/*
* Copyright (c) 2013-2022, The PurpleI2P Project
*
* This file is part of Purple i2pd project and licensed under BSD3
*
* See full license text in LICENSE file at top of project tree
*/

#include "Win32Service.h"
#include <assert.h>
#include <windows.h>

#include "Log.h"

I2PService *I2PService::s_service = NULL;

BOOL I2PService::isService()
{
	BOOL bIsService = FALSE;
	HWINSTA hWinStation = GetProcessWindowStation();
	if (hWinStation != NULL)
	{
		USEROBJECTFLAGS uof = { 0 };
		if (GetUserObjectInformation(hWinStation, UOI_FLAGS, &uof, sizeof(USEROBJECTFLAGS), NULL) && ((uof.dwFlags & WSF_VISIBLE) == 0))
		{
			bIsService = TRUE;
		}
	}
	return bIsService;
}

BOOL I2PService::Run(I2PService &service)
{
	s_service = &service;
	SERVICE_TABLE_ENTRY serviceTable[] =
	{
		{ service.m_name, ServiceMain },
		{ NULL, NULL }
	};
	return StartServiceCtrlDispatcher(serviceTable);
}

void WINAPI I2PService::ServiceMain(DWORD dwArgc, PSTR *pszArgv)
{
	assert(s_service != NULL);
	s_service->m_statusHandle = RegisterServiceCtrlHandler(
		s_service->m_name, ServiceCtrlHandler);
	if (s_service->m_statusHandle == NULL)
	{
		throw GetLastError();
	}
	s_service->Start(dwArgc, pszArgv);
}


void WINAPI I2PService::ServiceCtrlHandler(DWORD dwCtrl)
{
	switch (dwCtrl)
	{
		case SERVICE_CONTROL_STOP: s_service->Stop(); break;
		case SERVICE_CONTROL_PAUSE: s_service->Pause(); break;
		case SERVICE_CONTROL_CONTINUE: s_service->Continue(); break;
		case SERVICE_CONTROL_SHUTDOWN: s_service->Shutdown(); break;
		case SERVICE_CONTROL_INTERROGATE: break;
		default: break;
	}
}

I2PService::I2PService(PSTR pszServiceName,
	BOOL fCanStop,
	BOOL fCanShutdown,
	BOOL fCanPauseContinue)
{
	m_name = (pszServiceName == NULL) ? (PSTR)"" : pszServiceName;
	m_statusHandle = NULL;
	m_status.dwServiceType = SERVICE_WIN32_OWN_PROCESS;
	m_status.dwCurrentState = SERVICE_START_PENDING;

	DWORD dwControlsAccepted = 0;
	if (fCanStop)
		dwControlsAccepted |= SERVICE_ACCEPT_STOP;
	if (fCanShutdown)
		dwControlsAccepted |= SERVICE_ACCEPT_SHUTDOWN;
	if (fCanPauseContinue)
		dwControlsAccepted |= SERVICE_ACCEPT_PAUSE_CONTINUE;

	m_status.dwControlsAccepted = dwControlsAccepted;
	m_status.dwWin32ExitCode = NO_ERROR;
	m_status.dwServiceSpecificExitCode = 0;
	m_status.dwCheckPoint = 0;
	m_status.dwWaitHint = 0;
	m_fStopping = FALSE;
	// Create a manual-reset event that is not signaled at first to indicate
	// the stopped signal of the service.
	m_hStoppedEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
	if (m_hStoppedEvent == NULL)
	{
		throw GetLastError();
	}
}

I2PService::~I2PService(void)
{
	if (m_hStoppedEvent)
	{
		CloseHandle(m_hStoppedEvent);
		m_hStoppedEvent = NULL;
	}
}

void I2PService::Start(DWORD dwArgc, PSTR *pszArgv)
{
	try
	{
		SetServiceStatus(SERVICE_START_PENDING);
		OnStart(dwArgc, pszArgv);
		SetServiceStatus(SERVICE_RUNNING);
	}
	catch (DWORD dwError)
	{
		LogPrint(eLogError, "Win32Service: Start error: ", dwError);
		SetServiceStatus(SERVICE_STOPPED, dwError);
	}
	catch (...)
	{
		LogPrint(eLogError, "Win32Service: failed to start: ", EVENTLOG_ERROR_TYPE);
		SetServiceStatus(SERVICE_STOPPED);
	}
}

