"""Base value object for DDD domain layer."""

from abc import ABC, abstractmethod
from dataclasses import dataclass
from typing import Any, Generic, TypeVar

T = TypeVar("T")


@dataclass(frozen=True, slots=True)
class ValueObject(ABC, Generic[T]):
    """Base class for all value objects."""

    value: T

    def __post_init__(self) -> None:
        self._validate()

    @abstractmethod
    def _validate(self) -> None:
        """Validate the value object. Raise ValueError if invalid."""
        ...

    def __eq__(self, other: object) -> bool:
        if not isinstance(other, ValueObject):
            return False
        return bool(self.value == other.value)

    def __hash__(self) -> int:
        return hash(self.value)

    def __str__(self) -> str:
        return str(self.value)

    def to_primitive(self) -> Any:
        """Convert value object to primitive type."""
        return self.value