1 files changed, 125 insertions, 0 deletions
diff --git a/tools/cru-py/cru/attr.py b/tools/cru-py/cru/attr.py
new file mode 100644
index 0000000..d07cc55
--- /dev/null
+++ b/tools/cru-py/cru/attr.py
@@ -0,0 +1,125 @@
+from collections.abc import Callable
+from dataclasses import dataclass
+from types import NoneType
+from typing import Any
+from copy import deepcopy
+
+
+@dataclass
+class CruAttr:
+    name: str
+    value: Any
+    description: str
+
+
+@dataclass
+class CruAttrDef:
+    name: str
+    default_description: str
+    allow_types: None | set[type]
+    allow_none: bool
+    default_value: Any
+    transformer: Callable[[Any], Any] | None
+    validator: Callable[[Any], None]
+
+    def __init__(self, name: str, default_description: str, *,
+                 allow_types: list[type] | type | None, allow_none: bool, default_value: Any = None,
+                 transformer: Callable[[Any], Any] | None = None,
+                 validator: Callable[[Any], None] | None = None) -> None:
+        self.name = name
+        self.default_description = default_description
+        self.default_value = default_value
+        #TODO: CONTINUE TOMORROW
+        if allow_types is None:
+            allow_types = []
+        elif isinstance(allow_types, type):
+            allow_types = [allow_types]
+        else:
+            for t in allow_types:
+                if not isinstance(t, type):
+                    raise TypeError(f"Invalid value of python type : {t}")
+        self.allow_types = set(filter(lambda tt: tt is not NoneType, allow_types))
+        self.allow_none = allow_none
+        self.transformer = transformer
+        self.validator = validator
+        self.default_value = self.transform_and_validate(self.default_value)
+        self.default_value = deepcopy(self.default_value)
+
+    def transform(self, value: Any) -> Any:
+        if self.transformer is not None:
+            return self.transformer(value)
+        return value
+
+    def validate(self, value: Any, /, override_allow_none: bool | None = None) -> None:
+        allow_none = override_allow_none if override_allow_none is not None else self.allow_none
+        if value is None and not allow_none:
+            raise TypeError(f"None is not allowed!")
+        if len(self.allow_types) != 0 and type(value) not in self.allow_types:
+            raise TypeError(f"Type of {value} is not allowed!")
+        if self.validator is not None:
+            return self.validator(value)
+        return None
+
+    def transform_and_validate(self, value: Any, /, override_allow_none: bool | None = None) -> Any:
+        value = self.transform(value)
+        self.validate(value, override_allow_none)
+        return value
+
+    def make(self, value: Any, description: None | str = None) -> CruAttr:
+        value = self.transform_and_validate(value)
+        return CruAttr(self.name, value if value is not None else deepcopy(self.default_value),
+                       description if description is not None else self.default_description)
+
+
+class CruAttrDefRegistry:
+
+    def __init__(self) -> None:
+        self._def_list = []
+
+    @property
+    def items(self) -> list[CruAttrDef]:
+        return self._def_list
+
+    def register(self, def_: CruAttrDef):
+        for i in self._def_list:
+            if i.name == def_.name:
+                raise ValueError(f"Attribute {def_.name} already exists!")
+        self._def_list.append(def_)
+
+    def register_with(self, name: str, default_description: str, *,
+                      allow_types: list[type] | type | None, allow_none: bool,
+                      default_value: Any = None,
+                      transformer: Callable[[Any], Any] | None = None,
+                      validator: Callable[[Any], None] | None = None
+                      ) -> CruAttrDef:
+        def_ = CruAttrDef(name, default_description, default_value=default_value, allow_types=allow_types,
+                          allow_none=allow_none, transformer=transformer, validator=validator)
+        self.register(def_)
+        return def_
+
+    def register_required(self, name: str, default_description: str, *,
+                      allow_types: list[type] | type | None,
+                      default_value: Any = None,
+                      transformer: Callable[[Any], Any] | None = None,
+                      validator: Callable[[Any], None] | None = None
+                      ) -> CruAttrDef:
+        return self.register_with(name, default_description, default_value=default_value, allow_types=allow_types,
+                          allow_none=False, transformer=transformer, validator=validator)
+
+    def register_optional(self, name: str, default_description: str, *,
+                      allow_types: list[type] | type | None,
+                      default_value: Any = None,
+                      transformer: Callable[[Any], Any] | None = None,
+                      validator: Callable[[Any], None] | None = None
+                      ) -> CruAttrDef:
+        return self.register_with(name, default_description, default_value=default_value, allow_types=allow_types,
+                          allow_none=True, transformer=transformer, validator=validator)
+
+    def get_item_optional(self, name: str) -> CruAttrDef | None:
+        for i in self._def_list:
+            if i.name == name:
+                return i
+        return None
+
+    def __getitem__(self, item) -> CruAttrDef | None:
+        return self.get_item_optional(item)