feat(useragent): added connection info setup screen

useragent/lib/features/arbiter_url.dart

@@ -0,0 +1,56 @@
+import 'dart:convert';
+
+class ArbiterUrl {
+  const ArbiterUrl({
+    required this.host,
+    required this.port,
+    required this.caCert,
+    this.bootstrapToken,
+  });
+
+  final String host;
+  final int port;
+  final List<int> caCert;
+  final String? bootstrapToken;
+
+  static const _scheme = 'arbiter';
+  static const _certQueryKey = 'cert';
+  static const _bootstrapTokenQueryKey = 'bootstrap_token';
+
+  static ArbiterUrl parse(String value) {
+    final uri = Uri.tryParse(value);
+    if (uri == null || uri.scheme != _scheme) {
+      throw const FormatException("Invalid URL scheme, expected 'arbiter://'");
+    }
+
+    if (uri.host.isEmpty) {
+      throw const FormatException('Missing host in URL');
+    }
+
+    if (!uri.hasPort) {
+      throw const FormatException('Missing port in URL');
+    }
+
+    final cert = uri.queryParameters[_certQueryKey];
+    if (cert == null || cert.isEmpty) {
+      throw const FormatException("Missing 'cert' query parameter in URL");
+    }
+
+    final decodedCert = _decodeCert(cert);
+
+    return ArbiterUrl(
+      host: uri.host,
+      port: uri.port,
+      caCert: decodedCert,
+      bootstrapToken: uri.queryParameters[_bootstrapTokenQueryKey],
+    );
+  }
+
+  static List<int> _decodeCert(String cert) {
+    try {
+      return base64Url.decode(base64Url.normalize(cert));
+    } on FormatException catch (error) {
+      throw FormatException("Invalid base64 in 'cert' query parameter: ${error.message}");
+    }
+  }
+}

useragent/lib/features/connection/connection.dart

@@ -0,0 +1,3 @@
+
+
+class Connection {}

useragent/lib/features/pk_manager.dart

@@ -1,6 +1,3 @@
-
-import 'package:flutter/services.dart';
-
 enum KeyAlgorithm {
   rsa, ecdsa, ed25519
 }
@@ -16,4 +13,4 @@ abstract class KeyHandle {
 abstract class KeyManager {
   Future<KeyHandle?> get();
   Future<KeyHandle> create();
-}
+}

useragent/lib/features/server_info_storage.dart

@@ -0,0 +1,67 @@
+import 'dart:convert';
+
+import 'package:flutter_secure_storage/flutter_secure_storage.dart';
+
+class StoredServerInfo {
+  const StoredServerInfo({
+    required this.address,
+    required this.port,
+    required this.caCertFingerprint,
+  });
+
+  final String address;
+  final int port;
+  final String caCertFingerprint;
+
+  Map<String, dynamic> toJson() => {
+    'address': address,
+    'port': port,
+    'caCertFingerprint': caCertFingerprint,
+  };
+
+  factory StoredServerInfo.fromJson(Map<String, dynamic> json) {
+    return StoredServerInfo(
+      address: json['address'] as String,
+      port: json['port'] as int,
+      caCertFingerprint: json['caCertFingerprint'] as String,
+    );
+  }
+}
+
+abstract class ServerInfoStorage {
+  Future<StoredServerInfo?> load();
+  Future<void> save(StoredServerInfo serverInfo);
+  Future<void> clear();
+}
+
+class SecureServerInfoStorage implements ServerInfoStorage {
+  static const _storageKey = 'server_info';
+
+  const SecureServerInfoStorage();
+
+  static const _storage = FlutterSecureStorage();
+
+  @override
+  Future<StoredServerInfo?> load() async {
+    final rawValue = await _storage.read(key: _storageKey);
+    if (rawValue == null) {
+      return null;
+    }
+
+    final decoded = jsonDecode(rawValue) as Map<String, dynamic>;
+    return StoredServerInfo.fromJson(decoded);
+  }
+
+  @override
+  Future<void> save(StoredServerInfo serverInfo) {
+    return _storage.write(
+      key: _storageKey,
+      value: jsonEncode(serverInfo.toJson()),
+    );
+  }
+
+  @override
+  Future<void> clear() {
+    return _storage.delete(key: _storageKey);
+  }
+}

