/** @file
 *
 * @par History
 *
 * @note Implementation of CNTService
 */


#include "NTService.h"
#include "ntservmsg.h"  // Event message ids
#include <stdio.h>

// Custom Controls Below Here
#define SERVICE_CONTROL_BEEP 0x000004B0
#define SERVICE_CONTROL_STOP_POL 0x000004B1
namespace Pol
{
namespace Clib
{
// static variables
CNTService* CNTService::m_pThis = nullptr;

CNTService::CNTService( const char* szServiceName )
{
  // copy the address of the current object so we can access it from
  // the static member callback functions.
  // WARNING: This limits the application to only one CNTService object.
  m_pThis = this;

  // Set the default service name and version
  strncpy( m_szServiceName, szServiceName, sizeof( m_szServiceName ) - 1 );
  m_iMajorVersion = 1;
  m_iMinorVersion = 0;
  m_hEventSource = nullptr;

  // set up the initial service status
  m_hServiceStatus = nullptr;
  m_Status.dwServiceType = SERVICE_WIN32_OWN_PROCESS;
  m_Status.dwCurrentState = SERVICE_STOPPED;
  m_Status.dwControlsAccepted = SERVICE_ACCEPT_STOP;
  m_Status.dwWin32ExitCode = 0;
  m_Status.dwServiceSpecificExitCode = 0;
  m_Status.dwCheckPoint = 0;
  m_Status.dwWaitHint = 0;
  m_bIsRunning = FALSE;
}

CNTService::~CNTService()
{
  DebugMsg( "CNTService::~CNTService()" );
  if ( m_hEventSource )
  {
    ::DeregisterEventSource( m_hEventSource );
  }
}

////////////////////////////////////////////////////////////////////////////////////////
// Default command line argument parsing

// Returns TRUE if it found an arg it recognised, FALSE if not
// Note: processing some arguments causes output to stdout to be generated.
BOOL CNTService::ParseStandardArgs( int argc, char* argv[] )
{
  // See if we have any command line args we recognise
  if ( argc <= 1 )
    return FALSE;

  if ( _stricmp( argv[1], "-v" ) == 0 )
  {
    // Spit out version info
    printf( "%s Version %d.%d\n", m_szServiceName, m_iMajorVersion, m_iMinorVersion );
    printf( "The service is %s installed\n", IsInstalled() ? "currently" : "not" );
    return TRUE;  // say we processed the argument
  }
  else if ( _stricmp( argv[1], "-i" ) == 0 )
  {
    // Request to install.
    if ( IsInstalled() )
    {
      printf( "%s is already installed\n", m_szServiceName );
    }
    else
    {
      // Try and install the copy that's running
      if ( Install() )
      {
        printf( "%s installed\n", m_szServiceName );
      }
      else
      {
        printf( "%s failed to install. Error %u\n", m_szServiceName, GetLastError() );
      }
    }
    return TRUE;  // say we processed the argument
  }
  else if ( _stricmp( argv[1], "-u" ) == 0 )
  {
    // Request to uninstall.
    if ( !IsInstalled() )
    {
      printf( "%s is not installed\n", m_szServiceName );
    }
    else
    {
      // Try and remove the copy that's installed
      if ( Uninstall() )
      {
        // Get the executable file path
        char szFilePath[MAX_PATH];
        ::GetModuleFileName( nullptr, szFilePath, sizeof( szFilePath ) );
        printf( "%s removed. (You must delete the file (%s) yourself.)\n", m_szServiceName,
                szFilePath );
      }
      else
      {
        printf( "Could not remove %s. Error %u\n", m_szServiceName, GetLastError() );
      }
    }
    return TRUE;  // say we processed the argument
  }
  else if ( _stricmp( argv[1], "-s" ) == 0 )
  {
    // run as a service
    printf( "Running as a service.\n" );

    if ( !StartService() )
    {
      printf( "Unable to run as a service.\n" );
    }

    return TRUE;
  }


  // Don't recognise the args
  return FALSE;
}

////////////////////////////////////////////////////////////////////////////////////////
// Install/uninstall routines

// Test if the service is currently installed
BOOL CNTService::IsInstalled()
{
  BOOL bResult = FALSE;

