#pragma once

#include <cstddef>
#include <tuple>
#include <vector>

#include <Entities/Components.h>
#include <Containers.h>
#include <utility.h>

class EntityManager;
class Entity;

using ComponentsContainer = std::tuple
<
	container::Array<Transform, util::MAX_ENTITIES>,
	container::Array<Texture, util::MAX_ENTITIES>,
	container::Array<BoundingBox, util::MAX_ENTITIES>
>;

class EntityMemoryPool
{
private:
	friend class EntityManager;
	friend class Entity;

	ComponentsContainer m_components;
	container::Array<Tag, util::MAX_ENTITIES> m_tags;
	container::Array<bool, util::MAX_ENTITIES> m_aliveStates;
	container::Array<size_t, util::MAX_ENTITIES> m_ids;
	
private:
	EntityMemoryPool();

	EntityMemoryPool(const EntityMemoryPool&) = delete;

	static EntityMemoryPool& instance()
	{
		static EntityMemoryPool pool{};
		return pool;
	}

	template<typename T>
	bool hasComponent(EntityIndex index) const
	{ return std::get<container::Array<T, util::MAX_ENTITIES>>(m_components)[index].active; }

	template<typename T>
	T& getComponent(EntityIndex index) 
	{
		return std::get<container::Array<T, util::MAX_ENTITIES>>(m_components)[index];
	}

	Tag getTag(EntityIndex index) const
	{
		return m_tags[index];
	}

	bool getAlive(EntityIndex index) const
	{
		return m_aliveStates[index];
	}

	size_t& getId(EntityIndex index)
	{
		return m_ids[index];
	}

	void removeEntity(EntityIndex index)
	{
		m_aliveStates[index] = false;
		return;
	}
};