use crate::*;

pub enum Expand<U, A> { X(U, A), Y(U, A), XY(U, U, A), }

impl<U, A> Expand<U, A> {
    #[inline] pub const fn x (x: U, item: A) -> Self { Self::X(x, item) }
    #[inline] pub const fn y (y: U, item: A) -> Self { Self::Y(y, item) }
    #[inline] pub const fn xy (x: U, y: U, item: A) -> Self { Self::XY(x, y, item) }
}

impl<O: Out, T: Draw<O> + Layout<O>> Content<O> for Expand<O::Unit, T> {
    fn content (&self) -> impl Draw<O> + Layout<O> + '_ {
        use Expand::*;
        match self { X(_, c) => c, Y(_, c) => c, XY(_, _, c) => c, }
    }
}

impl<O: Out, T: Draw<O> + Layout<O>> Draw<O> for Expand<O::Unit, T> {
    fn draw (&self, to: &mut O) {
        to.place_at(self.layout(to.area()), &self.content())
    }
}

impl<U: Coordinate, T> Expand<U, T> {
    #[inline] pub fn dx (&self) -> U {
        use Expand::*;
        match self { X(x, _) => *x, Y(_, _) => 0.into(), XY(x, _, _) => *x, }
    }
    #[inline] pub fn dy (&self) -> U {
        use Expand::*;
        match self { X(_, _) => 0.into(), Y(y, _) => *y, XY(_, y, _) => *y, }
    }
}

impl<O: Out, T: Layout<O>> Layout<O> for Expand<O::Unit, T> {
    fn layout (&self, to: O::Area) -> O::Area {
        [to.x(), to.y(), to.w().plus(self.dx()), to.h().plus(self.dy())].into()
    }
}