use std::error::Error;
use std::time::Duration;

use async_std::task;
use async_std::net::TcpListener;
use async_std::prelude::*;

use async_listen::{ListenExt, ByteStream, backpressure, error_hint};


fn main() -> Result<(), Box<dyn Error>> {
    task::block_on(async {
        let (_, bp) = backpressure::new(10);
        let listener = TcpListener::bind("localhost:8080").await?;
        eprintln!("Accepting connections on localhost:8080");
        let mut incoming = listener.incoming()
            .log_warnings(|e| {
                eprintln!("Accept error: {}. Paused listener for 0.5s. {}",
                          e, error_hint(&e))
            })
            .handle_errors(Duration::from_millis(500))
            .backpressure_wrapper(bp);
        while let Some(stream) = incoming.next().await {
            task::spawn(connection_loop(stream));
        }
        Ok(())
    })
}

async fn connection_loop(_stream: ByteStream) {
    task::sleep(Duration::from_secs(10)).await;
}