clean code

lib/main.dart

@@ -4,7 +4,8 @@ import 'package:twonly/src/providers/api_provider.dart';
 import 'package:twonly/src/providers/db_provider.dart';
 import 'package:flutter/material.dart';
 import 'package:logging/logging.dart';
-import 'package:twonly/src/providers/notify_provider.dart';
+import 'package:twonly/src/providers/messages_change_provider.dart';
+import 'package:twonly/src/providers/contacts_change_provider.dart';
 import 'package:twonly/src/utils/misc.dart';
 import 'src/app.dart';
 import 'src/settings/settings_controller.dart';
@@ -54,7 +55,8 @@ void main() async {
   runApp(
     MultiProvider(
       providers: [
-        ChangeNotifierProvider(create: (_) => NotifyProvider()),
+        ChangeNotifierProvider(create: (_) => MessagesChangeProvider()),
+        ChangeNotifierProvider(create: (_) => ContactChangeProvider()),
       ],
       child: MyApp(settingsController: settingsController),
     ),

lib/src/app.dart

@@ -1,7 +1,7 @@
-import 'package:fixnum/fixnum.dart';
 import 'package:provider/provider.dart';
 import 'package:twonly/main.dart';
-import 'package:twonly/src/providers/notify_provider.dart';
+import 'package:twonly/src/providers/contacts_change_provider.dart';
+import 'package:twonly/src/providers/messages_change_provider.dart';
 import 'package:twonly/src/utils/storage.dart';
 import 'package:twonly/src/views/onboarding_view.dart';
 import 'package:twonly/src/views/home_view.dart';
@@ -12,9 +12,16 @@ import 'package:flutter_localizations/flutter_localizations.dart';
 import 'dart:async';
 import 'settings/settings_controller.dart';
 
-Function(Int64) addSendingTo = (a) {};
+// these global function can be called from anywhere to update
-Function(Int64) removeSendingTo = (a) {};
+// the ui when something changed. The callbacks will be set by
-Function() updateNotifyProvider = () {};
+// MyApp widget.
+
+// this callback is called by the apiProvider
+Function(bool) globalCallbackConnectionState = (a) {};
+
+// these two callbacks are called on updated to the corresponding database
+Function globalCallBackOnContactChange = () {};
+Function(int) globalCallBackOnMessageChange = (a) {};
 
 /// The Widget that configures your application.
 class MyApp extends StatefulWidget {
@@ -28,7 +35,7 @@ class MyApp extends StatefulWidget {
 
 class _MyAppState extends State<MyApp> {
   Future<bool> _isUserCreated = isUserCreated();
-  bool _showOnboarding = true;
+  bool _showOnboarding = false;
   bool _isConnected = false;
   int redColorOpacity = 0; // Start with dark red
   bool redColorGoUp = true;
@@ -39,31 +46,38 @@ class _MyAppState extends State<MyApp> {
     super.initState();
     _startColorAnimation();
 
-    apiProvider.setConnectionStateCallback((isConnected) {
+    // init change provider to load data from the database
+    context.read<ContactChangeProvider>().update();
+    context.read<MessagesChangeProvider>().init();
+
+    // register global callbacks to the widget tree
+    globalCallbackConnectionState = (isConnected) {
       setState(() {
         _isConnected = isConnected;
       });
-    });
-    apiProvider.setUpdatedContacts(() {
-      context.read<NotifyProvider>().update();
-    });
-
-    addSendingTo = (a) {
-      context.read<NotifyProvider>().addSendingTo(a);
     };
 
-    removeSendingTo = (a) {
+    globalCallBackOnContactChange = () {
-      context.read<NotifyProvider>().removeSendingTo(a);
+      context.read<ContactChangeProvider>().update();
     };
 
-    updateNotifyProvider = () {
+    globalCallBackOnMessageChange = (userId) {
-      context.read<NotifyProvider>().update();
+      context.read<MessagesChangeProvider>().updateLastMessageFor(userId);
     };
 
