#[path = "../lib.rs"]
mod lib;

fn parse_xy(s: &str) -> Option<(i64, i64)> {
    let (_, ss) = s.split_once('=')?;
    let (xs, ys) = ss.split_once(',')?;
    let x = xs.parse::<i64>().ok()?;
    let y = ys.parse::<i64>().ok()?;
    return Some((x, y));
}

fn parse_line(s: &str) -> Option<(i64, i64, i64, i64)> {
    let (ps, vs) = s.split_once(' ')?;
    let (px, py) = parse_xy(ps)?;
    let (vx, vy) = parse_xy(vs)?;
    return Some((px, py, vx, vy));
}

fn print(bots: &Vec<(i64, i64, i64, i64)>, w: i64, h: i64) {
    let mut map = vec![vec![0; w as usize]; h as usize];
    for (x, y, _, _) in bots.iter() {
        map[*y as usize][*x as usize] += 1;
    }
    for row in map.iter() {
        for c in row.iter() {
            if *c == 0 {
                print!(" ");
            } else {
                print!("{}", c);
            }
        }
        println!("");
    }
    println!("");
}

fn part2() {
    // store output to a file and search for many consecutive 1s
    let w = 101;
    let h = 103;
    let mut bots = vec![];

    for line in lib::iter_input() {
        bots.push(parse_line(&line).unwrap());
    }

    for i in 0.. {
        println!("{}", i);
        print(&bots, w, h);
        bots = bots.iter().map(|(px, py, vx, vy)| {
            let x = (px + vx).rem_euclid(w);
            let y = (py + vy).rem_euclid(h);
            return (x, y, *vx, *vy);
        }).collect();
    }
}

fn main() {
    let mut quadrants = [0, 0, 0, 0];

    let w = 101;
    let h = 103;
    let t = 100;

    for line in lib::iter_input() {
        let (px, py, vx, vy) = parse_line(&line).unwrap();
        let x = (px + vx * t).rem_euclid(w);
        let y = (py + vy * t).rem_euclid(h);
        if x < w / 2 && y < h / 2 {
            quadrants[0] += 1;
        } else if x < w / 2 && y > h / 2 {
            quadrants[1] += 1;
        } else if x > w / 2 && y < h / 2 {
            quadrants[2] += 1;
        } else if x > w / 2 && y > h / 2 {
            quadrants[3] += 1;
        }
    }

    println!("part1: {}", quadrants.iter().fold(1, |a, b| a * b));

    part2();
}