const smoke = {
  title: document.title,
  titleLen: document.title.length,
  canonical: document.querySelector('link[rel="canonical"]')?.href,
  h1Count: document.querySelectorAll('h1').length,
  missingAlts: [...document.querySelectorAll('img')].filter(i => !i.hasAttribute('alt')).length,
  schema: [...document.querySelectorAll('script[type="application/ld+json"]')]
    .map(s => { try { return JSON.parse(s.innerText)['@type'] } catch(e) { return 'invalid' } }),
  brokenImages: [...document.querySelectorAll('img')].filter(i => !i.complete || i.naturalWidth === 0).length,
};
console.log(JSON.stringify(smoke, null, 2));

const audit = {
  title: document.title,
  titleLen: document.title.length,
  canonical: document.querySelector('link[rel="canonical"]')?.href,
  metaDesc: document.querySelector('meta[name="description"]')?.content,
  metaDescLen: document.querySelector('meta[name="description"]')?.content?.length,
  ogImage: document.querySelector('meta[property="og:image"]')?.content,
  ogTitle: document.querySelector('meta[property="og:title"]')?.content,
  twitterCard: document.querySelector('meta[name="twitter:card"]')?.content,
  h1Count: document.querySelectorAll('h1').length,
  h1Text: document.querySelector('h1')?.innerText,
  h2Count: document.querySelectorAll('h2').length,
  h2s: [...document.querySelectorAll('h2')].map(h => h.innerText.trim().slice(0, 60)),
  totalImages: document.querySelectorAll('img').length,
  missingAlts: [...document.querySelectorAll('img')].filter(i => !i.hasAttribute('alt')).length,
  brokenImages: [...document.querySelectorAll('img')].filter(i => !i.complete || i.naturalWidth === 0).length,
  externalLinksWithoutNoopener: [...document.querySelectorAll('a[target="_blank"]')]
    .filter(a => !a.rel?.includes('noopener')).length,
  schema: [...document.querySelectorAll('script[type="application/ld+json"]')]
    .map(s => {
      try {
        const d = JSON.parse(s.innerText);
        return d['@graph'] ? d['@graph'].map(x => x['@type']) : d['@type'];
      } catch(e) { return 'invalid' }
    }),
  hasSkipLink: [...document.querySelectorAll('a[href^="#"]')].slice(0, 3)
    .some(a => /skip/i.test(a.textContent) && !!document.getElementById(a.getAttribute('href').slice(1))),
  pageLanguage: document.documentElement.lang || 'NOT SET',
  hasFavicon: !!document.querySelector('link[rel*="icon"]'),
};
console.log(JSON.stringify(audit, null, 2));

fetch(window.location.origin, { method: 'HEAD' })
  .then(r => {
    const headers = {};
    for (const [k, v] of r.headers.entries()) headers[k] = v;
    console.log(JSON.stringify(headers, null, 2));
  });

const imgs = [...document.querySelectorAll('img')].map(i => ({
  src: i.src.split('/').pop().split('?')[0].slice(0, 60),
  alt: i.hasAttribute('alt') ? (i.alt === '' ? 'DECORATIVE (empty alt)' : i.alt) : 'MISSING',
  width: i.naturalWidth,
  height: i.naturalHeight,
  loaded: i.complete && i.naturalWidth > 0,
}));
console.table(imgs);
console.log({
  total: imgs.length,
  broken: imgs.filter(i => !i.loaded).length,
  noAlt: imgs.filter(i => i.alt === 'MISSING').length,
  decorative: imgs.filter(i => i.alt.startsWith('DECORATIVE')).length,
});

const headings = [...document.querySelectorAll('h1, h2, h3, h4, h5, h6')].map(h => ({
  level: parseInt(h.tagName[1]),
  text: h.innerText.trim().slice(0, 80),
}));
console.table(headings);

// Check for skipped levels
const levels = headings.map(h => h.level);
let skipped = false;
for (let i = 1; i < levels.length; i++) {
  if (levels[i] > levels[i-1] + 1) {
    console.warn(`Skipped from H${levels[i-1]} to H${levels[i]}: "${headings[i].text}"`);
    skipped = true;
  }
}
if (!skipped) console.log('No skipped heading levels');

function contrast(bg, fg) {
  function lum(hex) {
    return [hex.slice(1,3), hex.slice(3,5), hex.slice(5,7)]
      .map(h => parseInt(h, 16) / 255)
      .map(v => v <= 0.03928 ? v / 12.92 : Math.pow((v + 0.055) / 1.055, 2.4))
      .reduce((a, v, i) => a + v * [0.2126, 0.7152, 0.0722][i], 0);
  }
  const [l1, l2] = [lum(bg), lum(fg)];
  const r = ((Math.max(l1, l2) + 0.05) / (Math.min(l1, l2) + 0.05)).toFixed(2);
  return r + ':1 ' + (parseFloat(r) >= 4.5 ? 'PASS body' : parseFloat(r) >= 3 ? 'PASS large only' : 'FAIL');
}

// Examples
contrast('#FFFFFF', '#4B5563'); // body color check
contrast('#FFFFFF', '#9CA3AF'); // verify gray choices

[...document.querySelectorAll('form')].forEach((form, i) => {
  const fields = [...form.querySelectorAll('input, select, textarea')].map(field => ({
    type: field.type || field.tagName.toLowerCase(),
    name: field.name,
    hasLabel: !!form.querySelector(`label[for="${field.id}"]`) || !!field.closest('label'),
    required: field.required,
  }));
  console.log(`Form ${i + 1}:`);
  console.table(fields);
});

const externalLinks = [...document.querySelectorAll('a[href^="http"]')]
  .filter(a => !a.href.includes(window.location.host));
const issues = externalLinks.filter(a =>
  a.target === '_blank' && (!a.rel?.includes('noopener') || !a.rel?.includes('noreferrer'))
);
if (issues.length) {
  console.warn(`${issues.length} external links missing noopener/noreferrer:`);
  issues.forEach(a => console.warn(a.href));
} else {
  console.log(`All ${externalLinks.length} external links properly attributed`);
}