feat(service): Rework the blocklist service

Maybe fixes #14.

lib/data_classes.yaml

@@ -106,6 +106,13 @@ files:
         extends: BackgroundEvent
         implements:
           - JsonImplementation
+      # Triggered in response to a [GetBlocklistCommand]
+      - name: GetBlocklistResultEvent
+        extends: BackgroundEvent
+        implements:
+          - JsonImplementation
+        attributes:
+          entries: List<String>
       # Triggered by DownloadService or UploadService.
       - name: ProgressEvent
         extends: BackgroundEvent
@@ -527,6 +534,11 @@ files:
           stickerPack:
             type: StickerPack
             deserialise: true
+      - name: GetBlocklistCommand
+        extends: BackgroundCommand
+        implements:
+          - JsonImplementation
+        attributes:
     generate_builder: true
     # get${builder_Name}FromJson
     builder_name: "Command"

lib/service/blocking.dart

@@ -1,5 +1,8 @@
+import 'dart:async';
 import 'package:get_it/get_it.dart';
+import 'package:logging/logging.dart';
 import 'package:moxxmpp/moxxmpp.dart';
+import 'package:moxxyv2/service/database/database.dart';
 import 'package:moxxyv2/service/service.dart';
 import 'package:moxxyv2/shared/events.dart';
 
@@ -9,35 +12,93 @@ enum BlockPushType {
 }
 
 class BlocklistService {
-  
-  BlocklistService() :
-    _blocklistCache = List.empty(growable: true),
-    _requestedBlocklist = false;
-  final List<String> _blocklistCache;
-  bool _requestedBlocklist;
+  BlocklistService();
+  List<String>? _blocklist;
+  bool _requested = false;
+  bool? _supported;
+  final Logger _log = Logger('BlocklistService');
 
-  Future<List<String>> _requestBlocklist() async {
-    final manager = GetIt.I.get<XmppConnection>().getManagerById<BlockingManager>(blockingManager)!;
-    _blocklistCache
-      ..clear()
-      ..addAll(await manager.getBlocklist());
-    _requestedBlocklist = true;
-    return _blocklistCache;
+  void onNewConnection() {
+    // Invalidate the caches
+    _blocklist = null;
+    _requested = false;
+    _supported = null;
+  }
+
+  Future<bool> _checkSupport() async {
+    return _supported ??= await GetIt.I.get<XmppConnection>()
+      .getManagerById<BlockingManager>(blockingManager)!
+      .isSupported();
+  }
+  
+  Future<void> _requestBlocklist() async {
+    assert(_blocklist != null, 'The blocklist must be loaded from the database before requesting');
+
+    // Check if blocking is supported
+    if (!(await _checkSupport())) {
+      _log.warning('Blocklist requested but server does not support it.');
+      return;
+    }
+    
+    final blocklist = await GetIt.I.get<XmppConnection>()
+      .getManagerById<BlockingManager>(blockingManager)!
+      .getBlocklist();
+
+    // Diff the received blocklist with the cache
+    final newItems = List<String>.empty(growable: true);
+    final removedItems = List<String>.empty(growable: true);
+    final db = GetIt.I.get<DatabaseService>();
+    for (final item in blocklist) {
+      if (!_blocklist!.contains(item)) {
+        await db.addBlocklistEntry(item);
+        _blocklist!.add(item);
+        newItems.add(item);
+      }
+    }
+
+    // Diff the cache with the received blocklist
+    for (final item in _blocklist!) {
+      if (!blocklist.contains(item)) {
+        await db.removeBlocklistEntry(item);
+        _blocklist!.remove(item);
+        removedItems.add(item);
+      }
+    }
+      
+    _requested = true;
+
+    // Trigger an UI event if we have anything to tell the UI
+    if (newItems.isNotEmpty || removedItems.isNotEmpty) {
+      sendEvent(
+        BlocklistPushEvent(
+          added: newItems,
+          removed: removedItems,
+        ),
+      );
+    }
   }
     
