"""AuditEntry — append-only, immutable record of every mutation.

The actor is a User, or the assistant principal acting *on behalf of* a User
(actor_type = assistant, actor_user_id = the user it serves). No timestamps
mixin and no soft delete: this table is never updated or deleted.
"""

import uuid
from datetime import datetime

from sqlalchemy import DateTime, ForeignKey, String, func
from sqlalchemy import Enum as SAEnum
from sqlalchemy.dialects.postgresql import JSONB
from sqlalchemy.orm import Mapped, mapped_column

from app.models.base import Base
from app.models.enums import AuditActorType
from app.models.mixins import UUIDPrimaryKey


class AuditEntry(Base, UUIDPrimaryKey):
    __tablename__ = "audit_entries"

    created_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), server_default=func.now(), nullable=False, index=True
    )
    tree_id: Mapped[uuid.UUID | None] = mapped_column(
        ForeignKey("trees.id", ondelete="SET NULL"), index=True
    )
    actor_type: Mapped[AuditActorType] = mapped_column(
        SAEnum(AuditActorType, name="audit_actor_type"),
        default=AuditActorType.user,
        server_default=AuditActorType.user.value,
    )
    actor_user_id: Mapped[uuid.UUID | None] = mapped_column(
        ForeignKey("users.id", ondelete="SET NULL"), index=True
    )
    action: Mapped[str] = mapped_column(String(64))  # create | update | delete | restore | ...
    entity_type: Mapped[str] = mapped_column(String(64))
    entity_id: Mapped[uuid.UUID | None] = mapped_column()
    before: Mapped[dict | None] = mapped_column(JSONB)
    after: Mapped[dict | None] = mapped_column(JSONB)