-    context.read<NotifyProvider>().update();
+    // connect async to the backend api
     apiProvider.connect();
   }
 
+  @override
+  void dispose() {
+    // disable globalCallbacks to the flutter tree
+    globalCallbackConnectionState = (a) {};
+    globalCallBackOnContactChange = () {};
+    globalCallBackOnMessageChange = (a) {};
+    super.dispose();
+  }
+
   void _startColorAnimation() {
     // Change the color every second
     Future.delayed(Duration(milliseconds: 200), () {

lib/src/localization/app_en.arb

@@ -20,6 +20,8 @@
   "searchUsernameNotFound": "Username not found",
   "searchUsernameNewFollowerTitle": "Follow requests",
   "searchUsernameQrCodeBtn": "Scan QR code",
+  "chatListViewSearchUserNameBtn": "Add user",
+  "chatListViewSendFirstTwonly": "Send your first twonly!",
   "searchUsernameNotFoundLong": "\"{username}\" is not a twonly user. Please check the username and try again.",
   "errorUnknown": "An unexpected error has occurred. Please try again later.",
   "errorBadRequest": "The request could not be understood by the server due to malformed syntax. Please check your input and try again.",

lib/src/model/contacts_model.dart

@@ -2,6 +2,7 @@ import 'package:cv/cv.dart';
 import 'package:fixnum/fixnum.dart';
 import 'package:logging/logging.dart';
 import 'package:twonly/main.dart';
+import 'package:twonly/src/app.dart';
 
 class Contact {
   Contact(
@@ -98,6 +99,7 @@ class DbContacts extends CvModelBase {
       where: "$columnUserId = ?",
       whereArgs: [userId],
     );
+    globalCallBackOnContactChange();
   }
 
   static Future acceptUser(int userId) async {
@@ -111,6 +113,7 @@ class DbContacts extends CvModelBase {
       where: "$columnUserId = ?",
       whereArgs: [userId],
     );
+    globalCallBackOnContactChange();
   }
 
   static Future deleteUser(int userId) async {
@@ -119,6 +122,7 @@ class DbContacts extends CvModelBase {
       where: "$columnUserId = ?",
       whereArgs: [userId],
     );
+    globalCallBackOnContactChange();
   }
 
   static Future<bool> insertNewContact(
@@ -130,6 +134,7 @@ class DbContacts extends CvModelBase {
         DbContacts.columnUserId: userId,
         DbContacts.columnRequested: a
       });
+      globalCallBackOnContactChange();
       return true;
     } catch (e) {
       Logger("contacts_model/getUsers").shout("$e");

lib/src/model/messages_model.dart

@@ -3,6 +3,7 @@ import 'dart:convert';
 import 'package:cv/cv.dart';
 import 'package:logging/logging.dart';
 import 'package:twonly/main.dart';
+import 'package:twonly/src/app.dart';
 import 'package:twonly/src/model/json/message.dart';
 
 class DbMessage {
@@ -13,7 +14,8 @@ class DbMessage {
     required this.messageMessageKind,
     required this.messageContent,
     required this.messageOpenedAt,
-    required this.messageAcknowledge,
+    required this.messageAcknowledgeByUser,
+    required this.messageAcknowledgeByServer,
     required this.sendOrReceivedAt,
   });
 
@@ -22,9 +24,10 @@ class DbMessage {
   int? messageOtherId;
   int otherUserId;
   MessageKind messageMessageKind;
-  MessageContent messageContent;
+  MessageContent? messageContent;
   DateTime? messageOpenedAt;
-  bool messageAcknowledge;
+  bool messageAcknowledgeByUser;
+  bool messageAcknowledgeByServer;
   DateTime sendOrReceivedAt;
 }
 
