// Port of tmdbintegral/tmdb2imdb.php
// Builds bidirectional TMDb <-> IMDb id mappings from cached detail files.

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 } from '../config.js';
import { entryPath } from '../lib/paths.js';

export async function buildMapping(type) {
  const inputFile = join(TMDBINTEGRAL_DIR, `${type}.json`);
  const out1 = join(TMDBINTEGRAL_DIR, `${type}2imdb.json`);
  const out2 = join(TMDBINTEGRAL_DIR, `imdb2${type}.json`);

  const data1 = {};
  const data2 = {};

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

  for await (const line of rl) {
    if (!line) continue;
    let obj;
    try { obj = JSON.parse(line); } catch { continue; }
    const tmdb = obj.id;
    const path = entryPath(type, tmdb);
    if (!existsSync(path)) continue;
    let detail;
    try { detail = JSON.parse(readFileSync(path, 'utf8')); } catch { continue; }
    const imdb = detail?.external_ids?.imdb_id;
    if (imdb) {
      data1[tmdb] = imdb;
      data2[imdb] = tmdb;
    }
  }

  await writeFile(out1, JSON.stringify(data1));
  await writeFile(out2, JSON.stringify(data2));
}

if (import.meta.url === `file://${process.argv[1]}`) {
  const type = process.argv[2];
  if (type !== 'movie' && type !== 'tv') {
    console.error('Usage: node cron/tmdb2imdb.js movie|tv');
    process.exit(1);
  }
  buildMapping(type).catch((err) => {
    console.error(err);
    process.exit(1);
  });
}