use std::io;
use std::io::prelude::*;
use std::fs::File;
use sorted_vec::SortedVec;

fn read_lines(filename: &str) -> io::Result<io::Lines<io::BufReader<File>>> {
    let file = File::open(filename)?;
    Ok(io::BufReader::new(file).lines())
}

fn update_max(max: &mut SortedVec<i32>, current: i32) {
    if max.is_empty() {
        max.insert(current);
        return
    }
    if current <= max[0] { return }

    max.insert(current);
    if max.len() > 3 { max.remove_index(0); }
}

pub fn execute() -> Result<(), io::Error> {
    let mut max: SortedVec<i32> = SortedVec::new();
    let mut current = 0;

    for line in read_lines("input/day01.txt")? {
        let text = line?;
        current = match text.parse::<i32>() {
            Ok(value) => current + value,
            Err(_) => {
                update_max(&mut max, current);
                0
            },
        }
    }

    if let Some(x) = max.iter().last() {
    println!("Step 1 solution: {x}");
    }
    println!("Step 2 solution: {}", max.iter().fold(0i32, |sum, i| sum + (*i as i32)));
    Ok(())
}