from __future__ import annotations
import uuid
from datetime import datetime, timezone
from sqlalchemy import DateTime, ForeignKey, String, Text
from sqlalchemy.orm import Mapped, mapped_column
from .base import Base


class AuditEvent(Base):
    __tablename__ = "audit_events"

    id: Mapped[str] = mapped_column(String(36), primary_key=True, default=lambda: str(uuid.uuid4()))
    timestamp: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), nullable=False, default=lambda: datetime.now(timezone.utc)
    )
    user_id: Mapped[str | None] = mapped_column(
        String(36), ForeignKey("users.id", ondelete="SET NULL"), nullable=True
    )
    # Denormalized so display survives user deletion
    username: Mapped[str] = mapped_column(String(64), nullable=False, default="system")
    action: Mapped[str] = mapped_column(String(64), nullable=False)
    entity_type: Mapped[str | None] = mapped_column(String(64), nullable=True)
    entity_id: Mapped[str | None] = mapped_column(String(255), nullable=True)
    detail_json: Mapped[str | None] = mapped_column(Text, nullable=True)