#include <SFML/Graphics.hpp>
#include <iostream>
#include <cmath>

unsigned const screen_width  { 640 };
unsigned const screen_height { 640 };

void move_sprite(sf::Sprite& sprite, sf::Vector2f direction, float angle)
{
    sprite.setRotation(angle);
    sprite.move(direction);
}

int main()
{

    sf::RenderWindow window { sf::VideoMode { screen_width,
                                              screen_height },
                              "Basic SFML Example" };

    float const radius { 16.0 };
    sf::CircleShape circle { radius };
    circle.setOrigin(radius, radius);
    circle.setFillColor(sf::Color::Green);

    sf::Vector2u window_size { window.getSize() };
    circle.setPosition(window_size.x / 2, window_size.y / 2);

    sf::Texture texture { };
    if (!texture.loadFromFile("fighter.png"))
    {
        std::cerr << "Kan inte öppna: fighter.png" << std::endl;
        return 1;
    }

    sf::Sprite sprite { texture };
    sf::Vector2u texture_size { texture.getSize() };
    sprite.setOrigin(texture_size.x / 2, texture_size.y / 2);
    sprite.setPosition(window_size.x / 2, 3 * window_size.y / 4);

    // Mät tidsåtgång för varje varv i Main-loopen
    sf::Clock clock;

    // Antal bildrutor per sekund
    float const fps { 60.0f };
    
    // beräkna hur lång tid vi har per frame
    sf::Time const target { sf::milliseconds (1000.0 / fps) };

    // Vi vill ha 128 pixlar per sekund, så pixlar per bildruta blir 128 / fps 
    float const speed { 128.0f / fps };
    
    
    while (window.isOpen())
    {
        // Hantera inmatning

        // Börja tidtagning
        clock.restart();
        
        sf::Event event;
        while (window.pollEvent(event))
        {
            if (event.type == sf::Event::Closed)
            {
                window.close();
            }
            else if (event.type == sf::Event::MouseButtonPressed)
            {
                sf::Event::MouseButtonEvent mouse { event.mouseButton };
                if (mouse.button == sf::Mouse::Button::Left)
                {
                    circle.setPosition(mouse.x, mouse.y);
                }
            }
        }

        // Uppdatera logiken

        if (sf::Keyboard::isKeyPressed(sf::Keyboard::Key::W))
        {
            move_sprite(sprite, {0, -speed}, 0);
        }
        else if (sf::Keyboard::isKeyPressed(sf::Keyboard::Key::A))
        {
            move_sprite(sprite, {-speed, 0}, 270);
        }
        else if (sf::Keyboard::isKeyPressed(sf::Keyboard::Key::S))
        {
            move_sprite(sprite, {0, speed}, 180);
        }
        else if (sf::Keyboard::isKeyPressed(sf::Keyboard::Key::D))
        {
            move_sprite(sprite, {speed, 0}, 90);
        }

        // Rita
        
        window.clear();

        window.draw(sprite);
        window.draw(circle);
        
        window.display();

        // Plocka ut tidsåtgången för det här varvet
        sf::Time elapsed_time { clock.getElapsedTime() };

        // Vänta tills den här iterationen har tagit 'target' tid.
        sf::sleep(target - elapsed_time);
    }
    
}