Indicate disconnected Sia serverHEADmain

There are now three instead of two status states:

- "Connected" / MQTT connected, Sia server connected
- "Connection issue" / MQTT connected, Sia server disconnected
- "Disconnected" / all other cases (Sia server connection unknown)

2 files changed, 25 insertions, 6 deletions

diff --git a/lib/data.dart b/lib/data.dart
index 38fd564..2583d1a 100644
--- a/lib/data.dart
+++ b/lib/data.dart
@@ -13,6 +13,8 @@ class AppState with ChangeNotifier {
   late final MqttServerClient _client;
   bool _brokerConnected = false;
   bool get brokerConnected => _brokerConnected;
+  bool _serverConnected = false;
+  bool get serverConnected => _serverConnected;
 
   AppState() {
     _initMqtt();
@@ -53,6 +55,7 @@ class AppState with ChangeNotifier {
 
   void _onConnected() {
     _client.subscribe('$topicPrefix/contact/+/state', MqttQos.exactlyOnce);
+    _client.subscribe('$topicPrefix/server/health', MqttQos.exactlyOnce);
     _brokerConnected = true;
     notifyListeners();
   }
@@ -76,6 +79,23 @@ class AppState with ChangeNotifier {
     for (final MqttReceivedMessage<MqttMessage> message in messages) {
       final String topic = message.topic;
 
+      final MqttPublishMessage payloadMessage =
+        message.payload as MqttPublishMessage;
+      final String payload =
+        MqttPublishPayload.bytesToStringAsString(payloadMessage.payload.message);
+
+      if (topic == '$topicPrefix/server/health') {
+        if (payload == 'good') {
+          _serverConnected = true;
+          notifyListeners();
+        }
+
+        if (payload == 'bad') {
+          _serverConnected = false;
+          notifyListeners();
+        }
+      }
+
       // format <prefix>/contacts/<address>/state
       final List<String> parts = topic.split('/');
       if (parts.length != 4 || parts[1] != 'contact' || parts[3] != 'state') {
@@ -83,11 +103,6 @@ class AppState with ChangeNotifier {
       }
       final String address = parts[2];
 
-      final MqttPublishMessage payloadMessage =
-        message.payload as MqttPublishMessage;
-      final String payload =
-        MqttPublishPayload.bytesToStringAsString(payloadMessage.payload.message);
-
       final bool? parsedState = _parseBool(payload);
 
       if (parsedState != null) {
diff --git a/lib/ui.dart b/lib/ui.dart
index 38ace9a..e6cb6f4 100644
--- a/lib/ui.dart
+++ b/lib/ui.dart
@@ -58,9 +58,13 @@ class ConnectionStatus extends StatelessWidget {
       builder: (BuildContext context, AppState state, Widget? child) {
         Icon icon;
         Text text;
-        if (state.brokerConnected) {
+
+        if (state.brokerConnected && state.serverConnected) {
           icon = const Icon(Icons.cloud, color: Colors.green);
           text = const Text('Connected');
+        } else if (state.brokerConnected && !state.serverConnected) {
+          icon = const Icon(Icons.cloud_off, color: Colors.orange);
+          text = const Text('Connection issue');
         } else {
           icon = const Icon(Icons.cloud_off, color: Colors.red);
           text = const Text('Disconnected');