Set contact states based on MQTT

This is already the minimal viable product (MVP) for this app.

1 files changed, 65 insertions, 21 deletions

diff --git a/lib/data.dart b/lib/data.dart
index f8b7466..08f8881 100644
--- a/lib/data.dart
+++ b/lib/data.dart
@@ -1,43 +1,87 @@
 import 'dart:async';
 
 import 'package:flutter/foundation.dart';
+import 'package:mqtt_client/mqtt_client.dart';
+import 'package:mqtt_client/mqtt_server_client.dart';
 
 const String brokerHostname = 'sia.xengineering.eu';
 const int brokerPort = 1883;
 const String topicPrefix = 'sia';
 
 class AppState with ChangeNotifier {
-  Map<String, bool> contacts = <String, bool>{
-    'Living Room Window': false,
-    'Front Door': true,
-    'Back Door': false,
-    'Garage Window': true,
-  };
+  Map<String, bool> contacts = <String, bool>{};
 
-  Timer? _timer;
+  late final MqttServerClient _client;
 
   AppState() {
-    _timer = Timer.periodic(const Duration(seconds: 1), (_) {
-      toggleFirstContact();
-    });
+    _initMqtt();
   }
 
-  void toggleFirstContact() {
-    if (contacts.isEmpty) {
+  @override
+  void dispose() {
+    _client.disconnect();
+    super.dispose();
+  }
+
+  Future<void> _initMqtt() async {
+    _client = MqttServerClient(
+      brokerHostname,
+      'sia_app_${DateTime.now().millisecondsSinceEpoch}',
+    );
+
+    _client.port = brokerPort;
+    _client.keepAlivePeriod = 2;
+    _client.logging(on: false);
+
+    _client.onConnected = _onConnected;
+
+    try {
+      await _client.connect();
+    } catch (e) {
+      _client.disconnect();
       return;
     }
 
-    const String choosen = 'Living Room Window';
-    bool? state = contacts[choosen];
-    if (state != null) {
-      contacts[choosen] = !state;
-      notifyListeners();
+    _client.updates?.listen(_onMessage);
+  }
+
+  void _onConnected() {
+    _client.subscribe('$topicPrefix/contact/+/state', MqttQos.exactlyOnce);
+  }
+
+  void _onMessage(List<MqttReceivedMessage<MqttMessage>> messages) {
+    for (final MqttReceivedMessage<MqttMessage> message in messages) {
+      final String topic = message.topic;
+
+      // format <prefix>/contacts/<address>/state
+      final List<String> parts = topic.split('/');
+      if (parts.length != 4 || parts[1] != 'contact' || parts[3] != 'state') {
+        continue;
+      }
+      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) {
+        contacts[address] = parsedState;
+        notifyListeners();
+      }
     }
   }
 
-  @override
-  void dispose() {
-    _timer?.cancel();
-    super.dispose();
+  bool? _parseBool(String payload) {
+    switch (payload.toLowerCase()) {
+      case 'open':
+        return true;
+      case 'closed':
+        return false;
+      default:
+        return null;
+    }
   }
 }