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

fn intersect(vec: Vec<String>) -> Option<u8> {
    let base = vec.get(0)?;
    for c in base.chars() {
        if vec[1..].iter().all(|s| s.contains(c)) {
            return Some(c as u8);
        }
    }
    return None;
}

fn byte_to_priority(byte: u8) -> u8 {
    if byte >= b'a' {
        return byte - b'a' + 1;
    } else {
        return byte - b'A' + 27;
    }
}

fn part1() -> u64 {
    let mut score = 0;

    for line in lib::iter_input() {
        let (head, tail) = line.split_at(line.len() / 2);
        let vec = vec![head.to_string(), tail.to_string()];
        let common = intersect(vec).unwrap();
        score += byte_to_priority(common) as u64;
    }

    return score;
}

fn part2() -> u64 {
    let mut score: u64 = 0;
    let mut vec = vec![];

    for line in lib::iter_input() {
        vec.push(line);
        if vec.len() == 3 {
            let common = intersect(vec).unwrap();
            score += byte_to_priority(common) as u64;
            vec = vec![];
        }
    }

    return score;
}

fn main() {
    println!("part1: {}", part1());
    println!("part2: {}", part2());
}