Implement next-gen modules: chrs-code-edit (Git), chrs-discovery (LibP2P), and chrs-observer (TUI)

chrs-discovery/src/lib.rs

@@ -0,0 +1,69 @@
+//! chrs-discovery: LibP2P-based peer discovery for CHORUS.
+
+use libp2p::{
+    mdns,
+    swarm::{NetworkBehaviour, SwarmEvent},
+    gossipsub,
+};
+use futures::StreamExt;
+use std::error::Error;
+
+#[derive(NetworkBehaviour)]
+pub struct MyBehaviour {
+    pub mdns: mdns::tokio::Behaviour,
+    pub gossipsub: gossipsub::Behaviour,
+}
+
+pub struct SwarmManager;
+
+impl SwarmManager {
+    /// Initialize a new LibP2P swarm with mDNS discovery.
+    /// 
+    /// **Why**: Moving away from polling a database to real-time P2P discovery 
+    /// reduces latency and allows CHORUS to scale to dynamic, broker-less environments.
+    pub async fn start_discovery_loop() -> Result<(), Box<dyn Error>> {
+        let mut swarm = libp2p::SwarmBuilder::with_new_identity()
+            .with_tokio()
+            .with_tcp(
+                libp2p::tcp::Config::default(),
+                libp2p::noise::Config::new,
+                libp2p::yamux::Config::default,
+            )?
+            .with_behaviour(|key| {
+                let message_id_fn = |message: &gossipsub::Message| {
+                    let mut s = std::collections::hash_map::DefaultHasher::new();
+                    use std::hash::Hasher;
+                    std::hash::Hash::hash(&message.data, &mut s);
+                    gossipsub::MessageId::from(s.finish().to_string())
+                };
+
+                let gossipsub_config = gossipsub::ConfigBuilder::default()
+                    .message_id_fn(message_id_fn)
+                    .build()?;
+
+                Ok(MyBehaviour {
+                    mdns: mdns::tokio::Behaviour::new(mdns::Config::default(), key.public().to_peer_id())?,
+                    gossipsub: gossipsub::Behaviour::new(
+                        gossipsub::MessageAuthenticity::Signed(key.clone()),
+                        gossipsub_config,
+                    )?,
+                })
+            })?
+            .build();
+
+        swarm.listen_on("/ip4/0.0.0.0/tcp/0".parse()?)?;
+
+        println!("[DISCOVERY] Swarm started. Listening for peers via mDNS...");
+
+        loop {
+            match swarm.select_next_some().await {
+                SwarmEvent::Behaviour(MyBehaviourEvent::Mdns(mdns::Event::Discovered(list))) => {
+                    for (peer_id, _multiaddr) in list {
+                        println!("[DISCOVERY] mDNS discovered a new peer: {}", peer_id);
+                    }
+                }
+                _ => {}
+            }
+        }
+    }
+}