use std::env;
use std::fs;
use std::iter::zip;

fn main() {
    println!("Hello, AoC day 24!");

    let args: Vec<String> = env::args().collect();
    if args.len() != 2 {
        println!("wrong number of arguments!");
        std::process::exit(1);
    }

    let file_path = &args[1];

    let file = fs::read_to_string(file_path)
        .expect("should be able to read the file");

    let keys = file.split("\n\n")
        .filter(|section| section.starts_with("....."))
        .map(string_transpose)
        .map(|vec_of_vec_of_char| vec_of_vec_of_char
            .into_iter()
            .map(|vec_of_char| vec_of_char
                .into_iter()
                .filter(|c| *c == '#')
                .count() - 1
                )
            .collect::<Vec<_>>()
            )
        .collect::<Vec<_>>();
    let locks = file.split("\n\n")
        .filter(|section| section.starts_with("#####"))
        .map(string_transpose)
        .map(|vec_of_vec_of_char| vec_of_vec_of_char
            .into_iter()
            .map(|vec_of_char| vec_of_char
                .into_iter()
                .filter(|c| *c == '#')
                .count() - 1
                )
            .collect::<Vec<_>>()
            )
        .collect::<Vec<_>>();


    println!("{keys:?}, {locks:?}");

    let mut sum = 0;
    for lock in &locks {
        for key in &keys {
            if fits(lock, key) {
                sum += 1;
            }
        }
    }
    println!("the number of unique lock/key pairs is {sum}");
}
fn string_transpose(several_lines: &str) -> Vec<Vec<char>> {
    let mut output = Vec::with_capacity(several_lines.lines().next().unwrap().len());

    for line in several_lines.lines() {
        for (idx, chr) in line.chars().enumerate() {
            if idx == output.len() {
                output.push(vec![]);
            }
            output[idx].push(chr);
        }
    }

    return output
}

fn fits(lock: &Vec<usize>, key: &Vec<usize>) -> bool {
    //println!("testing {lock:?} against {key:?}");
    for (tumbler, tooth) in zip(lock, key) {
        //println!("tumbler: {tumbler}; tooth: {tooth}");
        if *tumbler + *tooth > 5 {
            return false;
        }
    }
    //println!("we good!");
    return true;
}