use crate::*;
use std::sync::{Arc, Mutex, RwLock};

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

/// Current input state
pub trait Input<E: Engine> {
    /// Type of input event
    type Event;
    /// Currently handled event
    fn event (&self) -> &Self::Event;
    /// Whether component should exit
    fn is_done (&self) -> bool;
    /// Mark component as done
    fn done (&self);
}

#[macro_export] macro_rules! handle {
    (<$E:ty>|$self:ident:$Struct:ty,$input:ident|$handler:expr) => {
        impl Handle<$E> for $Struct {
            fn handle (&mut $self, $input: &<$E as Engine>::Input) -> Perhaps<<$E as Engine>::Handled> {
                $handler
            }
        }
    }
}

impl<E: Engine, H: Handle<E>> Handle<E> for &mut H {
    fn handle (&mut self, context: &E::Input) -> Perhaps<E::Handled> {
        (*self).handle(context)
    }
}

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

impl<H, E: Engine> Handle<E> for Mutex<H> where H: Handle<E> {
    fn handle (&mut self, context: &E::Input) -> Perhaps<E::Handled> {
        self.get_mut().unwrap().handle(context)
    }
}

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

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

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