"""EntityHistory model — snapshot history for undo/restore functionality."""

from __future__ import annotations

import uuid
from datetime import datetime
from typing import Any

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

from app.core.db import Base, TenantMixin


class EntityHistory(Base, TenantMixin):
    """Snapshot history for undo/restore functionality.

    Every CRUD action (create/update/delete) stores a full entity snapshot
    so users can undo changes or revert to previous versions.
    """

    __tablename__ = "entity_history"

    id: Mapped[uuid.UUID] = mapped_column(
        PGUUID(as_uuid=True), primary_key=True, default=uuid.uuid4
    )
    user_id: Mapped[uuid.UUID | None] = mapped_column(
        PGUUID(as_uuid=True), ForeignKey("users.id", ondelete="SET NULL"), nullable=True, index=True
    )
    entity_type: Mapped[str] = mapped_column(String(50), nullable=False, index=True)
    entity_id: Mapped[uuid.UUID] = mapped_column(PGUUID(as_uuid=True), nullable=False, index=True)
    action: Mapped[str] = mapped_column(String(20), nullable=False)  # 'create', 'update', 'delete'
    snapshot_before: Mapped[dict[str, Any] | None] = mapped_column(JSONB, nullable=True)
    snapshot_after: Mapped[dict[str, Any] | None] = mapped_column(JSONB, nullable=True)
    changes: Mapped[dict[str, Any] | None] = mapped_column(JSONB, nullable=True)
    created_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), nullable=False, server_default=func.now(), index=True
    )