import uuid
from datetime import datetime, timezone

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


def uuid4_str() -> str:
    return str(uuid.uuid4())


def _utcnow() -> datetime:
    return datetime.now(timezone.utc)


class TimestampMixin:
    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=_utcnow, nullable=False)
    updated_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), default=_utcnow, onupdate=_utcnow, nullable=False
    )