@@ -38,19 +41,24 @@ class DbMessages extends CvModelBase {
   final messageOtherId = CvField<int?>(columnMessageOtherId);
 
   static const columnOtherUserId = "other_user_id";
-  final otherUserId = CvField<int?>(columnOtherUserId);
+  final otherUserId = CvField<int>(columnOtherUserId);
 
   static const columnMessageKind = "message_kind";
   final messageMessageKind = CvField<int>(columnMessageKind);
 
   static const columnMessageContentJson = "message_json";
-  final messageContentJson = CvField<String>(columnMessageContentJson);
+  final messageContentJson = CvField<String?>(columnMessageContentJson);
 
   static const columnMessageOpenedAt = "message_opened_at";
   final messageOpenedAt = CvField<DateTime?>(columnMessageOpenedAt);
 
-  static const columnMessageAcknowledge = "message_acknowledged";
+  static const columnMessageAcknowledgeByUser = "message_acknowledged_by_user";
-  final messageAcknowledge = CvField<int>(columnMessageAcknowledge);
+  final messageAcknowledgeByUser = CvField<int>(columnMessageAcknowledgeByUser);
+
+  static const columnMessageAcknowledgeByServer =
+      "message_acknowledged_by_server";
+  final messageAcknowledgeByServer =
+      CvField<int>(columnMessageAcknowledgeByServer);
 
   static const columnSendOrReceivedAt = "message_send_or_received_at";
   final sendOrReceivedAt = CvField<DateTime>(columnSendOrReceivedAt);
@@ -63,10 +71,11 @@ class DbMessages extends CvModelBase {
       CREATE TABLE IF NOT EXISTS $tableName (
       $columnMessageId INTEGER NOT NULL PRIMARY KEY,
       $columnMessageOtherId INTEGER DEFAULT NULL,
-      $columnOtherUserId INTEGER DEFAULT NULL,
+      $columnOtherUserId INTEGER NOT NULL,
       $columnMessageKind INTEGER NOT NULL,
-      $columnMessageAcknowledge INTEGER NOT NULL DEFAULT 0,
+      $columnMessageAcknowledgeByUser INTEGER NOT NULL DEFAULT 0,
-      $columnMessageContentJson TEXT NOT NULL,
+      $columnMessageAcknowledgeByServer INTEGER NOT NULL DEFAULT 0,
+      $columnMessageContentJson TEXT DEFAULT NULL,
       $columnMessageOpenedAt DATETIME DEFAULT NULL,
       $columnSendOrReceivedAt DATETIME DEFAULT CURRENT_TIMESTAMP,
       $columnUpdatedAt DATETIME DEFAULT CURRENT_TIMESTAMP
@@ -74,8 +83,33 @@ class DbMessages extends CvModelBase {
     """;
   }
 
-  static Future<int?> insertMyMessage(
+  static Future deleteMessageById(int messageId) async {
-      int userIdFrom, MessageKind kind, String jsonContent) async {
+    await dbProvider.db!.delete(
+      tableName,
+      where: '$columnMessageId = ?',
+      whereArgs: [messageId],
+    );
+    int? fromUserId = await getFromUserIdByMessageId(messageId);
+    if (fromUserId != null) {
+      globalCallBackOnMessageChange(fromUserId);
+    }
+  }
+
+  static Future<int?> getFromUserIdByMessageId(int messageId) async {
+    List<Map<String, dynamic>> result = await dbProvider.db!.query(
+      tableName,
+      columns: [columnOtherUserId],
+      where: '$columnMessageId = ?',
+      whereArgs: [messageId],
+    );
+    if (result.isNotEmpty) {
+      return result.first[columnOtherUserId] as int?;
+    }
+    return null;
+  }
+
+  static Future<int?> insertMyMessage(int userIdFrom, MessageKind kind,
+      {String? jsonContent}) async {
     try {
       int messageId = await dbProvider.db!.insert(tableName, {
         columnMessageKind: kind.index,
@@ -83,6 +117,7 @@ class DbMessages extends CvModelBase {
         columnOtherUserId: userIdFrom,
         columnSendOrReceivedAt: DateTime.now().toIso8601String()
       });
+      globalCallBackOnMessageChange(userIdFrom);
       return messageId;
     } catch (e) {
       Logger("contacts_model/getUsers").shout("$e");
@@ -97,8 +132,12 @@ class DbMessages extends CvModelBase {
         columnMessageOtherId: messageId,
         columnMessageKind: kind.index,
         columnMessageContentJson: jsonContent,
+        columnMessageAcknowledgeByServer: 1,
+        columnMessageAcknowledgeByUser:
+            0, // ack in case of sending corresponds to the opened flag
         columnOtherUserId: userIdFrom
       });
+      globalCallBackOnMessageChange(userIdFrom);
       return true;
     } catch (e) {
       Logger("contacts_model/getUsers").shout("$e");
@@ -106,56 +145,52 @@ class DbMessages extends CvModelBase {
     }
   }
 
