/***********************************************************************
 * Software License Agreement (BSD License)
 *
 * Copyright 2008-2009  Marius Muja (mariusm@cs.ubc.ca). All rights reserved.
 * Copyright 2008-2009  David G. Lowe (lowe@cs.ubc.ca). All rights reserved.
 *
 * THE BSD LICENSE
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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 AUTHOR ``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 AUTHOR 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 OBJECT_FACTORY_H_
#define OBJECT_FACTORY_H_

#include <map>

namespace cvflann
{

template<typename BaseClass, typename DerivedClass>
BaseClass* createObject()
{
	return new DerivedClass();
}

template<typename BaseClass, typename UniqueIdType>
class ObjectFactory
{
	typedef BaseClass* (*CreateObjectFunc)();
	std::map<UniqueIdType, CreateObjectFunc> object_registry;

	// singleton class, private constructor
	ObjectFactory() {};

public:
   typedef typename std::map<UniqueIdType, CreateObjectFunc>::iterator Iterator;


   template<typename DerivedClass>
   bool register_(UniqueIdType id)
   {
      if (object_registry.find(id) != object_registry.end())
               return false;

      object_registry[id] = &createObject<BaseClass, DerivedClass>;
      return true;
   }

   bool unregister(UniqueIdType id)
   {
      return (object_registry.erase(id) == 1);
   }

   BaseClass* create(UniqueIdType id)
   {
      Iterator iter = object_registry.find(id);

      if (iter == object_registry.end())
         return NULL;

      return ((*iter).second)();
   }

   static ObjectFactory<BaseClass,UniqueIdType>& instance()
   {
	   static ObjectFactory<BaseClass,UniqueIdType> the_factory;
	   return the_factory;
   }

};

}

#endif /* OBJECT_FACTORY_H_ */
