use sdl2::pixels::Color;

use sdl2::pixels::Color;

use sdl2::event::Event;

use sdl2::event::Event;

use sdl2::keyboard::Keycode;

use sdl2::keyboard::Keycode;

use sdl2::render::{WindowCanvas, Texture};

use sdl2::render::{WindowCanvas, Texture};

use sdl2::rect::{Point, Rect};

use sdl2::rect::{Point, Rect};

// "self" imports the "image" module itself as well as everything else we listed

// "self" imports the "image" module itself as well as everything else we listed

use sdl2::image::{self, LoadTexture, InitFlag};

use sdl2::image::{self, LoadTexture, InitFlag};

use std::time::Duration;

use std::time::Duration;

#[derive(Debug)]

#[derive(Debug)]

struct Player {

struct Player {

    position: Point,

    position: Point,

    sprite: Rect,

    sprite: Rect,

}

}

fn render(

fn render(

    canvas: &mut WindowCanvas,

    canvas: &mut WindowCanvas,

    color: Color,

    color: Color,

    texture: &Texture,

    texture: &Texture,

    player: &Player,

    player: &Player,

) -> Result<(), String> {

) -> Result<(), String> {

    canvas.set_draw_color(color);

    canvas.set_draw_color(color);

    canvas.clear();

    canvas.clear();

    let (width, height) = canvas.output_size()?;

    let (width, height) = canvas.output_size()?;

    // Treat the center of the screen as the (0, 0) coordinate

    // Treat the center of the screen as the (0, 0) coordinate

    let screen_position = player.position + Point::new(width as i32 / 2, height as i32 / 2);

    let screen_position = player.position + Point::new(width as i32 / 2, height as i32 / 2);

    let screen_rect = Rect::from_center(screen_position, player.sprite.width(), player.sprite.height());

    let screen_rect = Rect::from_center(screen_position, player.sprite.width(), player.sprite.height());

    canvas.copy(texture, player.sprite, screen_rect)?;

    canvas.copy(texture, player.sprite, screen_rect)?;

    canvas.present();

    canvas.present();

    Ok(())

    Ok(())

}

}

fn main() -> Result<(), String> {

fn main() -> Result<(), String> {

    let sdl_context = sdl2::init()?;

    let sdl_context = sdl2::init()?;

    let video_subsystem = sdl_context.video()?;

    let video_subsystem = sdl_context.video()?;

    // Leading "_" tells Rust that this is an unused variable that we don't care about. It has to

    // Leading "_" tells Rust that this is an unused variable that we don't care about. It has to

    // stay unused because if we don't have any variable at all then Rust will treat it as a

    // stay unused because if we don't have any variable at all then Rust will treat it as a

    // temporary value and drop it right away!

    // temporary value and drop it right away!

    let _image_context = image::init(InitFlag::PNG | InitFlag::JPG)?;

    let _image_context = image::init(InitFlag::PNG | InitFlag::JPG)?;

    let window = video_subsystem.window("game tutorial", 800, 600)

    let window = video_subsystem.window("game tutorial", 800, 600)

        .position_centered()

        .position_centered()

        .build()

        .build()

        .expect("could not initialize video subsystem");

        .expect("could not initialize video subsystem");

    let mut canvas = window.into_canvas().build()

    let mut canvas = window.into_canvas().build()

        .expect("could not make a canvas");

        .expect("could not make a canvas");

    let texture_creator = canvas.texture_creator();

    let texture_creator = canvas.texture_creator();

    let texture = texture_creator.load_texture("assets/bardo.png")?;

    let texture = texture_creator.load_texture("assets/bardo.png")?;

        position: Point::new(0, 0),

        position: Point::new(0, 0),

        sprite: Rect::new(0, 0, 26, 36),

        sprite: Rect::new(0, 0, 26, 36),

    };

    };

    let mut event_pump = sdl_context.event_pump()?;

    let mut event_pump = sdl_context.event_pump()?;

    let mut i = 0;

    let mut i = 0;

    'running: loop {

    'running: loop {

        // Handle events

        // Handle events

        for event in event_pump.poll_iter() {

        for event in event_pump.poll_iter() {

            match event {

            match event {

                Event::Quit {..} |

                Event::Quit {..} |

                Event::KeyDown { keycode: Some(Keycode::Escape), .. } => {

                Event::KeyDown { keycode: Some(Keycode::Escape), .. } => {

                    break 'running;

                    break 'running;

                },

                },

                _ => {}

                _ => {}

            }

            }

        }

        }

        // Update

        // Update

        i = (i + 1) % 255;

        i = (i + 1) % 255;

        // Render

        // Render

        render(&mut canvas, Color::RGB(i, 64, 255 - i), &texture, &player)?;

        render(&mut canvas, Color::RGB(i, 64, 255 - i), &texture, &player)?;

        // Time management!

        // Time management!

        ::std::thread::sleep(Duration::new(0, 1_000_000_000u32 / 60));

        ::std::thread::sleep(Duration::new(0, 1_000_000_000u32 / 60));

    }

    }

    Ok(())

    Ok(())

}

}