# -*- coding: utf-8 -*-
"""后台审计日志。

（自 auth_system.py 拆出，行为与原实现一致；DB 访问已迁移为原生异步。）
"""

import time

from .db import (
    _q,
    _x,
    write_transaction,
)

# ============ 日志 ============


# 日志裁剪计数器（原实现用 secrets.randbelow 触发——密码学随机数浪费熵池）
_LOG_WRITE_COUNTER = {'n': 0}


async def add_log(log_type: str, username: str, ip: str, action: str, detail: str = '') -> None:
    try:
        await _x('INSERT INTO logs (type, username, ip, action, detail, time) VALUES (?, ?, ?, ?, ?, ?)',
                 (log_type, username or '', ip or '-', action or '', detail or '',
                  time.strftime('%Y-%m-%d %H:%M:%S')))
        # 控制日志表体积（每 50 次写入触发一次裁剪）
        _LOG_WRITE_COUNTER['n'] += 1
        if _LOG_WRITE_COUNTER['n'] % 50 == 0:
            await _x('DELETE FROM logs WHERE id NOT IN (SELECT id FROM logs ORDER BY id DESC LIMIT 5000)')
    except Exception:
        pass


async def query_logs(log_type: str, limit: int = 100, offset: int = 0):
    """分页查询日志，返回 (日志列表, 总条数)"""
    limit = max(1, min(int(limit), 500))
    offset = max(0, int(offset))
    rows = await _q('SELECT * FROM logs WHERE type = ? ORDER BY id DESC LIMIT ? OFFSET ?',
                    (log_type, limit, offset))
    total_row = await _q('SELECT COUNT(*) AS c FROM logs WHERE type = ?', (log_type,))
    total = int(total_row[0]['c']) if total_row else 0
    return [dict(r) for r in rows], total


async def clear_logs(log_type: str) -> int:
    """清除指定类型的全部日志，返回删除条数"""
    async with write_transaction() as conn:
        cur = await conn.execute('DELETE FROM logs WHERE type = ?', (log_type,))
        return cur.rowcount