// ==============================================================
//	This file is part of Glest Shared Library (www.glest.org)
//
//	Copyright (C) 2001-2008 Martiño Figueroa
//
//	You can redistribute this code and/or modify it under 
//	the terms of the GNU General Public License as published 
//	by the Free Software Foundation; either version 2 of the 
//	License, or (at your option) any later version
// ==============================================================

#ifndef _SHARED_UTIL_FACTORY_
#define _SHARED_UTIL_FACTORY_

#include <map>
#include <string>
#include <stdexcept>
#include "platform_util.h"
#include "leak_dumper.h"

using std::map;
using std::string;
using std::pair;
using std::runtime_error;

namespace Shared {
	namespace Util {

		// =====================================================
		//	class SingleFactoryBase
		// =====================================================

		class SingleFactoryBase {
		public:
			virtual ~SingleFactoryBase() {
			}
			virtual void *newInstance() = 0;
		};

		// =====================================================
		//	class SingleFactory
		// =====================================================

		template<typename T>
		class SingleFactory : public SingleFactoryBase {
		public:
			virtual void *newInstance() {
				return new T();
			}
		};

		// =====================================================
		//	class MultiFactory
		// =====================================================

		template<typename T>
		class MultiFactory {
		private:
			typedef map<string, SingleFactoryBase*> Factories;
			typedef pair<string, SingleFactoryBase*> FactoryPair;

		private:
			Factories factories;

		public:
			virtual ~MultiFactory() {
				for (Factories::iterator it = factories.begin(); it != factories.end(); ++it) {
					delete it->second;
				}
				factories.clear();
			}

			template<typename R>
			void registerClass(string classId) {
				factories.insert(FactoryPair(classId, new SingleFactory<R>()));
			}

			T *newInstance(string classId) {
				Factories::iterator it = factories.find(classId);
				if (it == factories.end()) {
					throw megaglest_runtime_error("Unknown class identifier: " + classId);
				}
				return static_cast<T*>(it->second->newInstance());
			}

			bool isClassId(string classId) {
				return factories.find(classId) != factories.end();
			}
		};

	}
}//end namespace

#endif