-  static List<DbMessage> convertToDbMessage(List<dynamic> fromDb) {
-    try {
-      List<DbMessage> parsedUsers = [];
-      for (int i = 0; i < fromDb.length; i++) {
-        dynamic messageOpenedAt = fromDb[i][columnMessageOpenedAt];
-        if (messageOpenedAt != null) {
-          messageOpenedAt = DateTime.tryParse(fromDb[i][columnMessageOpenedAt]);
-        }
-        print("Datetime: ${fromDb[i][columnSendOrReceivedAt]}");
-        print(
-            "Datetime parsed: ${DateTime.tryParse(fromDb[i][columnSendOrReceivedAt])}");
-        parsedUsers.add(
-          DbMessage(
-            sendOrReceivedAt:
-                DateTime.tryParse(fromDb[i][columnSendOrReceivedAt])!,
-            messageId: fromDb[i][columnMessageId],
-            messageOtherId: fromDb[i][columnMessageOtherId],
-            otherUserId: fromDb[i][columnOtherUserId],
-            messageMessageKind:
-                MessageKindExtension.fromIndex(fromDb[i][columnMessageKind]),
-            messageContent: MessageContent.fromJson(
-                jsonDecode(fromDb[i][columnMessageContentJson])),
-            messageOpenedAt: messageOpenedAt,
-            messageAcknowledge: fromDb[i][columnMessageAcknowledge] == 1,
-          ),
-        );
-      }
-      return parsedUsers;
-    } catch (e) {
-      Logger("messages_model/convertToDbMessage").shout("$e");
-      return [];
-    }
-  }
-
   static Future<DbMessage?> getLastMessagesForPreviewForUser(
       int otherUserId) async {
-    var rows = await dbProvider.db!.query(tableName,
+    var rows = await dbProvider.db!.query(
+      tableName,
       where: "$columnOtherUserId = ?",
       whereArgs: [otherUserId],
       orderBy: "$columnUpdatedAt DESC",
-        limit: 1);
+      limit: 10,
+    );
 
     List<DbMessage> messages = convertToDbMessage(rows);
+
+    // check if there is a message which was not ack by the server
+    List<DbMessage> notAckByServer =
+        messages.where((c) => !c.messageAcknowledgeByServer).toList();
+    if (notAckByServer.isNotEmpty) return notAckByServer[0];
+
+    // check if there is a message which was not ack by the user
+    List<DbMessage> notAckByUser =
+        messages.where((c) => !c.messageAcknowledgeByUser).toList();
+    if (notAckByUser.isNotEmpty) return notAckByUser[0];
+
     if (messages.isEmpty) return null;
     return messages[0];
   }
 
-  static Future acknowledgeMessage(int fromUserId, int messageId) async {
+  static Future acknowledgeMessageByServer(int messageId) async {
     Map<String, dynamic> valuesToUpdate = {
-      columnMessageAcknowledge: 1,
+      columnMessageAcknowledgeByServer: 1,
+    };
+    await dbProvider.db!.update(
+      tableName,
+      valuesToUpdate,
+      where: "$messageId = ?",
+      whereArgs: [messageId],
+    );
+    int? fromUserId = await getFromUserIdByMessageId(messageId);
+    if (fromUserId != null) {
+      globalCallBackOnMessageChange(fromUserId);
+    }
+  }
+
+  // check fromUserId to prevent spoofing
+  static Future acknowledgeMessageByUser(int fromUserId, int messageId) async {
+    Map<String, dynamic> valuesToUpdate = {
+      columnMessageAcknowledgeByUser: 1,
     };
     await dbProvider.db!.update(
       tableName,
@@ -163,6 +198,7 @@ class DbMessages extends CvModelBase {
       where: "$messageId = ? AND $columnOtherUserId = ?",
       whereArgs: [messageId, fromUserId],
     );
+    globalCallBackOnMessageChange(fromUserId);
   }
 
