app: further harden refresh logic and prefer local first (#506)

* app: further harden refresh logic and prefer local first * address review comments * cover missing unit test vectors
2026-08-06 17:03:27 +02:00 · 2025-11-24 15:48:50 +01:00
parent 4946ea1751
commit 6f2db06f25
8 changed files with 382 additions and 88 deletions
@@ -34,11 +34,18 @@ jobs:
      TAG_NAME: ${{ github.ref_name }}
    steps:
    - uses: actions/checkout@v5
+    - name: Configure Android local.properties
+      run: |
+        cat > android/local.properties <<'EOF'
+        sdk.dir=${ANDROID_SDK_ROOT}
+        flutter.sdk=${FLUTTER_ROOT}
+        EOF
    - name: Set up Flutter
      uses: subosito/flutter-action@v2
      with:
        channel: stable
        cache: true
+        cache-key: ${{ runner.os }}-flutter-${{ hashFiles('app/pubspec.lock') }}
    - name: Install dependencies
      run: flutter pub get
    - name: Build release APK
@@ -72,6 +79,7 @@ jobs:
      with:
        channel: stable
        cache: true
+        cache-key: ${{ runner.os }}-flutter-${{ hashFiles('app/pubspec.lock') }}
    - name: Install dependencies
      run: flutter pub get
    - name: Build release IPA (no codesign)
@@ -17,6 +17,7 @@ import 'dart:collection';
 import 'dart:convert';
 import 'dart:math';

+import 'package:flutter/foundation.dart';
 import 'package:flutter/gestures.dart';
 import 'package:flutter/material.dart';
 import 'package:http/http.dart' as http;
@@ -35,6 +36,34 @@ const String _gitDirtyEnv =
    String.fromEnvironment('GIT_DIRTY', defaultValue: '');
 const Duration _requestTimeout = Duration(seconds: 5);

+void _logHttp(String message) {
+  debugPrint('D/$message');
+}
+
+Future<List<Map<String, dynamic>>> _decodeJsonList(String body) {
+  return compute(_decodeJsonListSync, body);
+}
+
+List<Map<String, dynamic>> _decodeJsonListSync(String body) {
+  final dynamic decoded = jsonDecode(body);
+  if (decoded is! List) {
+    throw const FormatException('Expected JSON array');
+  }
+  return decoded.whereType<Map<String, dynamic>>().toList();
+}
+
+Future<Map<String, dynamic>> _decodeJsonMap(String body) {
+  return compute(_decodeJsonMapSync, body);
+}
+
+Map<String, dynamic> _decodeJsonMapSync(String body) {
+  final dynamic decoded = jsonDecode(body);
+  if (decoded is! Map<String, dynamic>) {
+    throw const FormatException('Expected JSON object');
+  }
+  return decoded;
+}
+
 void main() {
  runApp(const PotatoMeshReaderApp());
 }
@@ -54,6 +83,7 @@ class PotatoMeshReaderApp extends StatefulWidget {
    this.initialDomain = 'potatomesh.net',
    this.repository,
    this.bootstrapper,
+    this.enableAutoRefresh = true,
  });

  /// Fetch function injected to simplify testing and offline previews.
@@ -73,6 +103,9 @@ class PotatoMeshReaderApp extends StatefulWidget {
  final Future<BootstrapResult> Function({ProgressCallback? onProgress})?
      bootstrapper;

+  /// Whether the chat view should periodically refresh messages.
+  final bool enableAutoRefresh;
+
  @override
  State<PotatoMeshReaderApp> createState() => _PotatoMeshReaderAppState();
 }
@@ -83,6 +116,7 @@ class _PotatoMeshReaderAppState extends State<PotatoMeshReaderApp> {
  late final MeshRepository _repository;
  final GlobalKey<ScaffoldMessengerState> _messengerKey =
      GlobalKey<ScaffoldMessengerState>();
+  bool _hasUserSelectedInstance = false;
  BootstrapProgress _progress =
      const BootstrapProgress(stage: 'loading instances');
  Future<BootstrapResult>? _bootstrapFuture;
@@ -114,6 +148,8 @@ class _PotatoMeshReaderAppState extends State<PotatoMeshReaderApp> {
      setState(() {
        _bootstrapResult = result;
        _endpointDomain = result.selectedDomain;
+        _hasUserSelectedInstance = _normalizeDomain(result.selectedDomain) !=
+            _normalizeDomain(widget.initialDomain);
        _endpointVersion += 1;
        _lastError = null;
      });
@@ -132,11 +168,47 @@ class _PotatoMeshReaderAppState extends State<PotatoMeshReaderApp> {
    });
  }

