i18n.py

from typing import Any, Dict, Optional

from aiogram import Dispatcher
from aiogram.types import TelegramObject, User
from aiogram.utils.i18n import I18n
from aiogram.utils.i18n import I18nMiddleware as BaseI18nMiddleware
from babel import Locale, UnknownLocaleError

from src.configs.env import I18N_DEFAULT_LOCALE, I18N_DOMAIN, I18N_LOCALES_PATH
from src.database import db
from src.models.user import UserModel


class I18nMiddleware(BaseI18nMiddleware):
  def get_internal_locale(self, language_code: str):
    if language_code and language_code in self.i18n.available_locales:
      return language_code

  def get_external_locale(self, user_id: str):
    user: UserModel = db.users.find_one({"user_id": user_id})

    if user and user.settings.language_code and user.settings.language_code in self.i18n.available_locales:
      return user.settings.language_code

  async def get_locale(self, event: TelegramObject, data: Dict[str, Any]) -> str:
    user: Optional[User] = data.get("event_from_user", None)

    if user is None:
      return self.i18n.default_locale

    internal_locale = self.get_internal_locale(user.language_code)
    print("internal_locale:", internal_locale)  # ! en
    external_locale = self.get_external_locale(user.id)
    print("external_locale:", external_locale)  # ! None

    locale = external_locale if external_locale else internal_locale

    try:
      locale = Locale.parse(locale, sep="-")
      print("locale:", locale)  # ! en
    except UnknownLocaleError:
      return self.i18n.default_locale


def setup(dispatcher: Dispatcher):
  i18n = I18n(path=I18N_LOCALES_PATH,
              default_locale=I18N_DEFAULT_LOCALE, domain=I18N_DOMAIN)
  i18nMiddleware = I18nMiddleware(i18n=i18n)

  return dispatcher.message.middleware(i18nMiddleware)