/*
    Copyright (C) 2008 Andreas Baumann <abaumann@yahoo.com>

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "service/service.h"

#include "log/log.h"		/* for logging */
#include "log/messages.h"	/* for i18n */

#include "i18n/gettext.h"	/* for i18n */	

#include <WinSvc.h>		/* for service functions */

static SERVICE_STATUS_HANDLE service_status_handle;
static SERVICE_STATUS service_status;
static HANDLE service_stop_event = NULL;
static LPSERVICE_MAIN_FUNCTION service_service_main = NULL;

LPWOLF_SERVICE_SUSPEND_FUNCTION wolf_service_events_suspend = NULL;

#define SERVICE_NAME "testservice"

wolf_error_t wolf_service_install(	wolf_service_params_t params ) {
	SC_HANDLE scm;
	SC_HANDLE service;
	char errbuf[512];
	DWORD res;
	TCHAR binary_path[MAX_PATH];
	BOOL rt;
	SERVICE_DESCRIPTION descr;

	wolf_log( WOLF_LOG_DEBUG, WOLF_CATEGORY_SERVICE, WOLF_MSG_SERVICE_INSTALLING_SERVICE,
		_( "Installing service '%s'" ), params.service_name );

	/* get service control manager with enough rights on the local
	 * machine to install the service
	 */
	scm = (SC_HANDLE)OpenSCManager(
		NULL,		/* local computer */
		SERVICES_ACTIVE_DATABASE,
		SC_MANAGER_ALL_ACCESS );
	
	if( scm == NULL ) {
		wolf_system_error_msg( errbuf, 512 );
		wolf_log( WOLF_LOG_ERR, WOLF_CATEGORY_SERVICE, WOLF_MSG_SERVICE_CANT_OPEN_SCM_FOR_INSTALL,
			_( "Unable to open the service control manager to register service '%s': %s (%d)" ),
			params.service_name, errbuf, GetLastError( ) );
		return WOLF_ERR_INTERNAL;
	}

	/* Get the full path of the service binary */
	res = GetModuleFileName(
		NULL,			/* current process */
		binary_path,
		MAX_PATH );

	if( res == MAX_PATH ) {
		wolf_system_error_msg( errbuf, 512 );
		wolf_log( WOLF_LOG_ERR, WOLF_CATEGORY_SERVICE, WOLF_MSG_SERVICE_CANT_GET_PATH_OF_BINARY,
			_( "Unable to get full path of the binary of service '%s': %s (%d)" ),
			params.service_name, errbuf, GetLastError( ) );
		CloseServiceHandle( scm );
		return WOLF_ERR_INTERNAL;
	}

	/* create the service */
	service = CreateService(
		scm,
		params.service_name,
		params.service_display_name,
		SERVICE_ALL_ACCESS,
		SERVICE_WIN32_OWN_PROCESS, /* run isolated in its own process */
		SERVICE_DEMAND_START,	/* let the user choose the start type */
		SERVICE_ERROR_NORMAL,	/* report error and continue boot */
		binary_path,
		NULL,			/* order group */
		NULL,			/* tag in the order group */
		NULL,			/* service dependencies */
		NULL,			/* Local System Account */
		NULL );

	if( service == NULL ) {
		wolf_system_error_msg( errbuf, 512 );
		wolf_log( WOLF_LOG_ERR, WOLF_CATEGORY_SERVICE, WOLF_MSG_SERVICE_CANT_CREATE_SERVICE,
			_( "Unable to create service '%s': %s (%d)" ),
			params.service_name, errbuf, GetLastError( ) );
		(void)CloseServiceHandle( scm );
		return WOLF_ERR_INTERNAL;
	}

	/* set description of the service */
	descr.lpDescription = (LPTSTR)params.service_description;
	rt = ChangeServiceConfig2( service, SERVICE_CONFIG_DESCRIPTION, &descr );
	if( !rt ) {
		wolf_system_error_msg( errbuf, 512 );
		wolf_log( WOLF_LOG_ERR, WOLF_CATEGORY_SERVICE, WOLF_MSG_SERVICE_CANT_SET_SERVICE_DESCRIPTION,
			_( "Unable to set description of service '%s': %s (%d)" ),
			params.service_name, errbuf, GetLastError( ) );
		(void)CloseServiceHandle( service );
		(void)CloseServiceHandle( scm );
		return WOLF_ERR_INTERNAL;
	}