useragent/lib/main.dart

@@ -1,14 +1,35 @@
 import 'package:arbiter/router.dart';
 import 'package:flutter/material.dart' hide Router;
 import 'package:hooks_riverpod/hooks_riverpod.dart';
+import 'package:sizer/sizer.dart';
 
 void main() {
   WidgetsFlutterBinding.ensureInitialized();
-  runApp(
-    ProviderScope(
-      child: MaterialApp.router(
-        routerConfig: Router().config(),
-      ),
-    ),
-  );
+  runApp(const ProviderScope(child: App()));
+}
+
+class App extends StatefulWidget {
+  const App({super.key});
+
+  @override
+  State<App> createState() => _AppState();
+}
+
+class _AppState extends State<App> {
+  late final Router _router;
+
+  @override
+  void initState() {
+    super.initState();
+    _router = Router();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Sizer(
+      builder: (context, orientation, deviceType) {
+        return MaterialApp.router(routerConfig: _router.config());
+      },
+    );
+  }
 }

useragent/lib/providers/server_info.dart

@@ -0,0 +1,51 @@
+import 'package:arbiter/features/server_info_storage.dart';
+import 'package:cryptography/cryptography.dart';
+import 'package:riverpod_annotation/riverpod_annotation.dart';
+
+part 'server_info.g.dart';
+
+@riverpod
+ServerInfoStorage serverInfoStorage(Ref ref) {
+  return const SecureServerInfoStorage();
+}
+
+@Riverpod(keepAlive: true)
+class ServerInfo extends _$ServerInfo {
+  @override
+  Future<StoredServerInfo?> build() {
+    final storage = ref.watch(serverInfoStorageProvider);
+    return storage.load();
+  }
+
+  Future<void> save({
+    required String address,
+    required int port,
+    required List<int> caCert,
+  }) async {
+    final storage = ref.read(serverInfoStorageProvider);
+    final fingerprint = await _fingerprint(caCert);
+    final serverInfo = StoredServerInfo(
+      address: address,
+      port: port,
+      caCertFingerprint: fingerprint,
+    );
+
+    state = await AsyncValue.guard(() async {
+      await storage.save(serverInfo);
+      return serverInfo;
+    });
+  }
+
+  Future<void> clear() async {
+    final storage = ref.read(serverInfoStorageProvider);
+    state = await AsyncValue.guard(() async {
+      await storage.clear();
+      return null;
+    });
+  }
+
+  Future<String> _fingerprint(List<int> caCert) async {
+    final digest = await Sha256().hash(caCert);
+    return digest.bytes.map((byte) => byte.toRadixString(16).padLeft(2, '0')).join();
+  }
+}

