"""Base model classes."""

from datetime import datetime

from sqlalchemy import func
from sqlalchemy.orm import DeclarativeBase, Mapped, mapped_column


class Base(DeclarativeBase):
    """Base class for all models."""

    pass


class TimestampMixin:
    """Mixin for created_at and updated_at timestamps."""

    created_at: Mapped[datetime] = mapped_column(
        default=func.now(),
        nullable=False,
    )
    updated_at: Mapped[datetime] = mapped_column(
        default=func.now(),
        onupdate=func.now(),
        nullable=False,
    )