#ifndef ALSK_ALSK_IMPL_CALLABLE_H
#define ALSK_ALSK_IMPL_CALLABLE_H

#include "../skeleton/utility.h"
#include "../executor/executorstate.h"

namespace alsk {

template<typename Context, typename Executor>
struct CallableState {
	Context context;
	exec::ExecutorState<Executor> executor;

	// out-of-class definition to silence -Winline
	~CallableState() noexcept;
};

template<typename Context, typename Executor>
CallableState<Context, Executor>::~CallableState() noexcept {}

template<typename> struct Callable;

template<
	template<typename...> class Impl,
	template<typename...> class Skel, typename R, typename... Operands, typename... Tasks,
	typename Tag, typename Executor, typename State
		>
struct Callable<Impl<Skel<R(Operands...), Tasks...>, Tag, Executor, State>>:
Impl<Skel<R(Operands...), Tasks...>, Tag, Executor, State> {
	using Skeleton        = Skel<R(Operands...), Tasks...>;
	using Implementation  = Impl<Skeleton, Tag, Executor, State>;
	using ThisType        = Callable<Implementation>;

private:
	std::size_t _parTasksCount;

public:
	State state;

	template<typename... Args, std::enable_if_t<sizeof...(Args) == 2>* = nullptr>
	constexpr Callable(Args&&... args):
		Implementation(std::forward<Args>(args)..., state),
		_parTasksCount{0}
	{}

	// out-of-class definition to silence -Winline
	~Callable() noexcept;

	constexpr decltype(auto) operator()(Operands... operands) {
		update();
		return Implementation::operator()(operands...);
	}

	template<typename F, typename T>
	constexpr decltype(auto) traverse(F&& function, T&& init) {
		return SkeletonTraversal<Skeleton>::execute(Implementation::skeleton, std::forward<F>(function), std::forward<T>(init));
	}

	static constexpr tmp::Depth parallelizableLevels() {
		return skeletonParallelHeight<Skeleton>;
	}

	std::size_t parallelTasksCount() const { return _parTasksCount; }

	constexpr void update() {
		auto traverser = [](std::size_t, auto&& skl, auto&&... values) {
			using Skl = decltype(skl);
			auto subpar = max(values...);
			skl.step = subpar;
			return SkeletonTraitsT<Skl>::parallelizability(std::forward<Skl>(skl)) * subpar;
		};

		_parTasksCount = traverse(traverser, 1ul);

		ThisType::executor.config(*this);
		state.context.setup(ThisType::executor.contextIdCount(static_cast<Implementation&>(*this), _parTasksCount));
	}
};

template<
	template<typename...> class Impl,
	template<typename...> class Skel, typename R, typename... Operands, typename... Tasks,
	typename Tag, typename Executor, typename State
		>
Callable<Impl<Skel<R(Operands...), Tasks...>, Tag, Executor, State>>::~Callable() noexcept {}

}

#endif