//===-- MIUtilSingletonHelper.h ---------------------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

//++
// File:		MIUtilSingletonHelper.h
//
// Overview:	Contains template functions to aid the initialisation and
//				shutdown of MI modules. MI modules (or components) can 
//				use other MI modules to help them achieve their one task
//				(Modules only do one task).
//
// Environment:	Compilers:	Visual C++ 12.
//							gcc (Ubuntu/Linaro 4.8.1-10ubuntu9) 4.8.1
//				Libraries:	See MIReadmetxt. 
//
// Copyright:	None.
//--

#pragma once

namespace MI
{

// In house headers:
#include "MIUtilString.h"
#include "MICmnResources.h"

//++ ============================================================================
// Details:	Short cut helper function to simplify repeated initialisation of
//			MI components (singletons) required by a client module.
// Type:	Template method.
// Args:	vErrorResrcId	- (R)  The string resource ID error message identifier to place in errMsg.
//			vwrbOk			- (RW) On input True = Try to initalise MI driver module.
//								   On output True = MI driver module initialise successfully.
//			vwrErrMsg		- (W)  MI driver module initialise error description on failure.
// Return:	MIstatus::success - Functional succeeded.
//			MIstatus::failure - Functional failed.
// Authors:	Aidan Dodds 17/03/2014.
// Changes:	None.
//--
template< typename T >
bool ModuleInit( const MIint vErrorResrcId, bool & vwrbOk, CMIUtilString & vwrErrMsg )
{
	if( vwrbOk && !T::Instance().Initialize() )
	{
		vwrbOk = MIstatus::failure;
		vwrErrMsg = CMIUtilString::Format( MIRSRC( vErrorResrcId ), T::Instance().GetErrorDescription().c_str() );
	}

	return vwrbOk;
}

//++ ============================================================================
// Details:	Short cut helper function to simplify repeated shutodown of
//			MI components (singletons) required by a client module.
// Type:	Template method.
// Args:	vErrorResrcId	- (R)  The string resource ID error message identifier 
//								   to place in errMsg.
//			vwrbOk			- (W)  If not already false make false on module 
//								   shutdown failure.
//			vwrErrMsg		- (RW) Append to existing error description string MI 
//								   driver module initialise error description on 
//								   failure.
// Return:	True - Module shutdown succeeded.
//			False - Module shutdown failed.
// Authors:	Aidan Dodds 17/03/2014.
// Changes:	None.
//--
template< typename T >
bool ModuleShutdown( const MIint vErrorResrcId, bool & vwrbOk, CMIUtilString & vwrErrMsg )
{
	bool bOk = MIstatus::success;

	if( !T::Instance().Shutdown() )
	{
		const bool bMoreThanOneError( !vwrErrMsg.empty() );
		bOk = MIstatus::failure;
		if( bMoreThanOneError )
			vwrErrMsg += ", ";
		vwrErrMsg += CMIUtilString::Format( MIRSRC( vErrorResrcId ), T::Instance().GetErrorDescription().c_str() );
	}
	
	vwrbOk = bOk ? vwrbOk : MIstatus::failure;

	return bOk;
}

} // namespace MI