use wasm_bindgen::prelude::*;
use std::cell::RefCell;
use std::rc::Rc;
use js_sys::Date;
use wasm_bindgen::JsCast;

mod drawing;
mod shapes;
mod circle;

use shapes::*;
use circle::CircleShapes;

fn request_animation_frame(f: &Closure<dyn FnMut()>) {
    web_sys::window()
        .unwrap()
        .request_animation_frame(
            f.as_ref()
            .unchecked_ref()
        ).unwrap();
}

#[wasm_bindgen(start)]
pub fn start() {
    let canvas_id = "circle_canvas";
    let document = web_sys::window().unwrap().document().unwrap();
    let canvas = document.get_element_by_id(canvas_id).unwrap();
    let canvas: web_sys::HtmlCanvasElement = canvas
        .dyn_into::<web_sys::HtmlCanvasElement>()
        .map_err(|_| ())
        .unwrap();
  
    let context = canvas
        .get_context("2d")
        .unwrap()
        .unwrap()
        .dyn_into::<web_sys::CanvasRenderingContext2d>()
        .unwrap();


    let f = Rc::new(RefCell::new(None));
    let g = f.clone();

    let mut timestamp: Option<f64> = None;
    let mut factor = 2;
    let mut modulo = 10;

    *g.borrow_mut() = Some(Closure::wrap(Box::new(move || {
        match timestamp {
            Some(date) if (Date::now() - date) < 250. => (),
            _ => {
                timestamp = Some(Date::now());
                context.begin_path();  
                let iter = CircleShapes::new(modulo, factor, Circle {center: Point {x: 400.0, y: 400.0}, radius: 400.0});
                for shape in iter {
                    drawing::draw_shape(shape, &context);
                }
                context.stroke();
        
                factor += 1;
                if factor == modulo {
                    factor = 2;
                    modulo += 1;
                }
            }
        }

        request_animation_frame(f.borrow().as_ref().unwrap());
    }) as Box<dyn FnMut()>));

    request_animation_frame(g.borrow().as_ref().unwrap());
}