Unify and simplify pubsub peer discovery logic

Enable PeerExchange globally and replace Anchat-specific discovery with
a generic, application-agnostic approach that uses periodic monitoring
and a single proactive announcement to find topic peers.

pkg/client/client.go

@@ -157,18 +157,13 @@ func (c *Client) Connect() error {
 		zap.Strings("listen_addrs", addrStrs),
 	)
 
-	// Create LibP2P PubSub with enhanced discovery for Anchat
+	// Create LibP2P GossipSub with PeerExchange enabled (gossip-based peer exchange).
+	// Peer exchange helps propagate peer addresses via pubsub gossip and is enabled
+	// globally so discovery works without Anchat-specific branches.
 	var ps *libp2ppubsub.PubSub
-	if c.config.AppName == "anchat" {
-		// For Anchat, use more aggressive GossipSub settings for better peer discovery
-		ps, err = libp2ppubsub.NewGossipSub(context.Background(), h,
-			libp2ppubsub.WithPeerExchange(true), // Enable peer exchange
-			libp2ppubsub.WithFloodPublish(true), // Flood publish for small networks
-		)
-	} else {
-		// Standard GossipSub for other applications
-		ps, err = libp2ppubsub.NewGossipSub(context.Background(), h)
-	}
+	ps, err = libp2ppubsub.NewGossipSub(context.Background(), h,
+		libp2ppubsub.WithPeerExchange(true),
+	)
 	if err != nil {
 		h.Close()
 		return fmt.Errorf("failed to create pubsub: %w", err)

pkg/pubsub/discovery_integration.go

@@ -7,7 +7,9 @@ import (
 	pubsub "github.com/libp2p/go-libp2p-pubsub"
 )
 
-// announceTopicInterest helps with peer discovery by announcing interest in a topic
+// announceTopicInterest helps with peer discovery by announcing interest in a topic.
+// It starts lightweight monitoring and performs a single proactive announcement to
+// encourage peers to respond. This implementation is application-agnostic.
 func (m *Manager) announceTopicInterest(topicName string) {
 	// Wait a bit for the subscription to be established
 	time.Sleep(100 * time.Millisecond)
@@ -21,108 +23,43 @@ func (m *Manager) announceTopicInterest(topicName string) {
 		return
 	}
 
-	// For Anchat specifically, be more aggressive about finding peers
-	if len(m.namespace) > 6 && m.namespace[:6] == "anchat" {
-		go m.aggressiveTopicPeerDiscovery(topicName, topic)
-	} else {
-		// Start a periodic check to monitor topic peer growth
-		go m.monitorTopicPeers(topicName, topic)
-	}
+	// Start periodic monitoring for topic peers
+	go m.monitorTopicPeers(topicName, topic)
+
+	// Perform a single proactive announcement to the topic to encourage peers to respond
+	go m.forceTopicPeerDiscovery(topicName, topic)
 }
 