useragent/lib/providers/server_info.g.dart

@@ -0,0 +1,102 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+
+part of 'server_info.dart';
+
+// **************************************************************************
+// RiverpodGenerator
+// **************************************************************************
+
+// GENERATED CODE - DO NOT MODIFY BY HAND
+// ignore_for_file: type=lint, type=warning
+
+@ProviderFor(serverInfoStorage)
+final serverInfoStorageProvider = ServerInfoStorageProvider._();
+
+final class ServerInfoStorageProvider
+    extends
+        $FunctionalProvider<
+          ServerInfoStorage,
+          ServerInfoStorage,
+          ServerInfoStorage
+        >
+    with $Provider<ServerInfoStorage> {
+  ServerInfoStorageProvider._()
+    : super(
+        from: null,
+        argument: null,
+        retry: null,
+        name: r'serverInfoStorageProvider',
+        isAutoDispose: true,
+        dependencies: null,
+        $allTransitiveDependencies: null,
+      );
+
+  @override
+  String debugGetCreateSourceHash() => _$serverInfoStorageHash();
+
+  @$internal
+  @override
+  $ProviderElement<ServerInfoStorage> $createElement(
+    $ProviderPointer pointer,
+  ) => $ProviderElement(pointer);
+
+  @override
+  ServerInfoStorage create(Ref ref) {
+    return serverInfoStorage(ref);
+  }
+
+  /// {@macro riverpod.override_with_value}
+  Override overrideWithValue(ServerInfoStorage value) {
+    return $ProviderOverride(
+      origin: this,
+      providerOverride: $SyncValueProvider<ServerInfoStorage>(value),
+    );
+  }
+}
+
+String _$serverInfoStorageHash() => r'fc06865e7314b1a2493c5de1a9347923a3d21c5c';
+
+@ProviderFor(ServerInfo)
+final serverInfoProvider = ServerInfoProvider._();
+
+final class ServerInfoProvider
+    extends $AsyncNotifierProvider<ServerInfo, StoredServerInfo?> {
+  ServerInfoProvider._()
+    : super(
+        from: null,
+        argument: null,
+        retry: null,
+        name: r'serverInfoProvider',
+        isAutoDispose: false,
+        dependencies: null,
+        $allTransitiveDependencies: null,
+      );
+
+  @override
+  String debugGetCreateSourceHash() => _$serverInfoHash();
+
+  @$internal
+  @override
+  ServerInfo create() => ServerInfo();
+}
+
+String _$serverInfoHash() => r'6e94f52de03259695a2166b766004eec60ff45fa';
+
+abstract class _$ServerInfo extends $AsyncNotifier<StoredServerInfo?> {
+  FutureOr<StoredServerInfo?> build();
+  @$mustCallSuper
+  @override
+  void runBuild() {
+    final ref =
+        this.ref as $Ref<AsyncValue<StoredServerInfo?>, StoredServerInfo?>;
+    final element =
+        ref.element
+            as $ClassProviderElement<
+              AnyNotifier<AsyncValue<StoredServerInfo?>, StoredServerInfo?>,
+              AsyncValue<StoredServerInfo?>,
+              Object?,
+              Object?
+            >;
+    element.handleCreate(ref, build);
+  }
+}

useragent/lib/router.dart

@@ -1,8 +1,4 @@
-import 'package:arbiter/screens/dashboard/about.dart';
-import 'package:arbiter/screens/dashboard/calc.dart';
 import 'package:auto_route/auto_route.dart';
-import 'package:flutter/material.dart';
-import 'package:flutter_adaptive_scaffold/flutter_adaptive_scaffold.dart';
 
 import 'router.gr.dart';
 
@@ -11,6 +7,7 @@ class Router extends RootStackRouter {
   @override
   List<AutoRoute> get routes => [
     AutoRoute(page: Bootstrap.page, path: '/bootstrap', initial: true),
+    AutoRoute(page: ServerInfoSetupRoute.page, path: '/server-info'),
 
     AutoRoute(
       page: DashboardRouter.page,

useragent/lib/router.gr.dart

@@ -13,33 +13,34 @@ import 'package:arbiter/screens/bootstrap.dart' as _i2;
 import 'package:arbiter/screens/dashboard.dart' as _i4;
 import 'package:arbiter/screens/dashboard/about.dart' as _i1;
 import 'package:arbiter/screens/dashboard/calc.dart' as _i3;
-import 'package:auto_route/auto_route.dart' as _i5;
+import 'package:arbiter/screens/server_info_setup.dart' as _i5;
+import 'package:auto_route/auto_route.dart' as _i6;
 
 /// generated route for
 /// [_i1.AboutScreen]
-class AboutRoute extends _i5.PageRouteInfo<void> {
-  const AboutRoute({List<_i5.PageRouteInfo>? children})
+class AboutRoute extends _i6.PageRouteInfo<void> {
+  const AboutRoute({List<_i6.PageRouteInfo>? children})
     : super(AboutRoute.name, initialChildren: children);
 
   static const String name = 'AboutRoute';
 
-  static _i5.PageInfo page = _i5.PageInfo(
+  static _i6.PageInfo page = _i6.PageInfo(
     name,
     builder: (data) {
-      return _i1.AboutScreen();
+      return const _i1.AboutScreen();
     },
   );
 }
 
