From 765594f7ee03a980f4eba22b08372c070558e86a Mon Sep 17 00:00:00 2001
From: James Rich <2199651+jamesarich@users.noreply.github.com>
Date: Wed, 22 Apr 2026 11:05:24 -0500
Subject: [PATCH] fix: MQTT proxy connection and probe test failures (#5215)

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 .../core/data/manager/MqttManagerImpl.kt          |  3 +++
 .../core/network/repository/MQTTRepositoryImpl.kt | 15 ++++++++-------
 2 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/core/data/src/commonMain/kotlin/org/meshtastic/core/data/manager/MqttManagerImpl.kt b/core/data/src/commonMain/kotlin/org/meshtastic/core/data/manager/MqttManagerImpl.kt
index 5693d343b..ac790a191 100644
--- a/core/data/src/commonMain/kotlin/org/meshtastic/core/data/manager/MqttManagerImpl.kt
+++ b/core/data/src/commonMain/kotlin/org/meshtastic/core/data/manager/MqttManagerImpl.kt
@@ -44,6 +44,7 @@ import org.meshtastic.mqtt.ProbeResult
 import org.meshtastic.mqtt.probe
 import org.meshtastic.proto.MqttClientProxyMessage
 import org.meshtastic.proto.ToRadio
+import kotlin.time.Clock
 
 @Single
 class MqttManagerImpl(
@@ -125,6 +126,8 @@ class MqttManagerImpl(
         val endpoint = resolveEndpoint(address, tlsEnabled)
         val result =
             MqttClient.probe(endpoint = endpoint) {
+                // Provide a valid client ID for the probe; brokers reject empty identifiers
+                clientId = "MeshtasticProbe-${Clock.System.now().toEpochMilliseconds()}"
                 val user = username?.takeUnless { it.isEmpty() }
                 val pass = password?.takeUnless { it.isEmpty() }
                 if (user != null) this.username = user
diff --git a/core/network/src/commonMain/kotlin/org/meshtastic/core/network/repository/MQTTRepositoryImpl.kt b/core/network/src/commonMain/kotlin/org/meshtastic/core/network/repository/MQTTRepositoryImpl.kt
index 47cfb6f7a..537e2af37 100644
--- a/core/network/src/commonMain/kotlin/org/meshtastic/core/network/repository/MQTTRepositoryImpl.kt
+++ b/core/network/src/commonMain/kotlin/org/meshtastic/core/network/repository/MQTTRepositoryImpl.kt
@@ -219,15 +219,17 @@ class MQTTRepositoryImpl(
     }
 }
 
+private const val MQTT_PORT_PLAIN = 1883
+private const val MQTT_PORT_TLS = 8883
+
 /**
  * Resolve a user-supplied broker address into an [MqttEndpoint].
  *
  * Address resolution rules:
  * - If [rawAddress] already contains a URI scheme (`scheme://…`), parse it directly via [MqttEndpoint.parse] and
  *   respect whatever transport / port the user encoded.
- * - Otherwise wrap it as a WebSocket endpoint (`ws[s]://host${WEBSOCKET_PATH}`) so the proxy works over CDNs and
- *   firewall-restricted networks where raw 1883/8883 may be blocked. The scheme is `wss` when [tlsEnabled] is `true`,
- *   `ws` otherwise.
+ * - Otherwise wrap it as a TCP endpoint using standard MQTT ports: port 8883 if [tlsEnabled] is `true`, port 1883
+ *   otherwise. This allows standard MQTT brokers to work out of the box.
  *
  * Extracted as a top-level function so [MQTTRepositoryImplTest] can exercise every branch without spinning up the full
  * repository, and so `MqttManagerImpl` (in `:core:data`) can reuse the same parsing rules for the probe API. Visibility
@@ -236,8 +238,7 @@ class MQTTRepositoryImpl(
 fun resolveEndpoint(rawAddress: String, tlsEnabled: Boolean): MqttEndpoint = if (rawAddress.contains("://")) {
     MqttEndpoint.parse(rawAddress)
 } else {
-    val scheme = if (tlsEnabled) "wss" else "ws"
-    MqttEndpoint.parse("$scheme://$rawAddress$WEBSOCKET_PATH")
+    val port = if (tlsEnabled) MQTT_PORT_TLS else MQTT_PORT_PLAIN
+    val scheme = if (tlsEnabled) "ssl" else "tcp"
+    MqttEndpoint.parse("$scheme://$rawAddress:$port")
 }
-
-private const val WEBSOCKET_PATH = "/mqtt"