#include "engine.hpp"

#include "util/function.hpp"

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

CLIGameEngine::CLIGameEngine(
	IGameFactory game_factory,
	ISceneFactory scene_factory,
	std::shared_ptr<IInputHandler> input_handler,
	std::shared_ptr<ICursorController> cursor_controller) noexcept
	: _game_factory(std::move(game_factory)),
	  _scene_factory(std::move(scene_factory)),
	  _input_handler(std::move(input_handler)),
	  _cursor_controller(std::move(cursor_controller))
{
}

void CLIGameEngine::start() noexcept
{
	std::shared_ptr<IScene> scene = _scene_factory(_cursor_controller);

	scene->enter();
	_input_handler->enter_raw_mode();

	auto game = _game_factory(scene, _cursor_controller);

	game->on_start();

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

			game->on_exit();
		}));

	_configure_input(game->get_input_config());

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

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

void CLIGameEngine::_configure_input(
	const std::unordered_map<char, std::shared_ptr<ICommand>> &input_config) noexcept
{
	for (const auto &config_pair : input_config)
	{
		auto key = config_pair.first;
		auto command = config_pair.second;

		_input_handler->subscribe(key, command);
	}
}