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

//++
// File:		MIUtilSystemWindows.cpp
//
// Overview:	CMIUtilSystemWindows implementation.
//
// Environment:	Compilers:	Visual C++ 12.
//							gcc (Ubuntu/Linaro 4.8.1-10ubuntu9) 4.8.1
//				Libraries:	See MIReadmetxt. 
//
// Copyright:	None.
//--

#if defined( _MSC_VER )

// Third party headers
#include <memory>		// std::unique_ptr
#include <Windows.h>
#include <WinBase.h>	// ::FormatMessage()

// In-house headers:
#include "MIUtilSystemWindows.h"
#include "MICmnResources.h"

//++ ------------------------------------------------------------------------------------
// Details:	CMIUtilSystemWindows constructor.
// Type:	Method.
// Args:	None.
// Return:	None.
// Throws:	None.
//--
CMIUtilSystemWindows::CMIUtilSystemWindows( void )
{
}

//++ ------------------------------------------------------------------------------------
// Details:	CMIUtilSystemWindows destructor.
// Type:	Method.
// Args:	None.
// Return:	None.
// Throws:	None.
//--
CMIUtilSystemWindows::~CMIUtilSystemWindows( void )
{
}

//++ ------------------------------------------------------------------------------------
// Details:	Retrieve the OS system error message for the given system error code. 
// Type:	Method.
// Args:	vError		- (R) OS error code value.
//			vrwErrorMsg	- (W) The error message.
// Return:	MIstatus::success - Functional succeeded.
//			MIstatus::failure - Functional failed.
// Throws:	None.
//--
bool CMIUtilSystemWindows::GetOSErrorMsg( const MIint vError, CMIUtilString & vrwErrorMsg  ) const
{
	// Reset
	vrwErrorMsg.clear();

	const MIuint nBufLen = 1024;
	std::unique_ptr< char[] > pBuffer;
	pBuffer.reset( new char[ nBufLen ] ); 
		
	// CMIUtilString Format is not used as cannot replicate the behavior of ::FormatMessage which
	// can take into account locality while retrieving the error message from the system.
	const int nLength = ::FormatMessage( FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
										nullptr, (DWORD) vError, MAKELANGID( LANG_NEUTRAL, SUBLANG_DEFAULT ), 
										reinterpret_cast< LPTSTR >( &pBuffer[ 0 ] ),
										nBufLen, nullptr );
	bool bOk = MIstatus::success;
	if( nLength != 0 )
		vrwErrorMsg = &pBuffer[ 0 ];
	else
		bOk = MIstatus::failure;

	return bOk;
}

//++ ------------------------------------------------------------------------------------
// Details:	Retrieve if possible the OS last error description.
// Type:	Method.
// Args:	None.
// Return:	CMIUtilString - Error description.
// Throws:	None.
//--
CMIUtilString CMIUtilSystemWindows::GetOSLastError( void ) const
{
	CMIUtilString errorMsg;
	const DWORD dwLastError = ::GetLastError();
	if( dwLastError != 0 )
	{
		if( !GetOSErrorMsg( dwLastError, errorMsg ) )
			errorMsg = MIRSRC( IDE_OS_ERR_RETRIEVING );
	}
	else
		errorMsg = MIRSRC( IDE_OS_ERR_UNKNOWN );
	
	return errorMsg;
}

//++ ------------------------------------------------------------------------------------
// Details:	Retrieves the fully qualified path for the this application. If the function
//			fails the string is filled with the error message.
// Type:	Method.
// Args:	vrwFileNamePath	- (W) The excutable's name and path or last error description.
// Return:	MIstatus::success - Functional succeeded.
//			MIstatus::failure - Functional failed.
// Throws:	None.
//--
bool CMIUtilSystemWindows::GetExecutablesPath( CMIUtilString & vrwFileNamePath ) const
{
	bool bOk = MIstatus::success;
	HMODULE hModule = ::GetModuleHandle( nullptr );
	char pPath[ MAX_PATH ];
	const DWORD nLen = ::GetModuleFileName( hModule, &pPath[ 0 ], MAX_PATH );
	const CMIUtilString strLastErr( GetOSLastError() );
	if( (nLen != 0) && (strLastErr == "Unknown OS error") )
		vrwFileNamePath = &pPath[ 0 ];
	else
	{
		bOk = MIstatus::failure;
		vrwFileNamePath = strLastErr;
	}

	return bOk;
}

//++ ------------------------------------------------------------------------------------
// Details:	Retrieves the fully qualified path for the Log file for this application. 
//			If the function fails the string is filled with the error message.
// Type:	Method.
// Args:	vrwFileNamePath	- (W) The Log file's name and path or last error description.
// Return:	MIstatus::success - Functional succeeded.
//			MIstatus::failure - Functional failed.
// Throws:	None.
//--
bool CMIUtilSystemWindows::GetLogFilesPath( CMIUtilString & vrwFileNamePath ) const
{
	return GetExecutablesPath( vrwFileNamePath );
}

#endif // #if defined( _MSC_VER )