From 91571eafccb329ec1e7c96320c9b7a974bb426ea Mon Sep 17 00:00:00 2001
From: Tobias Blum <github@tobiasblum.de>
Date: Sat, 19 Aug 2017 22:22:36 +0200
Subject: [PATCH] Limit number of MQTT connection tries

as proposed by @nimbl at https://github.com/toblum/McLighting/issues/22
---
 Arduino/McLighting/McLighting.ino     | 10 ++++++----
 Arduino/McLighting/definitions.h      |  4 ++++
 Arduino/McLighting/request_handlers.h | 10 +++++++---
 3 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/Arduino/McLighting/McLighting.ino b/Arduino/McLighting/McLighting.ino
index 53b5cc2..1a9dd38 100644
--- a/Arduino/McLighting/McLighting.ino
+++ b/Arduino/McLighting/McLighting.ino
@@ -303,7 +303,7 @@ void setup() {
       String(String(HOSTNAME) + "/in").toCharArray(mqtt_intopic, strlen(HOSTNAME) + 4);
       String(String(HOSTNAME) + "/out").toCharArray(mqtt_outtopic, strlen(HOSTNAME) + 5);
   
-      DBG_OUTPUT_PORT.printf("Connect %s %d\n", mqtt_host, String(mqtt_port).toInt());
+      DBG_OUTPUT_PORT.printf("MQTT active: %s:%d\n", mqtt_host, String(mqtt_port).toInt());
       
       mqtt_client.setServer(mqtt_host, String(mqtt_port).toInt());
       mqtt_client.setCallback(mqtt_callback);
@@ -532,16 +532,18 @@ void setup() {
 void loop() {
   server.handleClient();
   webSocket.loop();
+  
   #ifdef ENABLE_OTA
     ArduinoOTA.handle();
   #endif
 
   #ifdef ENABLE_MQTT
-    if (mqtt_host != "" && String(mqtt_port).toInt() > 0) {
+    if (mqtt_host != "" && String(mqtt_port).toInt() > 0 && mqtt_reconnect_retries < MQTT_MAX_RECONNECT_TRIES) {
       if (!mqtt_client.connected()) {
-        mqtt_reconnect();
+        mqtt_reconnect(); 
+      } else {
+        mqtt_client.loop();
       }
-      mqtt_client.loop();
     }
   #endif
   
diff --git a/Arduino/McLighting/definitions.h b/Arduino/McLighting/definitions.h
index 93311ff..41bd8b6 100644
--- a/Arduino/McLighting/definitions.h
+++ b/Arduino/McLighting/definitions.h
@@ -9,6 +9,10 @@ const char HOSTNAME[] = "ESP8266_01";   // Friedly hostname
 #define ENABLE_MQTT   // If defined, enable MQTT client code.
 #ifdef ENABLE_MQTT
   #define MQTT_MAX_PACKET_SIZE 256
+  #define MQTT_MAX_RECONNECT_TRIES 4
+
+  int mqtt_reconnect_retries = 0;
+  
   char mqtt_intopic[strlen(HOSTNAME) + 3];      // Topic in will be: <HOSTNAME>/in
   char mqtt_outtopic[strlen(HOSTNAME) + 4];     // Topic out will be: <HOSTNAME>/out
   
diff --git a/Arduino/McLighting/request_handlers.h b/Arduino/McLighting/request_handlers.h
index 89c9fe8..c0819fb 100644
--- a/Arduino/McLighting/request_handlers.h
+++ b/Arduino/McLighting/request_handlers.h
@@ -390,11 +390,12 @@ void checkForRequests() {
   
   void mqtt_reconnect() {
     // Loop until we're reconnected
-    while (!mqtt_client.connected()) {
-      DBG_OUTPUT_PORT.print("Attempting MQTT connection... ");
+    while (!mqtt_client.connected() && mqtt_reconnect_retries < MQTT_MAX_RECONNECT_TRIES) {
+      mqtt_reconnect_retries++;
+      DBG_OUTPUT_PORT.printf("Attempting MQTT connection %d / %d ...\n", mqtt_reconnect_retries, MQTT_MAX_RECONNECT_TRIES);
       // Attempt to connect
       if (mqtt_client.connect(mqtt_clientid, mqtt_user, mqtt_pass)) {
-        DBG_OUTPUT_PORT.println("connected!");
+        DBG_OUTPUT_PORT.println("MQTT connected!");
         // Once connected, publish an announcement...
         char * message = new char[18 + strlen(HOSTNAME) + 1];
         strcpy(message, "McLighting ready: ");
@@ -413,5 +414,8 @@ void checkForRequests() {
         delay(5000);
       }
     }
+    if (mqtt_reconnect_retries >= MQTT_MAX_RECONNECT_TRIES) {
+      DBG_OUTPUT_PORT.printf("MQTT connection failed, giving up after %d tries ...\n", mqtt_reconnect_retries);
+    }
   }  
 #endif