//go:build windows
// +build windows

package service

import (
	"fmt"
	"time"

	"github.com/evil7/hostsync/config"
	"github.com/evil7/hostsync/core"
	"github.com/evil7/hostsync/utils"
	"golang.org/x/sys/windows"
	"golang.org/x/sys/windows/svc"
	"golang.org/x/sys/windows/svc/mgr"
)

// NewServiceManager 创建服务管理器 (Windows)
func NewServiceManager() ServiceManager {
	return &WindowsServiceManager{}
}

// WindowsServiceManager Windows服务管理器
type WindowsServiceManager struct{}

// WindowsService 实现 Windows 服务接口
type WindowsService struct {
	stopChan    chan struct{}
	cronManager *core.CronManager
}

func (ws *WindowsService) Execute(args []string, r <-chan svc.ChangeRequest, changes chan<- svc.Status) (bool, uint32) {
	const cmdsAccepted = svc.AcceptStop | svc.AcceptShutdown | svc.AcceptPauseAndContinue

	changes <- svc.Status{State: svc.StartPending}
	// 启动服务逻辑
	if err := ws.startServiceLogic(); err != nil {
		utils.LogError("启动服务逻辑失败: %v", err)
		return true, 1
	}

	changes <- svc.Status{State: svc.Running, Accepts: cmdsAccepted}
	for c := range r {
		switch c.Cmd {
		case svc.Interrogate:
			changes <- c.CurrentStatus
		case svc.Stop, svc.Shutdown:
			changes <- svc.Status{State: svc.StopPending}
			ws.stopServiceLogic()
			return false, 0
		case svc.Pause:
			changes <- svc.Status{State: svc.Paused, Accepts: cmdsAccepted}
		case svc.Continue:
			changes <- svc.Status{State: svc.Running, Accepts: cmdsAccepted}
		default:
			utils.LogWarning("unexpected control request #%d", c)
		}
	}
	return false, 0
}

func (ws *WindowsService) startServiceLogic() error {
	utils.LogInfo("启动 HostSync 定时任务服务...")

	// 初始化配置
	config.Init()

	// 创建定时任务管理器
	ws.cronManager = core.NewCronManager()
	ws.cronManager.Start()

	// 加载hosts文件中的定时任务
	hostsManager := core.NewHostsManager()
	if err := hostsManager.Load(); err != nil {
		return fmt.Errorf("加载hosts文件失败: %v", err)
	}

	if err := ws.cronManager.LoadFromHosts(hostsManager); err != nil {
		return fmt.Errorf("加载定时任务失败: %v", err)
	}

	utils.LogSuccess("HostSync 定时任务服务已启动，共加载 %d 个任务", len(ws.cronManager.ListJobs()))

	// 启动状态监控
	go func() {
		ticker := time.NewTicker(5 * time.Minute)
		defer ticker.Stop()

		for {
			select {
			case <-ws.stopChan:
				return
			case <-ticker.C:
				utils.LogDebug("HostSync 定时任务服务运行正常")
			}
		}
	}()

	return nil
}

func (ws *WindowsService) stopServiceLogic() {
	utils.LogInfo("正在停止 HostSync 定时任务服务...")

	if ws.cronManager != nil {
		ws.cronManager.Stop()
		utils.LogInfo("定时任务管理器已停止")
	}

	close(ws.stopChan)
	utils.LogSuccess("HostSync 定时任务服务已停止")
}

// RunAsWindowsService 作为 Windows 服务运行
func RunAsWindowsService() error {
	service := &WindowsService{
		stopChan: make(chan struct{}),
	}
	return svc.Run(getServiceName(), service)
}

func (m *WindowsServiceManager) Install(execPath string) error {
	if err := ensureLogDir(); err != nil {
		return fmt.Errorf("创建日志目录失败: %v", err)
	}

	manager, err := mgr.Connect()
	if err != nil {
		return fmt.Errorf("连接服务管理器失败: %v", err)
	}
	defer manager.Disconnect()

	serviceName := getServiceName()
	displayName := getServiceDisplayName()
	description := getServiceDescription()

	// 检查服务是否已存在
	service, err := manager.OpenService(serviceName)
	if err == nil {
		service.Close()
		return fmt.Errorf("服务 %s 已存在", serviceName)
	}
	// 获取用户配置目录
	userConfigDir, err := getUserConfigDir()
	if err != nil {
		return fmt.Errorf("获取用户配置目录失败: %v", err)
	}

