generateClassAndDelegate method

String generateClassAndDelegate(List<LocalizationSheet> sheets, String className, bool includeFlutterDelegates)

Generate just the class + delegate bodies — no file header, no imports.

Used by the builder (inline mode) where the caller owns the header and writes sheet class bodies before calling this.

Implementation

String generateClassAndDelegate(
  List<LocalizationSheet> sheets,
  String className,
  bool includeFlutterDelegates,
) {
  final buffer = StringBuffer();

  final allLanguageCodes = <String>{};
  for (final sheet in sheets) {
    allLanguageCodes.addAll(sheet.languageCodes);
  }
  final sortedLanguages = allLanguageCodes.toList()..sort();

  buffer.writeln('class $className {');
  buffer.writeln('  final String languageCode;');
  buffer.writeln();

  buffer.writeln('  static const List<String> supportedLanguages = [');
  for (final lang in sortedLanguages) {
    buffer.writeln("    '$lang',");
  }
  buffer.writeln('  ];');
  buffer.writeln();

  for (final sheet in sheets) {
    final sheetClassName =
        '${StringUtils.sanitizeClassName(sheet.name)}Localizations';
    final propertyName = StringUtils.sanitizePropertyName(sheet.name);
    buffer.writeln('  late final $sheetClassName $propertyName;');
  }
  buffer.writeln();

  buffer.writeln('  $className(this.languageCode) {');
  for (final sheet in sheets) {
    final sheetClassName =
        '${StringUtils.sanitizeClassName(sheet.name)}Localizations';
    final propertyName = StringUtils.sanitizePropertyName(sheet.name);
    buffer.writeln('    $propertyName = $sheetClassName(languageCode);');
  }
  buffer.writeln('  }');
  buffer.writeln();

  // Locale resolution is pure Dart, so it is emitted in every mode.
  buffer.writeln('  /// Resolve a language tag to a supported language code.');
  buffer.writeln('  ///');
  buffer.writeln("  /// Accepts 'en', 'en_US' and 'en-US'. Falls back from a");
  buffer.writeln('  /// country variant to any variant of the same language,');
  buffer.writeln('  /// and returns null when nothing matches.');
  buffer.writeln('  static String? resolveLanguage(String languageTag) {');
  buffer.writeln(
    "    final normalized = languageTag.toLowerCase().replaceAll('-', '_');",
  );
  buffer.writeln('    for (final lang in supportedLanguages) {');
  buffer.writeln('      if (lang.toLowerCase() == normalized) return lang;');
  buffer.writeln('    }');
  buffer.writeln();
  buffer.writeln("    final base = normalized.split('_').first;");
  buffer.writeln('    for (final lang in supportedLanguages) {');
  buffer.writeln('      if (lang.toLowerCase() == base) return lang;');
  buffer.writeln('    }');
  buffer.writeln('    for (final lang in supportedLanguages) {');
  buffer.writeln(
    "      if (lang.toLowerCase().split('_').first == base) return lang;",
  );
  buffer.writeln('    }');
  buffer.writeln();
  buffer.writeln('    return null;');
  buffer.writeln('  }');
  buffer.writeln();

  if (includeFlutterDelegates) {
    final languageService = LanguageService();
    final addedGetters = <String>{};

    for (final lang in sortedLanguages.take(5)) {
      final capitalizedLang = languageService.getLanguageName(lang);
      final camelCaseLang = StringUtils.sanitizePropertyName(lang);
      buffer.writeln('  /// Get $capitalizedLang instance');
      buffer.writeln(
        "  static $className get $camelCaseLang => $className('$lang');",
      );
      addedGetters.add(camelCaseLang);
    }
    buffer.writeln();

    for (final lang in sortedLanguages.take(5)) {
      final fullName = languageService.getLanguageName(lang);
      final camelCaseFullName = StringUtils.sanitizePropertyName(fullName);
      final camelCaseLang = StringUtils.sanitizePropertyName(lang);
      if (!addedGetters.contains(camelCaseFullName) &&
          camelCaseFullName != camelCaseLang) {
        buffer.writeln(
          "  static $className get $camelCaseFullName => $className('$lang');",
        );
      }
    }
    buffer.writeln();

    buffer.writeln('  static $className of(BuildContext context) {');
    buffer.writeln('    final locale = Localizations.localeOf(context);');
    buffer.writeln(
      '    return $className(resolveLanguage(locale.toLanguageTag()) ?? supportedLanguages.first);',
    );
    buffer.writeln('  }');
    buffer.writeln();

    buffer.writeln('  /// Get system language with fallback');
    buffer.writeln('  static String getSystemLanguage() {');
    buffer.writeln('    try {');
    buffer.writeln(
      '      for (final locale in PlatformDispatcher.instance.locales) {',
    );
    buffer.writeln(
      '        final match = resolveLanguage(locale.toLanguageTag());',
    );
    buffer.writeln('        if (match != null) return match;');
    buffer.writeln('      }');
    buffer.writeln('    } catch (e) {');
    buffer.writeln(
      '      // PlatformDispatcher is unavailable outside a Flutter runtime',
    );
    buffer.writeln('    }');
    buffer.writeln();
    buffer.writeln("    return resolveLanguage('en') ?? supportedLanguages.first;");
    buffer.writeln('  }');
    buffer.writeln();

    buffer.writeln('  /// Get current localization based on system language');
    buffer.writeln(
      '  static $className get current => $className(getSystemLanguage());',
    );
    buffer.writeln();

    buffer.writeln('  /// Delegate for localizations');
    buffer.writeln(
      '  static const ${className}Delegate delegate = ${className}Delegate();',
    );
    buffer.writeln();
    buffer.writeln(
      "  /// All localization delegates including Flutter's built-in delegates",
    );
    buffer.writeln(
      '  static const List<LocalizationsDelegate<dynamic>> delegates = [',
    );
    buffer.writeln('    delegate, // Custom localizations');
    buffer.writeln('    GlobalMaterialLocalizations.delegate,');
    buffer.writeln('    GlobalWidgetsLocalizations.delegate,');
    buffer.writeln('    GlobalCupertinoLocalizations.delegate,');
    buffer.writeln('  ];');
    buffer.writeln();
  }

  buffer.writeln('}');

  if (includeFlutterDelegates) {
    buffer.writeln();
    buffer.writeln(
      'class ${className}Delegate extends LocalizationsDelegate<$className> {',
    );
    buffer.writeln('  const ${className}Delegate();');
    buffer.writeln();
    buffer.writeln('  @override');
    buffer.writeln('  bool isSupported(Locale locale) {');
    buffer.writeln(
      '    return $className.resolveLanguage(locale.toLanguageTag()) != null;',
    );
    buffer.writeln('  }');
    buffer.writeln();
    buffer.writeln('  @override');
    buffer.writeln('  Future<$className> load(Locale locale) async {');
    buffer.writeln(
      '    return $className($className.resolveLanguage(locale.toLanguageTag()) ?? $className.supportedLanguages.first);',
    );
    buffer.writeln('  }');
    buffer.writeln();
    buffer.writeln('  @override');
    buffer.writeln('  bool shouldReload(${className}Delegate old) => false;');
    buffer.writeln('}');
  }

  return buffer.toString();
}