import express from 'express';

const router = express.Router();

// DuckDuckGo Instant Answer API - no key required
async function ddgInstantAnswer(query) {
  const url = `https://api.duckduckgo.com/?q=${encodeURIComponent(query)}&format=json&no_html=1&skip_disambig=1`;
  const res = await fetch(url, {
    headers: { 'User-Agent': 'IQAI-Dashboard/1.0' }
  });
  if (!res.ok) throw new Error('DDG search failed');
  return res.json();
}

// DuckDuckGo HTML search scraper for more results
async function ddgWebSearch(query) {
  const url = `https://html.duckduckgo.com/html/?q=${encodeURIComponent(query)}`;
  const res = await fetch(url, {
    headers: {
      'User-Agent': 'Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36',
      'Accept': 'text/html'
    }
  });
  if (!res.ok) return [];
  const html = await res.text();

  // Parse result links and snippets from DDG HTML
  const results = [];
  const resultRegex = /<a[^>]+class="result__a"[^>]*href="([^"]*)"[^>]*>([\s\S]*?)<\/a>/gi;
  const snippetRegex = /<a[^>]+class="result__snippet"[^>]*>([\s\S]*?)<\/a>/gi;

  const links = [...html.matchAll(resultRegex)].slice(0, 8);
  const snippets = [...html.matchAll(snippetRegex)].slice(0, 8);

  for (let i = 0; i < Math.min(links.length, 5); i++) {
    const title = links[i][2].replace(/<[^>]+>/g, '').trim();
    const snippet = snippets[i] ? snippets[i][1].replace(/<[^>]+>/g, '').trim() : '';
    const href = links[i][1];
    // DDG redirects through their own URLs, extract the real URL
    const realUrl = href.startsWith('//duckduckgo.com/l/?uddg=')
      ? decodeURIComponent(href.split('uddg=')[1]?.split('&')[0] || href)
      : href;
    if (title && !title.includes('DuckDuckGo')) {
      results.push({ title, snippet, url: realUrl });
    }
  }
  return results;
}

router.get('/', async (req, res) => {
  const { q } = req.query;
  if (!q) return res.status(400).json({ error: 'Query parameter q is required' });

  try {
    const [instant, webResults] = await Promise.allSettled([
      ddgInstantAnswer(q),
      ddgWebSearch(q)
    ]);

    const answer = instant.status === 'fulfilled' ? instant.value : null;
    const results = webResults.status === 'fulfilled' ? webResults.value : [];

    // Format for injection into AI prompt
    const formatted = formatSearchResults(q, answer, results);

    res.json({
      query: q,
      answer,
      results,
      formatted
    });
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
});

function formatSearchResults(query, instant, webResults) {
  const lines = [`[WEB SEARCH RESULTS FOR: "${query}"]`, ''];

  if (instant?.AbstractText) {
    lines.push(`Summary: ${instant.AbstractText}`);
    if (instant.AbstractSource) lines.push(`Source: ${instant.AbstractSource}`);
    lines.push('');
  }

  if (instant?.Answer) {
    lines.push(`Direct Answer: ${instant.Answer}`);
    lines.push('');
  }

  if (webResults.length > 0) {
    lines.push('Web Results:');
    webResults.forEach((r, i) => {
      lines.push(`${i + 1}. ${r.title}`);
      if (r.snippet) lines.push(`   ${r.snippet}`);
      lines.push(`   URL: ${r.url}`);
    });
    lines.push('');
  }

  if (instant?.RelatedTopics?.length > 0) {
    const topics = instant.RelatedTopics
      .filter(t => t.Text)
      .slice(0, 3)
      .map(t => `- ${t.Text}`);
    if (topics.length > 0) {
      lines.push('Related Topics:');
      lines.push(...topics);
      lines.push('');
    }
  }

  lines.push('[END SEARCH RESULTS]');
  return lines.join('\n');
}

export { router as searchRouter };