feat: Bonjour auto-discovery + VPN IP field in connection flow

Matthias Nott

2026-03-24 96c8bb5db1a2e0ced999a366e3cf28f9895ec39f

 lib/services/mqtt_service.dart
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@@ -2,6 +2,7 @@
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 import 'dart:convert';
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 import 'dart:io';
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+import 'package:bonsoir/bonsoir.dart';
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 import 'package:flutter/widgets.dart';
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 import 'package:path_provider/path_provider.dart' as pp;
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 import 'package:mqtt_client/mqtt_client.dart';
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@@ -102,29 +103,50 @@
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     }
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     final clientId = await _getClientId();
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-    final hosts = _getHosts();
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-    _mqttLog('MQTT: hosts=${hosts.join(", ")} port=${config.port}');
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-    for (final host in hosts) {
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+    // Connection order: local → Bonjour → VPN → remote
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+    final attempts = <MapEntry<String, int>>[];  // host → timeout ms
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+    if (config.localHost != null && config.localHost!.isNotEmpty) {
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+      attempts.add(MapEntry(config.localHost!, 2500));
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+    }
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+    // Bonjour placeholder — inserted dynamically below
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+    if (config.vpnHost != null && config.vpnHost!.isNotEmpty) {
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+      attempts.add(MapEntry(config.vpnHost!, 3000));
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+    }
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+    if (config.host.isNotEmpty) {
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+      attempts.add(MapEntry(config.host, 5000));
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+    }
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+    _mqttLog('MQTT: attempts=${attempts.map((e) => e.key).join(", ")} port=${config.port}');
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+
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+    // Try configured local host first
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+    for (final attempt in attempts) {
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       if (_intentionalClose) return;
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-
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-      _mqttLog('MQTT: trying $host:${config.port}');
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+      _mqttLog('MQTT: trying ${attempt.key}:${config.port}');
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       try {
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-        final connected = await _tryConnect(
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-          host,
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-          clientId,
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-          timeout: host == hosts.first && hosts.length > 1 ? 2500 : 5000,
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-        );
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-        _mqttLog('MQTT: $host result=$connected');
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-        if (connected) return;
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+        if (await _tryConnect(attempt.key, clientId, timeout: attempt.value)) return;
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       } catch (e) {
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-        _mqttLog('MQTT: $host error=$e');
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-        continue;
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+        _mqttLog('MQTT: ${attempt.key} error=$e');
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+      }
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+
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+      // After local host fails, try Bonjour discovery before VPN/remote
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+      if (attempt.key == config.localHost && !_intentionalClose) {
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+        _mqttLog('MQTT: trying Bonjour discovery...');
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+        final bonjourHost = await _discoverViaMdns();
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+        if (bonjourHost != null && !_intentionalClose) {
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+          _mqttLog('MQTT: Bonjour found $bonjourHost');
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+          try {
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+            if (await _tryConnect(bonjourHost, clientId, timeout: 3000)) return;
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+          } catch (e) {
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+            _mqttLog('MQTT: Bonjour host $bonjourHost error=$e');
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+          }
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+        } else {
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+          _mqttLog('MQTT: Bonjour discovery returned nothing');
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+        }
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       }
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     }
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     // All hosts failed — retry after delay
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-    _mqttLog('MQTT: all hosts failed, retrying in 5s');
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+    _mqttLog('MQTT: all attempts failed, retrying in 5s');
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     _setStatus(ConnectionStatus.reconnecting);
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     Future.delayed(const Duration(seconds: 5), () {
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       if (!_intentionalClose && _status != ConnectionStatus.connected) {
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@@ -133,14 +155,43 @@
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     });
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   }
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-  /// Returns [localHost, remoteHost] for dual-connect attempts.
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-  List<String> _getHosts() {
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-    if (config.localHost != null &&
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-        config.localHost!.isNotEmpty &&
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-        config.localHost != config.host) {
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-      return [config.localHost!, config.host];
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+  /// Discover AIBroker on local network via Bonjour/mDNS.
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+  /// Returns the IP address or null if not found within timeout.
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+  Future<String?> _discoverViaMdns({Duration timeout = const Duration(seconds: 3)}) async {
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+    try {
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+      final discovery = BonsoirDiscovery(type: '_mqtt._tcp');
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+      await discovery.initialize();
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+
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+      final completer = Completer<String?>();
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+      StreamSubscription? sub;
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+
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+      sub = discovery.eventStream?.listen((event) {
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+        switch (event) {
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+          case BonsoirDiscoveryServiceResolvedEvent():
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+            final ip = event.service.host;
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+            _mqttLog('MQTT: Bonjour resolved: ${event.service.name} at $ip:${event.service.port}');
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+            if (ip != null && ip.isNotEmpty && !completer.isCompleted) {
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+              completer.complete(ip);
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+            }
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+          case BonsoirDiscoveryServiceFoundEvent():
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+            _mqttLog('MQTT: Bonjour found: ${event.service.name}');
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+          default:
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+            break;
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+        }
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+      });
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+
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+      await discovery.start();
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+
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+      final ip = await completer.future.timeout(timeout, onTimeout: () => null);
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+
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+      await sub?.cancel();
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+      await discovery.stop();
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+
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+      return ip;
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+    } catch (e) {
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+      _mqttLog('MQTT: Bonjour discovery error: $e');
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+      return null;
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     }
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-    return [config.host];
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   }
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   Future<bool> _tryConnect(String host, String clientId, {int timeout = 5000}) async {