   /// Returns the blocklist from the database
   Future<List<String>> getBlocklist() async {
-    if (!_requestedBlocklist) {
-      _blocklistCache
-        ..clear()
-        ..addAll(await _requestBlocklist());
+    if (_blocklist == null) {
+      _blocklist = await GetIt.I.get<DatabaseService>().getBlocklistEntries();
+
+      if (!_requested) {
+        unawaited(_requestBlocklist());
+      }
+
+      return _blocklist!;
     }
-   
-    return _blocklistCache;
+
+    if (!_requested) {
+      unawaited(_requestBlocklist());
+    }
+
+    return _blocklist!;
   }
 
   void onUnblockAllPush() {
-    _blocklistCache.clear();
+    _blocklist = List<String>.empty(growable: true);
     sendEvent(
       BlocklistUnblockAllEvent(),
     );
@@ -45,21 +106,25 @@ class BlocklistService {
   
   Future<void> onBlocklistPush(BlockPushType type, List<String> items) async {
     // We will fetch it later when getBlocklist is called
-    if (!_requestedBlocklist) return;
+    if (!_requested) return;
 
     final newBlocks = List<String>.empty(growable: true);
     final removedBlocks = List<String>.empty(growable: true);
     for (final item in items) {
       switch (type) {
         case BlockPushType.block: {
-          if (_blocklistCache.contains(item)) continue;
-          _blocklistCache.add(item);
+          if (_blocklist!.contains(item)) continue;
+          _blocklist!.add(item);
           newBlocks.add(item);
+
+          await GetIt.I.get<DatabaseService>().addBlocklistEntry(item);
         }
         break;
         case BlockPushType.unblock: {
-          _blocklistCache.removeWhere((i) => i == item);
+          _blocklist!.removeWhere((i) => i == item);
           removedBlocks.add(item);
+
+          await GetIt.I.get<DatabaseService>().removeBlocklistEntry(item);
         }
         break;
       }
@@ -74,17 +139,47 @@ class BlocklistService {
   }
 
   Future<bool> blockJid(String jid) async {
-    final manager = GetIt.I.get<XmppConnection>().getManagerById<BlockingManager>(blockingManager)!;
-    return manager.block([ jid ]);
+    // Check if blocking is supported
+    if (!(await _checkSupport())) {
+      _log.warning('Blocking $jid requested but server does not support it.');
+      return false;
+    }
+
+    _blocklist!.add(jid);
+    await GetIt.I.get<DatabaseService>()
+      .addBlocklistEntry(jid);
+    return GetIt.I.get<XmppConnection>()
+      .getManagerById<BlockingManager>(blockingManager)!
+      .block([jid]);
   }
 
   Future<bool> unblockJid(String jid) async {
-    final manager = GetIt.I.get<XmppConnection>().getManagerById<BlockingManager>(blockingManager)!;
-    return manager.unblock([ jid ]);
+    // Check if blocking is supported
+    if (!(await _checkSupport())) {
+      _log.warning('Unblocking $jid requested but server does not support it.');
+      return false;
+    }
+
+    _blocklist!.remove(jid);
+    await GetIt.I.get<DatabaseService>()
+      .removeBlocklistEntry(jid);
+    return GetIt.I.get<XmppConnection>()
+      .getManagerById<BlockingManager>(blockingManager)!
+      .unblock([jid]);
   }
 
   Future<bool> unblockAll() async {
-    final manager = GetIt.I.get<XmppConnection>().getManagerById<BlockingManager>(blockingManager)!;
-    return manager.unblockAll();
+    // Check if blocking is supported
+    if (!(await _checkSupport())) {
+      _log.warning('Unblocking all JIDs requested but server does not support it.');
+      return false;
+    }
+
+    _blocklist!.clear();
+    await GetIt.I.get<DatabaseService>()
+      .removeAllBlocklistEntries();
+    return GetIt.I.get<XmppConnection>()
+      .getManagerById<BlockingManager>(blockingManager)!
+      .unblockAll();
   }
 }

lib/service/database/constants.dart

@@ -14,6 +14,7 @@ const xmppStateTable = 'XmppState';
 const contactsTable = 'Contacts';
 const stickersTable = 'Stickers';
 const stickerPacksTable = 'StickerPacks';
+const blocklistTable = 'Blocklist';
 
 const typeString = 0;
 const typeInt = 1;

lib/service/database/creation.dart

@@ -158,6 +158,15 @@ Future<void> createDatabase(Database db, int version) async {
       restricted     INTEGER NOT NULL
     )''',
   );
+
+  // Blocklist
+  await db.execute(
+    '''
+    CREATE TABLE $blocklistTable (
+      jid TEXT PRIMARY KEY
+    );
+    ''',
+  );
   
