/*
	XMLUtils.h - Xerces wrappers & convenience functions
	
	AUTHOR	:	Simon Brenner <simon@wildfiregames.com>, <simon.brenner@home.se>
	EXAMPLE	:
		Simple usage:
	
		CVFSEntityResolver *entRes=new CVFSEntityResolver(filename);
		parser->setEntityResolver(entRes);
	
		CVFSInputSource src;
		if (src.OpenFile("this/is/a/vfs/path.xml")==0)
			parser->parse(src);
			
		delete entRes;
		
		The input source object should be kept alive as long as the parser is
		using its input stream (i.e. until the parse is complete). The same
		goes for the entity resolver.
*/

#ifndef _XercesVFS_H
#define _XercesVFS_H

// Temporarily undefine new, because the Xerces headers don't like it
#ifdef HAVE_DEBUGALLOC
# undef new
#endif

#include <xercesc/util/XMLString.hpp>
#include <xercesc/util/PlatformUtils.hpp>

#include <xercesc/sax/InputSource.hpp>
#include <xercesc/sax/EntityResolver.hpp>
#include <xercesc/util/BinMemInputStream.hpp>

#include <xercesc/sax/SAXParseException.hpp>
#include <xercesc/sax/ErrorHandler.hpp>

#ifdef HAVE_DEBUGALLOC
# define new new(_NORMAL_BLOCK, __FILE__, __LINE__)
#endif

#include "zlib.h" // for crc32

#include "res/h_mgr.h"
#include "lib.h"
#include "XercesErrorHandler.h"
#include "CStr.h"

XERCES_CPP_NAMESPACE_USE

CStr XMLTranscode(const XMLCh *);
XMLCh *XMLTranscode(const char *);

/*
	CLASS		: CVFSInputSource
	DESCRIPTION	:
		Use instead of LocalFileInputSource to read XML files from VFS
*/
class CVFSInputSource: public InputSource
{
	Handle m_hFile;
	void *m_pBuffer;
	size_t m_BufferSize;
	
public:
	CVFSInputSource():
		m_hFile(0),
		m_pBuffer(NULL),
		m_BufferSize(0)
	{}
	
	~CVFSInputSource();
	
	// Open a VFS path for XML parsing
	// returns 0 if successful, -1 on failure
	int OpenFile(const char *path);

	// Calculate the CRC32 checksum of the file's contents
	unsigned long CRC32(unsigned long seed) { return crc32(seed, (Bytef*)m_pBuffer, (int)m_BufferSize); }

	virtual BinInputStream *makeStream() const;
};

class CVFSEntityResolver: public EntityResolver
{
	const char *m_DocName;

public:
	virtual InputSource *resolveEntity(
		const XMLCh *const publicId,
		const XMLCh *const systemId);
	
	inline CVFSEntityResolver(const char *docName):
		m_DocName(docName)
	{}
};

#endif // _XercesVFS_H