	(void)CloseServiceHandle( service );
	(void)CloseServiceHandle( scm );

	wolf_log( WOLF_LOG_DEBUG, WOLF_CATEGORY_SERVICE, WOLF_MSG_SERVICE_SERVICE_INSTALLED,
		_( "Service '%s' installed successfully" ), params.service_name );

	return WOLF_OK;
}

wolf_error_t wolf_service_remove(	LPCTSTR service_name ) {
	SC_HANDLE scm;
	char errbuf[512];
	SC_HANDLE service;
	DWORD res;

	wolf_log( WOLF_LOG_DEBUG, WOLF_CATEGORY_SERVICE, WOLF_MSG_SERVICE_UNINSTALLING_SERVICE,
		_( "Unistalling service '%s'" ), service_name );

	/* get service control manager with enough rights on the local
	 * machine to uninstall the service
	 */
	scm = (SC_HANDLE)OpenSCManager(
		NULL,		/* local computer */
		SERVICES_ACTIVE_DATABASE,
		SC_MANAGER_ALL_ACCESS );
	
	if( scm == NULL ) {
		wolf_system_error_msg( errbuf, 512 );
		wolf_log( WOLF_LOG_ERR, WOLF_CATEGORY_SERVICE, WOLF_MSG_SERVICE_CANT_OPEN_SCM_FOR_UNINSTALL,
			_( "Unable to open the service control manager to uninstall '%s': %s (%d)" ),
			service_name, errbuf, GetLastError( ) );
		return WOLF_ERR_INTERNAL;
	}

	/* open the service handle and delete the service */
	service = OpenService( scm, service_name, SERVICE_ALL_ACCESS );
	
	if( service == NULL ) {
		wolf_system_error_msg( errbuf, 512 );
		wolf_log( WOLF_LOG_ERR, WOLF_CATEGORY_SERVICE, WOLF_MSG_SERVICE_CANT_OPEN_SERVICE,
			_( "Unable to open service '%s': %s (%d)" ),
			service_name, errbuf, GetLastError( ) );
		(void)CloseServiceHandle( scm );
		return WOLF_ERR_INTERNAL;
	}

	res = DeleteService( service );
	if( res == 0 ) {
		wolf_system_error_msg( errbuf, 512 );
		wolf_log( WOLF_LOG_ERR, WOLF_CATEGORY_SERVICE, WOLF_MSG_SERVICE_CANT_DELETE_SERVICE,
			_( "Unable to uninstall service '%s': %s (%d)" ),
			service_name, errbuf, GetLastError( ) );
		(void)CloseServiceHandle( service );
		(void)CloseServiceHandle( scm );
		return WOLF_ERR_INTERNAL;
	}

	(void)CloseServiceHandle( service );
	(void)CloseServiceHandle( scm );

	wolf_log( WOLF_LOG_DEBUG, WOLF_CATEGORY_SERVICE, WOLF_MSG_SERVICE_SERVICE_UNINSTALLED,
		_( "Service '%s' uninstalled successfully" ), service_name );

	return WOLF_OK;
}

/* constants and values from WinSvc.h: */
static const char *wolf_service_state_to_str(	DWORD current_state ) {
	switch( current_state ) {
		case SERVICE_STOPPED:		return "SERVICE_STOPPED";
		case SERVICE_START_PENDING:	return "SERVICE_START_PENDING";
		case SERVICE_STOP_PENDING:	return "SERVICE_STOP_PENDING";
		case SERVICE_RUNNING:		return "SERVICE_RUNNING";
		case SERVICE_CONTINUE_PENDING:	return "SERVICE_CONTINUE_PENDING";
		case SERVICE_PAUSE_PENDING:	return "SERVICE_PAUSE_PENDING";
		case SERVICE_PAUSED:		return "SERVICE_PAUSED";
		default:			return "<unknown service state>";
	}
}

