/*
 * Copyright 2005-2007 Gerald Schmidt.
 *
 * This file is part of Xml Copy Editor.
 *
 * Xml Copy Editor is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License.
 *
 * Xml Copy Editor 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Xml Copy Editor; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

#include <cstring>
#include "replace.h"

int Replace::run (
    std::string& buffer,
    const std::string& find,
    const std::string& replace,
    bool matchCase )
{
	if ( buffer.empty() || find.empty() )
		return 0;

	std::string output;
	size_t capacity = buffer.size();
	int diff = replace.size() - find.size();
	if ( diff > 0 )
		capacity += diff * BUFSIZ;

	output.reserve ( capacity );
	size_t findLength = find.size();
	int matchCount = 0;

	// comparison function pointer
	int ( *comp ) ( const char *, const char *, size_t ) =
#ifdef __WXMSW__
	    ( matchCase ) ? strncmp : strnicmp;
#else
	    ( matchCase ) ? strncmp : strncasecmp;
#endif

	char *bufferPtr;
	const char *findPtr, *replacePtr;
	bufferPtr = ( char * ) buffer.c_str();
	findPtr = find.c_str();
	replacePtr = replace.c_str();

	while ( *bufferPtr )
	{
		if ( !comp ( ( const char * ) bufferPtr, findPtr, findLength ) )
		{
			++matchCount;
			output += replacePtr;
			bufferPtr += findLength;
		}
		else
		{
			output += *bufferPtr;
			++bufferPtr;
		}
	}
	if ( !matchCount )
		return 0;
	buffer = output;
	return matchCount;
}