#!/usr/bin/env node
// Verifies that all i18n translation files share the exact same set of keys.
// Exits with a non-zero status (and prints the differences) if any key is
// present in one language but missing in another, so CI can catch drift.

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

const scriptDir = dirname(fileURLToPath(import.meta.url));
const i18nDir = join(scriptDir, '..', 'src', 'assets', 'i18n');

function collectLeafKeys(value, prefix, keys) {
  for (const key of Object.keys(value)) {
    const fullKey = prefix ? `${prefix}.${key}` : key;
    const child = value[key];
    const isNestedObject = child !== null && typeof child === 'object' && !Array.isArray(child);
    if (isNestedObject) {
      collectLeafKeys(child, fullKey, keys);
    } else {
      keys.add(fullKey);
    }
  }
  return keys;
}

function loadKeys(fileName) {
  const content = readFileSync(join(i18nDir, fileName), 'utf8');
  const parsed = JSON.parse(content);
  return collectLeafKeys(parsed, '', new Set());
}

const files = readdirSync(i18nDir).filter((name) => name.endsWith('.json'));
if (files.length < 2) {
  console.log('i18n check: nothing to compare (fewer than two language files).');
  process.exit(0);
}

const keysByFile = new Map(files.map((file) => [file, loadKeys(file)]));

const allKeys = new Set();
for (const keys of keysByFile.values()) {
  for (const key of keys) {
    allKeys.add(key);
  }
}

let hasError = false;
for (const [file, keys] of keysByFile) {
  const missing = [...allKeys].filter((key) => !keys.has(key)).sort();
  if (missing.length > 0) {
    hasError = true;
    console.error(`\n[${file}] missing ${missing.length} key(s):`);
    for (const key of missing) {
      console.error(`  - ${key}`);
    }
  }
}

if (hasError) {
  console.error('\ni18n check failed: translation files are out of sync.');
  process.exit(1);
}

console.log(`i18n check passed: ${files.join(', ')} share ${allKeys.size} keys.`);