shared/i10n/lib/src/
├── json/
│   ├── ko.i18n.json          # Base (Korean)
│   ├── en.i18n.json          # English
│   ├── ja.i18n.json          # Japanese
│   ├── zh-Hans.i18n.json     # Simplified Chinese
│   ├── de.i18n.json          # German
│   ├── fr.i18n.json          # French
│   ├── es.i18n.json          # Spanish
│   ├── it.i18n.json          # Italian
│   ├── pt.i18n.json          # Portuguese
│   ├── ru.i18n.json          # Russian
│   └── ar.i18n.json          # Arabic
└── translations/
    └── translations.g.dart    # Generated code

// shared/i10n/lib/src/json/ko.i18n.json
{
   " common " : {
     " app_name " :  " Unibook " ,
     " ok " :  " 확인 " ,
     " cancel " :  " 취소 " ,
     " save " :  " 저장 " ,
     " delete " :  " 삭제 " ,
     " edit " :  " 수정 " ,
     " loading " :  " 로딩 중... " ,
     " error " :  " 오류가 발생했습니다 " ,
     " retry " :  " 다시 시도 " 
   },
   " auth " : {
     " login " :  " 로그인 " ,
     " logout " :  " 로그아웃 " ,
     " sign_up " :  " 회원가입 " ,
     " email " :  " 이메일 " ,
     " password " :  " 비밀번호 " ,
     " forgot_password " :  " 비밀번호 찾기 " 
   },
   " home " : {
     " title " :  " 홈 " ,
     " welcome " :  " 환영합니다 " ,
     " feed " :  " 피드 " ,
     " empty " :  " 표시할 내용이 없습니다 " 
   }
}

{
   " user " : {
     " greeting " :  " {name}님, 안녕하세요! " ,
     " points " :  " {count} 포인트 보유 " ,
     " join_date " :  " {date}에 가입 " 
   },
   " notification " : {
     " new_message " :  " {sender}님이 메시지를 보냈습니다 " ,
     " mention " :  " {user}님이 회원님을 언급했습니다 " 
   }
}

{
   " items " : {
     " count(param=n) " : {
       " zero " :  " 항목 없음 " ,
       " one " :  " 항목 1개 " ,
       " other " :  " 항목 {n}개 " 
     }
  },
   " messages " : {
     " unread(param=count) " : {
       " zero " :  " 읽지 않은 메시지 없음 " ,
       " one " :  " 읽지 않은 메시지 1개 " ,
       " other " :  " 읽지 않은 메시지 {count}개 " 
     }
  }
}

{
   " profile " : {
     " welcome(param=gender) " : {
       " male " :  " 그가 환영합니다 " ,
       " female " :  " 그녀가 환영합니다 " ,
       " other " :  " 환영합니다 " 
     }
  }
}

{
   " pet " : {
     " type(context=PetType) " : {
       " dog " :  " 강아지 " ,
       " cat " :  " 고양이 " ,
       " bird " :  " 새 " ,
       " fish " :  " 물고기 " 
     }
  }
}

{
   " error " : {
     " network " : {
       " timeout " :  " 네트워크 시간 초과 " ,
       " no_connection " :  " 인터넷 연결 없음 " ,
       " server_error " :  " 서버 오류 " 
     },
     " validation " : {
       " required " :  " 필수 입력 항목입니다 " ,
       " email " :  " 올바른 이메일 형식이 아닙니다 " ,
       " min_length " :  " 최소 {min}자 이상 입력해주세요 " 
     }
  }
}

// shared/i10n/lib/src/json/en.i18n.json
{
   " common " : {
     " app_name " :  " Unibook " ,
     " ok " :  " OK " ,
     " cancel " :  " Cancel " ,
     " save " :  " Save " ,
     " delete " :  " Delete " ,
     " edit " :  " Edit " ,
     " loading " :  " Loading... " ,
     " error " :  " An error occurred " ,
     " retry " :  " Retry " 
   },
   " auth " : {
     " login " :  " Login " ,
     " logout " :  " Logout " ,
     " sign_up " :  " Sign Up " ,
     " email " :  " Email " ,
     " password " :  " Password " ,
     " forgot_password " :  " Forgot Password " 
   },
   " home " : {
     " title " :  " Home " ,
     " welcome " :  " Welcome " ,
     " feed " :  " Feed " ,
     " empty " :  " Nothing to show " 
   },
   " items " : {
     " count(param=n) " : {
       " zero " :  " No items " ,
       " one " :  " 1 item " ,
       " other " :  " {n} items " 
     }
  }
}

// Using BuildContext extension (provided by package:core)
Text(context.i10n.common.app_name)
Text(context.i10n.auth.login)
Text(context.i10n.home.title)

Text(context.i10n.user.greeting(name: user.name))
Text(context.i10n.user.points(count: user.points.toString()))

Text(context.i10n.items.count(n: itemCount))
Text(context.i10n.messages.unread(count: unreadCount))

Text(context.i10n.pet.type(context: pet.type))

// Cannot use directly in BLoC (requires BuildContext)
// Convert in UI layer and pass to BLoC

// Widget
final message = context.i10n.error.network.timeout;
bloc.add(ErrorEvent.show(message: message));

base_locale: ko
fallback_strategy: base_locale
input_directory: lib/src/json
input_file_pattern: .i18n.json
output_directory: lib/src/translations
output_file_name: translations.g.dart
output_format: single_file
key_case: snake
key_map_case: snake
param_case: snake
string_interpolation: braces
translate_var: translations
flat_map: false

dependencies:
  slang: ^3.31.0
  slang_flutter: ^3.31.0

dev_dependencies:
  slang_build_runner: ^3.31.0

melos run generate:locale

melos run translate:slang

// main.dart
void main() {
  WidgetsFlutterBinding.ensureInitialized();
  LocaleSettings.useDeviceLocale(); // or LocaleSettings.setLocale(AppLocale.ko);
  runApp(
    TranslationProvider(
      child: const MyApp(),
    ),
  );
}

// MyApp
class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      locale: TranslationProvider.of(context).flutterLocale,
      supportedLocales: AppLocaleUtils.supportedLocales,
      localizationsDelegates: GlobalMaterialLocalizations.delegates,
      home: const HomePage(),
    );
  }
}

// Change locale programmatically
LocaleSettings.setLocale(AppLocale.en);

// Available locale list
final locales = AppLocale.values;
// [AppLocale.ko, AppLocale.en, AppLocale.ja, AppLocale.zhHans,
//  AppLocale.de, AppLocale.fr, AppLocale.es, AppLocale.it,
//  AppLocale.pt, AppLocale.ru, AppLocale.ar]

// Check current locale
final current = LocaleSettings.currentLocale;

// Good example: nested structure + snake_case
{
   " user " : {
     " profile " : {
       " title " :  " 프로필 " ,
       " edit " :  " 프로필 수정 " ,
       " avatar " :  " 프로필 사진 " 
     }
  }
}

// Bad example
{
   " userProfileTitle " :  " 프로필 " ,  // camelCase, not nested
   " user_profile_edit " :  " 수정 "       // flat instead of nested
}

# Generate translation code
melos run generate:locale

# GPT auto-translation (English)
melos run translate:slang

# Check for missing translations
dart run slang analyze