  // Open the Service Control Manager
  SC_HANDLE hSCM = ::OpenSCManager( nullptr,                  // local machine
                                    nullptr,                  // ServicesActive database
                                    SC_MANAGER_ALL_ACCESS );  // full access
  if ( hSCM )
  {
    // Try to open the service
    SC_HANDLE hService = ::OpenService( hSCM, m_szServiceName, SERVICE_QUERY_CONFIG );
    if ( hService )
    {
      bResult = TRUE;
      ::CloseServiceHandle( hService );
    }

    ::CloseServiceHandle( hSCM );
  }

  return bResult;
}

BOOL CNTService::Install()
{
  // Open the Service Control Manager
  SC_HANDLE hSCM = ::OpenSCManager( nullptr,                  // local machine
                                    nullptr,                  // ServicesActive database
                                    SC_MANAGER_ALL_ACCESS );  // full access
  if ( !hSCM )
    return FALSE;

  // Get the executable file path
  char szFilePath[MAX_PATH];
  ::GetModuleFileName( nullptr, szFilePath, sizeof( szFilePath ) );
  strcat( szFilePath, " -s" );

  // Create the service
  SC_HANDLE hService = ::CreateService( hSCM, m_szServiceName, m_szServiceName, SERVICE_ALL_ACCESS,
                                        SERVICE_WIN32_OWN_PROCESS | SERVICE_INTERACTIVE_PROCESS,
                                        SERVICE_DEMAND_START,  // start condition
                                        SERVICE_ERROR_NORMAL, szFilePath, nullptr, nullptr, nullptr,
                                        nullptr, nullptr );
  if ( !hService )
  {
    ::CloseServiceHandle( hSCM );
    return FALSE;
  }

  // make registry entries to support logging messages
  // Add the source name as a subkey under the Application
  // key in the EventLog service portion of the registry.
  char szKey[256];
  HKEY hKey = nullptr;
  strcpy( szKey, "SYSTEM\\CurrentControlSet\\Services\\EventLog\\Application\\" );
  strcat( szKey, m_szServiceName );
  if (::RegCreateKey( HKEY_LOCAL_MACHINE, szKey, &hKey ) != ERROR_SUCCESS )
  {
    ::CloseServiceHandle( hService );
    ::CloseServiceHandle( hSCM );
    return FALSE;
  }

  // Add the Event ID message-file name to the 'EventMessageFile' subkey.
  ::RegSetValueEx( hKey, "EventMessageFile", 0, REG_EXPAND_SZ, (CONST BYTE*)szFilePath,
                   static_cast<DWORD>( strlen( szFilePath ) + 1 ) );

  // Set the supported types flags.
  DWORD dwData = EVENTLOG_ERROR_TYPE | EVENTLOG_WARNING_TYPE | EVENTLOG_INFORMATION_TYPE;
  ::RegSetValueEx( hKey, "TypesSupported", 0, REG_DWORD, (CONST BYTE*)&dwData, sizeof( DWORD ) );
  ::RegCloseKey( hKey );

  LogEvent( EVENTLOG_INFORMATION_TYPE, EVMSG_INSTALLED, m_szServiceName );

  // tidy up
  ::CloseServiceHandle( hService );
  ::CloseServiceHandle( hSCM );
  return TRUE;
}

BOOL CNTService::Uninstall()
{
  // Open the Service Control Manager
  SC_HANDLE hSCM = ::OpenSCManager( nullptr,                  // local machine
                                    nullptr,                  // ServicesActive database
                                    SC_MANAGER_ALL_ACCESS );  // full access
  if ( !hSCM )
    return FALSE;

  BOOL bResult = FALSE;
  SC_HANDLE hService = ::OpenService( hSCM, m_szServiceName, DELETE );
  if ( hService )
  {
    if (::DeleteService( hService ) )
    {
      LogEvent( EVENTLOG_INFORMATION_TYPE, EVMSG_REMOVED, m_szServiceName );
      bResult = TRUE;
    }
    else
    {
      LogEvent( EVENTLOG_ERROR_TYPE, EVMSG_NOTREMOVED, m_szServiceName );
    }
    ::CloseServiceHandle( hService );
  }

  ::CloseServiceHandle( hSCM );
  return bResult;
}

///////////////////////////////////////////////////////////////////////////////////////
// Logging functions