   // OMEMO
   await db.execute(

lib/service/database/database.dart

@@ -8,6 +8,7 @@ import 'package:moxxmpp/moxxmpp.dart';
 import 'package:moxxyv2/service/database/constants.dart';
 import 'package:moxxyv2/service/database/creation.dart';
 import 'package:moxxyv2/service/database/helpers.dart';
+import 'package:moxxyv2/service/database/migrations/0000_blocklist.dart';
 import 'package:moxxyv2/service/database/migrations/0000_contacts_integration.dart';
 import 'package:moxxyv2/service/database/migrations/0000_contacts_integration_avatar.dart';
 import 'package:moxxyv2/service/database/migrations/0000_contacts_integration_pseudo.dart';
@@ -79,7 +80,7 @@ class DatabaseService {
     _db = await openDatabase(
       dbPath,
       password: key,
-      version: 22,
+      version: 23,
       onCreate: createDatabase,
       onConfigure: (db) async {
         // In order to do schema changes during database upgrades, we disable foreign
@@ -176,6 +177,10 @@ class DatabaseService {
           _log.finest('Running migration for database version 22');
           await upgradeFromV21ToV22(db);
         }
+        if (oldVersion < 23) {
+          _log.finest('Running migration for database version 23');
+          await upgradeFromV22ToV23(db);
+        }
       },
     );
 
@@ -1257,4 +1262,35 @@ class DatabaseService {
         .toList(),
     );
   }
+
+  Future<void> addBlocklistEntry(String jid) async {
+    await _db.insert(
+      blocklistTable,
+      {
+        'jid': jid,
+      },
+    );
+  }
+
+  Future<void> removeBlocklistEntry(String jid) async {
+    await _db.delete(
+      blocklistTable,
+      where: 'jid = ?',
+      whereArgs: [jid],
+    );
+  }
+
+  Future<void> removeAllBlocklistEntries() async {
+    await _db.delete(
+      blocklistTable,
+    );
+  }
+
+  Future<List<String>> getBlocklistEntries() async {
+    final result = await _db.query(blocklistTable);
+
+    return result
+      .map((m) => m['jid']! as String)
+      .toList();
+  }
 }

lib/service/database/migrations/0000_blocklist.dart

@@ -0,0 +1,13 @@
+import 'package:moxxyv2/service/database/constants.dart';
+import 'package:moxxyv2/shared/models/preference.dart';
+import 'package:sqflite_sqlcipher/sqflite.dart';
+
+Future<void> upgradeFromV22ToV23(Database db) async {
+  await db.execute(
+    '''
+    CREATE TABLE $blocklistTable (
+      jid TEXT PRIMARY KEY
+    );
+    ''',
+  );
+}

lib/service/events.dart

@@ -79,6 +79,7 @@ void setupBackgroundEventHandler() {
       EventTypeMatcher<RemoveStickerPackCommand>(performRemoveStickerPack),
       EventTypeMatcher<FetchStickerPackCommand>(performFetchStickerPack),
       EventTypeMatcher<InstallStickerPackCommand>(performStickerPackInstall),
+      EventTypeMatcher<GetBlocklistCommand>(performGetBlocklist),
   ]);
 
   GetIt.I.registerSingleton<EventHandler>(handler);
@@ -890,3 +891,15 @@ Future<void> performStickerPackInstall(InstallStickerPackCommand command, { dyna
     );
   }
 }
+
+Future<void> performGetBlocklist(GetBlocklistCommand command, { dynamic extra }) async {
+  final id = extra as String;
+
+  final result = await GetIt.I.get<BlocklistService>().getBlocklist();
+  sendEvent(
+    GetBlocklistResultEvent(
+      entries: result,
+    ),
+    id: id,
+  );
+}

lib/service/httpfiletransfer/httpfiletransfer.dart

@@ -361,7 +361,7 @@ class HttpFileTransferService {
     // Prepare file and completer.
     final file = await File(downloadedPath).create();
     final fileSink = file.openWrite(mode: FileMode.writeOnlyAppend);
-    final downloadCompleter = Completer();
+    final downloadCompleter = Completer<void>();
 
     dio.Response<dio.ResponseBody>? response;
 

lib/service/xmpp.dart

@@ -665,6 +665,9 @@ class XmppService {
       unawaited(_initializeOmemoService(settings.jid.toString()));
 
       if (!event.resumed) {
+        // Reset the blocking service's cache
+        GetIt.I.get<BlocklistService>().onNewConnection();
+
         // Enable carbons
         final carbonsResult = await connection
           .getManagerById<CarbonsManager>(carbonsManager)!