/* constants and values from WinSvc.h: */
static const char *wolf_service_control_to_str(	DWORD control ) {
	switch( control ) {
		case SERVICE_CONTROL_STOP:		return "SERVICE_CONTROL_STOP";
		case SERVICE_CONTROL_PAUSE:		return "SERVICE_CONTROL_PAUSE";
		case SERVICE_CONTROL_CONTINUE:		return "SERVICE_CONTROL_CONTINUE";
		case SERVICE_CONTROL_INTERROGATE:	return "SERVICE_CONTROL_INTERROGATE";
		case SERVICE_CONTROL_SHUTDOWN:		return "SERVICE_CONTROL_SHUTDOWN";
		case SERVICE_CONTROL_PARAMCHANGE:	return "SERVICE_CONTROL_PARAMCHANGE";
		case SERVICE_CONTROL_NETBINDADD:	return "SERVICE_CONTROL_NETBINDADD";
		case SERVICE_CONTROL_NETBINDREMOVE:	return "SERVICE_CONTROL_NETBINDREMOVE";
		case SERVICE_CONTROL_NETBINDENABLE:	return "SERVICE_CONTROL_NETBINDENABLE";
		case SERVICE_CONTROL_NETBINDDISABLE:	return "SERVICE_CONTROL_NETBINDDISABLE";
		case SERVICE_CONTROL_DEVICEEVENT:	return "SERVICE_CONTROL_DEVICEEVENT";
		case SERVICE_CONTROL_HARDWAREPROFILECHANGE: return "SERVICE_CONTROL_HARDWAREPROFILECHANGE";
		case SERVICE_CONTROL_POWEREVENT:	return "SERVICE_CONTROL_POWEREVENT";
		case SERVICE_CONTROL_SESSIONCHANGE:	return "SERVICE_CONTROL_SESSIONCHANGE";
		default:				return "<unknown service control>";
	}
}

static void wolf_service_report_status(	DWORD current_state,
					DWORD exit_code,
					DWORD wait_hint ) {
	BOOL res;
	char errbuf[512];

	wolf_log( WOLF_LOG_DEBUG, WOLF_CATEGORY_SERVICE, WOLF_MSG_SERVICE_REPORT_STATUS,
		_( "reporting status with new state '%s' (%d) (currently in state '%s' (%d))" ),
		wolf_service_state_to_str( current_state ), current_state,
		wolf_service_state_to_str( service_status.dwCurrentState ), service_status.dwCurrentState );

	service_status.dwServiceType = SERVICE_WIN32_OWN_PROCESS;
	service_status.dwCurrentState = current_state;
	service_status.dwWin32ExitCode = exit_code;
	service_status.dwServiceSpecificExitCode = 0;
	service_status.dwWaitHint = wait_hint;
	service_status.dwControlsAccepted = SERVICE_ACCEPT_STOP | SERVICE_ACCEPT_SHUTDOWN;

	switch( current_state ) {
		case SERVICE_START_PENDING:
			/* during startup we should not accept events, otherwise our
			 * state machine could get troubled!
			 */
			service_status.dwControlsAccepted = 0;
			service_status.dwCheckPoint++;
			break;

		case SERVICE_RUNNING:
		case SERVICE_STOPPED:
			/* reset checkpoint for status bar in final states */
			service_status.dwCheckPoint = 0;
			break;

		default:
			/* increate the tick for transient states */
			service_status.dwCheckPoint++;
			break;
	}

	res = SetServiceStatus( service_status_handle, &service_status );
	if( !res ) {
		wolf_system_error_msg( errbuf, 512 );
		wolf_log( WOLF_LOG_ERR, WOLF_CATEGORY_SERVICE, WOLF_MSG_SERVICE_CANT_REPORT_STATUS,
			_( "Unable to report state '%s' (%d) of service '%s' to SCM '%s (%d)" ),
			wolf_service_state_to_str( current_state ), current_state,
			SERVICE_NAME, errbuf, GetLastError( ) );
		return;
	}
}

/* we get called here by the system and the service control manager,
 * be as short as possible, report states and trigger new events at
 * most!
 */
void WINAPI wolf_service_ctrl_handler(	DWORD control ) {
	char errbuf[512];
	BOOL res;

	wolf_log( WOLF_LOG_DEBUG, WOLF_CATEGORY_SERVICE, WOLF_MSG_SERVICE_HANDLING_EVENT,
		_( "service handler received status change '%s' (%d)" ),
		wolf_service_control_to_str( control ),
		control );

	switch( control ) {
		case SERVICE_CONTROL_STOP:
		case SERVICE_CONTROL_SHUTDOWN:
			wolf_service_report_status( SERVICE_STOP_PENDING, NO_ERROR, 1000 );
			SetEvent( service_stop_event );
			break;

		case SERVICE_CONTROL_INTERROGATE:
			/* fall through to send current status */
			break;
	}

	/* report current state */
	wolf_service_report_status( service_status.dwCurrentState, NO_ERROR, 1000 );
}

void WINAPI wolf_service_main( DWORD argc, LPTSTR *argv ) {
	char errbuf[512];
	BOOL res;

	/* close all loggers but the logging to the event log. If the service runs
	 * with interactive right, it could open a console on the desktop (maybe this
	 * is something for debugging later?).
	 */
	wolf_log_closelogtofile( );
	wolf_log_closelogtostderr( );