// This function makes an entry into the application event log
void CNTService::LogEvent( WORD wType, DWORD dwID, const char* pszS1, const char* pszS2,
                           const char* pszS3 )
{
  const char* ps[3];
  ps[0] = pszS1;
  ps[1] = pszS2;
  ps[2] = pszS3;

  WORD iStr = 0;
  for ( WORD i = 0; i < 3; i++ )
  {
    if ( ps[i] != nullptr )
      iStr++;
  }

  // Check the event source has been registered and if
  // not then register it now
  if ( !m_hEventSource )
  {
    m_hEventSource = ::RegisterEventSource( nullptr,            // local machine
                                            m_szServiceName );  // source name
  }

  if ( m_hEventSource )
  {
    ::ReportEvent( m_hEventSource, wType, 0, dwID,
                   nullptr,  // sid
                   iStr, 0, ps, nullptr );
  }
}

//////////////////////////////////////////////////////////////////////////////////////////////
// Service startup and registration

BOOL CNTService::StartService()
{
  SERVICE_TABLE_ENTRY st[] = {{m_szServiceName, ServiceMain}, {nullptr, nullptr}};

  DebugMsg( "Calling StartServiceCtrlDispatcher()" );
  BOOL b = ::StartServiceCtrlDispatcher( st );
  if ( !b )
  {
    DWORD rc = GetLastError();
    DebugMsg( "StartServiceCtrlDispatcher returned false: %d", rc );
  }
  DebugMsg( "Returned from StartServiceCtrlDispatcher()" );
  return b;
}

// static member function (callback)
void CNTService::ServiceMain( DWORD /*dwArgc*/, LPTSTR* /*lpszArgv*/ )
{
  // Get a pointer to the C++ object
  CNTService* pService = m_pThis;

  pService->DebugMsg( "Entering CNTService::ServiceMain()" );
  // Register the control request handler
  pService->m_Status.dwCurrentState = SERVICE_START_PENDING;
  pService->m_hServiceStatus = RegisterServiceCtrlHandler( pService->m_szServiceName, Handler );
  if ( pService->m_hServiceStatus == nullptr )
  {
    pService->LogEvent( EVENTLOG_ERROR_TYPE, EVMSG_CTRLHANDLERNOTINSTALLED );
    return;
  }

  // Start the initialisation
  if ( pService->Initialize() )
  {
    // Do the real work.
    // When the Run function returns, the service has stopped.
    pService->m_bIsRunning = TRUE;
    pService->m_Status.dwWin32ExitCode = 0;
    pService->m_Status.dwCheckPoint = 0;
    pService->m_Status.dwWaitHint = 0;
    pService->Run();
  }

  // Tell the service manager we are stopped
  pService->SetStatus( SERVICE_STOPPED );

  pService->DebugMsg( "Leaving CNTService::ServiceMain()" );
}

///////////////////////////////////////////////////////////////////////////////////////////
// status functions

void CNTService::SetStatus( DWORD dwState )
{
  DebugMsg( "CNTService::SetStatus(%lu, %lu)", m_hServiceStatus, dwState );
  m_Status.dwCurrentState = dwState;
  ::SetServiceStatus( m_hServiceStatus, &m_Status );
}

///////////////////////////////////////////////////////////////////////////////////////////
// Service initialization

BOOL CNTService::Initialize()
{
  DebugMsg( "Entering CNTService::Initialize()" );

  // Start the initialization
  SetStatus( SERVICE_START_PENDING );

  // Perform the actual initialization
  BOOL bResult = OnInit();

  // Set final state
  m_Status.dwWin32ExitCode = GetLastError();
  m_Status.dwCheckPoint = 0;
  m_Status.dwWaitHint = 0;
  if ( !bResult )
  {
    LogEvent( EVENTLOG_ERROR_TYPE, EVMSG_FAILEDINIT );
    SetStatus( SERVICE_STOPPED );
    return FALSE;
  }

  LogEvent( EVENTLOG_INFORMATION_TYPE, EVMSG_STARTED );
  SetStatus( SERVICE_RUNNING );

  DebugMsg( "Leaving CNTService::Initialize()" );
  return TRUE;
}

///////////////////////////////////////////////////////////////////////////////////////////////
// main function to do the real work of the service

