From fd0d482380b108c74e94bf9a3a9b70be3775bea4 Mon Sep 17 00:00:00 2001
From: Ian Gulliver <git@flamingcow.io>
Date: Fri, 30 Jan 2026 09:14:05 -0800
Subject: [PATCH] Update for new artnet discovery API

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
---
 go.mod  |  2 +-
 go.sum  |  4 ++--
 main.go | 68 +++++++++++++++++++++++++++++++++++++++++++++++++--------
 3 files changed, 62 insertions(+), 12 deletions(-)

diff --git a/go.mod b/go.mod
index 2f54aa7..ddc7493 100644
--- a/go.mod
+++ b/go.mod
@@ -4,7 +4,7 @@ go 1.25.6
 
 require (
 	github.com/BurntSushi/toml v1.6.0
-	github.com/gopatchy/artnet v0.0.0-20260128203426-0a3e9b1daf66
+	github.com/gopatchy/artnet v0.0.0-20260130164309-5e7400fe514e
 	github.com/gopatchy/sacn v0.0.0-20260130055955-54a46fbfe1f0
 )
 
diff --git a/go.sum b/go.sum
index 9138efb..873f3b0 100644
--- a/go.sum
+++ b/go.sum
@@ -2,8 +2,8 @@ github.com/BurntSushi/toml v1.6.0 h1:dRaEfpa2VI55EwlIW72hMRHdWouJeRF7TPYhI+AUQjk
 github.com/BurntSushi/toml v1.6.0/go.mod h1:ukJfTF/6rtPPRCnwkur4qwRxa8vTRFBF0uk2lLoLwho=
 github.com/google/gopacket v1.1.19 h1:ves8RnFZPGiFnTS0uPQStjwru6uO6h+nlr9j6fL7kF8=
 github.com/google/gopacket v1.1.19/go.mod h1:iJ8V8n6KS+z2U1A8pUwu8bW5SyEMkXJB8Yo/Vo+TKTo=
-github.com/gopatchy/artnet v0.0.0-20260128203426-0a3e9b1daf66 h1:QZrypvWOUbZeJsFRRx8UXf+MUbvkF/WR2KvNUynWFTM=
-github.com/gopatchy/artnet v0.0.0-20260128203426-0a3e9b1daf66/go.mod h1:V/D32mh1xfK/llCKbrqI2jxw4xL4hf6Ge2yLiIrp9/4=
+github.com/gopatchy/artnet v0.0.0-20260130164309-5e7400fe514e h1:KaCtixVKARhtTzqlqWyzXurNACaesAGxjFgnFd3jYT4=
+github.com/gopatchy/artnet v0.0.0-20260130164309-5e7400fe514e/go.mod h1:V/D32mh1xfK/llCKbrqI2jxw4xL4hf6Ge2yLiIrp9/4=
 github.com/gopatchy/multicast v0.0.0-20260130055828-12d0b38af995 h1:dwu07X0JnN6Ar3oZMLa/BokX04JRa3AeM38Nz7nwKnM=
 github.com/gopatchy/multicast v0.0.0-20260130055828-12d0b38af995/go.mod h1:mSeh6GX+fL6SWZYqxYHTdnddvzDx4qsGSBnlGwY5ZsA=
 github.com/gopatchy/sacn v0.0.0-20260130055955-54a46fbfe1f0 h1:j1uxCRJSu7G8UwlTykIDacbcQY2qoUpZ9t/SBHqLET8=
diff --git a/main.go b/main.go
index 88f5342..de5a606 100644
--- a/main.go
+++ b/main.go
@@ -94,12 +94,6 @@ func main() {
 		}
 	}
 
-	// Convert poll targets to slice
-	pollTargetSlice := make([]*net.UDPAddr, 0, len(pollTargets))
-	for _, addr := range pollTargets {
-		pollTargetSlice = append(pollTargetSlice, addr)
-	}
-
 	// Create ArtNet sender
 	artSender, err := artnet.NewSender()
 	if err != nil {
@@ -129,7 +123,15 @@ func main() {
 	for i, n := range srcNums {
 		outputUnivs[i] = artnet.Universe(n)
 	}
-	discovery := artnet.NewDiscovery(artSender, "artmap", "artmap", inputUnivs, outputUnivs, pollTargetSlice)
+
+	// Get local interface info for discovery
+	var localIP, broadcastIP net.IP
+	var localMAC net.HardwareAddr
+	if len(broadcasts) > 0 {
+		broadcastIP = broadcasts[0].IP
+		localIP, localMAC = detectLocalInterface(broadcastIP)
+	}
+	discovery := artnet.NewDiscovery(artSender, localIP, broadcastIP, localMAC, "artmap", "artmap", inputUnivs, outputUnivs)
 
 	// Create app
 	app := &App{
@@ -183,8 +185,10 @@ func main() {
 		log.Printf("[sacn] listening universes=%v", sacnUniverses)
 	}
 
-	// Start discovery
-	discovery.Start()
+	// Start discovery only if we have ArtNet outputs
+	if len(destNums) > 0 || len(artTargets) > 0 {
+		discovery.Start()
+	}
 
 	// Wait for interrupt
 	sigChan := make(chan os.Signal, 1)
@@ -362,6 +366,52 @@ func parseTargetAddr(s string, defaultPort int) (*net.UDPAddr, error) {
 	return &net.UDPAddr{IP: ip, Port: port}, nil
 }
 
+// detectLocalInterface returns local IP and MAC for an interface matching the broadcast address
+func detectLocalInterface(broadcast net.IP) (net.IP, net.HardwareAddr) {
+	ifaces, err := net.Interfaces()
+	if err != nil {
+		return nil, nil
+	}
+
+	for _, iface := range ifaces {
+		if iface.Flags&net.FlagLoopback != 0 || iface.Flags&net.FlagUp == 0 {
+			continue
+		}
+
+		addrs, err := iface.Addrs()
+		if err != nil {
+			continue
+		}
+
+		for _, addr := range addrs {
+			ipnet, ok := addr.(*net.IPNet)
+			if !ok {
+				continue
+			}
+
+			ip4 := ipnet.IP.To4()
+			if ip4 == nil {
+				continue
+			}
+
+			mask := ipnet.Mask
+			if len(mask) != 4 {
+				continue
+			}
+
+			bcast := make(net.IP, 4)
+			for i := 0; i < 4; i++ {
+				bcast[i] = ip4[i] | ^mask[i]
+			}
+
+			if bcast.Equal(broadcast) {
+				return ip4, iface.HardwareAddr
+			}
+		}
+	}
+	return nil, nil
+}
+
 // detectBroadcastAddrs returns broadcast addresses for all network interfaces
 func detectBroadcastAddrs() []*net.UDPAddr {
 	var addrs []*net.UDPAddr