use std::time::Instant;

use taffy::{
    prelude::{Rect, Size},
    style::{LengthPercentageAuto, Style},
};

fn build_style() -> Style {
    let margin = Rect {
        left: LengthPercentageAuto::Points(20.),
        top: LengthPercentageAuto::Points(20.),
        right: LengthPercentageAuto::Points(0.),
        bottom: LengthPercentageAuto::Points(0.),
    };

    let size = Size {
        width: taffy::style::Dimension::Auto,
        height: taffy::style::Dimension::Auto,

        // changing width and height to 100% decreases layout time by ~ 100x

        // width: taffy::style::Dimension::Percent(1.),
        // height: taffy::style::Dimension::Percent(1.),
    };

    let mut style = Style::DEFAULT;

    // adding flex column increases time by 10x 
    style.flex_direction = taffy::style::FlexDirection::Column;

    // adding margin increases layout time by 200 - 500ms
    style.margin = margin;

    style.size = size;
    style
}

fn main() {
    let mut app = taffy::Taffy::new();

    let root = app.new_leaf(build_style()).unwrap();

    let mut parent = root;

    // adding depth increases time ~ exponentially
    for _ in 0..200 {
        let child = app.new_leaf(build_style()).unwrap();
        app.add_child(parent, child).unwrap();

        // adding more siblings increases time ~ linearly from what I can tell
        let child = app.new_leaf(build_style()).unwrap();
        app.add_child(parent, child).unwrap();

        let child = app.new_leaf(build_style()).unwrap();
        app.add_child(parent, child).unwrap();

        parent = child;
    }

    let time_now = Instant::now();

    app.compute_layout(
        root,
        Size {
            width: taffy::style::AvailableSpace::Definite(800.),
            height: taffy::style::AvailableSpace::Definite(600.),
        },
    )
    .unwrap();

    // this takes about 1,500ms on my M1 Macbook Pro in dev build
    println!("Time elapsed: {:?}", time_now.elapsed());
}