"""Shared model mixins."""
from __future__ import annotations

import uuid
from datetime import datetime

from sqlalchemy import Boolean, DateTime, Integer, String, func
from sqlalchemy.orm import Mapped, mapped_column

from app.models.types import GUID


class UUIDPrimaryKeyMixin:
    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,
    )


class TenantMixin:
    """Row-level tenancy (ADR-003). Tenant comes from request context, never hardcoded."""

    tenant_id: Mapped[uuid.UUID] = mapped_column(GUID(), nullable=False)


class SoftDeleteMixin:
    is_deleted: Mapped[bool] = mapped_column(Boolean, default=False, nullable=False)
    deleted_at: Mapped[datetime | None] = mapped_column(
        DateTime(timezone=True), nullable=True
    )
    deleted_by: Mapped[str | None] = mapped_column(String(100), nullable=True)


class ActorAuditMixin:
    created_by: Mapped[str | None] = mapped_column(String(100), nullable=True)
    updated_by: Mapped[str | None] = mapped_column(String(100), nullable=True)


class OptimisticLockMixin:
    """Optimistic locking where concurrent updates must be conflict-safe."""

    version: Mapped[int] = mapped_column(Integer, default=1, nullable=False)