initial commit, functinal software

shared/src/orisys_app_shared/i18n/__init__.py

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+"""i18n helpers."""
+
+from orisys_app_shared.i18n.translator import Translator, get_translator, set_locale, t
+
+__all__ = ["Translator", "get_translator", "set_locale", "t"]

shared/src/orisys_app_shared/i18n/translator.py

@@ -0,0 +1,80 @@
+"""Simple JSON locale translator with en_US fallback."""
+
+from __future__ import annotations
+
+import json
+from pathlib import Path
+from typing import Any
+
+from orisys_app_shared.paths import locales_dir
+
+
+class Translator:
+    def __init__(self, locales_path: Path | None = None, locale: str = "zh_CN") -> None:
+        self._locales_path = locales_path or locales_dir()
+        self._locale = locale
+        self._strings: dict[str, Any] = {}
+        self._fallback: dict[str, Any] = {}
+        self.set_locale(locale)
+
+    @property
+    def locale(self) -> str:
+        return self._locale
+
+    def set_locale(self, locale: str) -> None:
+        self._locale = locale
+        self._fallback = self._load("en_US")
+        self._strings = self._load(locale)
+
+    def _load(self, locale: str) -> dict[str, Any]:
+        path = self._locales_path / f"{locale}.json"
+        if not path.is_file():
+            return {}
+        try:
+            data = json.loads(path.read_text(encoding="utf-8"))
+        except (OSError, json.JSONDecodeError):
+            return {}
+        return data if isinstance(data, dict) else {}
+
+    def t(self, key: str, **kwargs: Any) -> str:
+        value = self._lookup(self._strings, key)
+        if value is None:
+            value = self._lookup(self._fallback, key)
+        if value is None:
+            return key
+        text = str(value)
+        if kwargs:
+            try:
+                return text.format(**kwargs)
+            except (KeyError, ValueError):
+                return text
+        return text
+
+    @staticmethod
+    def _lookup(data: dict[str, Any], key: str) -> Any | None:
+        node: Any = data
+        for part in key.split("."):
+            if not isinstance(node, dict) or part not in node:
+                return None
+            node = node[part]
+        return node
+
+
+_translator: Translator | None = None
+
+
+def get_translator() -> Translator:
+    global _translator
+    if _translator is None:
+        _translator = Translator()
+    return _translator
+
+
+def t(key: str, **kwargs: Any) -> str:
+    return get_translator().t(key, **kwargs)
+
+
+def set_locale(locale: str) -> Translator:
+    tr = get_translator()
+    tr.set_locale(locale)
+    return tr