use std::error::Error;
use std::fs::File;
use std::io::{self, BufReader, prelude::*};
use std::{env, fs};

fn parse_line(line: &str) -> Result<(i64, i64), Box<dyn Error>> {
    // Split line on whitespace
    // Expecting "88789   64926"
    // Should end up with two string, if not something is wrong.
    let split_line: Vec<_> = line
        .splitn(2, char::is_whitespace)
        .map(|elm| elm.trim())
        .collect();

    // Parse and return our two elements
    let first_element = split_line[0].parse::<i64>()?;
    let second_element = split_line[1].parse::<i64>()?;
    return Ok((first_element, second_element));
}

fn main() -> Result<(), Box<dyn Error>> {
    // Handle command input
    let args: Vec<String> = env::args().collect();
    if args.len() != 2 {
        panic!(
            "{} must be run with a single argument of files name!",
            &args[0]
        )
    }
    let input_file_string = &args[1];

    let input_file = File::open(input_file_string)?;
    let input_reader = BufReader::new(input_file);

    for (index, line) in input_reader.lines().enumerate() {
        let line = line?;
        let parsed_line = parse_line(&line)?;
        println!("({},{})", parsed_line.0, parsed_line.1);
    }

    return Ok(());
}