#![feature(core_intrinsics)]

fn main() {
    let mut e = EventManager::default();
    e.add_listener(&foo);
}

trait IEventData {
    fn get_timestamp(&self) -> std::time::Duration;
    fn get_name() -> &'static str where Self: Sized;
}


trait IEventManager<'a> {
    fn add_listener<E, F>(&mut self, f: F) where E: 'static + IEventData + Sized, F: 'a + FnMut(&E);
}

struct Event;
impl IEventData for Event {
    fn get_timestamp(&self) -> std::time::Duration {
        std::time::Duration::from_millis(0)
    }
    fn get_name() -> &'static str {
        unsafe { std::intrinsics::type_name::<Self>() }
    }
}

fn foo(e: &Event) {}

#[derive(Default)]
struct EventManager<'a> {
    events: std::collections::VecDeque<Box<dyn IEventData>>,
    listeners: std::collections::HashMap<&'static str, Box<FnMut(&dyn std::any::Any) + 'a>>
}

impl<'a> IEventManager<'a> for EventManager<'a> {
    fn add_listener<E, F>(&mut self, mut f: F) where E: 'static + IEventData + Sized, F: 'a + FnMut(&E) {
        let name = E::get_name();
        self.listeners.insert(name, Box::new(move |e| f(e.downcast_ref::<E>().unwrap())));
    }
}