	/* register the event callback where we get called by the service
	 * manager and the system
	 */
	service_status_handle = RegisterServiceCtrlHandler(
		SERVICE_NAME, wolf_service_ctrl_handler );
	
	if( service_status_handle == 0 ) {
		wolf_system_error_msg( errbuf, 512 );
		wolf_log( WOLF_LOG_ERR, WOLF_CATEGORY_SERVICE, WOLF_MSG_SERVICE_CANT_REGISTER_SERVICE_CTRL_HANDLER,
			_( "Unable to register service control handler function for service '%s': %s (%d)" ),
			SERVICE_NAME, errbuf, GetLastError( ) );
		return;
	}

	/* signal that we are now up and running */
	wolf_service_report_status( SERVICE_START_PENDING, NO_ERROR, 3000 );

	/* register a stop event, the service control handler will send
	 * the event. From now on we have a service event handler installed,
	 * so if something goes wrong we can set the service state to
	 * SERVICE_STOPPED and terminate gracefully.
	 */
	service_stop_event = CreateEvent(
		NULL,		/* default security attributes */
		TRUE,		/* manual reset event */
		FALSE,		/* not signalled */
		NULL );		/* no name */
	if( service_stop_event == NULL ) {
		wolf_system_error_msg( errbuf, 512 );
		wolf_log( WOLF_LOG_ERR, WOLF_CATEGORY_SERVICE, WOLF_MSG_SERVICE_CANT_CREATE_STOP_EVENT,
			_( "Unable to create the stop event for service '%s': %s (%d)" ),
			SERVICE_NAME, errbuf, GetLastError( ) );
		wolf_service_report_status( SERVICE_STOPPED, NO_ERROR, 1000 );
		return;
	}

	wolf_service_report_status( SERVICE_RUNNING, NO_ERROR, 1000 );

	/* now call the user-defined service main function */
	service_service_main( argc, argv );

	wolf_service_report_status( SERVICE_STOPPED, NO_ERROR, 1000 );

	wolf_log_closelogtoeventlog( );

	return;
}

wolf_service_event_t wolf_service_events_suspend_console( int timeout, wolf_error_t *error ) {
	DWORD res;
	char errbuf[512];

	res = WaitForSingleObject( service_stop_event, timeout * 1000 );
	switch( res ) {
		case WAIT_OBJECT_0:
			/* stop signal received */
			*error = WOLF_OK;
			return WOLF_SERVICE_EVENT_TERMINATE;

		case WAIT_TIMEOUT:
			*error = WOLF_ERR_TIMEOUT;
			return WOLF_SERVICE_NO_EVENT;

		default:
			wolf_system_error_msg( errbuf, 512 );
			wolf_log( WOLF_LOG_ERR, WOLF_CATEGORY_SERVICE, WOLF_MSG_SERVICE_WAIT_FOR_OBJECT_FAILED,
				_( "Waiting for events in the service '%s' failed: %s (%d)" ),
				SERVICE_NAME, errbuf, GetLastError( ) );
			*error = WOLF_ERR_INTERNAL;
			return WOLF_SERVICE_NO_EVENT;
	}
}

wolf_service_event_t wolf_service_events_suspend_service( int timeout, wolf_error_t *error ) {
	DWORD res;
	char errbuf[512];

	res = WaitForSingleObject( service_stop_event, timeout * 1000 );
	switch( res ) {
		case WAIT_OBJECT_0:
			/* stop signal received */
			wolf_service_report_status( SERVICE_STOP_PENDING, NO_ERROR, 1000 );
			*error = WOLF_OK;
			return WOLF_SERVICE_EVENT_TERMINATE;

		case WAIT_TIMEOUT:
			*error = WOLF_ERR_TIMEOUT;
			return WOLF_SERVICE_NO_EVENT;

		default:
			wolf_system_error_msg( errbuf, 512 );
			wolf_log( WOLF_LOG_ERR, WOLF_CATEGORY_SERVICE, WOLF_MSG_SERVICE_WAIT_FOR_OBJECT_FAILED,
				_( "Waiting for events in the service '%s' failed: %s (%d)" ),
				SERVICE_NAME, errbuf, GetLastError( ) );
			wolf_service_report_status( SERVICE_STOPPED, NO_ERROR, 1000 );
			*error = WOLF_ERR_INTERNAL;
			return WOLF_SERVICE_NO_EVENT;
	}
}

