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

namespace psemek::ui::impl
{

	single_container_base::single_container_base(react::value<geom::vector<float, 2>> margin)
		: margin_(margin)
		, child_size_constraints_(default_size_constraints())
		, size_constraints_(react::map([](size_polygon const & child_constraints, geom::vector<float, 2> const & margin){
				return shift(child_constraints, margin);
			}, react::join(child_size_constraints_), margin))
	{}

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

		if (child())
			child()->reshape(geom::shrink(new_shape, *margin_));
	}

	react::value<size_polygon> single_container_base::size_constraints() const
	{
		return size_constraints_;
	}

	void single_container_base::set_child(std::unique_ptr<component> child)
	{
		single_container::set_child(std::move(child));
		child_size_constraints_.set(this->child() ? this->child()->size_constraints() : default_size_constraints());
	}

	std::unique_ptr<component> single_container_base::release_child()
	{
		auto child = single_container::release_child();
		child_size_constraints_.set(default_size_constraints());
		return child;
	}


}