use tiny_http::{Response, Server};

fn main() {
    let clickee_urls_raw = std::env::var("CLICKEE_URLS").expect("CLICKEE_URLS must be set");
    let clickee_urls = clickee_urls_raw.split(",").collect::<Vec<_>>();
    let port = std::env::var("PORT")
        .unwrap_or_else(|_| "8000".to_string())
        .parse::<u16>()
        .expect("PORT must be a number");
    let server = Server::http(("0.0.0.0", port)).unwrap();

    for request in server.incoming_requests() {
        let get_header = |name| {
            request
                .headers()
                .iter()
                .find(|h| h.field.equiv(name))
                .map(|h| h.value.to_string())
        };
        let ip = get_header("x-real-ip")
            .or_else(|| request.remote_addr().map(|a| a.to_string()))
            .unwrap_or_else(|| "unknown".to_string());
        let ua = get_header("user-agent").unwrap_or_else(|| "unknown".to_string());

        let mut sent_click = false;
        for url in clickee_urls.iter() {
            match tinyget::get(*url).send_lazy() {
                Ok(_) => sent_click = true,
                Err(err) => println!("clickee ({url}) not online (error: {err}), using next one"),
            }
        }

        if sent_click {
            println!("clicker clicked: {ua} from {ip}");
        } else {
            println!("no clickee available");
        }

        let resp = Response::empty(sent_click.then_some(200).unwrap_or(502));
        if let Err(err) = request.respond(resp) {
            println!("error responding to clicker: {err}");
        }
    }
}