   @override
@@ -173,4 +209,42 @@ class DbMessages extends CvModelBase {
         messageOpenedAt,
         sendOrReceivedAt
       ];
+
+  static List<DbMessage> convertToDbMessage(List<dynamic> fromDb) {
+    try {
+      List<DbMessage> parsedUsers = [];
+      for (int i = 0; i < fromDb.length; i++) {
+        dynamic messageOpenedAt = fromDb[i][columnMessageOpenedAt];
+        if (messageOpenedAt != null) {
+          messageOpenedAt = DateTime.tryParse(fromDb[i][columnMessageOpenedAt]);
+        }
+        dynamic content = fromDb[i][columnMessageContentJson];
+        if (content != null) {
+          content = MessageContent.fromJson(
+              jsonDecode(fromDb[i][columnMessageContentJson]));
+        }
+        parsedUsers.add(
+          DbMessage(
+            sendOrReceivedAt:
+                DateTime.tryParse(fromDb[i][columnSendOrReceivedAt])!,
+            messageId: fromDb[i][columnMessageId],
+            messageOtherId: fromDb[i][columnMessageOtherId],
+            otherUserId: fromDb[i][columnOtherUserId],
+            messageMessageKind:
+                MessageKindExtension.fromIndex(fromDb[i][columnMessageKind]),
+            messageContent: content,
+            messageOpenedAt: messageOpenedAt,
+            messageAcknowledgeByUser:
+                fromDb[i][columnMessageAcknowledgeByUser] == 1,
+            messageAcknowledgeByServer:
+                fromDb[i][columnMessageAcknowledgeByServer] == 1,
+          ),
+        );
+      }
+      return parsedUsers;
+    } catch (e) {
+      Logger("messages_model/convertToDbMessage").shout("$e");
+      return [];
+    }
+  }
 }

lib/src/proto/api/client_to_server.pb.dart

@@ -742,21 +742,12 @@ class ApplicationData_GetPrekeysByUserId extends $pb.GeneratedMessage {
 }
 
 class ApplicationData_GetUploadToken extends $pb.GeneratedMessage {
-  factory ApplicationData_GetUploadToken({
+  factory ApplicationData_GetUploadToken() => create();
-    $core.int? len,
-  }) {
-    final $result = create();
-    if (len != null) {
-      $result.len = len;
-    }
-    return $result;
-  }
   ApplicationData_GetUploadToken._() : super();
   factory ApplicationData_GetUploadToken.fromBuffer($core.List<$core.int> i, [$pb.ExtensionRegistry r = $pb.ExtensionRegistry.EMPTY]) => create()..mergeFromBuffer(i, r);
   factory ApplicationData_GetUploadToken.fromJson($core.String i, [$pb.ExtensionRegistry r = $pb.ExtensionRegistry.EMPTY]) => create()..mergeFromJson(i, r);
 
   static final $pb.BuilderInfo _i = $pb.BuilderInfo(_omitMessageNames ? '' : 'ApplicationData.GetUploadToken', package: const $pb.PackageName(_omitMessageNames ? '' : 'client_to_server'), createEmptyInstance: create)
-    ..a<$core.int>(1, _omitFieldNames ? '' : 'len', $pb.PbFieldType.OU3)
     ..hasRequiredFields = false
   ;
 