// This function performs the main work of the service.
// When this function returns the service has stopped.
void CNTService::Run()
{
  DebugMsg( "Entering CNTService::Run()" );

  while ( m_bIsRunning )
  {
    DebugMsg( "Sleeping..." );
    Sleep( 5000 );
  }

  // nothing more to do
  DebugMsg( "Leaving CNTService::Run()" );
}

//////////////////////////////////////////////////////////////////////////////////////
// Control request handlers

// static member function (callback) to handle commands from the
// service control manager
void CNTService::Handler( DWORD dwOpcode )
{
  // Get a pointer to the object
  CNTService* pService = m_pThis;

  pService->DebugMsg( "CNTService::Handler(%lu)", dwOpcode );
  switch ( dwOpcode )
  {
  case SERVICE_CONTROL_STOP:  // 1
    pService->SetStatus( SERVICE_STOP_PENDING );
    pService->OnStop();
    pService->m_bIsRunning = FALSE;
    pService->LogEvent( EVENTLOG_INFORMATION_TYPE, EVMSG_STOPPED );
    break;

  case SERVICE_CONTROL_PAUSE:  // 2
    pService->OnPause();
    break;

  case SERVICE_CONTROL_CONTINUE:  // 3
    pService->OnContinue();
    break;

  case SERVICE_CONTROL_INTERROGATE:  // 4
    pService->OnInterrogate();
    break;

  case SERVICE_CONTROL_SHUTDOWN:  // 5
    pService->OnShutdown();
    break;

  default:
    if ( dwOpcode >= SERVICE_CONTROL_USER )
    {
      if ( !pService->OnUserControl( dwOpcode ) )
      {
        pService->LogEvent( EVENTLOG_ERROR_TYPE, EVMSG_BADREQUEST );
      }
    }
    else
    {
      pService->LogEvent( EVENTLOG_ERROR_TYPE, EVMSG_BADREQUEST );
    }
    break;
  }

  // Report current status
  pService->DebugMsg( "Updating status (%lu, %lu)", pService->m_hServiceStatus,
                      pService->m_Status.dwCurrentState );
  ::SetServiceStatus( pService->m_hServiceStatus, &pService->m_Status );
}

// Called when the service is first initialized
BOOL CNTService::OnInit()
{
  DebugMsg( "CNTService::OnInit()" );
  return TRUE;
}

// Called when the service control manager wants to stop the service
void CNTService::OnStop()
{
  DebugMsg( "CNTService::OnStop()" );
}

// called when the service is interrogated
void CNTService::OnInterrogate()
{
  DebugMsg( "CNTService::OnInterrogate()" );
}

// called when the service is paused
void CNTService::OnPause()
{
  DebugMsg( "CNTService::OnPause()" );
}

// called when the service is continued
void CNTService::OnContinue()
{
  DebugMsg( "CNTService::OnContinue()" );
}

// called when the service is shut down
void CNTService::OnShutdown()
{
  DebugMsg( "CNTService::OnShutdown()" );
}

// called when the service gets a user control message
BOOL CNTService::OnUserControl( DWORD dwOpcode )
{
  CNTService* pService = m_pThis;

  switch ( dwOpcode )
  {
  case SERVICE_CONTROL_BEEP:  // 1200
    Beep( 1200, 200 );
    break;
  case SERVICE_CONTROL_STOP_POL:  // 1201
    pService->SetStatus( SERVICE_STOP_PENDING );
    pService->OnStop();
    pService->m_bIsRunning = FALSE;
    pService->LogEvent( EVENTLOG_INFORMATION_TYPE, EVMSG_STOPPED );
    break;
  default:
    DebugMsg( "CNTService::OnUserControl(%8.8lXH)", dwOpcode );
    return FALSE;  // say not handled
    break;
  }

  // if it makes it this far, something's wrong anyway.
  // left in for contrivance
  DebugMsg( "CNTService::OnUserControl(%8.8lXH)", dwOpcode );
  return FALSE;  // say not handled
}


////////////////////////////////////////////////////////////////////////////////////////////
// Debugging support

void CNTService::DebugMsg( const char* pszFormat, ... )
{
  char buf[1024];
  sprintf( buf, "[%s](%lu): ", m_szServiceName, GetCurrentThreadId() );
  va_list arglist;
  va_start( arglist, pszFormat );
  vsprintf( &buf[strlen( buf )], pszFormat, arglist );
  va_end( arglist );
  strcat( buf, "\n" );
  OutputDebugString( buf );
}
}
}