extern crate gunpowder_treason as gt;
#[macro_use] extern crate itertools;
extern crate rand;

use std::collections::HashSet;
use rand::Rng;

fn main() {
    let (w, h) = (11.0, 14.0);
    let mut drawing = gt::svg(w, h);
    drawing.add(gt::rect((0.0, 0.0), (11.0, 14.0)));

    let mut rng = rand::thread_rng();

    let mut points: HashSet<(usize, usize)> = iproduct!(2..40, 2..52).collect();
    let mut src: Vec<(usize, usize)> = points.clone().into_iter().collect();
    rng.shuffle(&mut src);

    // for &(x, y) in points.iter() {
    //     drawing.add(gt::line(x as f64 / 2.0, y as f64 / 2.0));
    // }

    while let Some((mut x, mut y)) = src.pop() {
        if !points.remove(&(x, y)) { continue; }
        let mut do_add = false;
        let mut line = gt::line(x as f64 / 4.0, y as f64 / 4.0);
        'find_next: loop {
            let mut neighbors = vec![
                (x - 1, y),
                (x + 1, y),
                (x, y - 1),
                (x, y + 1),
                (x, y - 1),
                (x, y + 1),
                (x, y - 1),
                (x, y + 1),
            ];
            rng.shuffle(&mut neighbors);
            'check_neighbors: for &(xn, yn) in neighbors.iter() {
                if points.remove(&(xn, yn)) {
                    do_add = true;
                    line = line.to(xn as f64 / 4.0, yn as f64 / 4.0);
                    x = xn;
                    y = yn;
                    continue 'find_next;
                }
            }
            break 'find_next;
        }
        if do_add {
            drawing.add(line);
        }
    }

    drawing.to_stdout();
}