use anyhow::Result;
use buffer_graphics_lib::Graphics;
use pixels_graphics_lib::prelude::*;
use pixels_graphics_lib::window_prefs::WindowPreferences;
use winit::keyboard::KeyCode;

/// Running this example will create preference directories and files on your computer!
///
/// This example shows how to use `WindowPreferences` to save and restore the window size and position
/// It also has a small text demo

fn main() -> Result<()> {
    let width = 240;
    let height = 160;
    let system = WindowPrefsScene::new("Example Text", width, height);
    run(
        width,
        height,
        "Window Pos Example",
        Box::new(system),
        Options::default(),
    )?;
    Ok(())
}

struct WindowPrefsScene {
    text: &'static str,
    pos: (usize, usize),
    colors: Vec<Color>,
    idx: usize,
    should_exit: bool,
}

impl WindowPrefsScene {
    pub fn new(text: &'static str, width: usize, height: usize) -> Self {
        let (w, h) = PixelFont::Standard6x7.measure(text);
        let pos = (width / 2 - w / 2, height / 2 - h / 2);
        WindowPrefsScene {
            text,
            pos,
            colors: vec![GREEN, RED, BLUE, WHITE, MAGENTA, YELLOW, CYAN],
            idx: 0,
            should_exit: false,
        }
    }
}

impl System for WindowPrefsScene {
    fn window_prefs(&mut self) -> Option<WindowPreferences> {
        Some(
            WindowPreferences::new("app", "pixels-graphics-lib-example", "window-pos2", 1).unwrap(),
        )
    }

    fn update(&mut self, _delta: &Timing, _: &Window) {
        if self.idx < self.colors.len() - 1 {
            self.idx += 1;
        } else {
            self.idx = 0;
        }
    }

    fn render(&mut self, graphics: &mut Graphics<'_>) {
        graphics.clear(BLACK);
        let mut color_idx = self.idx;
        for (i, letter) in self.text.chars().enumerate() {
            let mut pos = self.pos;
            pos.0 += PixelFont::Standard6x7.size().0 * i + PixelFont::Standard6x7.spacing() * i;
            graphics.draw_letter(
                (pos.0 as isize, pos.1 as isize),
                letter,
                PixelFont::Standard6x7,
                self.colors[color_idx],
            );

            color_idx += 1;
            if color_idx >= self.colors.len() {
                color_idx = 0;
            }
        }
    }

    fn on_key_down(&mut self, keys: Vec<KeyCode>) {
        if keys.contains(&KeyCode::Escape) {
            self.should_exit = true;
        }
    }

    fn should_exit(&mut self) -> bool {
        self.should_exit
    }
}