import uuid
from datetime import datetime

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


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


class TimestampMixin:
    """Mixin that adds created_at and updated_at columns."""

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


def generate_uuid() -> uuid.UUID:
    return uuid.uuid4()