/****************************************************************************
** libebml : parse EBML files, see http://embl.sourceforge.net/
**
** <file/class description>
**
** Copyright (C) 2002-2004 Ingo Ralf Blum.  All rights reserved.
**
** This library is free software; you can redistribute it and/or
** modify it under the terms of the GNU Lesser General Public
** License as published by the Free Software Foundation; either
** version 2.1 of the License, or (at your option) any later version.
** 
** This library 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
** Lesser General Public License for more details.
** 
** You should have received a copy of the GNU Lesser General Public
** License along with this library; if not, write to the Free Software
** Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
**
** See http://www.matroska.org/license/lgpl/ for LGPL licensing information.
**
** Contact license@matroska.org if any conditions of this licensing are
** not clear to you.
**
**********************************************************************/

/*!
	\file
	\version \$Id: StdIOCallback.cpp 1298 2008-02-21 22:14:18Z mosu $
	\author Steve Lhomme     <robux4 @ users.sf.net>
	\author Moritz Bunkus <moritz @ bunkus.org>
*/

#include <cassert>
#include <climits>
#if !defined(__GNUC__) || (__GNUC__ > 2)
#include <sstream>
#endif // GCC2

#include "ebml/StdIOCallback.h"
#include "ebml/Debug.h"
#include "ebml/EbmlConfig.h"

using namespace std;

START_LIBEBML_NAMESPACE

CRTError::CRTError(int nError, const std::string & Description)
	:std::runtime_error(Description+": "+strerror(nError))
	,Error(nError)
{
}

CRTError::CRTError(const std::string & Description,int nError)
	:std::runtime_error(Description+": "+strerror(nError))
	,Error(nError)
{
}


StdIOCallback::StdIOCallback(const char*Path, const open_mode aMode)
{
	assert(Path!=0);

	const char *Mode;
	switch (aMode)
	{
	case MODE_READ:
		Mode = "rb";
		break;
	case MODE_SAFE:
		Mode = "rb+";
		break;
	case MODE_WRITE:
		Mode = "wb";
		break;
	case MODE_CREATE:
		Mode = "wb+";
		break;
	default:
		throw 0;
	}

	File=fopen(Path,Mode);
	if(File==0)
	{
#if !defined(__GNUC__) || (__GNUC__ > 2)
		stringstream Msg;
		Msg<<"Can't open stdio file \""<<Path<<"\" in mode \""<<Mode<<"\"";
		throw CRTError(Msg.str());
#endif // GCC2
	}
	mCurrentPosition = 0;
}


StdIOCallback::~StdIOCallback()throw()
{
	close();
}



uint32 StdIOCallback::read(void*Buffer,size_t Size)
{
	assert(File!=0);
	
	size_t result = fread(Buffer, 1, Size, File);
	mCurrentPosition += result;
	return result;
}

void StdIOCallback::setFilePointer(int64 Offset,seek_mode Mode)
{
	assert(File!=0);

	// There is a numeric cast in the boost library, which would be quite nice for this checking
/* 
	SL : replaced because unknown class in cygwin
	assert(Offset <= numeric_limits<long>::max());
	assert(Offset >= numeric_limits<long>::min());
*/

	assert(Offset <= LONG_MAX);
	assert(Offset >= LONG_MIN);

	assert(Mode==SEEK_CUR||Mode==SEEK_END||Mode==SEEK_SET);

	if(fseek(File,Offset,Mode)!=0)
	{
#if !defined(__GNUC__) || (__GNUC__ > 2)
		ostringstream Msg;
		Msg<<"Failed to seek file "<<File<<" to offset "<<(unsigned long)Offset<<" in mode "<<Mode;
		throw CRTError(Msg.str());
#endif // GCC2
		mCurrentPosition = ftell(File);
	}
	else
	{
		switch ( Mode )
		{
			case SEEK_CUR:
				mCurrentPosition += Offset;
				break;
			case SEEK_END:
				mCurrentPosition = ftell(File);
				break;
			case SEEK_SET:
				mCurrentPosition = Offset;
				break;
		}
	}
}

size_t StdIOCallback::write(const void*Buffer,size_t Size)
{
	assert(File!=0);
	uint32 Result = fwrite(Buffer,1,Size,File);
	mCurrentPosition += Result;
	return Result;
}

uint64 StdIOCallback::getFilePointer()
{
	assert(File!=0);

#if 0
	long Result=ftell(File);
	if(Result<0)
	{
#if !defined(__GNUC__) || (__GNUC__ > 2)
		stringstream Msg;
		Msg<<"Can't tell the current file pointer position for "<<File;
		throw CRTError(Msg.str());
#endif // GCC2
	}
#endif

	return mCurrentPosition;
}

void StdIOCallback::close()
{
	if(File==0)
		return;

	if(fclose(File)!=0)
	{
#if !defined(__GNUC__) || (__GNUC__ > 2)
		stringstream Msg;
		Msg<<"Can't close file "<<File;
		throw CRTError(Msg.str());
#endif // GCC2
	}

	File=0;
}

END_LIBEBML_NAMESPACE