 /// generated route for
 /// [_i2.Bootstrap]
-class Bootstrap extends _i5.PageRouteInfo<void> {
-  const Bootstrap({List<_i5.PageRouteInfo>? children})
+class Bootstrap extends _i6.PageRouteInfo<void> {
+  const Bootstrap({List<_i6.PageRouteInfo>? children})
     : super(Bootstrap.name, initialChildren: children);
 
   static const String name = 'Bootstrap';
 
-  static _i5.PageInfo page = _i5.PageInfo(
+  static _i6.PageInfo page = _i6.PageInfo(
     name,
     builder: (data) {
       return const _i2.Bootstrap();
@@ -49,13 +50,13 @@ class Bootstrap extends _i5.PageRouteInfo<void> {
 
 /// generated route for
 /// [_i3.CalcScreen]
-class CalcRoute extends _i5.PageRouteInfo<void> {
-  const CalcRoute({List<_i5.PageRouteInfo>? children})
+class CalcRoute extends _i6.PageRouteInfo<void> {
+  const CalcRoute({List<_i6.PageRouteInfo>? children})
     : super(CalcRoute.name, initialChildren: children);
 
   static const String name = 'CalcRoute';
 
-  static _i5.PageInfo page = _i5.PageInfo(
+  static _i6.PageInfo page = _i6.PageInfo(
     name,
     builder: (data) {
       return const _i3.CalcScreen();
@@ -65,16 +66,32 @@ class CalcRoute extends _i5.PageRouteInfo<void> {
 
 /// generated route for
 /// [_i4.DashboardRouter]
-class DashboardRouter extends _i5.PageRouteInfo<void> {
-  const DashboardRouter({List<_i5.PageRouteInfo>? children})
+class DashboardRouter extends _i6.PageRouteInfo<void> {
+  const DashboardRouter({List<_i6.PageRouteInfo>? children})
     : super(DashboardRouter.name, initialChildren: children);
 
   static const String name = 'DashboardRouter';
 
-  static _i5.PageInfo page = _i5.PageInfo(
+  static _i6.PageInfo page = _i6.PageInfo(
     name,
     builder: (data) {
       return const _i4.DashboardRouter();
     },
   );
 }
+
+/// generated route for
+/// [_i5.ServerInfoSetupScreen]
+class ServerInfoSetupRoute extends _i6.PageRouteInfo<void> {
+  const ServerInfoSetupRoute({List<_i6.PageRouteInfo>? children})
+    : super(ServerInfoSetupRoute.name, initialChildren: children);
+
+  static const String name = 'ServerInfoSetupRoute';
+
+  static _i6.PageInfo page = _i6.PageInfo(
+    name,
+    builder: (data) {
+      return const _i5.ServerInfoSetupScreen();
+    },
+  );
+}

useragent/lib/screens/bootstrap.dart

@@ -14,13 +14,13 @@ class Bootstrap extends HookConsumerWidget {
 
   @override
   Widget build(BuildContext context, WidgetRef ref) {
-    final container = ProviderScope.containerOf(  context);
+    final container = ProviderScope.containerOf(context);
     final completer = useMemoized(() {
       final completer = Completer<void>();
       completer.future.then((_) async {
         if (context.mounted) {
           final router = AutoRouter.of(context);
-          router.replace(const DashboardRouter());
+          router.replace(const ServerInfoSetupRoute());
         }
       });
 

useragent/lib/screens/dashboard/about.dart

@@ -2,9 +2,10 @@ import 'package:auto_route/auto_route.dart';
 import 'package:flutter/material.dart';
 import 'package:mtcore/markettakers.dart' as mt;
 