/* constants and values from WinCon.h: */
static const char *wolf_service_console_ctrl_to_str(	DWORD ctrl ) {
	switch( ctrl ) {
		case CTRL_C_EVENT:		return "CTRL_C_EVENT";
		case CTRL_BREAK_EVENT:		return "CTRL_BREAK_EVENT";
		case CTRL_CLOSE_EVENT:		return "CTRL_CLOSE_EVENT";
		case CTRL_LOGOFF_EVENT:		return "CTRL_LOGOFF_EVENT";
		case CTRL_SHUTDOWN_EVENT:	return "CTRL_SHUTDOWN_EVENT";
		default:			return "<unknown control>";
	}
}

static BOOL WINAPI wolf_service_console_ctrl_handler( DWORD ctrl ) {
	wolf_log( WOLF_LOG_DEBUG, WOLF_CATEGORY_SERVICE, WOLF_MSG_SERVICE_CONSOLE_CTRL_RECEIVED,
		_( "Got a console control event '%s' (%d)" ),
		wolf_service_console_ctrl_to_str( ctrl ), ctrl );

	switch( ctrl ) {
		case CTRL_C_EVENT:
		case CTRL_BREAK_EVENT:
		case CTRL_CLOSE_EVENT:
		case CTRL_LOGOFF_EVENT:
		case CTRL_SHUTDOWN_EVENT:
			SetEvent( service_stop_event );
			return TRUE;
	}

	return FALSE;
}

wolf_error_t wolf_service_start_console( 	LPTSTR service_name,
						LPSERVICE_MAIN_FUNCTION service_main,
						DWORD argc,
						LPTSTR *argv ) {
	BOOL res;
	char errbuf[512];

	/* register the user-defined service main (what he should actually program */
	service_service_main = service_main;

	/* register the right suspend function */
	wolf_service_events_suspend = wolf_service_events_suspend_console;

	/* register a stop event, the console control handler will send
	 * the event.
	 */
	service_stop_event = CreateEvent(
		NULL,		/* default security attributes */
		TRUE,		/* manual reset event */
		FALSE,		/* not signalled */
		NULL );		/* no name */
	if( service_stop_event == NULL ) {
		wolf_system_error_msg( errbuf, 512 );
		wolf_log( WOLF_LOG_ERR, WOLF_CATEGORY_SERVICE, WOLF_MSG_SERVICE_CANT_CREATE_STOP_EVENT,
			_( "Unable to create the stop event for service '%s': %s (%d)" ),
			SERVICE_NAME, errbuf, GetLastError( ) );
		return WOLF_ERR_INTERNAL;
	}

	/* catch console events for proper termination of the service in console mode */
	res = SetConsoleCtrlHandler( wolf_service_console_ctrl_handler, TRUE );	
	if( !res ) {
		wolf_system_error_msg( errbuf, 512 );
		wolf_log( WOLF_LOG_ERR, WOLF_CATEGORY_SERVICE, WOLF_MSG_SERVICE_CANT_REGISTER_CONSOLE_CTRL_HANDLER,
			_( "Unable to register the console control handler for foreground service '%s': %s (%d)" ),
			service_name, errbuf, GetLastError( ) );
		return WOLF_ERR_INTERNAL;
	}

	/* now call the user-defined service main function */
	service_service_main( argc, argv );

	return WOLF_OK;
}

wolf_error_t wolf_service_start( 	LPTSTR service_name,
					LPSERVICE_MAIN_FUNCTION service_main ) {
	BOOL res;
	char errbuf[512];
	SERVICE_TABLE_ENTRY dispatch_table[2] =
		{ { service_name, wolf_service_main },
		  { NULL, NULL } };

	/* register the user-defined service main (what he should actually program */
	service_service_main = service_main;

	/* register the right suspend function */
	wolf_service_events_suspend = wolf_service_events_suspend_service;

	/* register the wolf_service_main to the SCM, which is the entry point for
	 * the service (doing some things we want to hide from the service developer),
	 * and which in the end calls 'service_service_main' (the user-defined main
	 * service function.
	 */
	res = StartServiceCtrlDispatcher( dispatch_table );
	if( !res ) {
		/* this is as far as I know the only way to determine
		 * whether the binary runs not as a service..
		 */
		if( GetLastError( ) == ERROR_FAILED_SERVICE_CONTROLLER_CONNECT ) {
			return WOLF_ERR_INVALID_STATE;
		}

		wolf_system_error_msg( errbuf, 512 );
		wolf_log( WOLF_LOG_ERR, WOLF_CATEGORY_SERVICE, WOLF_MSG_SERVICE_CANT_DISPATCH_SERVICE,
			_( "Unable to dispatch service '%s': %s (%d)" ),
			service_name, errbuf, GetLastError( ) );
		return WOLF_ERR_INTERNAL;
	}

	return WOLF_OK;
}