/*
 * Copyright 2003,2004 The Apache Software Foundation.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
 
#include <log4cxx/helpers/transform.h>

using namespace log4cxx;
using namespace log4cxx::helpers;

String Transform::CDATA_START  = _T("<![CDATA[");
String Transform::CDATA_END    = _T("]]>");
String Transform::CDATA_PSEUDO_END = _T("]]&gt;");
String Transform::CDATA_EMBEDED_END = CDATA_END + CDATA_PSEUDO_END + CDATA_START;
String::size_type Transform::CDATA_END_LEN = CDATA_END.length();


void Transform::appendEscapingTags(
	ostream& buf, const String& input)
{
	//Check if the string is zero length -- if so, return
	//what was sent in.

	if(input.length() == 0 )
	{
		return;
	}

	String::const_iterator it = input.begin();
	String::const_iterator itEnd = input.end();
	TCHAR ch;
	while(it != itEnd)
	{
		ch = *it++;
		if(ch == _T('<'))
		{
			buf << _T("&lt;");
		}
		else if(ch == _T('>'))
		{
			buf << _T("&gt;");
		}
		else
		{
			buf.put(ch);
		}
	}
}

void Transform::appendEscapingCDATA(
	ostream& buf, const String& input)
{
	if(input.length() == 0 )
	{
		return;
	}

	String::size_type end = input.find(CDATA_END);
	if (end == String::npos)
	{
		buf << input;
		return;
	}

	String::size_type start = 0;
	while (end != String::npos)
	{
		buf << input.substr(start, end-start);
		buf << CDATA_EMBEDED_END;
		start = end + CDATA_END_LEN;
		if (start < input.length())
		{
			end = input.find(CDATA_END, start);
		}
		else
		{
			return;
		}
	}

	buf << input.substr(start);
}