open-dis-rust 0.4.2

//     open-dis-rust - Rust implementation of the IEEE 1278.1-2012 Distributed Interactive
//                     Simulation (DIS) application protocol
//     Copyright (C) 2025 Cameron Howell
//
//     Licensed under the BSD 2-Clause License

#![warn(rust_2018_idioms)]

use std::error::Error;
use std::net::SocketAddr;
use std::{env, io};
use tokio::net::UdpSocket;

struct Server {
    socket: UdpSocket,
    buf: Vec<u8>,
    to_send: Option<(usize, SocketAddr)>,
}

impl Server {
    async fn run(self) -> Result<(), io::Error> {
        let Self {
            socket,
            mut buf,
            mut to_send,
        } = self;

        loop {
            if let Some((size, peer)) = to_send {
                let amt = socket.send_to(&buf[..size], &peer).await?;

                println!("Echoed {amt}/{size} bytes to {peer}");
            }

            to_send = Some(socket.recv_from(&mut buf).await?);
        }
    }
}

#[tokio::main]
async fn main() -> Result<(), Box<dyn Error>> {
    let addr = env::args()
        .nth(1)
        .unwrap_or_else(|| "127.0.0.1:3000".to_string());

    let socket = UdpSocket::bind(&addr).await?;
    println!("Listening on {}", socket.local_addr()?);

    let server = Server {
        socket,
        buf: vec![0; 1024],
        to_send: None,
    };

    server.run().await?;

    Ok(())
}