#![feature(associated_type_defaults)]

//mod component; pub use self::component::*;
mod engine; pub use self::engine::*;
mod handle; pub use self::handle::*;
mod command; pub use self::command::*;
mod event_map; pub use self::event_map::*;

pub(crate) use std::marker::PhantomData;
pub(crate) use std::error::Error;

/// Standard result type.
pub(crate) type Usually<T> = Result<T, Box<dyn Error>>;

/// Standard optional result type.
pub(crate) type Perhaps<T> = Result<Option<T>, Box<dyn Error>>;

#[cfg(test)] #[test] fn test_dimensions () {
    assert_eq!(Area::center(&[10u16, 10, 20, 20]), [20, 20]);
}

#[cfg(test)] #[test] fn test_stub_engine () -> Usually<()> {
    struct TestEngine(bool);
    struct TestInput(bool);
    struct TestOutput([u16;4]);
    enum TestEvent { Test1 }
    impl Engine for TestEngine {
        type Input   = TestInput;
        type Handled = ();
        type Output  = TestOutput;
        type Unit    = u16;
        type Size    = [u16;2];
        type Area    = [u16;4];
        fn exited (&self) -> bool {
            self.0
        }
    }
    impl Input<TestEngine> for TestInput {
        type Event = TestEvent;
        fn event (&self) -> &Self::Event {
            &TestEvent::Test1
        }
        fn is_done (&self) -> bool {
            self.0
        }
        fn done (&self) {}
    }
    impl Output<TestEngine> for TestOutput {
        fn area (&self) -> [u16;4] {
            self.0
        }
        fn area_mut (&mut self) -> &mut [u16;4] {
            &mut self.0
        }
        fn place (&mut self, _: [u16;4], _: &impl Render<TestEngine>) {
            ()
        }
    }
    impl Content<TestEngine> for String {
        fn render (&self, to: &mut TestOutput) {
            to.area_mut().set_w(self.len() as u16);
        }
    }
    Ok(())
}