#include <psemek/ui/impl/aligned_base.hpp>
#include <psemek/react/join.hpp>
#include <psemek/react/map.hpp>

namespace psemek::ui::impl
{

	namespace
	{

		size_constraints compute_size_constraints(size_constraints const & child_size_constraints)
		{
			return {
				.box = {{
					{child_size_constraints.box[0].min, size_constraints::infinity},
					{child_size_constraints.box[1].min, size_constraints::infinity},
				}}
			};
		}

	}

	aligned_base::aligned_base()
		: align_({halignment::center, valignment::center})
		, child_size_constraints_(size_constraints::max())
		, size_constraints_(react::map(compute_size_constraints, react::join(child_size_constraints_)))
	{}

	void aligned_base::reshape(geom::box<float, 2> const & new_shape)
	{
		single_container::reshape(new_shape);

		auto [ halign, valign ] = **align_;

		auto child_size_constraints = **child_size_constraints_;

		if (auto child = this->child())
			child->reshape({
				align(new_shape[0], child_size_constraints.box[0].min, halign),
				align(new_shape[1], child_size_constraints.box[1].min, valign),
			});
	}

	react::value<struct size_constraints> aligned_base::size_constraints() const
	{
		return size_constraints_;
	}

	void aligned_base::set_child(std::unique_ptr<component> child)
	{
		if (child)
			child_size_constraints_.set(child->size_constraints());
		else
			child_size_constraints_.set(size_constraints::max());

		single_container::set_child(std::move(child));
	}

	std::unique_ptr<component> aligned_base::release_child()
	{
		child_size_constraints_.set(size_constraints::max());

		return single_container::release_child();
	}

	void aligned_base::update(aligned const & value)
	{
		align_.set(react::map([](auto const & halign, auto const & valign){ return std::pair{halign, valign}; }, value.halign, value.valign));
	}

}