use std::{
    fs::File,
    io::{BufReader, Read},
    path::Path,
};

mod part1;
mod part2;

pub fn solve(input: &Path) -> anyhow::Result<()> {
    println!("part one orig: {}", part_one_orig(input)?);
    println!("part one: {}", part1::part_one(input)?);
    println!("part two: {}", part2::part_two(input)?);

    Ok(())
}

fn part_one_orig(input: &Path) -> anyhow::Result<i32> {
    let mut reader = BufReader::new(File::open(input)?);
    let mut buf = String::new();
    reader.read_to_string(&mut buf)?;

    let mut answer = 0;
    loop {
        if let Some(mul_beg) = buf.find("mul(") {
            if let Some(mul_end) = buf[mul_beg..].find(")").map(|i| i + mul_beg) {
                let mul_input = &buf.clone()[mul_beg + 4..mul_end];
                let mut mul_inputs = mul_input.split(",");

                let mut err = false;
                let first: i32 = match mul_inputs.next().unwrap_or_default().parse() {
                    Ok(f) => f,
                    Err(_) => {
                        err = true;
                        0
                    }
                };
                let second: i32 = match mul_inputs.next().unwrap_or_default().parse() {
                    Ok(f) => f,
                    Err(_) => {
                        err = true;
                        0
                    }
                };

                if err {
                    buf.replace_range(mul_beg..mul_beg + 4, "");
                } else {
                    answer += first * second;
                    buf.replace_range(mul_beg..mul_end + 1, "");
                }
            }
        } else {
            break;
        }
    }

    Ok(answer)
}