const express = require('express');
const cors = require('cors');
const cinecheck = require('./aggregators/cinecheck-adapter');
const commonsense = require('./aggregators/commonsense-adapter');
const filmages = require('./aggregators/filmages-adapter');
const { mergeResults } = require('./merge');

const app = express();
app.use(cors());

// Helper to normalize text and get words for matching
function getWords(text) {
  if (!text || typeof text !== 'string') return [];
  return text
    .toLowerCase()
    // Remove punctuation, keep letters, numbers, and whitespace. Handles Unicode.
    .replace(/[^\p{L}\p{N}\s]/gu, '')
    .replace(/\s+/g, ' ') // Normalize multiple spaces to single
    .trim()
    .split(' ')
    .filter(Boolean); // Remove empty strings from split
}

app.get('/search', async (req, res) => {
  const q = req.query.q;
  if (!q) {
    return res.status(400).json({ error: "Missing query. Predictable." });
  }
  try {
    const [cine, cs, fa] = await Promise.all([
      cinecheck.searchAndEnrich(q).catch(e => { console.error('Cinecheck failed:', e.message); return []; }),
      commonsense.searchAndEnrich(q).catch(e => { console.error('Commonsense failed:', e.message); return []; }),
      filmages.searchAndEnrich(q).catch(e => { console.error('Filmages failed:', e.message); return []; })
    ]);

    console.log('===== SEARCH LOGS =====');
    console.log('Cinecheck results:', cine.length);
    console.log('CSM results:', cs.length);
    console.log('Filmages results:', fa.length);
    console.log('Raw CSM data:', cs); // Inspect full data

    let merged = mergeResults([cine, cs, fa]);

    // Sort merged results based on query relevance
    const queryWords = getWords(q);
    if (queryWords.length > 0) {
      merged.forEach(item => {
        const titleWords = getWords(item.title);
        const uniqueQueryWords = [...new Set(queryWords)];
        const uniqueTitleWords = [...new Set(titleWords)];

        let commonWordCount = 0;
        for (const qw of uniqueQueryWords) {
          if (uniqueTitleWords.includes(qw)) {
            commonWordCount++;
          }
        }

        item.matchScore1 = uniqueQueryWords.length > 0 ? commonWordCount / uniqueQueryWords.length : 0;

        const unionLength = new Set([...uniqueQueryWords, ...uniqueTitleWords]).size;
        item.matchScore2 = unionLength > 0 ? commonWordCount / unionLength : 0;
      });

      merged.sort((a, b) => {
        if (b.matchScore1 !== a.matchScore1) return b.matchScore1 - a.matchScore1;
        if (b.matchScore2 !== a.matchScore2) return b.matchScore2 - a.matchScore2;
        return getWords(a.title).length - getWords(b.title).length; // Shorter titles preferred as tertiary sort
      });
    }

    res.json(merged);
  } catch (e) {
    console.error('General search error:', e);
    res.status(500).json({ error: e.message || "Server's taking a nap." });
  }
});

const PORT = 3000;
app.listen(PORT, () => {
  console.log(`Backend sorting your life out on http://localhost:${PORT}. You're welcome.`);
});