/*
 * 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.
 */

#ifndef _LOG4CXX_HELPERS_CHARSETDECODER_H
#define _LOG4CXX_HELPERS_CHARSETDECODER_H

#include <log4cxx/helpers/object.h>

namespace log4cxx
{
namespace helpers
{
class CharsetDecoder;
LOG4CXX_PTR_DEF(CharsetDecoder);
class ByteBuffer;


/**
*   An abstract engine to transform a sequences of bytes in a specific charset
*   into a LogString.
*/
class LOG4CXX_EXPORT CharsetDecoder : public Object
{
	public:
		DECLARE_ABSTRACT_LOG4CXX_OBJECT(CharsetDecoder)
		BEGIN_LOG4CXX_CAST_MAP()
		LOG4CXX_CAST_ENTRY(CharsetDecoder)
		END_LOG4CXX_CAST_MAP()
	protected:
		/**
		*  Protected constructor.
		*/
		CharsetDecoder();
	public:
		/**
		*  Destructor.
		*/
		virtual ~CharsetDecoder();

		/**
		 *   Get decoder for default charset.
		 */
		static CharsetDecoderPtr getDefaultDecoder();
		/**
		 *  Get decoder for specified character set.
		 *  @param charset the following values should be recognized:
		 *     "US-ASCII", "ISO-8859-1", "UTF-8",
		 *     "UTF-16BE", "UTF-16LE".
		 *  @return decoder
		 *  @throws IllegalArgumentException if charset is not recognized.
		 */
		static CharsetDecoderPtr getDecoder(const LogString& charset);

		/**
		 *   Get decoder for UTF-8.
		 */
		static CharsetDecoderPtr getUTF8Decoder();
		/**
		 *   Get decoder for ISO-8859-1.
		 */
		static CharsetDecoderPtr getISOLatinDecoder();


		/**
		 *  Decodes as many bytes as possible from the given
		 *   input buffer, writing the results to the given output string.
		 *  @param in input buffer.
		 *  @param out output string.
		 *  @return APR_SUCCESS if not encoding errors were found.
		 */
		virtual log4cxx_status_t decode(ByteBuffer& in,
			LogString& out) = 0;

		/**
		 *  Determins if status value indicates an invalid byte sequence.
		 */
		inline static bool isError(log4cxx_status_t stat)
		{
			return (stat != 0);
		}

	private:
		/**
		*  Private copy constructor.
		*/
		CharsetDecoder(const CharsetDecoder&);
		/**
		*  Private assignment operator.
		*/
		CharsetDecoder& operator=(const CharsetDecoder&);
		/**
		 *  Creates a new decoder for the default charset.
		 */
		static CharsetDecoder* createDefaultDecoder();
};

} // namespace helpers
}  //namespace log4cxx

#endif //_LOG4CXX_HELPERS_CHARSETENCODER_H