feat: Implement Bonjour service discovery for iOS clients

frosthaven_assistant/lib/Layout/menus/server_discovery_dialog.dart

@@ -0,0 +1,80 @@
+import 'package:flutter/material.dart';
+import 'package:frosthaven_assistant/services/network/client.dart';
+import 'package:frosthaven_assistant/services/service_locator.dart';
+
+class ServerDiscoveryDialog extends StatefulWidget {
+  const ServerDiscoveryDialog({super.key});
+
+  @override
+  State<ServerDiscoveryDialog> createState() => _ServerDiscoveryDialogState();
+}
+
+class _ServerDiscoveryDialogState extends State<ServerDiscoveryDialog> {
+  final _client = getIt<Client>();
+  List<DiscoveredServer> _servers = [];
+  bool _isDiscovering = false;
+
+  @override
+  void initState() {
+    super.initState();
+    _discoverServers();
+  }
+
+  void _discoverServers() {
+    setState(() {
+      _isDiscovering = true;
+      _servers = [];
+    });
+    _client.discoverServers().listen((server) {
+      setState(() {
+        if (!_servers.any((s) => s.address == server.address && s.port == server.port)) {
+          _servers.add(server);
+        }
+      });
+    }).onDone(() {
+      setState(() {
+        _isDiscovering = false;
+      });
+    });
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return AlertDialog(
+      title: const Text('Discover Servers'),
+      content: SizedBox(
+        width: 400,
+        height: 300,
+        child: _isDiscovering && _servers.isEmpty
+            ? const Center(child: CircularProgressIndicator())
+            : _servers.isEmpty
+                ? const Center(child: Text('No servers found.'))
+                : ListView.builder(
+                    itemCount: _servers.length,
+                    itemBuilder: (context, index) {
+                      final server = _servers[index];
+                      return ListTile(
+                        title: Text(server.name),
+                        subtitle: Text('${server.address}:${server.port}'),
+                        onTap: () {
+                          Navigator.of(context).pop(server);
+                        },
+                      );
+                    },
+                  ),
+      ),
+      actions: [
+        TextButton(
+          onPressed: () {
+            Navigator.of(context).pop();
+          },
+          child: const Text('Cancel'),
+        ),
+        TextButton(
+          onPressed: _isDiscovering ? null : _discoverServers,
+          child: const Text('Refresh'),
+        ),
+      ],
+    );
+  }
+}

frosthaven_assistant/lib/Layout/menus/settings_menu.dart

@@ -3,6 +3,7 @@ import 'dart:math';
 
 import 'package:flutter/material.dart';
 import 'package:frosthaven_assistant/Layout/menus/save_menu.dart';
+import 'package:frosthaven_assistant/Layout/menus/server_discovery_dialog.dart';
 import 'package:frosthaven_assistant/Resource/commands/clear_unlocked_classes_command.dart';
 import 'package:frosthaven_assistant/Resource/commands/set_ally_deck_in_og_gloom_command.dart';
 import 'package:frosthaven_assistant/Resource/commands/track_standees_command.dart';
@@ -443,17 +444,35 @@ class SettingsMenuState extends State<SettingsMenu> {
                                         });
                                   }),
 
-                              Container(
-                                margin: const EdgeInsets.only(top: 10),
-                                width: 200,
-                                height: 40,
-                                child: TextField(
-                                    controller: _serverTextController,
-                                    decoration: const InputDecoration(
-                                      counterText: "",
-                                      helperText: "server ip address",
-                                    ),
-                                    maxLength: 20),
+                              Row(
+                                mainAxisAlignment: MainAxisAlignment.center,
+                                children: [
+                                  Container(
+                                    margin: const EdgeInsets.only(top: 10),
+                                    width: 200,
+                                    height: 40,
+                                    child: TextField(
+                                        controller: _serverTextController,
+                                        decoration: const InputDecoration(
+                                          counterText: "",
+                                          helperText: "server ip address",
+                                        ),
+                                        maxLength: 20),
+                                  ),
+                                  IconButton(
+                                    icon: const Icon(Icons.search),
+                                    onPressed: () async {
+                                      final result = await showDialog<DiscoveredServer>(
+                                        context: context,
+                                        builder: (context) => const ServerDiscoveryDialog(),
+                                      );
+                                      if (result != null) {
+                                        _serverTextController.text = result.address;
+                                        _portTextController.text = result.port.toString();
+                                      }
+                                    },
+                                  ),
+                                ],
                               ),
 
