use regex::Regex;

fn main() {
    let content = std::fs::read_to_string("input.txt").unwrap();
    let data: Vec<_> = content.lines().collect();

    part1(&data);
    part2(&data);
}

fn part2(data: &[&str]) {
    let mut new_length = 0;
    let mut old_length = 0;

    let re_quote = Regex::new("\"").unwrap();
    let re_backslash = Regex::new(r"\\").unwrap();

    for line in data {
        old_length += line.len();
        let found = re_quote.replace_all(line, "AA");
        let found = re_backslash.replace_all(found.as_ref(), "BB");

        new_length += found.len() + 2; // add first and last quote
    }
    let result = new_length - old_length;
    println!("{result}");
}

fn part1(data: &[&str]) {
    let mut literal_length = 0;
    let mut memory_length = 0;

    let re_hex = Regex::new(r"\\x[a-f0-9]{2}").unwrap();
    let re_backslash = Regex::new(r"\\\\").unwrap();
    let re_doublequote = Regex::new(r"\x5c\x22").unwrap();

    for line in data {
        literal_length += line.len();
        let found = re_hex.replace_all(line, "A");
        let found = re_backslash.replace_all(found.as_ref(), "B");
        let found = re_doublequote.replace_all(found.as_ref(), "C");

        memory_length += found.len() - 2; // remove first and last quote
    }
    let result = literal_length - memory_length;
    println!("{result}");
}

// https://adventofcode.com/2015/day/8