#include <functional>
#include <ostream>
#pragma once
#include "ecs.h"

#include "io/write.h"
#include "io/read.h"

#include <iostream>

namespace ecs::serial {
	namespace internal {
		extern std::unordered_map<size_t, std::tuple<std::function<void(std::ostream&, ecs::Component*)>, std::function<void(std::istream&, ecs::Component*)>, std::function<ecs::Component*()>>> functions;
	}

	template <typename T>
	void serialize_member(std::ostream&, T*) {
		// We reached the end
	}

	template <typename T, typename M, typename... Args>
	void serialize_member(std::ostream& os, T* t, M T::*m, Args... args) {
		io::write<M>(os, t->*m);

		serialize_member(os, t, args...);
	}

	template <typename T>
	void deserialize_member(std::istream&, T*) {
		// We reached the end
	}

	template <typename T, typename M, typename... Args>
	void deserialize_member(std::istream& is, T* t, M T::*m, Args... args) {
		t->*m = io::read<M>(is);

		deserialize_member(is, t, args...);
	}

	// @todo Allow for custom serializers and deserializers (maybe for this we do need a difference between update and new)
	template <typename T, typename... Args>
	void register_component(Args... args) {
		// Serialize component
		auto serialize = [args...] (std::ostream& os, ecs::Component* component) {
			T* t = static_cast<T*>(component);
			serialize_member(os, t, args...);
		};

		// Deserialize component
		auto deserialize = [args...] (std::istream& is, ecs::Component* component) {
			T* t = static_cast<T*>(component);
			deserialize_member(is, t, args...);
		};

		auto create = [] () -> Component* {
			return new T();
		};

		internal::functions.insert({ComponentID::id<T>, {serialize, deserialize, create}});
	}

	void register_component_custom(size_t id, std::function<void(std::ostream&, ecs::Component*)> serialize, std::function<void(std::istream&, Component*)> deserialize, std::function<ecs::Component*()> create);

	void serialize(std::ostream& os, Entity* entity);
	void deserialize(std::istream& is, Manager& manager);

	void serialize_ids(std::ostream& os);
	void deserialize_ids(std::istream& is);
}