import { readdir, readFile, mkdir, writeFile } from 'node:fs/promises';
import path from 'node:path';

// Include dependency notices with the static distributable, without fetching
// anything at build time. Some upstream Pi packages omit a LICENSE file;
// their repository license is included in public/licenses/pi-LICENSE.
export async function collectLicenses() {
  const notices = [];
  async function scan(root) {
    for (const entry of await readdir(root, { withFileTypes: true })) {
      if (!entry.isDirectory() || entry.name.startsWith('.')) continue;
      const directory = path.join(root, entry.name);
      if (entry.name.startsWith('@')) { await scan(directory); continue; }
      let pkg;
      try { pkg = JSON.parse(await readFile(path.join(directory, 'package.json'), 'utf8')); } catch { continue; }
      const texts = [];
      for (const file of await readdir(directory, { withFileTypes: true })) {
        if (file.isFile() && /^(licen[cs]e|copying|notice|thirdpartynotices)/i.test(file.name)) texts.push(await readFile(path.join(directory, file.name), 'utf8'));
      }
      notices.push(`${pkg.name}@${pkg.version} (${pkg.license ?? 'see upstream'})\n${texts.join('\n')}\n`);
    }
  }
  await scan('node_modules');
  await mkdir('dist/licenses', { recursive: true });
  await writeFile('dist/licenses/dependencies.txt', notices.sort().join('\n----------------------------------------\n\n'));
  await writeFile('dist/licenses/pi-components.json', await readFile('vendor/pi-coding-agent/provenance.json'));
}