void I2PService::OnStart(DWORD dwArgc, PSTR *pszArgv)
{
	LogPrint(eLogInfo, "Win32Service: in OnStart (", EVENTLOG_INFORMATION_TYPE, ")");
	if(m_daemonStart)
		m_daemonStart();
	else
	{
		LogPrint(eLogError, "Win32Service: failed to start: Unable to call callback");
		SetServiceStatus(SERVICE_STOPPED);
	}
	_worker = new std::thread(std::bind(&I2PService::WorkerThread, this));
}

void I2PService::WorkerThread()
{
	while (!m_fStopping)
	{
		::Sleep(1000); // Simulate some lengthy operations.
	}
	// Signal the stopped event.
	SetEvent(m_hStoppedEvent);
}

void I2PService::Stop()
{
	DWORD dwOriginalState = m_status.dwCurrentState;
	try
	{
		SetServiceStatus(SERVICE_STOP_PENDING);
		OnStop();
		SetServiceStatus(SERVICE_STOPPED);
	}
	catch (DWORD dwError)
	{
		LogPrint(eLogInfo, "Win32Service: Stop error: ", dwError);
		SetServiceStatus(dwOriginalState);
	}
	catch (...)
	{
		LogPrint(eLogError, "Win32Service: Failed to stop: ", EVENTLOG_ERROR_TYPE);
		SetServiceStatus(dwOriginalState);
	}
}

void I2PService::OnStop()
{
	// Log a service stop message to the Application log.
	LogPrint(eLogInfo, "Win32Service: in OnStop (", EVENTLOG_INFORMATION_TYPE, ")");
	if(m_daemonStop)
		m_daemonStop();
	else
		LogPrint(eLogError, "Win32Service: failed to stop: Unable to call callback");

	m_fStopping = TRUE;
	if (WaitForSingleObject(m_hStoppedEvent, INFINITE) != WAIT_OBJECT_0)
	{
		throw GetLastError();
	}
	_worker->join();
	delete _worker;
}

void I2PService::Pause()
{
	try
	{
		SetServiceStatus(SERVICE_PAUSE_PENDING);
		OnPause();
		SetServiceStatus(SERVICE_PAUSED);
	}
	catch (DWORD dwError)
	{
		LogPrint(eLogError, "Win32Service: Pause error: ", dwError);
		SetServiceStatus(SERVICE_RUNNING);
	}
	catch (...)
	{
		LogPrint(eLogError, "Win32Service: Failed to pause: ", EVENTLOG_ERROR_TYPE);
		SetServiceStatus(SERVICE_RUNNING);
	}
}

void I2PService::OnPause()
{
}

void I2PService::Continue()
{
	try
	{
		SetServiceStatus(SERVICE_CONTINUE_PENDING);
		OnContinue();
		SetServiceStatus(SERVICE_RUNNING);
	}
	catch (DWORD dwError)
	{
		LogPrint(eLogError, "Win32Service: Continue error: ", dwError);
		SetServiceStatus(SERVICE_PAUSED);
	}
	catch (...)
	{
		LogPrint(eLogError, "Win32Service: Failed to resume: ", EVENTLOG_ERROR_TYPE);
		SetServiceStatus(SERVICE_PAUSED);
	}
}

void I2PService::OnContinue()
{
}

void I2PService::Shutdown()
{
	try
	{
		OnShutdown();
		SetServiceStatus(SERVICE_STOPPED);
	}
	catch (DWORD dwError)
	{
		LogPrint(eLogError, "Win32Service: Shutdown error: ", dwError);
	}
	catch (...)
	{
		LogPrint(eLogError, "Win32Service: Failed to shut down: ", EVENTLOG_ERROR_TYPE);
	}
}

void I2PService::OnShutdown()
{
}

void I2PService::SetServiceStatus(DWORD dwCurrentState,
	DWORD dwWin32ExitCode,
	DWORD dwWaitHint)
{
	static DWORD dwCheckPoint = 1;
	m_status.dwCurrentState = dwCurrentState;
	m_status.dwWin32ExitCode = dwWin32ExitCode;
	m_status.dwWaitHint = dwWaitHint;
	m_status.dwCheckPoint =
		((dwCurrentState == SERVICE_RUNNING) ||
		(dwCurrentState == SERVICE_STOPPED)) ?
		0 : dwCheckPoint++;

	::SetServiceStatus(m_statusHandle, &m_status);
}

//*****************************************************************************

void FreeHandles(SC_HANDLE schSCManager, SC_HANDLE schService)
{
	if (schSCManager)
	{
		CloseServiceHandle(schSCManager);
		schSCManager = NULL;
	}
	if (schService)
	{
		CloseServiceHandle(schService);
		schService = NULL;
	}
}