#!/usr/bin/env python3
# -*- coding: utf-8 -*-
r"""Windows 服务外壳 (2026-09-17 用户令 1: "windows 下为 windows 服务")。

## 为什么用 ctypes 直接调 SCM，而不是 pywin32

真 Windows 服务**必须**实现 SCM 的控制协议（`StartServiceCtrlDispatcher` + 控制处理回调），
`sc create` 一个 `python.exe xxx.py` 是**不行的**（cmd/python 不跟 SCM 握手 ⇒ 起服务报 1053）。
实现它有两条路：

  · `pywin32`（`win32serviceutil`）—— 要往包里加一个新依赖（本包离线轮子的原则是"能不加就不加"）；
  · **ctypes 直连 advapi32**（本文件）—— 零依赖、只用标准库，与"单包离线"的口径一致。

## 用法

    python scripts\win_service.py                 # 由服务控制管理器拉起（正常路径，别手工跑）
    python scripts\win_service.py --debug         # 前台调试：控制台里跑守护循环，Ctrl+C 退出
    python scripts\win_service.py --debug --once  # 只跑一轮巡检就退出（无权限也能自证）
    python scripts\win_service.py --selftest      # 只做前置条件自检

    # 注册/卸载走 service_ctl.py（需要管理员）：
    python scripts\service_ctl.py install --dry-run
    python scripts\service_ctl.py install

## 与 SCM 的约定

    SERVICE_WIN32_OWN_PROCESS · 接受 STOP/SHUTDOWN/INTERROGATE
    启动过程中报 START_PENDING（带 wait hint），就绪后报 RUNNING，收到 STOP 后停服务再报 STOPPED
    服务崩溃的自动重启交给 SCM 的恢复策略（`sc failure ... actions= restart/60000/...`，见 service_ctl.py）
"""
from __future__ import annotations

import ctypes
import pathlib
import sys
import threading
import time

ROOT = pathlib.Path(__file__).resolve().parents[1]
sys.path.insert(0, str(ROOT))
from src import version as V                                        # noqa: E402
import service_worker as SW                                         # noqa: E402  (同目录)

SERVICE_WIN32_OWN_PROCESS = 0x00000010
SERVICE_ACCEPT_STOP = 0x00000001
SERVICE_ACCEPT_SHUTDOWN = 0x00000004
SERVICE_CONTROL_STOP = 0x00000001
SERVICE_CONTROL_INTERROGATE = 0x00000004
SERVICE_CONTROL_SHUTDOWN = 0x00000005
SERVICE_STOPPED, SERVICE_START_PENDING, SERVICE_STOP_PENDING = 0x00000001, 0x00000002, 0x00000003
SERVICE_RUNNING, SERVICE_CONTINUE_PENDING = 0x00000004, 0x00000005
NO_ERROR = 0
ERROR_FAILED_SERVICE_CONTROLLER_CONNECT = 1063

advapi32 = ctypes.windll.advapi32 if hasattr(ctypes, 'windll') else None


class SERVICE_STATUS(ctypes.Structure):
    _fields_ = [('dwServiceType', ctypes.c_ulong), ('dwCurrentState', ctypes.c_ulong),
                ('dwControlsAccepted', ctypes.c_ulong), ('dwWin32ExitCode', ctypes.c_ulong),
                ('dwServiceSpecificExitCode', ctypes.c_ulong), ('dwCheckPoint', ctypes.c_ulong),
                ('dwWaitHint', ctypes.c_ulong)]


class SERVICE_TABLE_ENTRY(ctypes.Structure):
    _fields_ = [('lpServiceName', ctypes.c_wchar_p), ('lpServiceProc', ctypes.c_void_p)]


HANDLER = ctypes.WINFUNCTYPE(ctypes.c_ulong, ctypes.c_ulong, ctypes.c_ulong, ctypes.c_void_p, ctypes.c_void_p)
MAIN = ctypes.WINFUNCTYPE(None, ctypes.c_ulong, ctypes.POINTER(ctypes.c_wchar_p))

