use std::{env, fs, process};

struct Config {
    file_path: String,
    command: String
}

impl Config {
    fn new(args: &[String]) -> Result<Config, &'static str> {

        if args.len() < 3 || args.len() == 0 {
            return Err("invalid arguments")
        }

        let path = args[2].clone();
        let command = args[1].clone();

        Ok(Config { file_path: path, command })
    }
}

fn main() {
    let args: Vec<String> = env::args().collect();

    let config = Config::new(&args).unwrap_or_else(|_err| {
        print_help();
        process::exit(1)
    });


    let file_contents = fs::read_to_string(config.file_path).expect("Invalid file path, please make sure the path to the file is correct");

    match config.command.as_str() {
       "-c" | "--bytes" => count_bytes(&file_contents),
       "-l" | "--lines" => count_lines(&file_contents),
       "-w" | "--words" => count_words(&file_contents),
       "-m" | "--chars" => count_chars(&file_contents),
       "-h" | "--help" => print_help(),
       _ => print_help(),
    }
}


fn count_bytes(contents: &String) {
    println!("{}", contents.bytes().len())
}

fn count_chars(contents: &String) {
    println!("{}", contents.chars().count())
}

fn count_lines(contents: &String) {
    println!("{}", contents.lines().count())
}

fn count_words(contents: &String) {
    print!("{}", contents.split_whitespace().count())
}

fn print_help() {
    println!("
         yap [-COMMAND] [PATH_TO_FILE] 

         -c, --bytes - count the amount of bytes in a file
         -l, --lines - count the amount of lines in a file
         -w, --words - count the amount of words in a file
         -m, --chars - count the amount of characters in a file
         -h, --help - list the available command line arguments
        "
       );
}