"""审计：和业务修改在同一个事务里写入，写失败整个操作就失败（架构 §3.10）。"""

from __future__ import annotations

import json
from typing import Any
from uuid import UUID

from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession

from bid_doctor.audit.models import AuditEvent
from bid_doctor.core.crypto import sha256
from bid_doctor.core.db import TenantContext
from bid_doctor.core.ids import uuid7


async def record(
    session: AsyncSession,
    ctx: TenantContext,
    action: str,
    object_type: str,
    object_id: UUID | None,
    *,
    project_id: UUID | None = None,
    before: dict[str, Any] | None = None,
    after: dict[str, Any] | None = None,
    actor_kind: str = "user",
) -> None:
    digest = (
        sha256(json.dumps([before, after], ensure_ascii=False, sort_keys=True, default=str))
        if before or after
        else None
    )
    session.add(
        AuditEvent(
            id=uuid7(),
            tenant_id=ctx.tenant_id,
            actor_kind=actor_kind,
            actor_user_id=ctx.user_id if actor_kind == "user" else None,
            actor_name=ctx.actor_name or None,
            action=action,
            object_type=object_type,
            object_id=object_id,
            project_id=project_id,
            before=before,
            after=after,
            content_digest=digest,
            request_id=ctx.request_id or None,
        )
    )


async def events_for(session: AsyncSession, object_type: str, object_id: UUID) -> list[AuditEvent]:
    """某个对象的修改记录，按时间倒序（FR-M2-08「谁在何时改了什么」）。"""
    rows = await session.execute(
        select(AuditEvent)
        .where(AuditEvent.object_type == object_type, AuditEvent.object_id == object_id)
        .order_by(AuditEvent.created_at.desc(), AuditEvent.id.desc())
    )
    return list(rows.scalars().all())


async def last_before(session: AsyncSession, action: str, object_id: UUID) -> dict[str, Any] | None:
    """某个对象最近一次某种操作之前的状态（例如撤销归档时回到归档前的项目状态）。"""
    row = (
        await session.execute(
            select(AuditEvent.before)
            .where(AuditEvent.action == action, AuditEvent.object_id == object_id)
            .order_by(AuditEvent.id.desc())
            .limit(1)
        )
    ).scalar_one_or_none()
    return row if isinstance(row, dict) else None