+  String _normalizeDomain(String domain) {
+    var cleaned = domain.trim().toLowerCase();
+    if (cleaned.startsWith('https://')) cleaned = cleaned.substring(8);
+    if (cleaned.startsWith('http://')) cleaned = cleaned.substring(7);
+    if (cleaned.endsWith('/')) {
+      cleaned = cleaned.substring(0, cleaned.length - 1);
+    }
+    return cleaned;
+  }
+
+  String? _instanceNameFor(String domain) {
+    final normalized = _normalizeDomain(domain);
+    final candidates = <MeshInstance>[
+      ..._repository.instances,
+      if (_bootstrapResult != null) ..._bootstrapResult!.instances,
+    ];
+    for (final instance in candidates) {
+      if (_normalizeDomain(instance.domain) == normalized) {
+        return instance.displayName;
+      }
+    }
+    return null;
+  }
+
+  Future<List<MeshInstance>> _loadInstances({bool refresh = false}) async {
+    if (!refresh && _repository.instances.isNotEmpty) {
+      return _repository.instances;
+    }
+    final instances = await widget.instanceFetcher();
+    await _repository.updateInstances(instances);
+    return instances;
+  }
+
  Future<void> _handleEndpointChanged(String newDomain) async {
    if (newDomain.isEmpty || newDomain == _endpointDomain) {
      return;
    }

+    final previousDomain = _endpointDomain;
+    final previousSelectedDomain = _repository.selectedDomain;
+    await _repository.rememberSelectedDomain(newDomain);
    final future = _repository
        .loadDomainData(
          domain: newDomain,
@@ -154,6 +226,10 @@ class _PotatoMeshReaderAppState extends State<PotatoMeshReaderApp> {

    setState(() {
      _bootstrapFuture = future;
+      _endpointDomain = newDomain;
+      _hasUserSelectedInstance = true;
+      _endpointVersion += 1;
+      _lastError = null;
    });

    try {
@@ -162,14 +238,18 @@ class _PotatoMeshReaderAppState extends State<PotatoMeshReaderApp> {
      setState(() {
        _bootstrapResult = result;
        _endpointDomain = result.selectedDomain;
-        _endpointVersion += 1;
+        _hasUserSelectedInstance = true;
        _lastError = null;
      });
    } catch (error) {
      if (!mounted) return;
      setState(() {
        _lastError = error;
+        _endpointDomain = previousDomain;
+        _hasUserSelectedInstance = _normalizeDomain(previousDomain) !=
+            _normalizeDomain(widget.initialDomain);
      });
+      await _repository.rememberSelectedDomain(previousSelectedDomain);
      _messengerKey.currentState?.showSnackBar(
        SnackBar(content: Text('Failed to switch instance: $error')),
      );
@@ -213,8 +293,7 @@ class _PotatoMeshReaderAppState extends State<PotatoMeshReaderApp> {
        future: _bootstrapFuture,
        builder: (context, snapshot) {
          final effectiveResult = snapshot.data ?? _bootstrapResult;
-          if (snapshot.connectionState != ConnectionState.done ||
-              effectiveResult == null) {
+          if (effectiveResult == null) {
            return LoadingScreen(
              progress: _progress,
              error: _lastError ?? snapshot.error,
@@ -224,13 +303,21 @@ class _PotatoMeshReaderAppState extends State<PotatoMeshReaderApp> {
          final domain = _repository.selectedDomain.isNotEmpty
              ? _repository.selectedDomain
              : effectiveResult.selectedDomain;
+          final instanceName = _hasUserSelectedInstance
+              ? _instanceNameFor(domain) ?? domain
+              : null;
+          final initialMessages = (effectiveResult.selectedDomain == domain)
+              ? effectiveResult.messages
+              : const <MeshMessage>[];
          return MessagesScreen(
            key: ValueKey<String>(domain),
            fetcher: _fetchMessagesForCurrentDomain,
            resetToken: _endpointVersion,
            domain: domain,
            repository: _repository,
-            initialMessages: effectiveResult.messages,
+            instanceName: instanceName,
+            enableAutoRefresh: widget.enableAutoRefresh,
+            initialMessages: initialMessages,
            onOpenSettings: (context) {
              Navigator.of(context).push(
                MaterialPageRoute(
@@ -239,12 +326,8 @@ class _PotatoMeshReaderAppState extends State<PotatoMeshReaderApp> {
                        ? _repository.selectedDomain
                        : domain,
                    onDomainChanged: _handleEndpointChanged,
-                    loadInstances: () async {
-                      if (_repository.instances.isNotEmpty) {
-                        return _repository.instances;
-                      }
-                      return widget.instanceFetcher();
-                    },
+                    loadInstances: ({bool refresh = false}) =>
+                        _loadInstances(refresh: refresh),
                  ),
                ),
              );
@@ -469,6 +552,7 @@ class MeshRepository implements MeshNodeResolver {
  final Map<String, List<MeshNode>> _nodesByDomain = {};
  final Map<String, List<MeshMessage>> _messagesByDomain = {};
  final Map<String, bool> _messagesLoaded = {};
+  final Map<String, Set<String>> _nodeFetchInFlight = {};
  List<MeshInstance> _instances = const [];
  String _selectedDomain = 'potatomesh.net';

