"""操作审计记录服务，统一处理详情脱敏与序列化。"""

from __future__ import annotations

import json
from collections.abc import Mapping
from datetime import datetime
from typing import Any

from sqlalchemy.orm import Session

from ..models import Account, AuditLog, User
from .account_events_service import CATEGORY_OPS, emit

_SENSITIVE_KEY_PARTS = (
    "cookie",
    "token",
    "password",
    "passwd",
    "secret",
    "signature",
    "sign",
    "qr_data",
    "authorization",
    "credential",
    "private_key",
)


def _safe_value(value: Any, key: str = "") -> Any:
    """递归过滤敏感字段，避免把凭据、二维码和签名写入审计表。"""
    key_lower = key.lower()
    if any(part in key_lower for part in _SENSITIVE_KEY_PARTS):
        return "[已脱敏]"
    if isinstance(value, Mapping):
        return {str(k): _safe_value(v, str(k)) for k, v in value.items()}
    if isinstance(value, (list, tuple)):
        return [_safe_value(item) for item in value]
    if isinstance(value, (str, int, float, bool)) or value is None:
        return value
    return str(value)


def record_audit(
    db: Session,
    current: User | None,
    *,
    action: str,
    target: str = "",
    detail: Mapping[str, Any] | str | None = None,
    success: bool = True,
) -> AuditLog:
    """加入一条审计记录；调用方负责与业务变更一起提交事务。"""
    if isinstance(detail, Mapping):
        detail_text = json.dumps(
            _safe_value(detail), ensure_ascii=False, separators=(",", ":")
        )
    elif detail is None:
        detail_text = ""
    else:
        detail_text = str(_safe_value(detail))
    if not success:
        detail_text = json.dumps(
            {"message": detail_text}, ensure_ascii=False, separators=(",", ":")
        )
    entry = AuditLog(
        user_id=current.id if current else None,
        username=current.username if current else "supplier",
        action=action,
        target=target,
        detail=detail_text,
        success=success,
    )
    db.add(entry)
    return entry


def record_account_action(
    db: Session,
    current: User | None,
    *,
    account: Account,
    action: str,
    event_type: str,
    title: str,
    target: str = "",
    detail: Mapping[str, Any] | str | None = None,
    success: bool = True,
    occurred_at: datetime | None = None,
) -> AuditLog:
    """账号相关操作：**审计与账号时间线一次写完**。

    为什么合成一个函数：这两件事必须成对出现 ——
    只写审计，账号时间线里就缺一条「谁在什么时候改了什么」；
    只发事件，合规审计里就缺一条。
    分两次调用写，迟早有人漏一边（S4 之前 `assigned` / `tag_changed`
    这两个事件类型定义了、前端也渲染了，但**从来没有代码发过**）。

    顺带把 `account_id` 落到审计上：审计页可以按账号过滤，且账号被删除后
    仍然查得到 —— `audit_logs.account_id` 是普通整型列、**没有外键**，
    所以允许指向已删除的账号（这正是删除账号时也记它的原因）。
    """
    entry = record_audit(
        db,
        current,
        action=action,
        target=target or account.username,
        detail=detail,
        success=success,
    )
    entry.account_id = account.id

    # 事件是旁路：emit 内部吞异常，记不上也绝不影响业务写入。
    emit(
        db,
        account_id=account.id,
        event_type=event_type,
        title=title,
        category=CATEGORY_OPS,
        occurred_at=occurred_at,
        # 细节同时给事件一份（先脱敏，避免凭据类字段进时间线）。
        # Mapping 直接作为事件 detail，不再套一层 —— 时间线里看到的就是
        # {"from": ..., "to": ...}，前端不必再往里挖一层。
        detail=dict(_safe_value(dict(detail))) if isinstance(detail, Mapping) else None,
        source="audit",
        actor_type="user",
        actor_id=current.id if current else None,
    )
    return entry