from datetime import datetime

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


class Base(DeclarativeBase):
    metadata = MetaData()


class TimestampMixin:
    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
    )