@@ -482,15 +566,24 @@ class MeshRepository implements MeshNodeResolver {
    return _store!;
  }

+  /// Persist the selected domain choice without performing network calls.
+  Future<void> rememberSelectedDomain(String domain) async {
+    _selectedDomain = _domainKey(domain);
+    final store = await _ensureStore();
+    await store.saveSelectedDomain(_selectedDomain);
+  }
+
  String _domainKey(String domain) {
    var cleaned = domain.trim();
+    if (cleaned.isEmpty) return 'potatomesh.net';
+    cleaned = cleaned.toLowerCase();
    if (cleaned.startsWith('https://')) cleaned = cleaned.substring(8);
    if (cleaned.startsWith('http://')) cleaned = cleaned.substring(7);
    if (cleaned.endsWith('/')) {
      cleaned = cleaned.substring(0, cleaned.length - 1);
    }
    if (cleaned.isEmpty) return 'potatomesh.net';
-    return cleaned.toLowerCase();
+    return cleaned;
  }

  /// Kicks off the full bootstrap flow including federation discovery, node
@@ -704,6 +797,13 @@ class MeshRepository implements MeshNodeResolver {
    }
  }

+  /// Overwrites the cached instances and persists them to local storage.
+  Future<void> updateInstances(List<MeshInstance> instances) async {
+    _instances = instances;
+    final store = await _ensureStore();
+    await store.saveInstances(instances);
+  }
+
  @override
  MeshNode? findNode(String domain, String nodeId) {
    final key = _domainKey(domain);
@@ -729,12 +829,12 @@ class MeshRepository implements MeshNodeResolver {
    Future<void> enqueueFromDomain(String domain) async {
      try {
        final uri = _buildInstancesUri(domain);
+        _logHttp('GET $uri');
        final resp = await client.get(uri).timeout(_requestTimeout);
+        _logHttp('HTTP ${resp.statusCode} $uri');
        if (resp.statusCode != 200) return;
-        final dynamic decoded = jsonDecode(resp.body);
-        if (decoded is! List) return;
+        final decoded = await _decodeJsonList(resp.body);
        final parsed = decoded
-            .whereType<Map<String, dynamic>>()
            .map(MeshInstance.fromJson)
            .where((instance) => instance.domain.isNotEmpty)
            .toList();
@@ -895,17 +995,16 @@ class MeshRepository implements MeshNodeResolver {
      return _nodesByDomain[key]!;
    }
    final uri = _buildNodesUri(domain, limit: limit);
+    _logHttp('GET $uri');
    final resp = await client.get(uri).timeout(_requestTimeout);
+    _logHttp('HTTP ${resp.statusCode} $uri');
    if (resp.statusCode != 200) {
      throw Exception('HTTP ${resp.statusCode}: ${resp.body}');
    }
-    final dynamic decoded = jsonDecode(resp.body);
-    if (decoded is! List) {
-      throw Exception('Unexpected nodes response, expected JSON array');
-    }
+    final decoded = await _decodeJsonList(resp.body);
    final nodes = <MeshNode>[];
    var index = 0;
-    for (final entry in decoded.whereType<Map<String, dynamic>>()) {
+    for (final entry in decoded) {
      index += 1;
      final node = MeshNode.fromJson(entry);
      if (node.nodeId.isEmpty) continue;
@@ -941,18 +1040,17 @@ class MeshRepository implements MeshNodeResolver {
    final limit = initialFetch ? 1000 : 100;

    final uri = _buildMessagesUri(domain, limit: limit);
+    _logHttp('GET $uri');
    final resp = await client.get(uri).timeout(_requestTimeout);
+    _logHttp('HTTP ${resp.statusCode} $uri');
    if (resp.statusCode != 200) {
      throw Exception('HTTP ${resp.statusCode}: ${resp.body}');
    }
-    final dynamic decoded = jsonDecode(resp.body);
-    if (decoded is! List) {
-      throw Exception('Unexpected response shape, expected JSON array');
-    }
+    final decoded = await _decodeJsonList(resp.body);

