Refactor message routing

This allows to route incoming MQTT messages in the _onMessage() method
and handle it in different handlers per topic.

1 files changed, 26 insertions, 24 deletions

diff --git a/lib/data.dart b/lib/data.dart
index 4962a50..201550e 100644
--- a/lib/data.dart
+++ b/lib/data.dart
@@ -161,36 +161,38 @@ class AppState with ChangeNotifier {
 
   void _onMessage(List<MqttReceivedMessage<MqttMessage>> messages) {
     for (final MqttReceivedMessage<MqttMessage> message in messages) {
-      final String topic = message.topic;
+      final List<String> parts = message.topic.split('/');
+      final String payload = MqttPublishPayload.bytesToStringAsString(
+        (message.payload as MqttPublishMessage).payload.message);
 
-      final MqttPublishMessage payloadMessage =
-        message.payload as MqttPublishMessage;
-      final String payload =
-        MqttPublishPayload.bytesToStringAsString(payloadMessage.payload.message);
-
-      if (topic == '$topicPrefix/server/health') {
-        if (payload == 'good') {
-          process(MachineEvent.reachable);
-        }
-
-        if (payload == 'bad') {
-          process(MachineEvent.unreachable);
-        }
+      if (message.topic == '$topicPrefix/server/health') {
+        _onHealthMessage(payload);
+        return;
       }
 
-      // format <prefix>/contacts/<address>/state
-      final List<String> parts = topic.split('/');
-      if (parts.length != 4 || parts[1] != 'contact' || parts[3] != 'state') {
-        continue;
+      if (parts.length == 4 && parts[1] == 'contact' && parts[3] == 'state') {
+        String address = parts[2];
+        _onContactMessage(payload, address);
+        return;
       }
-      final String address = parts[2];
+    }
+  }
 
-      final bool? parsedState = _parseBool(payload);
+  void _onHealthMessage(String payload) {
+    switch (payload) {
+      case 'good':
+        process(MachineEvent.reachable);
+      case 'bad':
+        process(MachineEvent.unreachable);
+    }
+  }
 
-      if (parsedState != null) {
-        contacts[address] = parsedState;
-        notifyListeners();
-      }
+  void _onContactMessage(String payload, String address) {
+    final bool? parsedState = _parseBool(payload);
+
+    if (parsedState != null) {
+      contacts[address] = parsedState;
+      notifyListeners();
     }
   }