import 'package:flutter_test/flutter_test.dart';

import 'arb_test_helpers.dart';
import 'identical_value_allowlist.dart';

/// WU18 task 18.1b -- the anti-copy guard.
///
/// A key-parity test alone is NOT sufficient: it passes just as happily if
/// all 11 non-`es` locales simply copy the Spanish template value verbatim
/// for every key -- which would certify the exact bug it exists to catch
/// (see `reference/l10n-spanish-template-fallback`). This test collects
/// every value in a non-`es` locale that is byte-identical to the Spanish
/// template's value for the same key and fails unless that (locale, key)
/// pair is explicitly, individually allowlisted in
/// `identical_value_allowlist.dart`.
///
/// Scope note: `en` is deliberately excluded from this guard. Unlike the
/// other 11 locales -- which this change batch-translates for the first
/// time -- `en` and `es` have been hand-maintained together by every work
/// unit throughout this whole redesign (`en`/`es`-only new keys, never
/// left lagging), so `en` never carries the "silently fell back to the
/// template" risk this guard exists to catch.
const _auditedLocales = [
  'ar',
  'bn',
  'de',
  'fr',
  'hi',
  'id',
  'it',
  'ja',
  'pt',
  'ru',
  'zh',
];

void main() {
  test('every non-es value identical to the Spanish template is a '
      'deliberately allowlisted exception, not an accidental untranslated '
      'copy', () {
    final es = readArb('es');
    final unlisted = <String>[];

    for (final locale in _auditedLocales) {
      final arb = readArb(locale);
      for (final key in realKeys(arb)) {
        // Missing keys are arb_parity_test's job, not this one's.
        if (!es.containsKey(key)) continue;
        if (arb[key] == es[key] &&
            !identicalValueAllowlist.contains((locale, key))) {
          unlisted.add('$locale/$key = "${arb[key]}"');
        }
      }
    }

    expect(
      unlisted,
      isEmpty,
      reason:
          'Found value(s) identical to the Spanish template that are NOT '
          'in identical_value_allowlist.dart -- this is very likely an '
          'untranslated copy-paste, not a deliberate cognate/brand-name/'
          'symbol exception. Translate it, or add a reviewed, individual '
          'allowlist entry with a justification comment if it truly is '
          'untranslatable:\n${unlisted.join('\n')}',
    );
  });

  test(
    'every allowlisted pair is a real, current collision (no stale entries)',
    () {
      final es = readArb('es');
      final stale = <String>[];

      for (final entry in identicalValueAllowlist) {
        final (locale, key) = entry;
        final arb = readArb(locale);
        final stillCollides =
            arb.containsKey(key) && es.containsKey(key) && arb[key] == es[key];
        if (!stillCollides) {
          stale.add('$locale/$key');
        }
      }

      expect(
        stale,
        isEmpty,
        reason:
            'identical_value_allowlist.dart has entries that no longer '
            'correspond to a real identical value -- remove them, the '
            'allowlist must only contain genuine, current exceptions:\n'
            '${stale.join('\n')}',
      );
    },
  );
}