    final messages = <MeshMessage>[];
    var index = 0;
-    for (final entry in decoded.whereType<Map<String, dynamic>>()) {
+    for (final entry in decoded) {
      index += 1;
      final message = MeshMessage.fromJson(entry);
      messages.add(message);
@@ -1004,29 +1102,43 @@ class MeshRepository implements MeshNodeResolver {
    required List<MeshMessage> messages,
    required http.Client client,
  }) async {
+    final store = await _ensureStore();
    final key = _domainKey(domain);
    var nodes = List<MeshNode>.from(_nodesByDomain[key] ?? const []);
+    if (nodes.isEmpty) {
+      final cached = store.loadNodes(domain);
+      if (cached.isNotEmpty) {
+        nodes = List<MeshNode>.from(cached);
+        _nodesByDomain[key] = nodes;
+        NodeShortNameCache.instance.prime(domain: domain, nodes: cached);
+      }
+    }
    final knownIds = nodes.map((n) => _normalizeNodeId(n.nodeId)).toSet();
+    final inFlight = _nodeFetchInFlight.putIfAbsent(key, () => {});
    for (final message in messages) {
      final rawNodeId = message.lookupNodeId.trim();
      final nodeId = _normalizeNodeId(rawNodeId);
      if (nodeId.isEmpty || knownIds.contains(nodeId)) continue;
+      if (inFlight.contains(nodeId)) continue;
+      inFlight.add(nodeId);
      try {
        final uri = _buildNodeUri(domain, rawNodeId);
-        final resp = await client.get(uri);
+        _logHttp('GET $uri');
+        final resp = await client.get(uri).timeout(_requestTimeout);
+        _logHttp('HTTP ${resp.statusCode} $uri');
        if (resp.statusCode != 200) continue;
-        final dynamic decoded = jsonDecode(resp.body);
-        if (decoded is Map<String, dynamic>) {
-          final node = MeshNode.fromJson(decoded);
-          if (node.nodeId.isEmpty) continue;
-          nodes = List<MeshNode>.from(nodes)..add(node);
-          _nodesByDomain[key] = nodes;
-          NodeShortNameCache.instance.prime(domain: domain, nodes: [node]);
-          await _store?.saveNodes(domain, nodes);
-          knownIds.add(_normalizeNodeId(node.nodeId));
-        }
+        final decoded = await _decodeJsonMap(resp.body);
+        final node = MeshNode.fromJson(decoded);
+        if (node.nodeId.isEmpty) continue;
+        nodes = List<MeshNode>.from(nodes)..add(node);
+        _nodesByDomain[key] = nodes;
+        NodeShortNameCache.instance.prime(domain: domain, nodes: [node]);
+        await _store?.saveNodes(domain, nodes);
+        knownIds.add(_normalizeNodeId(node.nodeId));
      } catch (_) {
        // Swallow node lookup errors during refresh.
+      } finally {
+        inFlight.remove(nodeId);
      }
    }
  }
@@ -1052,6 +1164,8 @@ class MessagesScreen extends StatefulWidget {
    required this.domain,
    this.repository,
    this.initialMessages = const [],
+    this.instanceName,
+    this.enableAutoRefresh = true,
  });

  /// Fetch function used to load messages from the PotatoMesh API.
@@ -1072,6 +1186,12 @@ class MessagesScreen extends StatefulWidget {
  /// Messages obtained during the bootstrap phase to avoid re-fetching.
  final List<MeshMessage> initialMessages;

+  /// Human-friendly name of the selected instance if the user picked one.
+  final String? instanceName;
+
+  /// Whether periodic background refresh is enabled.
+  final bool enableAutoRefresh;
+
  @override
  State<MessagesScreen> createState() => _MessagesScreenState();
 }
@@ -1104,7 +1224,8 @@ class _MessagesScreenState extends State<MessagesScreen>
  void didUpdateWidget(covariant MessagesScreen oldWidget) {
    super.didUpdateWidget(oldWidget);
    if (oldWidget.fetcher != widget.fetcher ||
-        oldWidget.resetToken != widget.resetToken) {
+        oldWidget.resetToken != widget.resetToken ||
+        oldWidget.enableAutoRefresh != widget.enableAutoRefresh) {
      _restartAutoRefresh();
      setState(() {
        _messages = List<MeshMessage>.from(widget.initialMessages);
@@ -1184,6 +1305,7 @@ class _MessagesScreenState extends State<MessagesScreen>
  }

  void _startAutoRefresh() {
+    if (!widget.enableAutoRefresh) return;
    _refreshTimer?.cancel();
    if (!_isForeground) return;
    _refreshTimer =
@@ -1228,6 +1350,10 @@ class _MessagesScreenState extends State<MessagesScreen>

