#include "engine.hpp"

#include "util/function.hpp"

#include <chrono>
#include <thread>
#include <utility>

CLIGameEngine::CLIGameEngine(
	IGameFactory game_factory,
	IComponentRendererFactory component_renderer_factory,
	std::shared_ptr<IUserInputObserver> user_input_observer,
	std::shared_ptr<ICursorController> cursor_controller,
	std::shared_ptr<IScene> scene) noexcept
	: _game_factory(std::move(game_factory)),
	  _component_renderer_factory(std::move(component_renderer_factory)),
	  _user_input_observer(std::move(user_input_observer)),
	  _cursor_controller(std::move(cursor_controller)),
	  _scene(std::move(scene))
{
}

void CLIGameEngine::start() noexcept
{
	auto component_renderer = _component_renderer_factory(_cursor_controller);

	_scene->enter();

	_cursor_controller->set_bounds(_scene->size());

	auto game = _game_factory(_scene, _cursor_controller, _user_input_observer);

	game->on_start();

	std::atexit(normalize_lambda(
		[this, &game]()
		{
			_scene->leave();

			game->on_exit();
		}));

	auto listen_input_thread = std::thread(normalize_lambda(
		[this]()
		{
			_user_input_observer->listen();
		}));

	auto last_update_time = std::chrono::system_clock::now();

	const auto get_millis_since_update = [&last_update_time]()
	{
		return std::chrono::duration_cast<std::chrono::milliseconds>(
			std::chrono::system_clock::now() - last_update_time);
	};

	while (true)
	{
		const auto time_since_last_update = get_millis_since_update();

		if (time_since_last_update.count() < MIN_TIME_SINCE_LAST_UPDATE_MILLIS)
		{
			while (get_millis_since_update().count() < MIN_TIME_SINCE_LAST_UPDATE_MILLIS)
			{
			}
		}

		game->on_update();

		for (auto [component, position] : _scene->get_components())
		{
			if (component->get_need_render())
			{
				component_renderer->render(component, position);
				component->set_need_render(false);
			}
		}

		last_update_time = std::chrono::system_clock::now();
	}
}