Split public and private i18n APIs (#6022)

redbot/core/_i18n.py

@@ -0,0 +1,79 @@
+from __future__ import annotations
+
+from contextvars import ContextVar
+from typing import TYPE_CHECKING, List, Optional
+
+from babel.core import Locale, UnknownLocaleError
+
+if TYPE_CHECKING:
+    from redbot.core.i18n import Translator
+
+
+__all__ = (
+    "current_locale",
+    "current_locale_default",
+    "current_regional_format",
+    "current_regional_format_default",
+    "translators",
+    "set_global_locale",
+    "set_global_regional_format",
+    "set_contextual_locale",
+    "set_contextual_regional_format",
+)
+
+
+current_locale = ContextVar("current_locale")
+current_locale_default = "en-US"
+current_regional_format = ContextVar("current_regional_format")
+current_regional_format_default = None
+
+translators: List[Translator] = []
+
+
+def _reload_locales() -> None:
+    for translator in translators:
+        translator.load_translations()
+
+
+def _get_standardized_locale_name(language_code: str) -> str:
+    try:
+        locale = Locale.parse(language_code, sep="-")
+    except (ValueError, UnknownLocaleError):
+        raise ValueError("Invalid language code. Use format: `en-US`")
+    if locale.territory is None:
+        raise ValueError(
+            "Invalid format - language code has to include country code, e.g. `en-US`"
+        )
+    return f"{locale.language}-{locale.territory}"
+
+
+def set_global_locale(language_code: str, /) -> str:
+    global current_locale_default
+    current_locale_default = _get_standardized_locale_name(language_code)
+    _reload_locales()
+    return current_locale_default
+
+
+def set_global_regional_format(language_code: Optional[str], /) -> Optional[str]:
+    global current_regional_format_default
+    if language_code is not None:
+        language_code = _get_standardized_locale_name(language_code)
+    current_regional_format_default = language_code
+    return language_code
+
+
+def set_contextual_locale(language_code: str, /, verify_language_code: bool = False) -> str:
+    if verify_language_code:
+        language_code = _get_standardized_locale_name(language_code)
+    current_locale.set(language_code)
+    _reload_locales()
+    return language_code
+
+
+def set_contextual_regional_format(
+    language_code: str, /, verify_language_code: bool = False
+) -> str:
+    if verify_language_code and language_code is not None:
+        language_code = _get_standardized_locale_name(language_code)
+    current_regional_format.set(language_code)
+    return language_code