	// 服务启动参数 - 包含配置目录参数以确保服务以系统权限运行时能找到配置文件
	binPath := fmt.Sprintf(`"%s"`, execPath)
	args := []string{"service", "run", "--config", userConfigDir}
	config := mgr.Config{
		ServiceType:    windows.SERVICE_WIN32_OWN_PROCESS,
		StartType:      windows.SERVICE_AUTO_START,
		ErrorControl:   windows.SERVICE_ERROR_NORMAL,
		BinaryPathName: binPath,
		DisplayName:    displayName,
		Description:    description,
		Dependencies:   []string{"Tcpip", "Dnscache"},
	}

	service, err = manager.CreateService(serviceName, execPath, config, args...)
	if err != nil {
		return fmt.Errorf("创建服务失败: %v", err)
	}
	defer service.Close() // 设置服务故障恢复策略
	err = service.SetRecoveryActions([]mgr.RecoveryAction{
		{Type: windows.SC_ACTION_RESTART, Delay: 5 * time.Second},
		{Type: windows.SC_ACTION_RESTART, Delay: 5 * time.Second},
		{Type: windows.SC_ACTION_RESTART, Delay: 5 * time.Second}}, uint32((24 * time.Hour).Seconds()))
	if err != nil {
		utils.LogWarning("设置服务恢复策略失败: %v", err)
	}

	return nil
}

func (m *WindowsServiceManager) Uninstall() error {
	manager, err := mgr.Connect()
	if err != nil {
		return fmt.Errorf("连接服务管理器失败: %v", err)
	}
	defer manager.Disconnect()

	serviceName := getServiceName()
	service, err := manager.OpenService(serviceName)
	if err != nil {
		// 服务不存在，认为卸载成功
		return nil
	}
	defer service.Close()

	// 先停止服务
	status, err := service.Query()
	if err != nil {
		return fmt.Errorf("查询服务状态失败: %v", err)
	}

	if status.State != svc.Stopped {
		_, err = service.Control(svc.Stop)
		if err != nil {
			return fmt.Errorf("停止服务失败: %v", err)
		}

		// 等待服务停止
		timeout := time.Now().Add(30 * time.Second)
		for status.State != svc.Stopped {
			if time.Now().After(timeout) {
				return fmt.Errorf("等待服务停止超时")
			}
			time.Sleep(300 * time.Millisecond)
			status, err = service.Query()
			if err != nil {
				return fmt.Errorf("查询服务状态失败: %v", err)
			}
		}
	}

	// 删除服务
	err = service.Delete()
	if err != nil {
		return fmt.Errorf("删除服务失败: %v", err)
	}

	return nil
}

func (m *WindowsServiceManager) Start() error {
	manager, err := mgr.Connect()
	if err != nil {
		return fmt.Errorf("连接服务管理器失败: %v", err)
	}
	defer manager.Disconnect()

	serviceName := getServiceName()
	service, err := manager.OpenService(serviceName)
	if err != nil {
		return fmt.Errorf("打开服务失败: %v", err)
	}
	defer service.Close()

	err = service.Start()
	if err != nil {
		return fmt.Errorf("启动服务失败: %v", err)
	}

	return nil
}

func (m *WindowsServiceManager) Stop() error {
	manager, err := mgr.Connect()
	if err != nil {
		return fmt.Errorf("连接服务管理器失败: %v", err)
	}
	defer manager.Disconnect()

	serviceName := getServiceName()
	service, err := manager.OpenService(serviceName)
	if err != nil {
		return fmt.Errorf("打开服务失败: %v", err)
	}
	defer service.Close()

	status, err := service.Query()
	if err != nil {
		return fmt.Errorf("查询服务状态失败: %v", err)
	}

	if status.State == svc.Stopped {
		return nil // 服务已经停止
	}

	_, err = service.Control(svc.Stop)
	if err != nil {
		return fmt.Errorf("停止服务失败: %v", err)
	}

	return nil
}

func (m *WindowsServiceManager) Restart() error {
	if err := m.Stop(); err != nil {
		return err
	}

	// 等待一下再启动
	time.Sleep(2 * time.Second)
	return m.Start()
}

func (m *WindowsServiceManager) Status() (ServiceStatus, error) {
	manager, err := mgr.Connect()
	if err != nil {
		return StatusUnknown, fmt.Errorf("连接服务管理器失败: %v", err)
	}
	defer manager.Disconnect()

	serviceName := getServiceName()
	service, err := manager.OpenService(serviceName)
	if err != nil {
		return StatusNotInstalled, nil
	}
	defer service.Close()

	status, err := service.Query()
	if err != nil {
		return StatusUnknown, fmt.Errorf("查询服务状态失败: %v", err)
	}

	switch status.State {
	case svc.Running:
		return StatusRunning, nil
	case svc.Stopped:
		return StatusStopped, nil
	case svc.StartPending, svc.ContinuePending:
		return StatusRunning, nil
	case svc.StopPending, svc.PausePending, svc.Paused:
		return StatusStopped, nil
	default:
		return StatusUnknown, nil
	}
}