                               Container(

frosthaven_assistant/lib/services/network/client.dart

@@ -5,6 +5,7 @@ import 'dart:io';
 import 'package:flutter/foundation.dart';
 import 'package:frosthaven_assistant/services/network/communication.dart';
 import 'package:frosthaven_assistant/services/network/network.dart';
+import 'package:multicast_dns/multicast_dns.dart';
 
 import '../../Resource/settings.dart';
 import '../../Resource/state/game_state.dart';
@@ -179,4 +180,42 @@ class Client {
     }
     _serverResponsive = true;
   }
+
+  Stream<DiscoveredServer> discoverServers() async* {
+    final MDnsClient client = MDnsClient();
+    await client.start();
+
+    const String name = '_frosthaven._tcp.local';
+    await for (final PtrResourceRecord ptr in client.lookup<PtrResourceRecord>(
+      ResourceRecordQuery.serverPointer(name),
+    )) {
+      await for (final SrvResourceRecord srv in client.lookup<SrvResourceRecord>(
+        ResourceRecordQuery.service(ptr.domainName),
+      )) {
+        await for (final IPAddressResourceRecord ip
+            in client.lookup<IPAddressResourceRecord>(
+          ResourceRecordQuery.addressIPv4(srv.target),
+        )) {
+          yield DiscoveredServer(
+            name: ptr.domainName,
+            address: ip.address.address,
+            port: srv.port,
+          );
+        }
+      }
+    }
+    client.stop();
+  }
+}
+
+class DiscoveredServer {
+  DiscoveredServer({
+    required this.name,
+    required this.address,
+    required this.port,
+  });
+
+  final String name;
+  final String address;
+  final int port;
 }

frosthaven_assistant/pubspec.yaml

@@ -66,6 +66,7 @@ dependencies:
   format: ^1.4.0
   frosthaven_assistant_server:
     path: ../frosthaven_assistant_server
+  multicast_dns: ^0.3.3
 
 
 

