use std::io::{self, Write};

fn main() {
    let mut input = String::new();
    let mut integer = 0;
    let mut total = 0;
    while integer >= 0 {
        print!("Enter a positive integer (to exit, enter a negative number): ");
        io::stdout().flush().expect("can't flush std out.");
        match io::stdin().read_line(&mut input) {
            Ok(_) => {}
            Err(err) => eprintln!("error reading from standard input. ERR: {}", err),
        }
        match input.strip_suffix("\n") {
            Some(str) => input = str.to_string(),
            None => {
                println!("You entered nothing.");
                continue;
            }
        }
        match input.parse::() {
            Ok(value) => {
                if value < 0 {
                    break;
                }
                integer += 1;
                total += value;
            }
            Err(err) => eprintln!(
                "invalid input {input}. must be a postive or negative integer. ERR: {err}"
            ),
        }
        input.clear();
    }
    if integer > 0{
        println!("The total numbers of positive integers entered is {integer}");
    }
    println!("The sum of all positive integer(s) is {total}.");
}