use crate::core::*;

pub struct Stack<'a>(pub &'a[Box<dyn Render + Sync>]);

impl<'a> Render for Stack<'a> {
    fn render (&self, buf: &mut Buffer, area: Rect) -> Usually<Rect> {
        let mut area2 = area.clone();
        for layer in self.0.iter() {
            area2 = layer.render(buf, area2)?;
        }
        Ok(area)
    }
}

pub struct Column(pub Vec<Box<dyn Device>>);

pub struct Row(pub Vec<Box<dyn Device>>);

impl Column {
    pub fn new (items: Vec<Box<dyn Device>>) -> Self {
        Self(items)
    }
    pub fn draw (buf: &mut Buffer, area: Rect, items: &[impl Render], gap: i16)
        -> Usually<(Rect, Vec<Rect>)>
    {
        let mut w = 0u16;
        let mut h = 0u16;
        let mut rects = vec![];
        for (_i, device) in items.iter().enumerate() {
            let y      = area.y + h;
            let rect   = Rect { x: area.x, y, width: area.width, height: area.height - h };
            let result = device.render(buf, rect)?;
            rects.push(result);
            w = w.max(result.width);
            h = ((h + result.height) as i16 + gap).max(0) as u16;
        }
        Ok((Rect { x: area.x, y: area.y, width: w, height: h }, rects))
    }
}

impl Render for Column {
    fn render (&self, buf: &mut Buffer, area: Rect) -> Usually<Rect> {
        Ok(Column::draw(buf, area, &self.0, 0)?.0)
    }
}

impl Row {
    pub fn new (items: Vec<Box<dyn Device>>) -> Self {
        Self(items)
    }
    pub fn draw (buf: &mut Buffer, area: Rect, items: &[impl Render], gap: i16)
        -> Usually<(Rect, Vec<Rect>)>
    {
        let mut w = 0u16;
        let mut h = 0u16;
        let mut rects = vec![];
        for (_i, device) in items.iter().enumerate() {
            let x      = area.x + w;
            let rect   = Rect { x, y: area.y, width: area.width - w, height: area.height };
            let result = device.render(buf, rect)?;
            rects.push(result);
            w = ((w + result.width) as i16 + gap).max(0) as u16;
            h = h.max(result.height);
        }
        Ok((Rect { x: area.x, y: area.y, width: w, height: h }, rects))
    }
}

impl Render for Row {
    fn render (&self, buf: &mut Buffer, area: Rect) -> Usually<Rect> {
        Ok(Row::draw(buf, area, &self.0, 0)?.0)
    }
}