#!/usr/bin/env node
// Generates lib/i18n/messages.js from lib/messages/*.json.
//
// The launcher (node) reads the JSON directly; the pages cannot, because they
// are opened from file:// where fetching local JSON is blocked. Rather than
// maintain two copies of every string, the JSON stays the source of truth and
// this emits a plain <script> the pages can load.
//
//   node lib/i18n/build-messages.mjs [--check]
//
// --check exits non-zero if the generated file is stale, for CI.

import { readFileSync, writeFileSync, readdirSync, existsSync } from 'node:fs';
import { dirname, join } from 'node:path';
import { fileURLToPath } from 'node:url';

const here = dirname(fileURLToPath(import.meta.url));
const messagesDir = join(here, '..', 'messages');
const outputPath = join(here, 'messages.js');
const skillsOutputPath = join(here, 'skills-data.js');

const catalogues = {};
for (const file of readdirSync(messagesDir).sort()) {
  if (!file.endsWith('.json')) continue;
  catalogues[file.replace(/\.json$/, '')] = JSON.parse(readFileSync(join(messagesDir, file), 'utf8'));
}

const generated = `/* GENERATED FILE — do not edit.
 * Source: lib/messages/*.json
 * Regenerate: node lib/i18n/build-messages.mjs
 *
 * Exists because pages opened from file:// cannot fetch local JSON.
 */
window.UCLAW_I18N_MESSAGES = ${JSON.stringify(catalogues, null, 2)};
`;

// The skill catalogue travels the same way and for the same reason: SkillHub is
// opened from file://, where fetching manifest.json is blocked.
function buildSkillsData() {
  for (const candidate of [join(here, '..', '..', 'skills'), join(here, '..', '..', '..', 'skills')]) {
    if (!existsSync(join(candidate, 'manifest.json'))) continue;
    const manifest = JSON.parse(readFileSync(join(candidate, 'manifest.json'), 'utf8'));
    return `/* GENERATED FILE — do not edit.
 * Source: skills/manifest.json
 * Regenerate: node lib/i18n/build-messages.mjs
 */
window.UCLAW_SKILLS = ${JSON.stringify({
      personas: manifest.personas,
      skills: manifest.skills
        .filter((s) => s.status === 'shipping')
        .map(({ id, categories, personas, emoji }) => ({ id, categories, personas, emoji })),
    }, null, 2)};
`;
  }
  return null;
}

const generatedSkills = buildSkillsData();

if (process.argv.includes('--check')) {
  let current = null;
  try { current = readFileSync(outputPath, 'utf8'); } catch { /* not generated yet */ }
  let currentSkills = null;
  try { currentSkills = readFileSync(skillsOutputPath, 'utf8'); } catch { /* not generated yet */ }
  if (current !== generated || (generatedSkills && currentSkills !== generatedSkills)) {
    process.stderr.write('lib/i18n generated files are stale — run: node lib/i18n/build-messages.mjs\n');
    process.exit(1);
  }
  process.stdout.write('generated files are up to date\n');
} else {
  writeFileSync(outputPath, generated, 'utf8');
  if (generatedSkills) writeFileSync(skillsOutputPath, generatedSkills, 'utf8');
  const count = Object.keys(catalogues).map((l) => `${l}:${Object.keys(catalogues[l]).length}`).join(' ');
  process.stdout.write(`wrote lib/i18n/messages.js (${count})\n`);
}