use {
    std::{
        io::{Read, Seek},
        rc::Rc,
    },
    wgpu::{Instance, Surface},
};

pub trait File: Seek + Read {}

impl File for std::fs::File {}

impl File for std::io::Cursor<Vec<u8>> {}

pub enum Event {
    MouseButtonPressed,
    OpenTestFile(Box<dyn File>),
}

#[derive(Debug, Clone, Copy)]
pub struct Size2i {
    pub width: u32,
    pub height: u32,
}

pub trait FrameTimer {
    fn mark_frame_start(&mut self);
    fn get_frame_time_seconds(&self) -> f64;
}

#[allow(async_fn_in_trait)]
// https://blog.rust-lang.org/2023/12/21/async-fn-rpit-in-traits.html#where-the-gaps-lie
pub trait MvuApp<M> {
    async fn init(
        &mut self,
        instance: &Instance,
        surface: Surface<'static>,
        new_size: Size2i,
        frame_timer: Box<dyn FrameTimer>,
    );
    async fn resize(&mut self, size: Size2i);
    async fn update(&self, model: Rc<M>, event: Event) -> Rc<M>;
    async fn view(&mut self, model: Rc<M>) -> Result<(), Box<dyn std::error::Error>>;
}