src/app/models/base.py

"""Declarative base and shared column mixins for ORM models."""

from __future__ import annotations

import uuid
from datetime import datetime

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

# Portable UUID column type: native ``UUID`` on PostgreSQL, ``CHAR(32)`` on
# other backends (e.g. SQLite used in tests). Single source of truth.
GUID = Uuid(as_uuid=True)


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


class UUIDMixin:
    id: Mapped[uuid.UUID] = mapped_column(
        GUID,
        primary_key=True,
        default=uuid.uuid4,
    )


class TimestampMixin:
    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,
    )