use clap::Parser;

#[derive(Parser, Debug)]
#[command(author, version, about, long_about = None)]
pub struct Args {
    #[arg(short, long, default_value = "titles/")]
    titles_path: String,
    #[arg(short, long, default_value = "art/")]
    art_path: String,
    #[arg(short, long, default_value = "banner.txt")]
    banner_path: String,
}

pub struct Config {
    pub title_file: String,
    pub art_file: String,
    pub banner_file: String,
}
impl Config {
    pub fn new(args: Args) -> Self {
        let title_file = rand_file_from_path(args.titles_path);
        let art_file = rand_file_from_path(args.art_path);
        let banner_file = args.banner_path;

        Self {
            title_file,
            art_file,
            banner_file,
        }
    }
}

fn get_file_count(dir: &str) -> usize {
    use std::fs;

    let files = match  fs::read_dir(&dir) {
        Ok(files) => files,
        Err(_) => path_not_found_error(&dir),
    };

    files.count()
}

fn rand_file_from_path(path: String) -> String {
    use rand::Rng;

    let mut rng = rand::thread_rng();
    let mut file = path.clone();
    
    file.push_str(&rng.gen_range(1..get_file_count(&path)).to_string());
    file.push_str(".txt");

    file.to_string()
}

fn path_not_found_error(path: &str) -> ! {
    eprintln!("This path does not exist: {}", path);
    std::process::exit(1);
}