// Port of tmdbintegral/search.php
// Builds the chunked search database files (searchmovieN.json / searchtvN.json).
//
// Each entry has the same positional shape as the PHP version:
//   [TMDB, TITLE, ENGLISHTITLE, ORIGINALTITLE,
//    FILTEREDTITLE, FILTEREDENGLISHTITLE, FILTEREDORIGINALTITLE,
//    YEARS[], POPULARITY]
// so the runtime search worker can use the same indices.

import { createReadStream, existsSync, readFileSync } from 'node:fs';
import { writeFile } from 'node:fs/promises';
import { createInterface } from 'node:readline';
import { join } from 'node:path';
import { TMDBINTEGRAL_DIR, NB_SEARCH_PARTS } from '../config.js';
import { entryPath } from '../lib/paths.js';
import { filterTitle } from '../lib/titleFilter.js';
import { mbStrlen } from '../lib/mbLevenshtein.js';

function lower(s) { return s.toLocaleLowerCase(); }

function extractEnglishTitle(detail, type) {
  const tr = detail?.translations?.translations;
  if (!Array.isArray(tr)) return '';
  for (const t of tr) {
    if (t.iso_639_1 === 'en') {
      return type === 'movie' ? (t.data?.title || '') : (t.data?.name || '');
    }
  }
  return '';
}

function buildEntry(masterObj, detail, type) {
  const tmdb = masterObj.id;
  const popularity = parseFloat(masterObj.popularity) || 0;

  let title, originalTitle, englishTitle;
  const years = [];

  if (type === 'movie') {
    const date = String(detail.release_date || '').split('-');
    years.push(parseInt(date[0], 10) || 0);
    title = detail.title || '';
    originalTitle = detail.original_title || '';
    englishTitle = extractEnglishTitle(detail, 'movie');
  } else {
    const date = String(detail.first_air_date || '').split('-');
    years.push(parseInt(date[0], 10) || 0);
    title = detail.name || '';
    originalTitle = detail.original_name || '';
    englishTitle = extractEnglishTitle(detail, 'tv');
    if (Array.isArray(detail.seasons)) {
      for (const s of detail.seasons) {
        const sd = String(s.air_date || '').split('-');
        const sy = parseInt(sd[0], 10);
        if (sy) years.push(sy);
      }
    }
  }

  if (!years[0]) return null;

  let ft = filterTitle(title);
  let fe = filterTitle(englishTitle);
  let fo = filterTitle(originalTitle);

  if (!ft && !fe && !fo) return null;

  if (ft && mbStrlen(ft) / mbStrlen(title) < 0.5) ft = '';
  if (fe && mbStrlen(fe) / mbStrlen(englishTitle) < 0.5) fe = '';
  if (fo && mbStrlen(fo) / mbStrlen(originalTitle) < 0.5) fo = '';

  // Dedupe years preserving order (PHP array_values(array_unique($years)))
  const seen = new Set();
  const uniqYears = [];
  for (const y of years) {
    if (!seen.has(y)) { seen.add(y); uniqYears.push(y); }
  }

  return [
    tmdb,
    title,
    englishTitle,
    originalTitle,
    lower(ft),
    lower(fe),
    lower(fo),
    uniqYears,
    popularity,
  ];
}

export async function buildSearch(type, nbParts = NB_SEARCH_PARTS) {
  const indexFile = join(TMDBINTEGRAL_DIR, `${type}.json`);
  const database = [];

  const stream = createReadStream(indexFile, { encoding: 'utf8' });
  const rl = createInterface({ input: stream, crlfDelay: Infinity });

  for await (const line of rl) {
    if (!line) continue;
    let masterObj;
    try { masterObj = JSON.parse(line); } catch { continue; }
    const path = entryPath(type, masterObj.id);
    if (!existsSync(path)) continue;
    let detail;
    try { detail = JSON.parse(readFileSync(path, 'utf8')); } catch { continue; }
    const entry = buildEntry(masterObj, detail, type);
    if (entry) database.push(entry);
  }

  const partSize = Math.ceil(database.length / nbParts);
  const writes = [];
  for (let p = 0; p < nbParts; p++) {
    const chunk = database.slice(p * partSize, (p + 1) * partSize);
    const out = join(TMDBINTEGRAL_DIR, `search${type}${p}.json`);
    console.log(`Writing ${chunk.length} entries to search${type}${p}.json`);
    writes.push(writeFile(out, JSON.stringify(chunk)));
  }
  await Promise.all(writes);
}

if (import.meta.url === `file://${process.argv[1]}`) {
  const type = process.argv[2];
  const nb = parseInt(process.argv[3] || String(NB_SEARCH_PARTS), 10);
  if (type !== 'movie' && type !== 'tv') {
    console.error('Usage: node cron/buildSearch.js movie|tv [nbParts]');
    process.exit(1);
  }
  buildSearch(type, nb).catch((err) => {
    console.error(err);
    process.exit(1);
  });
}