use super::*;
use crate::prelude::*;

// these methods should "not require any context" (require unit) because they're in core
event_ctx!(());

pub trait CoreWidget<W, Tag> {
    fn pad(self, padding: impl Into<Padding>) -> impl WidgetFn<Pad>;
    fn align(self, align: impl Into<Align>) -> impl WidgetFn<Aligned>;
    fn center(self) -> impl WidgetFn<Aligned>;
    fn label(self, label: impl Into<String>) -> impl WidgetIdFn<W>;
    fn sized(self, size: impl Into<Size>) -> impl WidgetFn<Sized>;
    fn width(self, len: impl Into<Len>) -> impl WidgetFn<Sized>;
    fn height(self, len: impl Into<Len>) -> impl WidgetFn<Sized>;
    fn max_width(self, width: impl Into<Len>) -> impl WidgetFn<MaxSize>;
    fn max_height(self, height: impl Into<Len>) -> impl WidgetFn<MaxSize>;
    fn offset(self, amt: impl Into<UiVec2>) -> impl WidgetFn<Offset>;
    fn scroll(self) -> impl WidgetIdFn<Scroll>;
    fn masked(self) -> impl WidgetFn<Masked>;
    fn background<T>(self, w: impl WidgetLike<T>) -> impl WidgetFn<Stack>;
    fn foreground<T>(self, w: impl WidgetLike<T>) -> impl WidgetFn<Stack>;
    fn layer_offset(self, offset: usize) -> impl WidgetFn<LayerOffset>;
    fn to_any(self) -> impl WidgetRet;
}

impl<W: WidgetLike<Tag>, Tag> CoreWidget<W::Widget, Tag> for W {
    fn pad(self, padding: impl Into<Padding>) -> impl WidgetFn<Pad> {
        |ui| Pad {
            padding: padding.into(),
            inner: self.add(ui).any(),
        }
    }

    fn align(self, align: impl Into<Align>) -> impl WidgetFn<Aligned> {
        move |ui| Aligned {
            inner: self.add(ui).any(),
            align: align.into(),
        }
    }

    fn center(self) -> impl WidgetFn<Aligned> {
        self.align(Align::CENTER)
    }

    fn label(self, label: impl Into<String>) -> impl WidgetIdFn<W::Widget> {
        |ui| {
            let id = self.add(ui);
            ui.set_label(&id, label.into());
            id
        }
    }

    fn sized(self, size: impl Into<Size>) -> impl WidgetFn<Sized> {
        let size = size.into();
        move |ui| Sized {
            inner: self.add(ui).any(),
            x: Some(size.x),
            y: Some(size.y),
        }
    }

    fn max_width(self, len: impl Into<Len>) -> impl WidgetFn<MaxSize> {
        let len = len.into();
        move |ui| MaxSize {
            inner: self.add(ui).any(),
            x: Some(len),
            y: None,
        }
    }

    fn max_height(self, len: impl Into<Len>) -> impl WidgetFn<MaxSize> {
        let len = len.into();
        move |ui| MaxSize {
            inner: self.add(ui).any(),
            x: None,
            y: Some(len),
        }
    }

    fn width(self, len: impl Into<Len>) -> impl WidgetFn<Sized> {
        let len = len.into();
        move |ui| Sized {
            inner: self.add(ui).any(),
            x: Some(len),
            y: None,
        }
    }

    fn height(self, len: impl Into<Len>) -> impl WidgetFn<Sized> {
        let len = len.into();
        move |ui| Sized {
            inner: self.add(ui).any(),
            x: None,
            y: Some(len),
        }
    }

    fn offset(self, amt: impl Into<UiVec2>) -> impl WidgetFn<Offset> {
        move |ui| Offset {
            inner: self.add(ui).any(),
            amt: amt.into(),
        }
    }

    fn scroll(self) -> impl WidgetIdFn<Scroll> {
        move |ui| {
            Scroll::new(self.add(ui).any(), Axis::Y)
                .on(CursorSense::Scroll, |ctx| {
                    let s = &mut ctx.ui[ctx.id];
                    s.scroll(ctx.data.scroll_delta.y * 50.0);
                })
                .add(ui)
        }
    }

    fn masked(self) -> impl WidgetFn<Masked> {
        move |ui| Masked {
            inner: self.add(ui).any(),
        }
    }

    fn background<T>(self, w: impl WidgetLike<T>) -> impl WidgetFn<Stack> {
        move |ui| Stack {
            children: vec![w.add(ui).any(), self.add(ui).any()],
            size: StackSize::Child(1),
        }
    }

    fn foreground<T>(self, w: impl WidgetLike<T>) -> impl WidgetFn<Stack> {
        move |ui| Stack {
            children: vec![self.add(ui).any(), w.add(ui).any()],
            size: StackSize::Child(0),
        }
    }

    fn layer_offset(self, offset: usize) -> impl WidgetFn<LayerOffset> {
        move |ui| LayerOffset {
            inner: self.add(ui).any(),
            offset,
        }
    }

    fn to_any(self) -> impl WidgetRet {
        |ui| self.add(ui).any()
    }
}

pub trait CoreWidgetArr<const LEN: usize, Wa: WidgetArrLike<LEN, Tag>, Tag> {
    fn span(self, dir: Dir) -> SpanBuilder<LEN, Wa, Tag>;
    fn stack(self) -> StackBuilder<LEN, Wa, Tag>;
}

impl<const LEN: usize, Wa: WidgetArrLike<LEN, Tag>, Tag> CoreWidgetArr<LEN, Wa, Tag> for Wa {
    fn span(self, dir: Dir) -> SpanBuilder<LEN, Wa, Tag> {
        SpanBuilder::new(self, dir)
    }
    fn stack(self) -> StackBuilder<LEN, Wa, Tag> {
        StackBuilder::new(self)
    }
}