config: implement reading app-specific configs from profile

data/profiles/home-lighting.json

@@ -13,5 +13,8 @@
     "Acid": ["Chimes", "Pulse", "MPU5060", "IdleColors", "Rainbow"],
     "Flashlight": ["Flashlight"]
   },
-  "surfaceMap": "default"
+  "surfaceMap": "default",
+  "defaults": {
+    "mqtt.ip": "10.0.0.2"
+  }
 }

src/Config.cpp

@@ -146,6 +146,9 @@ ConfigService::loadProfile(const char* profileName)
       Log.warning("config: Could not load profile %s!", profileName);
     }
 
+    JsonObject defaults = jsonConfig["defaults"];
+    MainLoop::instance()->dispatch(InputEvent{InputEvent::ConfigurationChanged, &defaults});
+
     String configName = jsonConfig["surfaceMap"];
     jsonConfig.clear();
     loadMap(configName);

src/Config.h

@@ -37,6 +37,7 @@ struct ConfigService: public Task {
     const CoordinateMapping* coordMap() const { return &m_jsonMap; }
     const char* loadedProfile() const;
     void overrideProfile(const char* profileName);
+    const char* getConfigValue(const char* key) const;
 
 private:
     HardwareConfig m_config;

src/platform/arduino/MQTTTelemetry.cpp

@@ -198,20 +198,27 @@ MQTTTelemetry::handleEventOnline(const InputEvent& evt)
   }
 }
 
+void
+MQTTTelemetry::handleConfigChange(const InputEvent& event)
+{
+  const JsonObject* obj = static_cast<JsonObject*>(event.value().asPointer());
+  strncpy(m_hostBuf, obj["mqtt.ip"].c_str(), sizeof(m_hostBuf));
+  m_mqtt.disconnect();
+}
+
 void
 MQTTTelemetry::loop()
 {
   BufferedInputSource::loop();
   OnlineTaskMixin::loop();
+  ConfigTaskMixin::loop();
 }
 
 void
 MQTTTelemetry::onOnline()
 {
-  const IPAddress server(10, 0, 0, 2);
-
   m_needHeartbeat = true;
-  m_mqtt.setServer(server, 1883);
+  m_mqtt.setServer(m_hostBuf, 1883);
   m_mqtt.setBufferSize(1024);
   m_mqtt.setCallback(&MQTTTelemetry::s_callback);
 }

src/platform/arduino/MQTTTelemetry.h

@@ -12,7 +12,7 @@
 #include <WiFi.h>
 #endif
 
-class MQTTTelemetry : public BufferedInputSource, OnlineTaskMixin {
+class MQTTTelemetry : public BufferedInputSource, OnlineTaskMixin, ConfigTaskMixin {
   public:
     MQTTTelemetry();
     void setSequencer(Sequencer* seq) { m_sequencer = seq; }
@@ -46,6 +46,7 @@ class MQTTTelemetry : public BufferedInputSource, OnlineTaskMixin {
     }
 
     void handleEventOnline(const InputEvent& evt) override;
+    void handleConfigChange(const InputEvent& evt) override;
     void loop() override;
 
     void loopOnline() override;
@@ -65,6 +66,7 @@ class MQTTTelemetry : public BufferedInputSource, OnlineTaskMixin {
     bool m_isOn = true;
     static char s_topicBuf[128];
     static char s_payloadBuf[512];
+    static char s_hostBuf[15];
 
     void publishDoc(const char* topic);
     void publishDoc(const char* topic, bool retain);