#include "defs.h"
#include <SFML/Graphics.hpp>
#include <SFML/Window.hpp>
#include <imgui-SFML.h>
#include <imgui.h>

static sf::RenderWindow window{};
static sf::Clock delta_clock{};
static sf::Time delta_time{};
static AppConfig cfg{};
static sf::View view{};

extern void configure(AppConfig &config);

void initialize_window() {
	cfg = AppConfig();
	configure(cfg);
	window.create(cfg.mode, cfg.window_title);
	if (cfg.frame_rate_limit) {
		window.setFramerateLimit(cfg.frame_rate_limit.value_or(0));
	}
	window.setVerticalSyncEnabled(cfg.vsync);
	view = window.getDefaultView();
}

void initialize_imgui() {
	if (!ImGui::SFML::Init(window))
		exit(-1);
}

extern void handle_input_event(sf::Event const &evt);
extern void handle_window_event(sf::Event const &evt);

void try_handle_input_event(sf::Event const &event) {
	bool const is_input_event{
		event.is<sf::Event::JoystickButtonPressed>() || event.is<sf::Event::JoystickButtonReleased>() ||
		event.is<sf::Event::JoystickMoved>() ||
		event.is<sf::Event::JoystickConnected>() || event.is<sf::Event::JoystickDisconnected>() ||
		event.is<sf::Event::KeyPressed>() || event.is<sf::Event::KeyReleased>() ||
		event.is<sf::Event::TouchBegan>() || event.is<sf::Event::TouchEnded>() ||
		event.is<sf::Event::TouchMoved>() ||
		event.is<sf::Event::MouseButtonPressed>() || event.is<sf::Event::MouseButtonReleased>() ||
		event.is<sf::Event::MouseMoved>() || event.is<sf::Event::MouseMovedRaw>()};
	if (is_input_event) {
		handle_input_event(event);
	}
}

void try_handle_window_event(sf::Event const &event) {
	bool const is_window_event{
		event.is<sf::Event::FocusGained>() ||
		event.is<sf::Event::FocusLost>() ||
		event.is<sf::Event::Resized>()};
	if (is_window_event) {
		handle_window_event(event);
	}
}

void poll_events() {
	while (std::optional const event{window.pollEvent()}) {
		ImGui::SFML::ProcessEvent(window, *event);
		try_handle_input_event(*event);
		try_handle_window_event(*event);

		if (event->is<sf::Event::Closed>()) {
			window.close();
		}
	}
}

extern void setup(void);
extern void loop(double delta);
extern void draw_scene(sf::RenderTarget &target, sf::RenderStates const &states);
extern void draw_main_menu_bar(void);
extern void draw_gui(void);
extern void shutdown(void);

int main() {
	initialize_window();
	initialize_imgui();
	setup();
	while (window.isOpen()) {
		// Event Polling
		poll_events();
		// Update
		delta_time = delta_clock.restart();
		ImGui::SFML::Update(window, delta_time);
		loop(delta_time.asSeconds());
		if (ImGui::BeginMainMenuBar()) {
			draw_main_menu_bar();
			ImGui::EndMainMenuBar();
		}
		draw_gui();
		// Render
		window.clear();
		draw_scene(window, cfg.default_render_states);
		ImGui::SFML::Render(window);
		window.display();
	}
	shutdown();
	ImGui::SFML::Shutdown();
	return 0;
}

AppConfig const &get_application_configuration() {
	return cfg;
}

sf::Time const &get_delta_time() {
	return delta_time;
}

sf::RenderWindow &get_window() {
	return window;
}

void set_render_view(sf::View const &view) {
	window.setView(view);
}