lib/ui/bloc/blocklist_bloc.dart

@@ -1,7 +1,11 @@
 import 'package:bloc/bloc.dart';
 import 'package:freezed_annotation/freezed_annotation.dart';
+import 'package:get_it/get_it.dart';
 import 'package:moxplatform/moxplatform.dart';
 import 'package:moxxyv2/shared/commands.dart';
+import 'package:moxxyv2/shared/events.dart';
+import 'package:moxxyv2/ui/bloc/navigation_bloc.dart';
+import 'package:moxxyv2/ui/constants.dart';
 
 part 'blocklist_bloc.freezed.dart';
 part 'blocklist_event.dart';
@@ -9,11 +13,44 @@ part 'blocklist_state.dart';
 
 class BlocklistBloc extends Bloc<BlocklistEvent, BlocklistState> {
   BlocklistBloc() : super(BlocklistState()) {
+    on<BlocklistRequestedEvent>(_onBlocklistRequested);
     on<UnblockedJidEvent>(_onJidUnblocked);
     on<UnblockedAllEvent>(_onUnblockedAll);
     on<BlocklistPushedEvent>(_onBlocklistPushed);
   }
 
+  Future<void> _onBlocklistRequested(BlocklistRequestedEvent event, Emitter<BlocklistState> emit) async {
+    final mustDoWork = state.blocklist.isEmpty;
+
+    if (mustDoWork) {
+      emit(
+        state.copyWith(
+          isWorking: true,
+        ),
+      );
+    }
+    
+    GetIt.I.get<NavigationBloc>().add(
+      PushedNamedEvent(
+        const NavigationDestination(blocklistRoute),
+      ),
+    );
+
+    if (state.blocklist.isEmpty) {
+      // ignore: cast_nullable_to_non_nullable
+      final result = await MoxplatformPlugin.handler.getDataSender().sendData(
+        GetBlocklistCommand(),
+      ) as GetBlocklistResultEvent;
+
+      emit(
+        state.copyWith(
+          blocklist: result.entries,
+          isWorking: false,
+        ),
+      );
+    }
+  }
+  
   Future<void> _onJidUnblocked(UnblockedJidEvent event, Emitter<BlocklistState> emit) async {
     await MoxplatformPlugin.handler.getDataSender().sendData(
       UnblockJidCommand(

lib/ui/bloc/blocklist_event.dart

@@ -2,9 +2,11 @@ part of 'blocklist_bloc.dart';
 
 abstract class BlocklistEvent {}
 
+/// Triggered when the blocklist page has been requested
+class BlocklistRequestedEvent extends BlocklistEvent {}
+
 /// Triggered when a JID is unblocked
 class UnblockedJidEvent extends BlocklistEvent {
-
   UnblockedJidEvent(this.jid);
   final String jid;
 }
@@ -16,7 +18,6 @@ class UnblockedAllEvent extends BlocklistEvent {
 
 /// Triggered when we receive a blocklist push
 class BlocklistPushedEvent extends BlocklistEvent {
-
   BlocklistPushedEvent(this.added, this.removed);
   final List<String> added;
   final List<String> removed;

lib/ui/bloc/blocklist_state.dart

@@ -4,5 +4,6 @@ part of 'blocklist_bloc.dart';
 class BlocklistState with _$BlocklistState {
   factory BlocklistState({
     @Default(<String>[]) List<String> blocklist,
+    @Default(false) bool isWorking,
   }) = _BlocklistState;
 }