-// aggressiveTopicPeerDiscovery for Anchat - actively seeks topic peers
-func (m *Manager) aggressiveTopicPeerDiscovery(topicName string, topic *pubsub.Topic) {
-	ticker := time.NewTicker(1 * time.Second)
-	defer ticker.Stop()
-
-	for i := 0; i < 30; i++ { // Monitor for 30 seconds
-		<-ticker.C
-		peers := topic.ListPeers()
-
-		// If we have peers, reduce frequency but keep monitoring
-		if len(peers) > 0 {
-			// Switch to normal monitoring once we have peers
-			go m.monitorTopicPeers(topicName, topic)
-			return
-		}
-
-		// For Anchat, try to actively discover and connect to peers on this topic
-		// This is critical because LibP2P pubsub requires direct connections for message propagation
-		m.forceTopicPeerDiscovery(topicName, topic)
-	}
-}
-
-// enhancedAnchatTopicDiscovery implements enhanced peer discovery specifically for Anchat
-func (m *Manager) enhancedAnchatTopicDiscovery(topicName string, topic *pubsub.Topic) {
-	// Wait for subscription to be fully established
-	time.Sleep(200 * time.Millisecond)
-
-	ticker := time.NewTicker(1 * time.Second)
-	defer ticker.Stop()
-
-	for i := 0; i < 20; i++ { // Monitor for 20 seconds
-		<-ticker.C
-
-		peers := topic.ListPeers()
-		if len(peers) > 0 {
-			// Success! We found topic peers
-			return
-		}
-
-		// Try various discovery strategies
-		if i%3 == 0 {
-			// Strategy: Send discovery heartbeat
-			ctx, cancel := context.WithTimeout(context.Background(), 500*time.Millisecond)
-			discoveryMsg := []byte("ANCHAT_DISCOVERY_PING")
-			topic.Publish(ctx, discoveryMsg)
-			cancel()
-		}
-
-		// Wait a bit and check again
-		time.Sleep(500 * time.Millisecond)
-		peers = topic.ListPeers()
-		if len(peers) > 0 {
-			return
-		}
-	}
-}
-
-// forceTopicPeerDiscovery uses multiple strategies to find and connect to topic peers
+// forceTopicPeerDiscovery uses a simple strategy to announce presence on the topic.
+// It publishes a lightweight discovery ping and returns quickly.
 func (m *Manager) forceTopicPeerDiscovery(topicName string, topic *pubsub.Topic) {
-	// Strategy 1: Check if pubsub knows about any peers for this topic
+	// If pubsub already reports peers for this topic, do nothing.
 	peers := topic.ListPeers()
 	if len(peers) > 0 {
-		return // We already have peers
+		return
 	}
 
-	// Strategy 2: Try to actively announce our presence and wait for responses
-	// Send a ping/heartbeat to the topic to announce our presence
+	// Send a short-lived discovery ping to the topic to announce presence.
 	ctx, cancel := context.WithTimeout(context.Background(), 1*time.Second)
 	defer cancel()
 
-	// Create a discovery message to announce our presence on this topic
-	discoveryMsg := []byte("ANCHAT_PEER_DISCOVERY")
-	topic.Publish(ctx, discoveryMsg)
+	discoveryMsg := []byte("PEER_DISCOVERY_PING")
+	_ = topic.Publish(ctx, discoveryMsg)
 
-	// Strategy 3: Wait briefly and check again
-	time.Sleep(500 * time.Millisecond)
-	_ = topic.ListPeers() // Check again but we don't need to use the result
-
-	// Note: In LibP2P, topics don't automatically form connections between subscribers
-	// The underlying network layer needs to ensure peers are connected first
-	// This is why our enhanced client peer discovery is crucial
+	// Wait briefly to allow peers to respond via pubsub peer exchange
+	time.Sleep(300 * time.Millisecond)
 }
 
-// monitorTopicPeers periodically checks topic peer connectivity
+// monitorTopicPeers periodically checks topic peer connectivity and stops once peers are found.
 func (m *Manager) monitorTopicPeers(topicName string, topic *pubsub.Topic) {
 	ticker := time.NewTicker(5 * time.Second)
 	defer ticker.Stop()
 
-	for i := 0; i < 6; i++ { // Monitor for 30 seconds
+	for i := 0; i < 6; i++ { // Monitor for ~30 seconds
 		<-ticker.C
 		peers := topic.ListPeers()
 
-		// If we have peers, we're good
+		// If we have peers, stop monitoring
 		if len(peers) > 0 {
 			return
 		}

pkg/pubsub/subscriptions.go

@@ -3,6 +3,7 @@ package pubsub
 import (
 	"context"
 	"fmt"
+
 	pubsub "github.com/libp2p/go-libp2p-pubsub"
 )
 
@@ -74,14 +75,9 @@ func (m *Manager) Subscribe(ctx context.Context, topic string, handler MessageHa
 		}
 	}()
 
-	// Force peer discovery for this topic
+	// Force peer discovery for this topic (application-agnostic)
 	go m.announceTopicInterest(namespacedTopic)
 
-	// For Anchat, also try to actively find topic peers through the libp2p pubsub system
-	if len(m.namespace) > 6 && m.namespace[:6] == "anchat" {
-		go m.enhancedAnchatTopicDiscovery(namespacedTopic, libp2pTopic)
-	}
-
 	return nil
 }