#include <psemek/ui/impl/controller.hpp>
#include <psemek/ui/impl/event_state.hpp>
#include <psemek/async/event_loop.hpp>

namespace psemek::ui::impl
{

	struct controller::impl
	{
		component_factory & factory;
		event_state state;

		util::signal<>::subscription_token root_token;
		std::unique_ptr<ui::impl::component> root;

		async::event_loop delayed_queue;

		impl(component_factory & factory)
			: factory(factory)
		{}

		void set_ui(react::value<std::any> ui)
		{
			root_token = ui.subscribe([this](std::any const & value)
			{
				root = factory.reconciliate(std::move(root), value, state, delayed_queue, [this]{ delayed_queue.post([this]{ reshape(); }); });
			}, true);
		}

		void reshape()
		{
			if (!root)
				return;

			root->reshape({{{0.f, state.size[0]}, {0.f, state.size[1]}}});
			on_event_impl(mouse_move_event{state.mouse, {0, 0}}, root.get());
		}

		template <typename Event>
		bool on_event(Event const & event)
		{
			apply(state, event);
			return on_event_impl(event, root.get());
		}

		template <typename Event>
		bool on_event_impl(Event const & event, component * element)
		{
			if (!element)
				return false;

			for (auto const & child : element->children())
				if (on_event_impl(event, child.get()))
					return true;

			return element->on_event(event);
		}

		void update(float dt)
		{
			delayed_queue.pump();
			animate_impl(dt, root.get());
		}

		void animate_impl(float dt, component * element)
		{
			if (!element)
				return;

			element->animate(dt);
			for (auto const & child : element->children())
				animate_impl(dt, child.get());
		}

		void draw(renderer & renderer)
		{
			draw_impl(renderer, root.get());
		}

		void draw_impl(renderer & renderer, component * element)
		{
			if (!element)
				return;

			element->draw(renderer);

			for (auto const & child : element->children())
				draw_impl(renderer, child.get());

			element->post_draw(renderer);
		}
	};

	controller::controller(component_factory & factory)
		: pimpl_(make_impl(factory))
	{}

	controller::~controller() = default;

	void controller::set_ui(react::value<std::any> ui)
	{
		impl().set_ui(std::move(ui));
	}

	component * controller::root()
	{
		return impl().root.get();
	}

	bool controller::on_event(resize_event const & event)
	{
		return impl().on_event(event);
	}

	bool controller::on_event(mouse_move_event const & event)
	{
		return impl().on_event(event);
	}

	bool controller::on_event(mouse_wheel_event const & event)
	{
		return impl().on_event(event);
	}

	bool controller::on_event(mouse_button_event const & event)
	{
		return impl().on_event(event);
	}

	bool controller::on_event(key_event const & event)
	{
		return impl().on_event(event);
	}

	void controller::update(float dt)
	{
		impl().update(dt);
	}

	void controller::draw(renderer & renderer)
	{
		impl().draw(renderer);
	}

}