from __future__ import annotations

from datetime import datetime

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


class Base(DeclarativeBase):
    """SQLAlchemy declarative base for all ORM models."""


class TimestampMixin:
    """created_at / updated_at mixin for entities."""

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