use std::collections::HashSet;


const REQUEST_URL: &str = "http://www.pythonchallenge.com/pc/def/linkedlist.php";


fn get_next_nothing(current_nothing: String) -> Result<String, reqwest::Error>
{
    let client = reqwest::blocking::Client::new();
    let resp = client.get(REQUEST_URL)
        .query(&[("nothing", current_nothing)])
        .send()?;

    let body = resp.text()?;
    let nothing = body.split_ascii_whitespace().last().unwrap();
    Ok(nothing.to_string())

}

fn main() -> Result<(), reqwest::Error> {

    let mut nothings= HashSet::new();
    let mut current_nothing = String::from("12345");


    while !nothings.contains(&current_nothing)
    {
        nothings.insert(current_nothing.clone());
        current_nothing = get_next_nothing(current_nothing)?;
        println!("Next nothing is: {}",current_nothing);

    }

    println!("{:?}", nothings);
    Ok(())
}