/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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/logstring.h>
#include <log4cxx/helpers/transform.h>

using namespace log4cxx;
using namespace log4cxx::helpers;


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

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

	logchar specials[] = { 0x22 /* " */, 0x26 /* & */, 0x3C /* < */, 0x3E /* > */, 0x00 };
	size_t start = 0;
	size_t special = input.find_first_of(specials, start);

	while (special != LogString::npos)
	{
		if (special > start)
		{
			buf.append(input, start, special - start);
		}

		switch (input[special])
		{
			case 0x22:
				buf.append(LOG4CXX_STR("&quot;"));
				break;

			case 0x26:
				buf.append(LOG4CXX_STR("&amp;"));
				break;

			case 0x3C:
				buf.append(LOG4CXX_STR("&lt;"));
				break;

			case 0x3E:
				buf.append(LOG4CXX_STR("&gt;"));
				break;

			default:
				buf.append(1, input[special]);
				break;
		}

		start = special + 1;

		if (special < input.size())
		{
			special = input.find_first_of(specials, start);
		}
		else
		{
			special = LogString::npos;
		}
	}

	if (start < input.size())
	{
		buf.append(input, start, input.size() - start);
	}
}

void Transform::appendEscapingCDATA(
	LogString& buf, const LogString& input)
{
	static const LogString CDATA_END(LOG4CXX_STR("]]>"));
	static const LogString CDATA_EMBEDED_END(LOG4CXX_STR("]]>]]&gt;<![CDATA["));

	const LogString::size_type CDATA_END_LEN = 3;


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

	LogString::size_type end = input.find(CDATA_END);

	if (end == LogString::npos)
	{
		buf.append(input);
		return;
	}

	LogString::size_type start = 0;

	while (end != LogString::npos)
	{
		buf.append(input, start, end - start);
		buf.append(CDATA_EMBEDED_END);
		start = end + CDATA_END_LEN;

		if (start < input.length())
		{
			end = input.find(CDATA_END, start);
		}
		else
		{
			return;
		}
	}

	buf.append(input, start, input.length() - start);
}