/**
 * Vergleicht flache Schlüsselpfade zwischen zwei Locale-Ordnern (gleiche JSON-Dateinamen).
 *
 * Aufruf: node scripts/check-i18n-locale-parity.mjs de fr
 */
import fs from 'fs';
import path from 'path';
import { fileURLToPath } from 'url';

const __dirname = path.dirname(fileURLToPath(import.meta.url));
const BASE = path.join(__dirname, '../src/i18n/locales');

function flattenLeaves(obj, prefix = '', out = {}) {
  if (obj === null || typeof obj !== 'object' || Array.isArray(obj)) {
    out[prefix] = obj;
    return out;
  }
  const keys = Object.keys(obj);
  if (keys.length === 0) {
    out[prefix] = obj;
    return out;
  }
  for (const k of keys) {
    const p = prefix ? `${prefix}.${k}` : k;
    const v = obj[k];
    if (v !== null && typeof v === 'object' && !Array.isArray(v)) {
      flattenLeaves(v, p, out);
    } else {
      out[p] = v;
    }
  }
  return out;
}

const [a, b] = process.argv.slice(2);
if (!a || !b) {
  console.error('Usage: node scripts/check-i18n-locale-parity.mjs <localeA> <localeB>');
  process.exit(2);
}

const dirA = path.join(BASE, a);
const dirB = path.join(BASE, b);
const files = fs.readdirSync(dirA).filter((f) => f.endsWith('.json'));
let errors = 0;

for (const f of files) {
  const pa = path.join(dirA, f);
  const pb = path.join(dirB, f);
  if (!fs.existsSync(pb)) {
    console.error(`Fehlt: ${b}/${f}`);
    errors++;
    continue;
  }
  const ja = JSON.parse(fs.readFileSync(pa, 'utf8'));
  const jb = JSON.parse(fs.readFileSync(pb, 'utf8'));
  const fa = flattenLeaves(ja);
  const fb = flattenLeaves(jb);
  const ka = new Set(Object.keys(fa));
  const kb = new Set(Object.keys(fb));
  for (const k of ka) {
    if (!kb.has(k)) {
      console.error(`[${f}] fehlt in ${b}: ${k}`);
      errors++;
    }
  }
  for (const k of kb) {
    if (!ka.has(k)) {
      console.error(`[${f}] extra in ${b}: ${k}`);
      errors++;
    }
  }
}

if (errors) {
  console.error(`\n${errors} Abweichung(en).`);
  process.exit(1);
}
console.log(`OK: Key-Parität ${a} ↔ ${b} für ${files.length} Dateien.`);