-
 @RoutePage()
 class AboutScreen extends StatelessWidget {
+  const AboutScreen({super.key});
+
   @override
   Widget build(BuildContext context) {
     return mt.AboutScreen(decription: "Arbiter is bla bla bla");

useragent/lib/screens/server_info_setup.dart

@@ -0,0 +1,284 @@
+import 'package:arbiter/features/arbiter_url.dart';
+import 'package:arbiter/features/server_info_storage.dart';
+import 'package:arbiter/providers/server_info.dart';
+import 'package:arbiter/router.gr.dart';
+import 'package:auto_route/auto_route.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter_hooks/flutter_hooks.dart';
+import 'package:hooks_riverpod/hooks_riverpod.dart';
+import 'package:sizer/sizer.dart';
+
+@RoutePage()
+class ServerInfoSetupScreen extends HookConsumerWidget {
+  const ServerInfoSetupScreen({super.key});
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    final storedServerInfo = ref.watch(serverInfoProvider);
+    final resolvedServerInfo = storedServerInfo.asData?.value;
+    final controller = useTextEditingController();
+    final errorText = useState<String?>(null);
+    final isSaving = useState(false);
+
+    useEffect(() {
+      final serverInfo = resolvedServerInfo;
+      if (serverInfo != null) {
+        WidgetsBinding.instance.addPostFrameCallback((_) {
+          if (context.mounted) {
+            context.router.replace(const DashboardRouter());
+          }
+        });
+      }
+      return null;
+    }, [context, resolvedServerInfo]);
+
+    Future<void> saveRemoteServerInfo() async {
+      errorText.value = null;
+      isSaving.value = true;
+
+      try {
+        final arbiterUrl = ArbiterUrl.parse(controller.text.trim());
+        await ref
+            .read(serverInfoProvider.notifier)
+            .save(
+              address: arbiterUrl.host,
+              port: arbiterUrl.port,
+              caCert: arbiterUrl.caCert,
+            );
+
+        if (context.mounted) {
+          context.router.replace(const DashboardRouter());
+        }
+      } on FormatException catch (error) {
+        errorText.value = error.message;
+      } catch (_) {
+        errorText.value = 'Failed to store connection settings.';
+      } finally {
+        isSaving.value = false;
+      }
+    }
+
+    if (storedServerInfo.isLoading) {
+      return const Scaffold(body: Center(child: CircularProgressIndicator()));
+    }
+
+    if (storedServerInfo.hasError) {
+      return Scaffold(
+        appBar: AppBar(title: const Text('Server Info Setup')),
+        body: Center(
+          child: Padding(
+            padding: EdgeInsets.symmetric(horizontal: 6.w),
+            child: Text(
+              'Failed to load stored server info.',
+              style: Theme.of(context).textTheme.bodyLarge,
+              textAlign: TextAlign.center,
+            ),
+          ),
+        ),
+      );
+    }
+
+    final serverInfo = resolvedServerInfo;
+    if (serverInfo != null) {
+      return _RedirectingView(serverInfo: serverInfo);
+    }
+
+    return Scaffold(
+      appBar: AppBar(title: const Text('Server Info Setup')),
+      body: LayoutBuilder(
+        builder: (context, constraints) {
+          final useRowLayout = constraints.maxWidth > constraints.maxHeight;
+          final gap = 2.h;
+          final horizontalPadding = 6.w;
+          final verticalPadding = 3.h;
+          final options = [
+            const _OptionCard(
+              title: 'Local',
+              subtitle: 'Will start and connect to a local service in a future update.',
+              enabled: false,
+              child: SizedBox.shrink(),
+            ),
+            _OptionCard(
+              title: 'Remote',
+              subtitle: 'Paste an Arbiter URL to store the server address, port, and CA fingerprint.',
+              child: _RemoteConnectionForm(
+                controller: controller,
+                errorText: errorText.value,
+                isSaving: isSaving.value,
+                onSave: saveRemoteServerInfo,
+              ),
+            ),
+          ];
+
+          return ListView(
+            padding: EdgeInsets.symmetric(
+              horizontal: horizontalPadding,
+              vertical: verticalPadding,
+            ),
+            children: [
+              _SetupHeader(gap: gap),
+              SizedBox(height: gap),
+              useRowLayout
