use crate::*;
#[cfg(test)] use proptest_derive::Arbitrary;
/// A cardinal direction.
#[derive(Copy, Clone, PartialEq, Debug)]
#[cfg_attr(test, derive(Arbitrary))]
pub enum Direction { North, South, East, West, Above, Below }
impl Direction {
    pub fn split_fixed <N: Coordinate> (self, area: impl Area<N>, a: N) -> ([N;4],[N;4]) {
        let [x, y, w, h] = area.xywh();
        match self {
            North => ([x, y.plus(h).minus(a), w, a], [x, y, w, h.minus(a)]),
            South => ([x, y, w, a], [x, y.plus(a), w, h.minus(a)]),
            East  => ([x, y, a, h], [x.plus(a), y, w.minus(a), h]),
            West  => ([x.plus(w).minus(a), y, a, h], [x, y, w.minus(a), h]),
            Above | Below => (area.xywh(), area.xywh())
        }
    }
}
#[cfg(test)] mod test {
    use super::*;
    use proptest::prelude::*;
    proptest! {
        #[test] fn proptest_direction (
            d in prop_oneof![
                Just(North), Just(South),
                Just(East),  Just(West),
                Just(Above), Just(Below)
            ],
            x in u16::MIN..u16::MAX,
            y in u16::MIN..u16::MAX,
            w in u16::MIN..u16::MAX,
            h in u16::MIN..u16::MAX,
            a in u16::MIN..u16::MAX,
        ) {
            let _ = d.split_fixed([x, y, w, h], a);
        }
    }
}