  @override
  Widget build(BuildContext context) {
+    final titleText =
+        (widget.instanceName != null && widget.instanceName!.trim().isNotEmpty)
+            ? '🥔 ${widget.instanceName!.trim()}'
+            : '🥔 PotatoMesh Reader';
    return Scaffold(
      appBar: AppBar(
        leading: Padding(
@@ -1238,7 +1364,7 @@ class _MessagesScreenState extends State<MessagesScreen>
            semanticsLabel: 'PotatoMesh logo',
          ),
        ),
-        title: const Text('🥔 PotatoMesh Reader'),
+        title: Text(titleText),
        actions: [
          IconButton(
            tooltip: 'Refresh',
@@ -1328,6 +1454,8 @@ class ChatLine extends StatelessWidget {
    required this.domain,
  });

+  static final Map<String, double> _indentCache = {};
+
  /// Message data to render.
  final MeshMessage message;
  final String domain;
@@ -1389,11 +1517,17 @@ class ChatLine extends StatelessWidget {
  }

  double _computeIndentPixels(TextStyle baseStyle, BuildContext context) {
+    final key =
+        '${baseStyle.fontFamily}-${baseStyle.fontSize}-${baseStyle.fontWeight}-${baseStyle.fontStyle}';
+    final cached = _indentCache[key];
+    if (cached != null) return cached;
    final painter = TextPainter(
      text: TextSpan(text: ' ', style: baseStyle),
      textDirection: Directionality.of(context),
    )..layout();
-    return painter.size.width * 8;
+    final width = painter.size.width * 8;
+    _indentCache[key] = width;
+    return width;
  }

  @override
@@ -1511,7 +1645,7 @@ class SettingsScreen extends StatefulWidget {
    super.key,
    required this.currentDomain,
    required this.onDomainChanged,
-    this.loadInstances = fetchInstances,
+    this.loadInstances = _defaultInstanceLoader,
  });

  /// Currently selected endpoint domain.
@@ -1521,7 +1655,12 @@ class SettingsScreen extends StatefulWidget {
  final ValueChanged<String> onDomainChanged;

  /// Loader used to fetch federation instance metadata.
-  final Future<List<MeshInstance>> Function() loadInstances;
+  final Future<List<MeshInstance>> Function({bool refresh}) loadInstances;
+
+  static Future<List<MeshInstance>> _defaultInstanceLoader(
+      {bool refresh = false}) {
+    return fetchInstances();
+  }

  @override
  State<SettingsScreen> createState() => _SettingsScreenState();
@@ -1557,14 +1696,14 @@ class _SettingsScreenState extends State<SettingsScreen> {
    }
  }

-  Future<void> _fetchInstances() async {
+  Future<void> _fetchInstances({bool refresh = false}) async {
    setState(() {
      _loading = true;
      _error = null;
    });

    try {
-      final fetched = await widget.loadInstances();
+      final fetched = await widget.loadInstances(refresh: refresh);
      if (!mounted) return;
      setState(() {
        _instances = fetched;
@@ -1674,18 +1813,33 @@ class _SettingsScreenState extends State<SettingsScreen> {
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
-                DropdownButtonFormField<String>(
-                  key: ValueKey<String>(_selectedDomain),
-                  initialValue: _selectedDomain.isNotEmpty
-                      ? _selectedDomain
-                      : _defaultDomain,
-                  isExpanded: true,
-                  decoration: const InputDecoration(
-                    labelText: 'Select endpoint',
-                    border: OutlineInputBorder(),
-                  ),
-                  items: endpointItems,
-                  onChanged: _loading ? null : _onEndpointChanged,
+                Row(
+                  crossAxisAlignment: CrossAxisAlignment.start,
+                  children: [
+                    Expanded(
+                      child: DropdownButtonFormField<String>(
+                        key: ValueKey<String>(_selectedDomain),
+                        initialValue: _selectedDomain.isNotEmpty
+                            ? _selectedDomain
+                            : _defaultDomain,
+                        isExpanded: true,
+                        decoration: const InputDecoration(
+                          labelText: 'Select endpoint',
+                          border: OutlineInputBorder(),
+                        ),
+                        items: endpointItems,
+                        onChanged: _loading ? null : _onEndpointChanged,
+                      ),
+                    ),
+                    const SizedBox(width: 8),
+                    IconButton(
+                      tooltip: 'Refresh instances',
+                      icon: const Icon(Icons.refresh),
+                      onPressed: _loading
+                          ? null
+                          : () => _fetchInstances(refresh: true),
+                    ),
+                  ],
                ),
                const SizedBox(height: 8),
                if (_loading)
@@ -1719,7 +1873,7 @@ class _SettingsScreenState extends State<SettingsScreen> {
              }
              return ListTile(
                leading: const Icon(Icons.storage),
-                title: const Text('PotatoMesh Info'),
+                title: const Text('Instance'),
                subtitle: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
@@ -2197,11 +2351,13 @@ Future<List<MeshMessage>> fetchMessages({
  int limit = 1000,
 }) async {
  final uri = _buildMessagesUri(domain, limit: limit);
+  _logHttp('GET $uri');

  final httpClient = client ?? http.Client();
  final shouldClose = client == null;

  final resp = await httpClient.get(uri).timeout(_requestTimeout);
+  _logHttp('HTTP ${resp.statusCode} $uri');
  if (shouldClose) {
    httpClient.close();
  }
@@ -2209,15 +2365,8 @@ Future<List<MeshMessage>> fetchMessages({
    throw Exception('HTTP ${resp.statusCode}: ${resp.body}');
  }