@@ -780,15 +771,6 @@ class ApplicationData_GetUploadToken extends $pb.GeneratedMessage {
   @$core.pragma('dart2js:noInline')
   static ApplicationData_GetUploadToken getDefault() => _defaultInstance ??= $pb.GeneratedMessage.$_defaultFor<ApplicationData_GetUploadToken>(create);
   static ApplicationData_GetUploadToken? _defaultInstance;
-
-  @$pb.TagNumber(1)
-  $core.int get len => $_getIZ(0);
-  @$pb.TagNumber(1)
-  set len($core.int v) { $_setUnsignedInt32(0, v); }
-  @$pb.TagNumber(1)
-  $core.bool hasLen() => $_has(0);
-  @$pb.TagNumber(1)
-  void clearLen() => clearField(1);
 }
 
 class ApplicationData_UploadData extends $pb.GeneratedMessage {
@@ -869,6 +851,56 @@ class ApplicationData_UploadData extends $pb.GeneratedMessage {
   void clearData() => clearField(3);
 }
 
+class ApplicationData_DownloadData extends $pb.GeneratedMessage {
+  factory ApplicationData_DownloadData({
+    $core.List<$core.int>? uploadToken,
+  }) {
+    final $result = create();
+    if (uploadToken != null) {
+      $result.uploadToken = uploadToken;
+    }
+    return $result;
+  }
+  ApplicationData_DownloadData._() : super();
+  factory ApplicationData_DownloadData.fromBuffer($core.List<$core.int> i, [$pb.ExtensionRegistry r = $pb.ExtensionRegistry.EMPTY]) => create()..mergeFromBuffer(i, r);
+  factory ApplicationData_DownloadData.fromJson($core.String i, [$pb.ExtensionRegistry r = $pb.ExtensionRegistry.EMPTY]) => create()..mergeFromJson(i, r);
+
+  static final $pb.BuilderInfo _i = $pb.BuilderInfo(_omitMessageNames ? '' : 'ApplicationData.DownloadData', package: const $pb.PackageName(_omitMessageNames ? '' : 'client_to_server'), createEmptyInstance: create)
+    ..a<$core.List<$core.int>>(1, _omitFieldNames ? '' : 'uploadToken', $pb.PbFieldType.OY)
+    ..hasRequiredFields = false
+  ;
+
+  @$core.Deprecated(
+  'Using this can add significant overhead to your binary. '
+  'Use [GeneratedMessageGenericExtensions.deepCopy] instead. '
+  'Will be removed in next major version')
+  ApplicationData_DownloadData clone() => ApplicationData_DownloadData()..mergeFromMessage(this);
+  @$core.Deprecated(
+  'Using this can add significant overhead to your binary. '
+  'Use [GeneratedMessageGenericExtensions.rebuild] instead. '
+  'Will be removed in next major version')
+  ApplicationData_DownloadData copyWith(void Function(ApplicationData_DownloadData) updates) => super.copyWith((message) => updates(message as ApplicationData_DownloadData)) as ApplicationData_DownloadData;
+
+  $pb.BuilderInfo get info_ => _i;
+
+  @$core.pragma('dart2js:noInline')
+  static ApplicationData_DownloadData create() => ApplicationData_DownloadData._();
+  ApplicationData_DownloadData createEmptyInstance() => create();
+  static $pb.PbList<ApplicationData_DownloadData> createRepeated() => $pb.PbList<ApplicationData_DownloadData>();
+  @$core.pragma('dart2js:noInline')
+  static ApplicationData_DownloadData getDefault() => _defaultInstance ??= $pb.GeneratedMessage.$_defaultFor<ApplicationData_DownloadData>(create);
+  static ApplicationData_DownloadData? _defaultInstance;
+
+  @$pb.TagNumber(1)
+  $core.List<$core.int> get uploadToken => $_getN(0);
+  @$pb.TagNumber(1)
+  set uploadToken($core.List<$core.int> v) { $_setBytes(0, v); }
+  @$pb.TagNumber(1)
+  $core.bool hasUploadToken() => $_has(0);
+  @$pb.TagNumber(1)
+  void clearUploadToken() => clearField(1);
+}
+
 enum ApplicationData_ApplicationData {
   textmessage, 
   getuserbyusername, 
@@ -876,6 +908,7 @@ enum ApplicationData_ApplicationData {
   getuploadtoken, 
   uploaddata, 
   getuserbyid, 
+  downloaddata, 
   notSet
 }
 
