127.0.0.1:3000'] = process.argv.slice(2);
if (!baseUrl) {
  console.error('usage: node alt/compare.mjs <bun-base-url> [rust-url]');
  process.exit(2);
}
const mediaId = process.env.TEST_MEDIA_ID || 'dQw4w9WgXcQ';
const testQuery = encodeURIComponent(process.env.TEST_QUERY || 'ytplayer-bench-seed');
const results = [];
const shape = value => Array.isArray(value) ? value.map(shape) : value && typeof value === 'object'
  ? Object.fromEntries(Object.keys(value).sort().map(key => [key, shape(value[key])])) : typeof value;
const headerSet = response => ({
  contentType: (response.headers.get('content-type') || '').split(';')[0],
  cache: response.headers.get('cache-control'),
  range: response.headers.get('content-range'),
  acceptRanges: response.headers.get('accept-ranges'),
  encoding: response.headers.get('content-encoding'),
  assetHash: response.headers.get('x-asset-hash'),
  etag: response.headers.get('etag'),
});
async function inspect(url, path, { method = 'GET', headers = {} } = {}) {
  const response = await fetch(new URL(path, url), { method, headers });
  const type = response.headers.get('content-type') || '';
  let body = null;
  if (type.includes('json')) body = await response.json();
  else if (type.startsWith('text/')) body = await response.text();
  else await response.arrayBuffer();
  return { status: response.status, headers: headerSet(response), shape: body ? shape(body) : null, body };
}
function check(name, a, b, fields) {
  const headersMatch = fields.every(field => a.headers[field] === b.headers[field]);
  const compatible = a.status === b.status && JSON.stringify(a.shape) === JSON.stringify(b.shape) && headersMatch;
  results.push({ name, compatible, base: { status: a.status, headers: a.headers, shape: a.shape }, candidate: { status: b.status, headers: b.headers, shape: b.shape } });
  console.log(`${compatible ? 'PASS' : 'DIFF'} ${name}: ${a.status} / ${b.status}${headersMatch ? '' : ` headers ${JSON.stringify(a.headers)} / ${JSON.stringify(b.headers)}`}`);
}
const [baseManifest, candidateManifest] = await Promise.all([inspect(baseUrl, '/api/manifest'), inspect(candidateUrl, '/api/manifest')]);
check('manifest', baseManifest, candidateManifest, ['cache', 'etag', 'contentType']);
for (const [name, url, manifest] of [['base', baseUrl, baseManifest.body], ['candidate', candidateUrl, candidateManifest.body]]) {
  const [index, sw] = await Promise.all([inspect(url, '/'), inspect(url, '/sw.js')]);
  const htmlText = index.body;
  const swText = sw.body;
  const tagPattern = new RegExp(`<meta[^>]*name="ytp-build"[^>]*content="${manifest.buildTag}"`);
  const stamped = index.status === 200 && tagPattern.test(htmlText) && (htmlText.includes(`styles.css?v=${manifest.files['/styles.css']?.h}`) || htmlText.includes(`styles.css?v=${manifest.buildTag}`));
  const workerStamped = sw.status === 200 && swText.includes(`"${manifest.buildTag}"`) && !swText.includes("typeof __BUILD_TAG__ !== 'undefined'");
  const compatible = stamped && workerStamped;
  results.push({ name: `${name}-shell-stamping`, compatible, stamped, workerStamped });
  console.log(`${compatible ? 'PASS' : 'DIFF'} ${name}-shell-stamping`);
}
const cssHash = baseManifest.body?.files?.['/styles.css']?.h || '';
const checks = [
  ['version', '/api/version'],
  ['static', `/styles.css?v=${cssHash}`],
  ['search-local', `/api/search/local?q=${testQuery}`],
  ['search', `/api/search?q=${testQuery}`],
  ['streams', `/api/streams?v=${mediaId}`],
  ['download-prepare', `/api/download/${mediaId}/prepare`],
  ['media-status', `/api/media/${mediaId}/status`],
];
for (const [name, path] of checks) {
  const [base, candidate] = await Promise.all([inspect(baseUrl, path), inspect(candidateUrl, path)]);
  const fields = name === 'static' ? ['contentType', 'cache', 'encoding', 'assetHash'] : ['contentType'];
  check(name, base, candidate, fields);
}
const [baseRange, rustRange] = await Promise.all([
  inspect(baseUrl, `/api/media/${mediaId}?g=1`, { headers: { Range: 'bytes=0-63' } }),
  inspect(candidateUrl, `/api/media/${mediaId}?g=1`, { headers: { Range: 'bytes=0-63' } }),
]);
check('media-range', baseRange, rustRange, ['contentType', 'cache', 'range', 'acceptRanges', 'etag']);
if (results.some(result => !result.compatible)) process.exitCode = 1;