/*******************************************************************************

 Copyright (c) 2009, Charles McGarvey
 All rights reserved.
 
 Redistribution   and   use  in  source  and  binary  forms,  with  or  without
 modification, are permitted provided that the following conditions are met:
 
   * Redistributions  of  source  code  must retain the above copyright notice,
     this list of conditions and the following disclaimer.
   * Redistributions  in binary form must reproduce the above copyright notice,
     this  list of conditions and the following disclaimer in the documentation
     and/or other materials provided with the distribution.
 
 THIS  SOFTWARE  IS  PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 AND  ANY  EXPRESS  OR  IMPLIED  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 DISCLAIMED.  IN  NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
 FOR  ANY  DIRECT,  INDIRECT,  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 DAMAGES  (INCLUDING,  BUT  NOT  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 SERVICES;  LOSS  OF  USE,  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 CAUSED  AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 OR  TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

*******************************************************************************/

#ifndef _MOOF_DESERIALIZER_HH_
#define _MOOF_DESERIALIZER_HH_

/**
 * @file Deserializer.hh
 * Deserialize structures and types from input on a stream.
 */

#include <istream>
#include <string>
#include <stdexcept>

#include <boost/shared_ptr.hpp>

#include <Moof/Exception.hh>


namespace Mf {


class Serializable;		// forward declaration
typedef boost::shared_ptr<Serializable> SerializableP;


class Deserializer
{
	class Impl;
	boost::shared_ptr<Impl> impl_;

public:

	/**
	 * Construction is initialization.  A deserializer can be constructed with
	 * either an input stream or a string representing a filename that will be
	 * read from.  If a stream is provided, it will not be closed after parsing,
	 * but the parser may read past the end of usable bytes, so you should not
	 * use a deserializer on a stream that you expect to continue to use after
	 * the deserialization.
	 * @param comments If true, C and C++-style comments will be allowed and
	 * ignored by the parser.
	 * @param check If true, UTF-8 strings will be checked for validity and an
	 * exception thrown if such a problem exists.  Otherwise strings will not be
	 * checked.
	 */

	Deserializer(const std::string& filePath, bool comments = false,
			bool check = false);
	Deserializer(std::istream& input, bool comments = false, bool check = false);


	/**
	 * Parse the object from of the stream.  The stream is considered to be
	 * dominated by the parser and may read and discard bytes past the end of
	 * the actual parsed object.  Only one object can be deserialized by the
	 * deserializer.
	 */

	SerializableP deserialize();

	/**
	 * Used by serializable objects to parse themselves.  These methods should
	 * generally not be used directory for deserialization.  This one returns
	 * the next object in the queue which has been parsed.  This method may
	 * block if more data is pending and an object has not bee constructed yet.
	 * The caller takes ownership of the object which has been allocated with
	 * the new operator and must therefore be sure to delete the object as
	 * appropriated.  Null (0) will be returned by this method to signify one of
	 * three things: 1) the end of an array, 2) the end of a map/dictionary, or
	 * 3) there is nothing more to be obtained.  Container objects will be empty
	 * and will have to be filled with their contained elements by repeatedly
	 * calling this method until a null is returned.  This method will continue
	 * to return the same value until pop() is called which will cause this
	 * method to return the next object as expected.
	 */

	Serializable* pullNext();

	/**
	 * If the object returned by pullNext() has been received successfully and
	 * the caller is ready for the next object, this method should be called to
	 * take that object off of the queue.
	 */

	void pop();


	/**
	 * This exception is thrown upon deserialization errors.
	 */

	struct Exception : public Mf::Exception
	{
		enum
		{
			PARSING_FAILED	= 1024
		};

		explicit Exception(unsigned error) :
			Mf::Exception(error) {}

		void raise()
		{
			throw *this;
		}

		const char* what() const throw()
		{
			switch (code)
			{
				case PARSING_FAILED:
					return "parsing failed";
			}
			return Mf::Exception::what();
		}
	};
};


} // namespace Mf


#endif // _MOOF_DESERIALIZER_HH_

/** vim: set ts=4 sw=4 tw=80: *************************************************/