use crate::UiRsc;

use super::*;
use std::marker::Unsize;

pub trait WidgetLike<Rsc: UiRsc, Tag>: Sized {
    type Widget: Widget + ?Sized + Unsize<dyn Widget>;

    fn add(self, rsc: &mut Rsc) -> WeakWidget<Self::Widget>;

    fn add_strong(self, rsc: &mut Rsc) -> StrongWidget<Self::Widget> {
        self.add(rsc).upgrade(rsc)
    }

    fn with_id<W2>(
        self,
        f: impl FnOnce(&mut Rsc, WeakWidget<Self::Widget>) -> WeakWidget<W2>,
    ) -> impl WidgetIdFn<Rsc, W2> {
        move |state| {
            let id = self.add(state);
            f(state, id)
        }
    }

    fn set_root(self, rsc: &mut Rsc, root: &mut impl HasRoot) {
        let id = self.add_strong(rsc);
        root.set_root(id);
    }
}

pub trait HasRoot {
    fn set_root(&mut self, root: StrongWidget);
}

pub trait WidgetArrLike<Rsc, const LEN: usize, Tag> {
    #[track_caller]
    fn add(self, state: &mut Rsc) -> WidgetArr<LEN>;
}

impl<Rsc, const LEN: usize> WidgetArrLike<Rsc, LEN, ArrTag> for WidgetArr<LEN> {
    fn add(self, _: &mut Rsc) -> WidgetArr<LEN> {
        self
    }
}

// variadic generics please save us
macro_rules! impl_widget_arr {
    ($n:expr;$($W:ident)*) => {
        impl_widget_arr!($n;$($W)*;$(${concat($W,Tag)})*);
    };
    ($n:expr;$($W:ident)*;$($Tag:ident)*) => {
        impl<Rsc: UiRsc, $($W: WidgetLike<Rsc, $Tag>,$Tag,)*> WidgetArrLike<Rsc, $n, ($($Tag,)*)> for ($($W,)*) {
            fn add(self, rsc: &mut Rsc) -> WidgetArr<$n> {
                #[allow(non_snake_case)]
                let ($($W,)*) = self;
                WidgetArr::new(
                    [$($W.add(rsc).upgrade(rsc),)*],
                )
            }
        }
    };
}

impl_widget_arr!(1;A);
impl_widget_arr!(2;A B);
impl_widget_arr!(3;A B C);
impl_widget_arr!(4;A B C D);
impl_widget_arr!(5;A B C D E);
impl_widget_arr!(6;A B C D E F);
impl_widget_arr!(7;A B C D E F G);
impl_widget_arr!(8;A B C D E F G H);
impl_widget_arr!(9;A B C D E F G H I);
impl_widget_arr!(10;A B C D E F G H I J);
impl_widget_arr!(11;A B C D E F G H I J K);
impl_widget_arr!(12;A B C D E F G H I J K L);