use crate::*;
use std::time::Duration;
use std::thread::JoinHandle;

/// Event source
pub trait Input: Send + Sync + Sized {
    /// Type of input event
    type Event;
    /// Result of handling input
    type Handled; // TODO: make this an Option<Box dyn Command<Self>> containing the undo
    /// Currently handled event
    fn event (&self) -> &Self::Event;
    /// Whether component should exit
    fn is_done (&self) -> bool;
    /// Mark component as done
    fn done (&self);
}

/// Input thread entrypoint.
pub trait InputRun<T> {
    fn run_input (engine: T, state: Self, timer: Duration) -> JoinHandle<()>;
}

/// Handle input through a mutable reference.
pub trait Handle<E: Input>: Send + Sync {
    fn handle (&mut self, _input: &E) -> Perhaps<E::Handled> {
        Ok(None)
    }
}

/// Handle input through an immutable reference (e.g. [Arc<RwLock>] or [Arc<Mutex>])
pub trait HandleRef<E: Input>: Send + Sync {
    fn handle (&self, _input: &E) -> Perhaps<E::Handled> {
        Ok(None)
    }
}