use crate::*;

/// Handle input
pub trait Handle<T, U>: Send + Sync {
    fn handle (&mut self, context: &mut T) -> Perhaps<U>;
}

impl<H, T, U> Handle<T, U> for &mut H where H: Handle<T, U> {
    fn handle (&mut self, context: &mut T) -> Perhaps<U> {
        (*self).handle(context)
    }
}

impl<H, T, U> Handle<T, U> for Option<H> where H: Handle<T, U> {
    fn handle (&mut self, context: &mut T) -> Perhaps<U> {
        if let Some(ref mut handle) = self {
            handle.handle(context)
        } else {
            Ok(None)
        }
    }
}

impl<H, T, U> Handle<T, U> for Mutex<H> where H: Handle<T, U> {
    fn handle (&mut self, context: &mut T) -> Perhaps<U> {
        self.lock().unwrap().handle(context)
    }
}

impl<H, T, U> Handle<T, U> for Arc<Mutex<H>> where H: Handle<T, U> {
    fn handle (&mut self, context: &mut T) -> Perhaps<U> {
        self.lock().unwrap().handle(context)
    }
}

impl<H, T, U> Handle<T, U> for RwLock<H> where H: Handle<T, U> {
    fn handle (&mut self, context: &mut T) -> Perhaps<U> {
        self.write().unwrap().handle(context)
    }
}

impl<H, T, U> Handle<T, U> for Arc<RwLock<H>> where H: Handle<T, U> {
    fn handle (&mut self, context: &mut T) -> Perhaps<U> {
        self.write().unwrap().handle(context)
    }
}