Improved reconnection

src/mqtt.cpp

@@ -37,6 +37,7 @@ const bool MQTTwrapper::disconnect()
     if (m_loopHandle)
     {
         vTaskDelete(m_loopHandle); // immediate terminate loop
+        m_loopHandle = NULL;
     }
     return true;
 }
@@ -75,6 +76,10 @@ const bool MQTTwrapper::unsubscribe(topic_t topic)
     return false;
 }
 
+const bool MQTTwrapper::connected() {
+    return m_loopHandle != NULL;
+}
+
 const bool MQTTwrapper::publish(topic_t topic, const ArduinoJson::JsonDocument obj)
 {
     std::string message;
@@ -127,35 +132,43 @@ void MQTTwrapper::onMessage(const std::string topic, const std::string message)
 
 void MQTTwrapper::clientLoop(void *params)
 {
-    auto client = (MQTTwrapper *)(params);
+    auto wrapper = (MQTTwrapper *)(params);
-    auto loopTime = client->m_config.m_mqttLoopTime;
+    auto &client = wrapper->m_client;
+    auto &config = wrapper->m_config;
+    auto &stateMap = wrapper->stateMap;
+    const auto loopTime = config.m_mqttLoopTime;
+    const auto mqttRetries = config.m_mqttRetries;
+    const auto clientName = config.m_mqttClientName;
     uint8_t connectAttempt(0);
     LOG_INFO("MQTT starting client loop");
-    while (connectAttempt++ < client->m_config.m_mqttRetries)
+    while (connectAttempt++ < mqttRetries)
     {
-        while (client->m_client.connected())
+        while (client.connected())
         {
-            client->m_client.loop();
+            client.loop();
             vTaskDelay(pdMS_TO_TICKS(loopTime));
         }
-        if (client->m_client.state() <= MQTT_CONNECTED)
+        if (client.state() != MQTT_CONNECTED)
         {
-            LOG_ERROR("MQTT disconnect reason ", client->m_client.state());
+            LOG_ERROR("MQTT disconnect reason ", stateMap.at(client.state()));
             vTaskDelay(pdMS_TO_TICKS(loopTime * 50));
-            const bool ok = client->m_client.connect(client->m_config.m_mqttClientName.c_str());
+            const bool ok = client.connect(clientName.c_str());
             LOG_WARN("MQTT reconnected", ok ? "True" : "False");
             if (ok)
             {
-                for (auto v : client->m_actionMap)
+                for (auto &v : wrapper->m_actionMap)
                 {
-                    LOG_WARN("MQTT resubscribing to",v.first.c_str());
+                    const std::string &topic(v.first);
-                    client->m_client.subscribe(v.first.c_str());
+                    LOG_WARN("MQTT resubscribing to", topic.c_str());
+                    if(!wrapper->m_client.subscribe(topic.c_str())){
+                        LOG_ERROR("Unable to resubscribe to", topic.c_str());
+                    }
                 }
                 connectAttempt = 0;
             }
         }
     }
     LOG_ERROR("MQTT client loop terminated, disconnected");
-    client->m_loopHandle = NULL;
+    wrapper->m_loopHandle = NULL;
     vTaskDelete(NULL); // delete the current task
 }

src/mqtt.h

@@ -21,7 +21,22 @@ class MQTTwrapper
 {
 
 private:
-    static MQTTwrapper *getInstance(MQTTwrapper *inst = nullptr)
+    const std::map<int, std::string> stateMap = {
+        {-4, "MQTT_CONNECTION_TIMEOUT"},
+        {-3, "MQTT_CONNECTION_LOST"},
+        {-2, "MQTT_CONNECT_FAILED"},
+        {-1, "MQTT_DISCONNECTED"},
+        {0, "MQTT_CONNECTED"},
+        {1, "MQTT_CONNECT_BAD_PROTOCOL"},
+        {2, "MQTT_CONNECT_BAD_CLIENT_ID"},
+        {3, "MQTT_CONNECT_UNAVAILABLE"},
+        {4, "MQTT_CONNECT_BAD_CREDENTIALS"},
+        {5, "MQTT_CONNECT_UNAUTHORIZED"}
+    };
+
+private:
+    static MQTTwrapper *
+    getInstance(MQTTwrapper *inst = nullptr)
     {
         static std::unique_ptr<MQTTwrapper> m_instance;
         if (inst)
@@ -37,6 +52,7 @@ public:
 
     const bool connect();
     const bool disconnect();
+    const bool connected();
 
     const bool subscribe(topic_t topic, action_t action);
     const bool unsubscribe(topic_t topic);