harmony/harmony_inventory_agent/src/local_presence/discover.rs

use mdns_sd::{ServiceDaemon, ServiceEvent};

use crate::local_presence::SERVICE_NAME;

pub type DiscoveryEvent = ServiceEvent;

pub fn discover_agents(timeout: Option<u64>, on_event: impl Fn(DiscoveryEvent) + Send + 'static) {
    // Create a new mDNS daemon.
    let mdns = ServiceDaemon::new().expect("Failed to create mDNS daemon");

    // Start browsing for the service type.
    // The receiver will be a stream of events.
    let receiver = mdns.browse(SERVICE_NAME).expect("Failed to browse");

    std::thread::spawn(move || {
        while let Ok(event) = receiver.recv() {
            on_event(event.clone());
            match event {
                ServiceEvent::ServiceResolved(resolved) => {
                    println!("Resolved a new service: {}", resolved.fullname);
                }
                other_event => {
                    println!("Received other event: {:?}", &other_event);
                }
            }
        }
    });

    if let Some(timeout) = timeout {
        // Gracefully shutdown the daemon.
        std::thread::sleep(std::time::Duration::from_secs(timeout));
        mdns.shutdown().unwrap();
    }
}