"""审计服务 — 写入与检索

写入方案的取舍（与 MOM/KCGL 不同，理由如下）
--------------------------------------------------
MOM 用 SQLAlchemy event listener + **同事务**写入：优点是全自动、业务代码零改动；
缺点是业务事务回滚时审计记录一起被回滚掉 —— 而失败/被拒的操作恰恰是最需要
留痕的（比如越权尝试、参数错误导致的 4xx）。

Track 改为：响应生成后，用**独立 session** 写入审计。
- 业务回滚不影响审计，失败操作照样留痕
- 审计写入失败也不影响业务（全包裹 try/except，仅记日志）
- 代价：审计与业务不是原子提交，极端情况（响应后进程立即被 kill）可能丢一条。
  对内部系统的操作审计，这个取舍划算。
"""
from __future__ import annotations

import logging
import uuid
from datetime import datetime

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

from app.core.database import AsyncSessionLocal
from app.models.audit_log import AuditLog

logger = logging.getLogger("track.audit")

# 绝不落库的敏感字段名（命中即替换为 ***）
# 登录请求体含明文密码，一旦进审计表就成了长期泄露面
_SENSITIVE_KEYS = frozenset(
    {"password", "passwd", "pwd", "token", "access_token", "refresh_token",
     "secret", "api_key", "authorization", "password_hash"}
)

# 模块 / 动作 的中文标签（前端下拉与列表展示用）
MODULE_LABELS: dict[str, str] = {
    "auth": "认证登录",
    "product": "产品管理",
    "task": "任务流转",
    "order": "订单管理",
    "record": "任务记录",
    "print": "标签打印",
    "material": "物料",
    "user": "用户",
    "notification": "消息通知",
    "upload": "文件上传",
    "dashboard": "看板统计",
    "analytics": "效能分析",
    "screen": "数据大屏",
    "holiday": "节假日配置",
    "app": "App版本",
    "external": "外部系统对接",
    "audit": "审计日志",
    "other": "其它",
}

ACTION_LABELS: dict[str, str] = {
    "create": "新增",
    "update": "修改",
    "delete": "删除",
    "read": "查询",
    "export": "导出",
    "login": "登录",
    "logout": "登出",
    "refresh": "刷新令牌",
    "print": "打印",
    "upload": "上传",
    "finalize": "收口",
    "receive": "接收",
    "transfer": "转交",
    "reject": "驳回",
    "recall": "撤回",
    "spawn": "派发",
    "end": "结束分支",
    "complete": "完结",
}


def sanitize_details(details: dict | None) -> dict | None:
    """递归剔除敏感字段，避免密码/令牌落库"""
    if not details:
        return details

    def _clean(value):
        if isinstance(value, dict):
            return {
                k: ("***" if str(k).lower() in _SENSITIVE_KEYS else _clean(v))
                for k, v in value.items()
            }
        if isinstance(value, list):
            return [_clean(v) for v in value]
        return value

    return _clean(details)


async def record_audit(
    *,
    action: str,
    module: str,
    user_id: str | None = None,
    display_name: str | None = None,
    role: str | None = None,
    target_type: str | None = None,
    target_id: str | None = None,
    target_name: str | None = None,
    details: dict | None = None,
    ip_address: str | None = None,
    user_agent: str | None = None,
    method: str | None = None,
    url: str | None = None,
    status_code: int | None = None,
    error_message: str | None = None,
    request_id: str | None = None,
) -> None:
    """写入一条审计记录。**绝不抛异常**：审计失败不能影响业务。"""
    try:
        async with AsyncSessionLocal() as session:
            session.add(
                AuditLog(
                    id=uuid.uuid4(),
                    user_id=user_id,
                    display_name=display_name,
                    role=role,
                    action=action,
                    module=module,
                    target_type=target_type,
                    target_id=str(target_id) if target_id is not None else None,
                    target_name=target_name,
                    details=sanitize_details(details),
                    ip_address=ip_address,
                    user_agent=user_agent[:500] if user_agent else None,
                    method=method,
                    url=url[:500] if url else None,
                    status_code=status_code,
                    error_message=error_message,
                    request_id=request_id,
                )
            )
            await session.commit()
    except Exception:
        # 用 exception 级别但吞掉异常：保证调用方业务流程不受影响
        logger.exception(
            "审计写入失败（已忽略，不影响业务）",
            extra={"extra_fields": {"action": action, "module": module, "url": url}},
        )


async def list_audit_logs(
    db: AsyncSession,
    *,
    user_id: str | None = None,
    module: str | None = None,
    action: str | None = None,
    target_id: str | None = None,
    request_id: str | None = None,
    status_code: int | None = None,
    start: datetime | None = None,
    end: datetime | None = None,
    skip: int = 0,
    limit: int = 50,
) -> tuple[list[AuditLog], int]:
    """审计日志检索（按时间倒序）。返回 (当前页, 真实总数)。

    真实总数走独立 COUNT —— 前端分页器依赖它，不能用 len(当前页)。
    """
    filters = []
    if user_id:
        filters.append(AuditLog.user_id.ilike(f"%{user_id}%"))
    if module:
        filters.append(AuditLog.module == module)
    if action:
        filters.append(AuditLog.action == action)
    if target_id:
        filters.append(AuditLog.target_id == target_id)
    if request_id:
        filters.append(AuditLog.request_id == request_id)
    if status_code is not None:
        filters.append(AuditLog.status_code == status_code)
    if start:
        filters.append(AuditLog.created_at >= start)
    if end:
        filters.append(AuditLog.created_at <= end)

    total = await db.scalar(
        select(func.count()).select_from(AuditLog).where(*filters)
    ) or 0

    rows = (
        await db.execute(
            select(AuditLog)
            .where(*filters)
            .order_by(AuditLog.created_at.desc())
            .offset(skip)
            .limit(limit)
        )
    ).scalars().all()

    return list(rows), total