use std::io::{Read, Write};
use std::net::{TcpListener, TcpStream};

fn handle_client(mut stream: TcpStream) -> std::io::Result<()> {
    let mut buf = [0; 1024];
    loop {
        let size = stream.read(&mut buf)?;
        if size == 0 {
            break;
        }
        let data = &buf[..size];
        println!("Received data: {:?}", data);

        stream.write_all(data)?;
        println!("Sent data back");
    }
    Ok(())
}

fn main() -> std::io::Result<()> {
    let listener = TcpListener::bind("127.0.0.1:30000")?;
    println!("Listening on {}", listener.local_addr()?);

    for stream in listener.incoming() {
        match stream {
            Ok(stream) => {
                println!("New client: {}", stream.peer_addr()?);
                std::thread::spawn(move || {
                    handle_client(stream).unwrap_or_else(|error| {
                        eprintln!("Error: {}", error);
                    });
                });
            }
            Err(error) => {
                eprintln!("Error: {}", error);
            }
        }
    }

    Ok(())
}