1 files changed, 101 insertions, 0 deletions
diff --git a/services/manager/_base.py b/services/manager/_base.py
new file mode 100644
index 0000000..2599d8f
--- /dev/null
+++ b/services/manager/_base.py
@@ -0,0 +1,101 @@
+from typing import Any
+
+from ._helper import remove_none
+from ._error import CruException
+
+
+class CruNamespaceError(CruException):
+    """Raised when a namespace is not found."""
+
+
+class _Cru:
+    NAME_PREFIXES = ("CRU_", "Cru", "cru_")
+
+    def __init__(self) -> None:
+        self._d: dict[str, Any] = {}
+
+    def all_names(self) -> list[str]:
+        return list(self._d.keys())
+
+    def get(self, name: str) -> Any:
+        return self._d[name]
+
+    def has_name(self, name: str) -> bool:
+        return name in self._d
+
+    @staticmethod
+    def _maybe_remove_prefix(name: str) -> str | None:
+        for prefix in _Cru.NAME_PREFIXES:
+            if name.startswith(prefix):
+                return name[len(prefix) :]
+        return None
+
+    def _check_name_exist(self, *names: str | None) -> None:
+        for name in names:
+            if name is None:
+                continue
+            if self.has_name(name):
+                raise CruNamespaceError(f"Name {name} exists in CRU.")
+
+    @staticmethod
+    def check_name_format(name: str) -> tuple[str, str]:
+        no_prefix_name = _Cru._maybe_remove_prefix(name)
+        if no_prefix_name is None:
+            raise CruNamespaceError(
+                f"Name {name} is not prefixed with any of {_Cru.NAME_PREFIXES}."
+            )
+        return name, no_prefix_name
+
+    @staticmethod
+    def _check_object_name(o) -> tuple[str, str]:
+        return _Cru.check_name_format(o.__name__)
+
+    def _do_add(self, o, *names: str | None) -> list[str]:
+        name_list: list[str] = remove_none(names)
+        for name in name_list:
+            self._d[name] = o
+        return name_list
+
+    def add(self, o, name: str | None) -> tuple[str, str | None]:
+        no_prefix_name: str | None
+        if name is None:
+            name, no_prefix_name = self._check_object_name(o)
+        else:
+            no_prefix_name = self._maybe_remove_prefix(name)
+
+        self._check_name_exist(name, no_prefix_name)
+        self._do_add(o, name, no_prefix_name)
+        return name, no_prefix_name
+
+    def add_with_alias(self, o, name: str | None = None, *aliases: str) -> list[str]:
+        final_names: list[str | None] = []
+        no_prefix_name: str | None
+        if name is None:
+            name, no_prefix_name = self._check_object_name(o)
+            self._check_name_exist(name, no_prefix_name)
+            final_names.extend([name, no_prefix_name])
+        for alias in aliases:
+            no_prefix_name = self._maybe_remove_prefix(alias)
+            self._check_name_exist(alias, no_prefix_name)
+            final_names.extend([alias, no_prefix_name])
+
+        return self._do_add(o, *final_names)
+
+    def add_objects(self, *objects):
+        final_list = []
+        for o in objects:
+            name, no_prefix_name = self._check_object_name(o)
+            self._check_name_exist(name, no_prefix_name)
+            final_list.append((o, name, no_prefix_name))
+        for o, name, no_prefix_name in final_list:
+            self._do_add(o, name, no_prefix_name)
+
+    def __getitem__(self, item):
+        return self.get(item)
+
+    def __getattr__(self, item):
+        return self.get(item)
+
+
+CRU_NAME_PREFIXES = _Cru.NAME_PREFIXES
+CRU = _Cru()