/*********************************************************************
 * \file   SHSystemManager.h
 * \author Daniel Chua Yee Chen
 * \brief  Declaration for the SHSystemManager class.
 * SHSystemManager is the interface class where users of the engine create
 * the systems that gives the components their functionality. This also ensures that the Init and Exit functions are ran at the appropriate time
 *
 * \copyright Copyright (c) 2021 DigiPen Institute of Technology. Reproduction
	 or disclosure of this file or its contents without the prior written
	 consent of DigiPen Institute of Technology is prohibited.
 *********************************************************************/


#ifndef SH_SYSTEM_MANAGER_H
#define SH_SYSTEM_MANAGER_H


#include <unordered_map>
#include <memory>
#include <string>
#include <cassert>
#include "../System/SHSystem.h"
#include "../General/SHFamily.h"

namespace SHADE
{

	typedef uint32_t SystemTypeID;
	typedef uint32_t SystemVersionID;
	typedef uint64_t SystemID;
	typedef SHFamilyID<SHSystem> SystemFamily;

	class SHSystemManager
	{
		//type definition for the container we use to store our system
		using SystemContainer = std::unordered_map<std::string, std::unique_ptr<SHSystem>>;

	private:
		static SystemContainer systemContainer;


	public:
		/*!*************************************************************************
		 * This class is used as a static class.
		 * No objects of this type should be created
		***************************************************************************/
		SHSystemManager() = delete;
		~SHSystemManager() = delete;

		/**************************************************************************
		 * \brief 
		 * Create a system of type T and map it to a name.
		 * throws an error if a system with the same name already exists.
		 * \param name
		 * name of the system
		 * \return 
		 * none
		***************************************************************************/
		template<typename T>
		static std::enable_if_t<std::is_base_of_v<SHSystem, T>, void> CreateSystem(std::string const& name)
		{
			if (systemContainer.find(name) != systemContainer.end())
			{
				assert("System Creation Error: System with the same name already exist.");
			}

			systemContainer.emplace(name, std::make_unique<T>());


		}

		/**************************************************************************
		 * \brief 
		 * Get a pointer to the System with a specified name.
		 * \param name
		 * Name of the system in the map
		 * \return 
		 * Base System pointer.
		***************************************************************************/
		static SHSystem* GetSystem(std::string name);

		/**************************************************************************
		 * \brief 
		 * Call the Init function of all systems.
		 * \return 
		 * none
		***************************************************************************/
		static void Init() noexcept;

		/**************************************************************************
		 * \brief 
		 * Call the Exit function of all systems.
		 * \return 
		***************************************************************************/
		static void Exit() noexcept;


	protected:


	};

}



#endif