"""审计事件数据访问。"""

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

from app.models.safety import AuditEvent


async def add_audit_event(session: AsyncSession, event: AuditEvent) -> AuditEvent:
    session.add(event)
    await session.flush()
    return event


async def list_audit_events(
    session: AsyncSession,
    *,
    pivot: str | None = None,
    character_id: str | None = None,
    page: int = 1,
    page_size: int = 50,
) -> tuple[list[AuditEvent], int]:
    """起居注时间河：按 created_at 倒序，可选按枢/人物过滤，返回 (条目, 总数)。"""
    conditions = []
    if pivot:
        conditions.append(AuditEvent.pivot == pivot)
    if character_id:
        conditions.append(AuditEvent.character_id == character_id)
    total_result = await session.execute(
        select(func.count()).select_from(AuditEvent).where(*conditions)
    )
    total = int(total_result.scalar_one())
    result = await session.execute(
        select(AuditEvent)
        .where(*conditions)
        .order_by(AuditEvent.created_at.desc())
        .offset((page - 1) * page_size)
        .limit(page_size)
    )
    return list(result.scalars().all()), total


async def list_audit_events_by_trace(session: AsyncSession, trace_id: str) -> list[AuditEvent]:
    """链路追踪：按 trace_id 查询审计事件，按 created_at 升序（与运行事件归并排序）。"""
    result = await session.execute(
        select(AuditEvent)
        .where(AuditEvent.trace_id == trace_id)
        .order_by(AuditEvent.created_at.asc())
    )
    return list(result.scalars().all())


async def summarize_by_trace(session: AsyncSession):
    """GROUP BY trace_id：(trace_id, 计数, 最近时间)，仅 trace_id 非空。供链路追踪列表聚合。"""
    result = await session.execute(
        select(AuditEvent.trace_id, func.count(), func.max(AuditEvent.created_at))
        .where(AuditEvent.trace_id.is_not(None))
        .group_by(AuditEvent.trace_id)
    )
    return [(row[0], int(row[1]), row[2]) for row in result.all()]