_status_handle = None
_stop_evt = threading.Event()


def _report(state: int, hint: int = 0, cp: int = 0) -> None:
    if not _status_handle:
        return
    st = SERVICE_STATUS(SERVICE_WIN32_OWN_PROCESS, state,
                        SERVICE_ACCEPT_STOP | SERVICE_ACCEPT_SHUTDOWN, NO_ERROR, 0, cp, hint)
    advapi32.SetServiceStatus(_status_handle, ctypes.byref(st))


def _handler(control, event_type, event_data, context):
    """SCM 控制回调：只处理 STOP/SHUTDOWN/INTERROGATE，其余直接确认。"""
    if control in (SERVICE_CONTROL_STOP, SERVICE_CONTROL_SHUTDOWN):
        _report(SERVICE_STOP_PENDING, 30000, 1)
        _stop_evt.set()
    elif control == SERVICE_CONTROL_INTERROGATE:
        _report(SERVICE_RUNNING)
    return NO_ERROR


@MAIN
def _service_main(argc, argv) -> None:
    global _status_handle
    _status_handle = advapi32.RegisterServiceCtrlHandlerExW(V.SERVICE_NAME, _HANDLER_REF, None)
    if not _status_handle:
        return
    _report(SERVICE_START_PENDING, 30000, 1)
    SW.log(f'服务已由 SCM 拉起（{V.SERVICE_DISPLAY}）')
    t = threading.Thread(target=_body, name='guanlan-supervisor', daemon=True)
    t.start()
    _report(SERVICE_RUNNING)
    _stop_evt.wait()
    SW.stop()
    _report(SERVICE_STOPPED)


_HANDLER_REF = HANDLER(_handler)


def _body() -> None:
    """服务主体：起组件 → 守护。异常必须自己吞掉并记 ERROR，否则线程静默死掉。"""
    try:
        SW.start()
        SW.supervise(_stop_evt)
    except Exception as e:
        SW.log(f'服务主体异常: {type(e).__name__}: {e}', 'ERROR')


def run_debug(once: bool = False) -> int:
    """前台调试（不需要 SCM）：--once 只跑一轮，用于无权限环境自证。"""
    if once:
        SW.log('调试模式：跑一轮巡检')
        ok = SW.ensure()
        SW.log(f'一轮巡检结果: 网关{"在听" if ok else "未就绪"}')
        return 0
    SW.log('调试模式：Ctrl+C 退出')
    try:
        SW.start()
        SW.supervise(_stop_evt)
    except KeyboardInterrupt:
        pass
    finally:
        SW.stop()
    return 0


def main() -> int:
    if '--selftest' in sys.argv:
        return SW.selftest()
    if '--debug' in sys.argv:
        return run_debug(once='--once' in sys.argv)
    if advapi32 is None:
        print('[X] 本文件只在 Windows 上有效（Linux 用 scripts/service_main.py + systemd）')
        return 2
    table = (SERVICE_TABLE_ENTRY * 2)()
    table[0].lpServiceName = V.SERVICE_NAME
    table[0].lpServiceProc = ctypes.cast(_service_main, ctypes.c_void_p)
    table[1].lpServiceName = None
    table[1].lpServiceProc = None
    ok = advapi32.StartServiceCtrlDispatcherW(ctypes.byref(table))
    if not ok:
        err = ctypes.windll.kernel32.GetLastError()
        if err in (ERROR_FAILED_SERVICE_CONTROLLER_CONNECT, 0):
            # 这条**正是无权限自证**：能走到这里说明 SCM 接口调用正确，只是本进程不是被 SCM 拉起的。
            print(f'[{V.SERVICE_NAME}] 不是由服务控制管理器启动的（WinError {ERROR_FAILED_SERVICE_CONTROLLER_CONNECT}）。')
            print('  想注册成服务（需管理员）: python scripts/service_ctl.py install')
            print('  想前台调试:              python scripts/win_service.py --debug [--once]')
            print('  只看前置条件:            python scripts/win_service.py --selftest')
        else:
            print(f'[X] StartServiceCtrlDispatcher 失败, WinError {err}')
        return 1
    return 0


if __name__ == '__main__':
    sys.exit(main())