matchLocale static method

List<String> matchLocale({ required List<String> files, Locale? locale, required String name, required String extension, })

Implementation

static List<String> matchLocale({
  required List<String> files,
  Locale? locale,
  required String name,
  required String extension,
}) {
  files.sort((a, b) {
    final aLocalized = a.startsWith(RegExp('^[a-z]+(-[a-z]+)?\\.lproj\\/'));
    final bLocalized = b.startsWith(RegExp('^[a-z]+(-[a-z]+)?\\.lproj\\/'));
    if (aLocalized && bLocalized) {
      return a.compareTo(b);
    } else if (aLocalized) {
      return -1;
    } else {
      return 1;
    }
  });
  files = files.reversed.toList();
  List<RegExp> expressions = <RegExp>[];

  // adding the fallbacks
  // - match only unlocalized
  // - match the five mostly spoken languages of the world, copied from Wikipedia
  // - match just *any* language
  expressions.addAll(
    [
      RegExp(
        '^[a-z]+(-[a-z]+)?\\.lproj\\/$name(@\\d+x)?\\.$extension\$',
        unicode: true,
        caseSensitive: false,
      ),
      ...['en', 'zh', 'hi', 'es', 'fr'].reversed.map(
            (language) => RegExp(
              '^$language(-[a-z]+)?\\.lproj\\/$name(@\\d+x)?\\.$extension\$',
              unicode: true,
              caseSensitive: false,
            ),
          ),
      RegExp(
        '^$name(@\\d+x)?\\.$extension\$',
        unicode: true,
        caseSensitive: false,
      ),
    ],
  );

  if (locale != null) {
    final language = locale.languageCode;
    expressions.add(
      RegExp(
        '^$language(-[a-z]+)?\\.lproj\\/$name(@\\d+x)?\\.$extension\$',
        unicode: true,
        caseSensitive: false,
      ),
    );

    final region = locale.countryCode;
    if (region != null) {
      expressions.add(
        RegExp(
          '^$language-$region\\.lproj\\/$name(@\\d+x)?\\.$extension\$',
          unicode: true,
          caseSensitive: false,
        ),
      );
    }
  }

  for (final regex in expressions.reversed) {
    final matches = <String>[];
    for (final file in files) {
      final match = regex.stringMatch(file);
      if (match != null) matches.add(match);
    }
    if (matches.isNotEmpty) return matches;
  }
  return [];
}