"""企业微信渠道插件生命周期钩子处理。

实现 ``LifecycleHookHandler`` Protocol，管理插件级资源（httpx 连接池），
响应宿主生命周期状态变迁。

设计要点：
- LifecycleHandler 为单实例（非 per-account），可持有 mutable 状态用于
  资源管理（与适配器的 INV-5 无 mutable 状态约束不同）。
- httpx 连接池在 ``onInit`` 创建并注入 ``WecomClient``，``onUnload``
  解除引用后关闭；连接数上限对齐 manifest.json 中
  ``resource_quota.max_connections=50``。
- ``onReconfigure`` 从配置 schema 派生不可热更新键列表
  （``hot_reloadable=False``），变更时抛 ``ConfigRestartRequiredError``。
- ``onFail`` 不抛异常，不阻断降级流程；logger 不可用时回退 ``stderr``。

依赖方向：仅 import ``yuxi.channels.contract.*`` + 标准库 + httpx，
不污染框架层。
"""

from __future__ import annotations

import sys
from typing import TYPE_CHECKING, Any

import httpx

from yuxi.channels.contract.dtos.config import ConfigField
from yuxi.channels.contract.errors import ConfigRestartRequiredError
from yuxi.channels.contract.ports.driven.cache_port import CachePort
from yuxi.channels.contract.ports.driven.config_port import ConfigPort
from yuxi.channels.contract.ports.driven.logger_port import LoggerPort

from ._constants import (
    HTTP_MAX_CONNECTIONS,
    HTTP_MAX_KEEPALIVE_CONNECTIONS,
    HTTP_TIMEOUT_SECONDS,
)

if TYPE_CHECKING:
    from .wecom_client import WecomClient


class WecomLifecycleHandler:
    """企业微信渠道插件生命周期钩子处理。

    单实例，管理插件级资源生命周期。``_http_client`` 为共享连接池，通过
    ``attach_http_client`` 注入 ``WecomClient`` 供其复用（避免每请求新建
    TCP 连接）；``onReconfigure`` 通过入参 ``old_config`` 做差异化校验，
    不再自行维护基线缓存。不可热更新键列表从配置 schema 派生
    （``hot_reloadable=False``），``config_schema`` 必填。
    """

    def __init__(
        self,
        config_port: ConfigPort,
        logger_port: LoggerPort,
        cache_port: CachePort,
        config_schema: tuple[ConfigField, ...],
        client: WecomClient | None = None,
    ) -> None:
        self._config = config_port
        self._logger = logger_port
        self._cache = cache_port
        self._client = client
        self._http_client: httpx.AsyncClient | None = None
        self._started: bool = False
        self._restart_required_keys: tuple[str, ...] = tuple(
            field.key for field in config_schema if not field.hot_reloadable
        )

    # ------------------------------------------------------------------
    # LifecycleHookHandler Protocol 实现
    # ------------------------------------------------------------------

    async def onInit(self) -> None:
        """初始化资源：创建 httpx 连接池并注入 WecomClient。"""
        self._http_client = httpx.AsyncClient(
            timeout=HTTP_TIMEOUT_SECONDS,
            limits=httpx.Limits(
                max_connections=HTTP_MAX_CONNECTIONS,
                max_keepalive_connections=HTTP_MAX_KEEPALIVE_CONNECTIONS,
            ),
        )
        if self._client is not None:
            self._client.attach_http_client(self._http_client)
        await self._logger.info("Wecom plugin initialized")

    async def onStart(self) -> None:
        """标记插件就绪。"""
        self._started = True
        await self._logger.info("Wecom plugin started")

    async def onStop(self) -> None:
        """停止插件：标记未就绪，等待在途请求完成。"""
        await self._logger.info(
            "Wecom plugin stopping, waiting for in-flight requests",
        )
        self._started = False

    async def onPause(self) -> None:
        """暂停插件：停止接收新请求。"""
        self._started = False
        await self._logger.info("Wecom plugin paused")

    async def onResume(self) -> None:
        """恢复插件：重新接收请求。"""
        self._started = True
        await self._logger.info("Wecom plugin resumed")

    async def onUnload(self) -> None:
        """释放所有资源：解除 WecomClient 引用后关闭 httpx 连接池。"""
        if self._client is not None:
            self._client.detach_http_client()
        if self._http_client is not None:
            try:
                await self._http_client.aclose()
            except Exception as exc:
                await self._logger.warn(
                    "Wecom httpx client close failed during unload",
                    error=str(exc),
                )
            self._http_client = None

        self._started = False
        await self._logger.info("Wecom plugin unloaded")

    async def onReconfigure(
        self,
        *,
        old_config: dict[str, Any] | None = None,
        new_config: dict[str, Any],
    ) -> None:
        """配置热更新：校验不可热更新字段。

        - 不可热更新键（``hot_reloadable=False``，如 ``corp_id`` /
          ``corp_secret`` / ``agent_id`` / ``encoding_aes_key`` / ``token`` /
          ``webhook_url`` / ``external_contact_secret`` / ``kf_secret``）变更
          抛 ``ConfigRestartRequiredError``（FR-37）。
        - ``old_config`` 为 ``None``（首次调用或无基线）时仅记录日志，不做对比。
        - 校验失败由宿主回滚，本方法无副作用。
        """
        if old_config is None:
            await self._logger.info("Wecom plugin initial config baseline set")
            return

        for key in self._restart_required_keys:
            new_value = new_config.get(key)
            old_value = old_config.get(key)
            if new_value != old_value:
                raise ConfigRestartRequiredError(key=key) from None

        await self._logger.info("Wecom plugin reconfigured")

    async def onFail(self, error: str) -> None:
        """失败清理：不抛异常，不阻断降级流程（FR-36）。

        logger 不可用时回退 ``sys.stderr.write``，确保失败信息不丢失。
        """
        self._started = False
        try:
            await self._logger.error("Wecom plugin failed", error=error)
        except Exception as exc:
            sys.stderr.write(f"Wecom plugin failed: {error}\nLogger error: {exc}\n")


__all__ = ["WecomLifecycleHandler"]