/****************************** Module Header ******************************\
* Module Name:  ServiceInstaller.cpp
* Project:      CppWindowsService
* Copyright (c) Microsoft Corporation.
* 
* The file implements functions that install and uninstall the service.
* 
* This source is subject to the Microsoft Public License.
* See http://www.microsoft.com/en-us/openness/resources/licenses.aspx#MPL.
* All other rights reserved.
* 
* THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND, 
* EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE IMPLIED 
* WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A PARTICULAR PURPOSE.
\***************************************************************************/

#pragma region "Includes"
#include "ServiceBase.h"
#include "ServiceInstaller.h"
#pragma endregion

static bool LogError(const char* funcname)
{
  fprintf(stderr, "%s failed with error 0x%08lx\n", funcname, GetLastError());
  return false;
}

class SCManager
{
  SC_HANDLE _handle;

public:
  bool IsOk() const { return _handle != NULL; }
  operator SC_HANDLE() const { return _handle; }

  bool Start(LPCTSTR pszServiceName);
  bool Stop(LPCTSTR pszServiceName);
  bool Delete(LPCTSTR pszServiceName);

  SCManager(DWORD mode)
  {
    _handle = ::OpenSCManager(NULL, NULL, mode);
    if (_handle == NULL)
      LogError("OpenSCManager");
  }
  ~SCManager()
  {
    if (_handle != NULL)
      CloseServiceHandle(_handle);
  }
};

bool SCManager::Stop(LPCTSTR pszServiceName)
{
    bool bDone = false;

    if (IsOk())
    {
      // Open the service with delete, stop, and query status permissions
      SC_HANDLE schService = ::OpenService(_handle, pszServiceName, SERVICE_STOP | SERVICE_QUERY_STATUS);
      if (schService == NULL)
      {
          LogError("OpenService");
          return false;
      }

      // Try to stop the service
      SERVICE_STATUS ssSvcStatus = {};
      if (::ControlService(schService, SERVICE_CONTROL_STOP, &ssSvcStatus))
      {
        wprintf(L"Stopping %s.", pszServiceName);
        while (::QueryServiceStatus(schService, &ssSvcStatus))
        {
            if (ssSvcStatus.dwCurrentState == SERVICE_STOP_PENDING)
            {
                wprintf(L".");
                Sleep(1000);
            }
            else 
              break;
        }

        bDone = ssSvcStatus.dwCurrentState == SERVICE_STOPPED;
        wprintf(L"\n");
      }

      ::CloseServiceHandle(schService);

      if (bDone)
          wprintf(L"\n%s is stopped.\n", pszServiceName);
      else
          wprintf(L"\n%s failed to stop.\n", pszServiceName);
    }
    return bDone;
}

bool SCManager::Start(LPCTSTR pszServiceName)
{
    bool bDone = false;
    if (IsOk())
    {
      SC_HANDLE schService = OpenService(_handle, pszServiceName, SERVICE_START);
      if (schService)
      {
        bDone = ::StartService(schService, 0, NULL) != 0;
        if (bDone)
          wprintf(L"%s started.\n", pszServiceName);
        else
          LogError("StartService");
      }
      else
        LogError("OpenService");
    }
    return bDone;
}


bool SCManager::Delete(LPCTSTR pszServiceName)
{
    bool bDone = false;
    if (IsOk())
    {
      // Open the service with delete, stop, and query status permissions
      SC_HANDLE schService = ::OpenService(_handle, pszServiceName, DELETE);
      if (schService)
      {
        // Now remove the service by calling DeleteService.
        bDone = ::DeleteService(schService) != 0;
        if (bDone)
          wprintf(L"%s has been removed.\n", pszServiceName);
        else
          LogError("DeleteService");

        // Centralized cleanup for all allocated resources.
        if (schService)
        {
            CloseServiceHandle(schService);
            schService = NULL;
        }
      }
      else
          LogError("OpenService");
    }
    return bDone;
}

//
//   FUNCTION: InstallService
//
//   PURPOSE: Install the current application as a service to the local 
//   service control manager database.
//
//   PARAMETERS:
//   * pszServiceName - the name of the service to be installed
//   * pszDisplayName - the display name of the service
//   * dwStartType - the service start option. This parameter can be one of 
//     the following values: SERVICE_AUTO_START, SERVICE_BOOT_START, 
//     SERVICE_DEMAND_START, SERVICE_DISABLED, SERVICE_SYSTEM_START.
//   * pszDependencies - a pointer to a double null-terminated array of null-
//     separated names of services or load ordering groups that the system 
//     must start before this service.
//   * pszAccount - the name of the account under which the service runs.
//   * pszPassword - the password to the account name.
//
//   NOTE: If the function fails to install the service, it prints the error 
//   in the standard output stream for users to diagnose the problem.
//
void InstallService(LPCTSTR pszServiceName, 
                    LPCTSTR pszDisplayName, 
                    DWORD   dwStartType,
                    LPCTSTR pszDependencies, 
                    LPCTSTR pszAccount, 
                    LPCTSTR pszPassword)
{
    TCHAR szPath[MAX_PATH];
    if (::GetModuleFileName(NULL, szPath, ARRAYSIZE(szPath)) == 0)
    {
        LogError("GetModuleFileName");
        return;
    }

    // Open the local default service control manager database
    SCManager schSCManager(SC_MANAGER_CONNECT | SC_MANAGER_CREATE_SERVICE);
    if (schSCManager.IsOk())
    {
      // Install the service into SCM by calling CreateService
      SC_HANDLE schService = ::CreateService(
          schSCManager,                   // SCManager database
          pszServiceName,                 // Name of service
          pszDisplayName,                 // Name to display
          SERVICE_QUERY_STATUS,           // Desired access
          SERVICE_WIN32_OWN_PROCESS,      // Service type
          dwStartType,                    // Service start type
          SERVICE_ERROR_NORMAL,           // Error control type
          szPath,                         // Service's binary
          NULL,                           // No load ordering group
          NULL,                           // No tag identifier
          pszDependencies,                // Dependencies
          pszAccount,                     // Service running account
          pszPassword                     // Password of the account
          );
      if (schService != NULL)
      {
        wprintf(L"%s has been installed.\n", pszServiceName);
        CloseServiceHandle(schService);
      }
      else
        LogError("CreateService");
    }
}


//
//   FUNCTION: UninstallService
//
//   PURPOSE: Stop and remove the service from the local service control 
//   manager database.
//
//   PARAMETERS: 
//   * pszServiceName - the name of the service to be removed.
//
//   NOTE: If the function fails to uninstall the service, it prints the 
//   error in the standard output stream for users to diagnose the problem.
//
void UninstallService(PWSTR pszServiceName)
{
    // Open the local default service control manager database
    SCManager schSCManager(SC_MANAGER_CONNECT);
    if (schSCManager.IsOk())
    {
      schSCManager.Stop(pszServiceName);
      schSCManager.Delete(pszServiceName);
    }
}

void StartService(PWSTR pszServiceName)
{
    SCManager schSCManager(SC_MANAGER_CONNECT);
    if (schSCManager.IsOk())
      schSCManager.Start(pszServiceName);
}

void StopService(PWSTR pszServiceName)
{
    SCManager schSCManager(SC_MANAGER_CONNECT);
    if (schSCManager.IsOk())
      schSCManager.Stop(pszServiceName);
}