"""反向隧道业务逻辑：会话注册 / 注销 / 查询。

SSH 服务收到 remote port-forward 请求时调 register 记一条 active 会话；
user 断开时调 close 标记 ended_at；HTTP 路由调 get_active 查隧道端口做反代。
"""

from __future__ import annotations

import logging

from ..config import get_settings
from ..dao.tunnel_session_dao import TunnelSessionDAO
from ..models.tunnel_session import TunnelSession

logger = logging.getLogger("zikai.tunnel")


class TunnelService:
    def __init__(self, dao: TunnelSessionDAO) -> None:
        self.dao = dao
        self.settings = get_settings().tunnel

    def register(
        self, user_name: str, user_ip: str, tunnel_port: int, local_port: int,
    ) -> TunnelSession:
        """登记一条活跃隧道会话。

        若该 user 已有活跃会话先关闭旧的（同一 user 同一时刻只保留一条）。
        """
        self.dao.close_active_by_user(user_name)
        session = TunnelSession(
            user_name=user_name,
            user_ip=user_ip,
            local_port=local_port,
            tunnel_port=tunnel_port,
            status="active",
        )
        saved = self.dao.create(session)
        logger.info(
            "隧道建立 user=%s ip=%s tunnel_port=%d local_port=%d",
            user_name, user_ip, tunnel_port, local_port,
        )
        return saved

    def close(self, user_name: str) -> int:
        """关闭该 user 的活跃会话（SSH 断开时调用），返回关闭条数。"""
        n = self.dao.close_active_by_user(user_name)
        if n:
            logger.info("隧道关闭 user=%s 条数=%d", user_name, n)
        return n

    def get_active(self, user_name: str) -> TunnelSession | None:
        return self.dao.get_active_by_user(user_name)

    def is_port_allowed(self, user_name: str, tunnel_port: int) -> bool:
        """校验该 user 是否被允许绑定该隧道端口（防 user 乱绑端口）。"""
        user = self.settings.find_user(user_name)
        return user is not None and user.tunnel_port == tunnel_port

    def reap_orphans(self) -> int:
        """兜底清理：关闭所有 active 会话（进程重启时 DB 里残留的孤儿记录）。

        由后台 reaper 在启动后调用一次。SSH 实际断开时已有 close() 处理，
        这里只兜底进程异常退出后 DB 与实际状态不一致的情况。
        """
        active = self.dao.list_active()
        for session in active:
            self.dao.close(session)
            logger.info("reaper 清理孤儿隧道 id=%d user=%s", session.id, session.user_name)
        return len(active)