use crate::prelude::*;

pub struct MaxSize<State> {
    pub inner: WidgetHandle<State>,
    pub x: Option<Len>,
    pub y: Option<Len>,
}

impl<State: 'static> MaxSize<State> {
    fn apply_to_outer(&self, ctx: &mut SizeCtx<State>) {
        if let Some(x) = self.x {
            ctx.outer.x.select_len(x.apply_rest());
        }
        if let Some(y) = self.y {
            ctx.outer.y.select_len(y.apply_rest());
        }
    }
}

impl<State: 'static> Widget<State> for MaxSize<State> {
    fn draw(&mut self, painter: &mut Painter<State>) {
        painter.widget(&self.inner);
    }

    fn desired_width(&mut self, ctx: &mut SizeCtx<State>) -> Len {
        self.apply_to_outer(ctx);
        let width = ctx.width(&self.inner);
        if let Some(x) = self.x {
            let width_px = width.apply_rest().to_abs(ctx.output_size().x);
            let x_px = x.apply_rest().to_abs(ctx.output_size().x);
            if width_px > x_px { x } else { width }
        } else {
            width
        }
    }

    fn desired_height(&mut self, ctx: &mut SizeCtx<State>) -> Len {
        self.apply_to_outer(ctx);
        let height = ctx.height(&self.inner);
        if let Some(y) = self.y {
            let height_px = height.apply_rest().to_abs(ctx.output_size().y);
            let y_px = y.apply_rest().to_abs(ctx.output_size().y);
            if height_px > y_px { y } else { height }
        } else {
            height
        }
    }
}