frosthaven_assistant_server/lib/bonjour.dart

@@ -0,0 +1,148 @@
+import 'dart:io';
+import 'dart:typed_data';
+import 'dart:convert';
+
+import 'package:multicast_dns/src/constants.dart';
+import 'package:multicast_dns/src/resource_record.dart';
+
+class Bonjour {
+  RawDatagramSocket? _socket;
+
+  Future<void> advertise(String ip, int port) async {
+    // Stop any existing advertising.
+    stop();
+
+    const String serviceName = '_frosthaven._tcp.local';
+    final String serverName = 'Frosthaven Assistant Server.$serviceName';
+
+    _socket = await RawDatagramSocket.bind(InternetAddress.anyIPv4, mDnsPort);
+    _socket!.joinMulticast(mDnsAddressIPv4);
+
+    final PtrResourceRecord ptr = PtrResourceRecord(
+      serviceName,
+      3600,
+      domainName: serverName,
+    );
+
+    final SrvResourceRecord srv = SrvResourceRecord(
+      serverName,
+      3600,
+      port: port,
+      target: ip,
+      weight: 0,
+      priority: 0,
+    );
+
+    final IPAddressResourceRecord ipAddress = IPAddressResourceRecord(
+      ip,
+      3600,
+      address: InternetAddress(ip),
+    );
+
+    final List<int> packet = _buildResponse([ptr, srv, ipAddress]);
+    _socket!.send(packet, mDnsAddressIPv4, mDnsPort);
+  }
+
+  void stop() {
+    _socket?.close();
+    _socket = null;
+  }
+
+  List<int> _buildResponse(List<ResourceRecord> records) {
+    final writer = _MDnsWriter(isQuery: false);
+    writer.writeRecords(records);
+    return writer.toUint8List();
+  }
+}
+
+class _MDnsWriter {
+  _MDnsWriter({this.isQuery = true}) {
+    // ID is always 0
+    _byteData.setUint16(0, 0);
+    // Flags
+    _byteData.setUint16(2, isQuery ? 0 : 0x8400); // Authoritative answer
+    // Question count
+    _byteData.setUint16(4, 0);
+    // Answer count
+    _byteData.setUint16(6, 0);
+    // Authority count
+    _byteData.setUint16(8, 0);
+    // Additional count
+    _byteData.setUint16(10, 0);
+  }
+
+  final bool isQuery;
+  final Uint8List _data = Uint8List(4096);
+  late final ByteData _byteData = ByteData.view(_data.buffer);
+  int _offset = 12;
+  final Map<String, int> _fqdnOffsets = <String, int>{};
+
+  void writeFQDN(String fqdn) {
+    if (_fqdnOffsets.containsKey(fqdn)) {
+      final int fqdnOffset = _fqdnOffsets[fqdn]!;
+      _byteData.setUint16(_offset, 0xc000 | fqdnOffset);
+      _offset += 2;
+      return;
+    }
+
+    _fqdnOffsets[fqdn] = _offset;
+    final List<String> parts = fqdn.split('.');
+    for (final String part in parts) {
+      final List<int> partBytes = utf8.encode(part);
+      _data[_offset++] = partBytes.length;
+      _data.setRange(_offset, _offset + partBytes.length, partBytes);
+      _offset += partBytes.length;
+    }
+    _data[_offset++] = 0;
+  }
+
+  void writeRecord(ResourceRecord record) {
+    writeFQDN(record.fullyQualifiedName);
+    _byteData.setUint16(_offset, record.resourceRecordType);
+    _offset += 2;
+    _byteData.setUint16(_offset, ResourceRecordClass.internet | 0x8000); // Cache flush
+    _offset += 2;
+    _byteData.setUint32(_offset, record.ttl);
+    _offset += 4;
+
+    final int dataLengthOffset = _offset;
+    _offset += 2;
+
+    final int dataStartOffset = _offset;
+
+    if (record is IPAddressResourceRecord) {
+      final List<int> addressBytes = record.address.rawAddress;
+      _data.setRange(_offset, _offset + addressBytes.length, addressBytes);
+      _offset += addressBytes.length;
+    } else if (record is PtrResourceRecord) {
+      writeFQDN(record.domainName);
+    } else if (record is SrvResourceRecord) {
+      _byteData.setUint16(_offset, record.priority);
+      _offset += 2;
+      _byteData.setUint16(_offset, record.weight);
+      _offset += 2;
+      _byteData.setUint16(_offset, record.port);
+      _offset += 2;
+      writeFQDN(record.target);
+    } else if (record is TxtResourceRecord) {
+      final List<int> textBytes = utf8.encode(record.text);
+      _data[_offset++] = textBytes.length;
+      _data.setRange(_offset, _offset + textBytes.length, textBytes);
+      _offset += textBytes.length;
+    }
+
+    final int dataLength = _offset - dataStartOffset;
+    _byteData.setUint16(dataLengthOffset, dataLength);
+  }
+
+  void writeRecords(List<ResourceRecord> records) {
+    _byteData.setUint16(6, records.length);
+    for (final ResourceRecord record in records) {
+      writeRecord(record);
+    }
+  }
+
+  Uint8List toUint8List() {
+    return Uint8List.view(_data.buffer, 0, _offset);
+  }
+}

frosthaven_assistant_server/lib/game_server.dart

@@ -48,6 +48,8 @@ abstract class GameServer {
   void send(String data);
   String currentStateMessage(String commandDescription);
   Future<String> getConnectToIP();
+  void startAdvertising(String ip, int port);
+  void stopAdvertising();
 
   void sendPing();
   void addClientConnection(Socket client);
@@ -84,6 +86,7 @@ abstract class GameServer {
           'Server Online: IP: $connectTo, Port: ${server.port.toString()}';
       log(info);
       setNetworkMessage(info);
+      startAdvertising(connectTo, server.port);
       resetState();
       send(currentStateMessage(""));
       var subscriptions = server.listen((Socket client) {
@@ -119,6 +122,7 @@ abstract class GameServer {
     serverEnabled = false;
     leftOverMessage = "";
 
+    stopAdvertising();
     resetState();
   }