-  final dynamic decoded = jsonDecode(resp.body);
-  if (decoded is! List) {
-    throw Exception('Unexpected response shape, expected JSON array');
-  }
-
-  final msgs = decoded
-      .whereType<Map<String, dynamic>>()
-      .map((m) => MeshMessage.fromJson(m))
-      .toList();
+  final decoded = await _decodeJsonList(resp.body);
+  final msgs = decoded.map(MeshMessage.fromJson).toList();

  return sortMessagesByRxTime(msgs);
 }
@@ -2232,6 +2381,7 @@ class NodeShortNameCache {
  MeshNodeResolver? _resolver;
  final Map<String, Future<String>> _cache = {};
  final Map<String, Map<String, String>> _primedShortNames = {};
+  bool _allowRemoteLookups = true;

  /// Registers a resolver that can supply locally cached node metadata.
  void registerResolver(MeshNodeResolver resolver) {
@@ -2244,6 +2394,11 @@ class NodeShortNameCache {
    _primedShortNames.clear();
  }

+  /// Enables or disables remote lookups for short names.
+  set allowRemoteLookups(bool enabled) {
+    _allowRemoteLookups = enabled;
+  }
+
  /// Seeds the cache with a batch of node metadata to avoid network calls.
  void prime({required String domain, required Iterable<MeshNode> nodes}) {
    final key = domain.trim();
@@ -2265,6 +2420,7 @@ class NodeShortNameCache {
    final trimmedId = nodeId.trim();
    final fallback = fallbackShortName(trimmedId);
    if (trimmedId.isEmpty) return Future.value(fallback);
+    if (!_allowRemoteLookups) return Future.value(fallback);

    final domainKey = domain.trim();
    final primed = _primedShortNames[domainKey];
@@ -2308,18 +2464,18 @@ class NodeShortNameCache {
    final shouldClose = client == null;

    try {
+      _logHttp('GET $uri');
      final resp = await httpClient.get(uri).timeout(_requestTimeout);
+      _logHttp('HTTP ${resp.statusCode} $uri');
      if (resp.statusCode != 200) return fallback;

-      final dynamic decoded = jsonDecode(resp.body);
-      if (decoded is Map<String, dynamic>) {
-        final raw = decoded['short_name'] ?? decoded['shortName'];
-        if (raw != null) {
-          final name = raw.toString().trim();
-          if (name.isNotEmpty) {
-            _storePrimed(domain, nodeId, name);
-            return padToWidth(name);
-          }
+      final decoded = await _decodeJsonMap(resp.body);
+      final raw = decoded['short_name'] ?? decoded['shortName'];
+      if (raw != null) {
+        final name = raw.toString().trim();
+        if (name.isNotEmpty) {
+          _storePrimed(domain, nodeId, name);
+          return padToWidth(name);
        }
      }

