clean-python/clean_python/base/domain/value_object.py

# (c) Nelen & Schuurmans

from typing import Optional
from typing import Type
from typing import TypeVar

from pydantic import BaseModel
from pydantic import ConfigDict
from pydantic import ValidationError

from .exceptions import BadRequest
from .types import Id

__all__ = ["ValueObject", "ValueObjectWithId"]


T = TypeVar("T", bound="ValueObject")


class ValueObject(BaseModel):
    model_config = ConfigDict(frozen=True)

    def run_validation(self: T) -> T:
        try:
            return self.__class__(**self.model_dump())
        except ValidationError as e:
            raise BadRequest(e)

    @classmethod
    def create(cls: Type[T], **values) -> T:
        try:
            return cls(**values)
        except ValidationError as e:
            raise BadRequest(e)

    def update(self: T, **values) -> T:
        try:
            return self.__class__(**{**self.model_dump(), **values})
        except ValidationError as e:
            raise BadRequest(e)

    def __hash__(self):
        return hash(self.__class__) + hash(tuple(self.__dict__.values()))


K = TypeVar("K", bound="ValueObjectWithId")


class ValueObjectWithId(ValueObject):
    id: Optional[Id] = None

    def update(self: K, **values) -> K:
        if "id" in values and self.id is not None and values["id"] != self.id:
            raise ValueError("Cannot change the id")
        return super().update(**values)