+                  ? Row(
+                      crossAxisAlignment: CrossAxisAlignment.start,
+                      children: [
+                        Expanded(child: options[0]),
+                        SizedBox(width: 3.w),
+                        Expanded(child: options[1]),
+                      ],
+                    )
+                  : Column(
+                      children: [
+                        options[0],
+                        SizedBox(height: gap),
+                        options[1],
+                      ],
+                    ),
+            ],
+          );
+        },
+      ),
+    );
+  }
+}
+
+class _SetupHeader extends StatelessWidget {
+  const _SetupHeader({required this.gap});
+
+  final double gap;
+
+  @override
+  Widget build(BuildContext context) {
+    return Column(
+      crossAxisAlignment: CrossAxisAlignment.start,
+      children: [
+        Text(
+          'Choose how this user agent should reach Arbiter.',
+          style: Theme.of(context).textTheme.headlineSmall,
+        ),
+        SizedBox(height: gap * 0.5),
+        Text(
+          'Remote accepts the shareable Arbiter URL emitted by the server.',
+          style: Theme.of(context).textTheme.bodyMedium,
+        ),
+      ],
+    );
+  }
+}
+
+class _RedirectingView extends StatelessWidget {
+  const _RedirectingView({required this.serverInfo});
+
+  final StoredServerInfo serverInfo;
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      body: Center(
+        child: Column(
+          mainAxisSize: MainAxisSize.min,
+          children: [
+            const CircularProgressIndicator(),
+            SizedBox(height: 2.h),
+            Text('Using saved server ${serverInfo.address}:${serverInfo.port}'),
+          ],
+        ),
+      ),
+    );
+  }
+}
+
+class _RemoteConnectionForm extends StatelessWidget {
+  const _RemoteConnectionForm({
+    required this.controller,
+    required this.errorText,
+    required this.isSaving,
+    required this.onSave,
+  });
+
+  final TextEditingController controller;
+  final String? errorText;
+  final bool isSaving;
+  final VoidCallback onSave;
+
+  @override
+  Widget build(BuildContext context) {
+    return Column(
+      crossAxisAlignment: CrossAxisAlignment.start,
+      children: [
+        TextField(
+          controller: controller,
+          decoration: const InputDecoration(
+            border: OutlineInputBorder(),
+            labelText: 'Arbiter URL',
+            hintText: 'arbiter://host:port?cert=...',
+          ),
+          minLines: 2,
+          maxLines: 4,
+        ),
+        if (errorText != null) ...[
+          SizedBox(height: 1.5.h),
+          Text(
+            errorText!,
+            style: TextStyle(color: Theme.of(context).colorScheme.error),
+          ),
+        ],
+        SizedBox(height: 2.h),
+        Align(
+          alignment: Alignment.centerLeft,
+          child: FilledButton(
+            onPressed: isSaving ? null : onSave,
+            child: Text(isSaving ? 'Saving...' : 'Save connection'),
+          ),
+        ),
+      ],
+    );
+  }
+}
+
+class _OptionCard extends StatelessWidget {
+  const _OptionCard({
+    required this.title,
+    required this.subtitle,
+    required this.child,
+    this.enabled = true,
+  });
+
+  final String title;
+  final String subtitle;
+  final Widget child;
+  final bool enabled;
+
+  @override
+  Widget build(BuildContext context) {
+    final theme = Theme.of(context);
+    return Card(
+      child: Padding(
+        padding: EdgeInsets.all(2.h),
+        child: Opacity(
+          opacity: enabled ? 1 : 0.55,
+          child: Column(
+            crossAxisAlignment: CrossAxisAlignment.start,
+            children: [
+              Row(
+                children: [
+                  Text(title, style: theme.textTheme.titleLarge),
+                  if (!enabled) ...[
+                    SizedBox(width: 2.w),
+                    const Chip(label: Text('Coming soon')),
+                  ],
+                ],
+              ),
+              SizedBox(height: 1.h),
+              Text(subtitle, style: theme.textTheme.bodyMedium),
+              if (enabled) ...[
+                SizedBox(height: 2.h),
+                child,
+              ],
+            ],
+          ),
+        ),
+      ),
+    );
+  }
+}