@@ -2422,13 +2578,12 @@ class InstanceVersionCache {
    final httpClient = client ?? http.Client();
    final shouldClose = client == null;
    try {
+      _logHttp('GET $uri');
      final resp = await httpClient.get(uri).timeout(_requestTimeout);
+      _logHttp('HTTP ${resp.statusCode} $uri');
      if (resp.statusCode != 200) return null;
-      final dynamic decoded = jsonDecode(resp.body);
-      if (decoded is Map<String, dynamic>) {
-        return InstanceVersion.fromJson(decoded);
-      }
-      return null;
+      final decoded = await _decodeJsonMap(resp.body);
+      return InstanceVersion.fromJson(decoded);
    } catch (_) {
      return null;
    } finally {
@@ -268,10 +268,10 @@ packages:
    dependency: "direct main"
    description:
      name: package_info_plus
-      sha256: "16eee997588c60225bda0488b6dcfac69280a6b7a3cf02c741895dd370a02968"
+      sha256: f69da0d3189a4b4ceaeb1a3defb0f329b3b352517f52bed4290f83d4f06bc08d
      url: "https://pub.dev"
    source: hosted
-    version: "8.3.1"
+    version: "9.0.0"
  package_info_plus_platform_interface:
    dependency: transitive
    description:
@@ -10,7 +10,7 @@ dependencies:
  flutter:
    sdk: flutter
  http: ^1.2.0
-  package_info_plus: ^8.1.0
+  package_info_plus: ^9.0.0
  flutter_svg: ^2.0.10+1
  url_launcher: ^6.3.1
  shared_preferences: ^2.3.2
@@ -0,0 +1,30 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+export GIT_TAG="$(git describe --tags --abbrev=0)"
+export GIT_COMMITS="$(git rev-list --count ${GIT_TAG}..HEAD)"
+export GIT_SHA="$(git rev-parse --short=9 HEAD)"
+export GIT_DIRTY="$(git diff --quiet --ignore-submodules HEAD || echo true || echo false)"
+flutter clean
+flutter pub get
+flutter build apk --release \
+  --dart-define=GIT_TAG="${GIT_TAG}" \
+  --dart-define=GIT_COMMITS="${GIT_COMMITS}" \
+  --dart-define=GIT_SHA="${GIT_SHA}" \
+  --dart-define=GIT_DIRTY="${GIT_DIRTY}"
+
+if [ "$GIT_COMMITS" -eq 0 ]; then
+    TAG_NAME="$GIT_TAG"
+else
+    TAG_NAME="${GIT_TAG}+${GIT_COMMITS}.g${GIT_SHA}"
+fi
+
+if [ "$GIT_DIRTY" = "true" ]; then
+    TAG_NAME="${TAG_NAME}.dirty"
+fi
+
+export APK_DIR="build/app/outputs/flutter-apk"
+mv -v "${APK_DIR}/app-release.apk" "${APK_DIR}/potatomesh-reader-android-${TAG_NAME}.apk"
+(cd "${APK_DIR}" && sha256sum "potatomesh-reader-android-${TAG_NAME}.apk" > "potatomesh-reader-android-${TAG_NAME}.apk.sha256sum")
+
@@ -327,4 +327,57 @@ void main() {
    expect(result.selectedDomain, 'cached.mesh');
    expect(result.messages.single.text, 'cached');
  });
+
+  test('loadMessages prefers cached nodes over remote lookups', () async {
+    final savedNodes = jsonEncode([
+      {'node_id': '!a', 'short_name': 'A', 'last_heard': 0}
+    ]);
+    SharedPreferences.setMockInitialValues({
+      'mesh.nodes.potatomesh.net': savedNodes,
+    });
+
+    var nodeDetailHits = 0;
+    final client = MockClient((request) async {
+      if (request.url.path == '/api/messages') {
+        return http.Response(
+          jsonEncode([
+            {
+              'id': 1,
+              'rx_iso': '2024-01-01T00:00:00Z',
+              'from_id': '!a',
+              'to_id': '^',
+              'channel': 1,
+              'portnum': 'TEXT',
+              'text': 'cached node'
+            }
+          ]),
+          200,
+        );
+      }
+      if (request.url.path.startsWith('/api/nodes/')) {
+        nodeDetailHits += 1;
+        return http.Response(
+          jsonEncode({'node_id': '!a', 'short_name': 'A', 'last_heard': 0}),
+          200,
+        );
+      }
+      return http.Response('[]', 200);
+    });
+
+    final repository = MeshRepository(client: client);
+    final messages = await repository.loadMessages(domain: 'potatomesh.net');
+
+    expect(messages.single.text, 'cached node');
+    expect(nodeDetailHits, 0);
+  });
+
+  test('rememberSelectedDomain persists normalized choice', () async {
+    final repo = MeshRepository();
+    await repo.rememberSelectedDomain('HTTP://Example.Mesh/');
+    expect(repo.selectedDomain, 'example.mesh');
+
+    final prefs = await SharedPreferences.getInstance();
+    final store = MeshLocalStore(prefs);
+    expect(store.loadSelectedDomain(), 'example.mesh');
+  });
 }
@@ -27,6 +27,7 @@ void main() {

  setUp(() {
    SharedPreferences.setMockInitialValues({});
+    NodeShortNameCache.instance.allowRemoteLookups = false;
    NodeShortNameCache.instance.clear();
  });

@@ -69,6 +70,7 @@ void main() {
    await tester.pumpWidget(PotatoMeshReaderApp(
      fetcher: fakeFetch,
      bootstrapper: bootstrapper,
+      enableAutoRefresh: false,
    ));
    await tester.pumpAndSettle();