lib/ui/pages/blocklist.dart

@@ -23,59 +23,74 @@ class BlocklistPage extends StatelessWidget {
   Widget _buildListView(BlocklistState state) {
     // ignore: non_bool_condition,avoid_dynamic_calls
     if (state.blocklist.isEmpty) {
-      return Padding(
-        padding: const EdgeInsets.symmetric(horizontal: paddingVeryLarge),
-        child: Column(
-          children: [
-            Padding(
-              padding: const EdgeInsets.only(top: 8),
-              child: Image.asset('assets/images/happy_news.png'),
+      return Column(
+        children: [
+          if (state.isWorking)
+            const LinearProgressIndicator(),
+
+          Padding(
+            padding: const EdgeInsets.symmetric(horizontal: paddingVeryLarge),
+            child: Column(
+              children: [
+                Padding(
+                  padding: const EdgeInsets.only(top: 8),
+                  child: Image.asset('assets/images/happy_news.png'),
+                ),
+                Padding(
+                  padding: const EdgeInsets.only(top: 8),
+                  child: Text(t.pages.blocklist.noUsersBlocked),
+                )
+              ],
             ),
-            Padding(
-              padding: const EdgeInsets.only(top: 8),
-              child: Text(t.pages.blocklist.noUsersBlocked),
-            )
-          ],
-        ),
+          ),
+        ],
       );
     }
 
-    return ListView.builder(
-      itemCount: state.blocklist.length,
-      itemBuilder: (BuildContext context, int index) {
-        // ignore: avoid_dynamic_calls
-        final jid = state.blocklist[index];
+    return Column(
+      children: [
+        if (state.isWorking)
+          const LinearProgressIndicator(),
 
-        return Padding(
-          padding: const EdgeInsets.symmetric(
-            horizontal: 32,
-            vertical: 16,
-          ),
-          child: Row(
-            children: [
-              Expanded(
-                child: Text(jid),
-              ),
-              IconButton(
-                icon: const Icon(Icons.delete),
-                color: Colors.red,
-                onPressed: () async {
-                  final result = await showConfirmationDialog(
-                    t.pages.blocklist.unblockJidConfirmTitle(jid: jid),
-                    t.pages.blocklist.unblockJidConfirmBody(jid: jid),
-                    context,
-                  );
+        ListView.builder(
+          shrinkWrap: true,
+          itemCount: state.blocklist.length,
+          itemBuilder: (BuildContext context, int index) {
+            // ignore: avoid_dynamic_calls
+            final jid = state.blocklist[index];
 
-                  if (result) {
-                    // ignore: use_build_context_synchronously
-                    context.read<BlocklistBloc>().add(UnblockedJidEvent(jid));
-                  }
-                },
+            return Padding(
+              padding: const EdgeInsets.symmetric(
+                horizontal: 32,
+                vertical: 16,
               ),
-            ],
-          ),
-        );
-      },
+              child: Row(
+                children: [
+                  Expanded(
+                    child: Text(jid),
+                  ),
+                  IconButton(
+                    icon: const Icon(Icons.delete),
+                    color: Colors.red,
+                    onPressed: () async {
+                      final result = await showConfirmationDialog(
+                        t.pages.blocklist.unblockJidConfirmTitle(jid: jid),
+                        t.pages.blocklist.unblockJidConfirmBody(jid: jid),
+                        context,
+                      );
+
+                      if (result) {
+                        // ignore: use_build_context_synchronously
+                        context.read<BlocklistBloc>().add(UnblockedJidEvent(jid));
+                      }
+                    },
+                  ),
+                ],
+              ),
+            );
+          },
+        ),
+      ],
     );
   }
 
@@ -108,6 +123,7 @@ class BlocklistPage extends StatelessWidget {
               icon: const Icon(Icons.more_vert),
               itemBuilder: (BuildContext context) => [
                 PopupMenuItem(
+                  enabled: state.blocklist.isNotEmpty,
                   value: BlocklistOptions.unblockAll,
                   child: Text(t.pages.blocklist.unblockAll),
                 ),

lib/ui/pages/settings/settings.dart

@@ -2,6 +2,7 @@ import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:get_it/get_it.dart';
 import 'package:moxxyv2/i18n/strings.g.dart';
+import 'package:moxxyv2/ui/bloc/blocklist_bloc.dart';
 import 'package:moxxyv2/ui/bloc/preferences_bloc.dart';
 import 'package:moxxyv2/ui/constants.dart';
 import 'package:moxxyv2/ui/helpers.dart';
@@ -76,7 +77,9 @@ class SettingsPage extends StatelessWidget {
               child: Icon(Icons.block),
             ),
             onTap: () {
-              Navigator.pushNamed(context, blocklistRoute);
+              GetIt.I.get<BlocklistBloc>().add(
+                BlocklistRequestedEvent(),
+              );
             },
           ),
           SettingsRow(