feat: simple cli implementation

src/main.rs

@@ -0,0 +1,68 @@
+use std::net::SocketAddr;
+
+use clap::Parser;
+use tokio::{io::{AsyncReadExt, AsyncWriteExt}, net::UdpSocket};
+
+#[derive(Parser)]
+struct CliArgs {
+	server: String,
+}
+
+#[tokio::main]
+async fn main() {
+	let args = CliArgs::parse();
+
+	let dest : SocketAddr = args.server.parse().unwrap();
+
+	// by default bind on any interface and request OS to give us a port
+	let mut addr : SocketAddr = "0.0.0.0:0".parse().unwrap();
+	let socket = UdpSocket::bind(addr).await.unwrap();
+
+
+	let packet = PingPacket { id: 0, time: chrono::Utc::now().timestamp_micros() as u64 };
+	let buf = packet.serialize().await.unwrap();
+
+	socket.send_to(&buf, dest).await.unwrap();
+
+	let mut buf = [0u8; 1024];
+	socket.recv(&mut buf).await.unwrap();
+
+	let pong = PongPacket::deserialize(&buf).await.unwrap();
+
+	println!("{pong:#?}");
+}
+
+struct PingPacket {
+	id: i32,
+	time: u64,
+}
+
+impl PingPacket {
+	async fn serialize(self) -> std::io::Result<Vec<u8>> {
+		let mut out = Vec::new();
+		out.write_i32(self.id).await?;
+		out.write_u64(self.time).await?;
+		Ok(out)
+	}
+}
+
+
+#[derive(Debug)]
+struct PongPacket {
+	version: u32,
+	time: u64,
+	users: i32,
+	max_users: i32,
+	bandwidth: i32,
+}
+
+impl PongPacket {
+	async fn deserialize(mut data: &[u8]) -> std::io::Result<Self> {
+		let version = data.read_u32().await?;
+		let time = data.read_u64().await?;
+		let users = data.read_i32().await?;
+		let max_users = data.read_i32().await?;
+		let bandwidth = data.read_i32().await?;
+		Ok(PongPacket { version, time, users, max_users, bandwidth })
+	}
+}