// Copyright (c) 2005-2009 Nokia Corporation and/or its subsidiary(-ies).

// All rights reserved.

// This component and the accompanying materials are made available

// under the terms of "Eclipse Public License v1.0"

// which accompanies this distribution, and is available

// at the URL "http://www.eclipse.org/legal/epl-v10.html".

//

// Initial Contributors:

// Nokia Corporation - initial contribution.

//

// Contributors:

//

// Description:

// Name        : mbrtowc.cpp

// Part of     : MRT LIBC

// Contains the source for the mbrtowc API implementation.

// Version     :

//

#include <e32std.h>

#include <utf.h>

#include <stdlib.h>

#include <string.h>

#include <wchar.h>

#include <stdio.h>

#include "wcharcnv.h"

#if (defined(__SYMBIAN32__) && (defined(__WINSCW__) || defined(__WINS__)))

#include "libc_wsd_defs.h"

#endif 

#ifdef EMULATOR

GET_STATIC_VAR_FROM_TLS(mbrtowc_mbs, mbstate_t)

#define mbs (*GET_WSD_VAR_NAME(mbrtowc_mbs, s)())

#endif //EMULATOR

extern "C" {

//-----------------------------------------------------------------------------

//Function Name : size_t mbrtowc(wchar_t *pwc, const char *s, size_t n, 

//				mbstate_t *ps) 

//Description   :inspects at most  n  bytes  of the  multibyte  string starting

//at s, extracts the next complete multi-byte character, converts it to a wide

//character and stores it at  *pwc.It  updates the shift state *ps.

//Return Value  : returns the number of bytes parsed from the multi-byte 

//sequence starting at s, if a non-L'\0' wide character  was  recognized. It 

//returns 0, if a Lâ\0â wide character was recognized. It returns (size_t)(-1)

//and sets errno to EILSEQ, if an invalid  multibyte sequence  was encountered.

//It returns (size_t)(-2) if it couldn't parse a complete multibyte character, 

//meaning that n should be increased.

//-----------------------------------------------------------------------------

EXPORT_C size_t mbrtowc(wchar_t *pwc, const char *s, size_t n, mbstate_t *ps)

{

	int rval = 0;

#ifndef EMULATOR	

	static mbstate_t mbs;

#endif //EMULATOR	

	if (ps == NULL)

		ps = &mbs;

	if (s)

	{

		wchar_t wide;

		//number of chars to convert has a max of MB_CUR_MAX

		TInt maxlen = (n > MB_CUR_MAX ? MB_CUR_MAX : n);

		TPtrC8 src((const TUint8*)s, maxlen);

		//length of 1 as we only want 1 wide character

		TPtr16 awc((TUint16*)&wide, 1);		

		TInt ret = ConvertToUnicodeFromUtf8(awc, src, ps);

		//return the number of chars converted which is the max number 

		//- the number not converted unless the character converted 

		//was the wide null character

		if (ret >= 0)

		{

			//rval = (L'\0' != wide) ? maxlen - ret : 0;

			if(L'\0' == wide)

			{

				rval = 0;

			}

			else

			{

				rval = ret;

			}

			if (pwc)

		    	{

			    	//only assign the return if we have a target

				*pwc = wide;	

			}

		}

		else

		{

			rval = ret;

		}

	}

	return (size_t)(rval);

} //end of function

} //extern "C"