@@ -109,6 +111,7 @@ void main() {
        home: MessagesScreen(
          fetcher: fetcher,
          domain: 'potatomesh.net',
+          enableAutoRefresh: false,
        ),
      ),
    );
@@ -148,6 +151,7 @@ void main() {
        home: MessagesScreen(
          fetcher: () async => [],
          domain: 'potatomesh.net',
+          enableAutoRefresh: false,
        ),
      ),
    );
@@ -162,13 +166,14 @@ void main() {
        home: MessagesScreen(
          fetcher: () async => [],
          domain: 'potatomesh.net',
+          enableAutoRefresh: false,
          onOpenSettings: (context) {
            Navigator.of(context).push(
              MaterialPageRoute(
                builder: (_) => SettingsScreen(
                  currentDomain: 'potatomesh.net',
                  onDomainChanged: (_) {},
-                  loadInstances: () async => const [],
+                  loadInstances: ({bool refresh = false}) async => const [],
                ),
              ),
            );
@@ -214,7 +219,7 @@ void main() {
      ];
    }

-    Future<List<MeshInstance>> loader() async => const [
+    Future<List<MeshInstance>> loader({bool refresh = false}) async => const [
          MeshInstance(name: 'Mesh Berlin', domain: 'berlin.mesh'),
        ];

@@ -232,11 +237,15 @@ void main() {
      return http.Response('[]', 200);
    });

+    final repository = MeshRepository(client: mockClient);
+
    Future<BootstrapResult> bootstrapper({ProgressCallback? onProgress}) async {
      onProgress?.call(const BootstrapProgress(stage: 'loading instances'));
      final initialMessages = await fetcher(domain: 'potatomesh.net');
+      final instances = await loader();
+      await repository.updateInstances(instances);
      return BootstrapResult(
-        instances: const [],
+        instances: instances,
        nodes: const [],
        messages: initialMessages,
        selectedDomain: 'potatomesh.net',
@@ -248,7 +257,8 @@ void main() {
        fetcher: fetcher,
        instanceFetcher: ({http.Client? client}) => loader(),
        bootstrapper: bootstrapper,
-        repository: MeshRepository(client: mockClient),
+        repository: repository,
+        enableAutoRefresh: false,
      ),
    );
    await tester.pumpAndSettle();
@@ -263,10 +273,17 @@ void main() {
    await tester.tap(find.text('Mesh Berlin').last);
    await tester.pumpAndSettle();
    await tester.pageBack();
-    await tester.pumpAndSettle(const Duration(seconds: 1));
+    final messagesFinder = find.byType(MessagesScreen);
+    for (var i = 0; i < 10 && messagesFinder.evaluate().isEmpty; i++) {
+      await tester.pump(const Duration(milliseconds: 100));
+    }

+    expect(messagesFinder, findsOneWidget);
+    expect(repository.selectedDomain, 'berlin.mesh');
    expect(calls.contains('berlin.mesh'), isTrue);
    expect(find.text('berlin.mesh'), findsOneWidget);
+    expect(find.text('potatomesh.net'), findsNothing);
+    expect(find.text('🥔 Mesh Berlin'), findsOneWidget);
  });

  testWidgets('ChatLine renders placeholders and nick colour', (tester) async {
@@ -25,7 +25,7 @@ void main() {
  testWidgets('SettingsScreen lists instances and updates selection',
      (tester) async {
    final selections = <String>[];
-    Future<List<MeshInstance>> loader() async => const [
+    Future<List<MeshInstance>> loader({bool refresh = false}) async => const [
          MeshInstance(name: 'Mesh Dresden', domain: 'map.meshdresden.eu'),
          MeshInstance(name: 'Mesh Berlin', domain: 'berlin.mesh'),
        ];
@@ -53,7 +53,8 @@ void main() {
  });

  testWidgets('SettingsScreen surfaces load errors', (tester) async {
-    Future<List<MeshInstance>> loader() => Future.error(StateError('boom'));
+    Future<List<MeshInstance>> loader({bool refresh = false}) =>
+        Future.error(StateError('boom'));

    await tester.pumpWidget(
      MaterialApp(
@@ -69,4 +70,34 @@ void main() {

    expect(find.textContaining('Failed to load instances'), findsOneWidget);
  });
+
+  testWidgets('SettingsScreen refresh button refetches instances',
+      (tester) async {
+    final refreshCalls = <bool>[];
+    Future<List<MeshInstance>> loader({bool refresh = false}) async {
+      refreshCalls.add(refresh);
+      return const [
+        MeshInstance(name: 'Mesh Berlin', domain: 'berlin.mesh'),
+      ];
+    }
+
+    await tester.pumpWidget(
+      MaterialApp(
+        home: SettingsScreen(
+          currentDomain: 'potatomesh.net',
+          onDomainChanged: (_) {},
+          loadInstances: loader,
+        ),
+      ),
+    );
+
+    await tester.pumpAndSettle();
+    expect(refreshCalls, [false]);
+
+    await tester.tap(find.byIcon(Icons.refresh));
+    await tester.pumpAndSettle();
+
+    expect(refreshCalls, contains(true));
+    expect(refreshCalls.length, greaterThanOrEqualTo(2));
+  });
 }