@@ -887,6 +920,7 @@ class ApplicationData extends $pb.GeneratedMessage {
     ApplicationData_GetUploadToken? getuploadtoken,
     ApplicationData_UploadData? uploaddata,
     ApplicationData_GetUserById? getuserbyid,
+    ApplicationData_DownloadData? downloaddata,
   }) {
     final $result = create();
     if (textmessage != null) {
@@ -907,6 +941,9 @@ class ApplicationData extends $pb.GeneratedMessage {
     if (getuserbyid != null) {
       $result.getuserbyid = getuserbyid;
     }
+    if (downloaddata != null) {
+      $result.downloaddata = downloaddata;
+    }
     return $result;
   }
   ApplicationData._() : super();
@@ -920,16 +957,18 @@ class ApplicationData extends $pb.GeneratedMessage {
     4 : ApplicationData_ApplicationData.getuploadtoken,
     5 : ApplicationData_ApplicationData.uploaddata,
     6 : ApplicationData_ApplicationData.getuserbyid,
+    7 : ApplicationData_ApplicationData.downloaddata,
     0 : ApplicationData_ApplicationData.notSet
   };
   static final $pb.BuilderInfo _i = $pb.BuilderInfo(_omitMessageNames ? '' : 'ApplicationData', package: const $pb.PackageName(_omitMessageNames ? '' : 'client_to_server'), createEmptyInstance: create)
-    ..oo(0, [1, 2, 3, 4, 5, 6])
+    ..oo(0, [1, 2, 3, 4, 5, 6, 7])
     ..aOM<ApplicationData_TextMessage>(1, _omitFieldNames ? '' : 'textmessage', subBuilder: ApplicationData_TextMessage.create)
     ..aOM<ApplicationData_GetUserByUsername>(2, _omitFieldNames ? '' : 'getuserbyusername', subBuilder: ApplicationData_GetUserByUsername.create)
     ..aOM<ApplicationData_GetPrekeysByUserId>(3, _omitFieldNames ? '' : 'getprekeysbyuserid', subBuilder: ApplicationData_GetPrekeysByUserId.create)
     ..aOM<ApplicationData_GetUploadToken>(4, _omitFieldNames ? '' : 'getuploadtoken', subBuilder: ApplicationData_GetUploadToken.create)
     ..aOM<ApplicationData_UploadData>(5, _omitFieldNames ? '' : 'uploaddata', subBuilder: ApplicationData_UploadData.create)
     ..aOM<ApplicationData_GetUserById>(6, _omitFieldNames ? '' : 'getuserbyid', subBuilder: ApplicationData_GetUserById.create)
+    ..aOM<ApplicationData_DownloadData>(7, _omitFieldNames ? '' : 'downloaddata', subBuilder: ApplicationData_DownloadData.create)
     ..hasRequiredFields = false
   ;
 
@@ -1022,6 +1061,17 @@ class ApplicationData extends $pb.GeneratedMessage {
   void clearGetuserbyid() => clearField(6);
   @$pb.TagNumber(6)
   ApplicationData_GetUserById ensureGetuserbyid() => $_ensure(5);
+
+  @$pb.TagNumber(7)
+  ApplicationData_DownloadData get downloaddata => $_getN(6);
+  @$pb.TagNumber(7)
+  set downloaddata(ApplicationData_DownloadData v) { setField(7, v); }
+  @$pb.TagNumber(7)
+  $core.bool hasDownloaddata() => $_has(6);
+  @$pb.TagNumber(7)
+  void clearDownloaddata() => clearField(7);
+  @$pb.TagNumber(7)
+  ApplicationData_DownloadData ensureDownloaddata() => $_ensure(6);
 }
 
 class Response_PreKey extends $pb.GeneratedMessage {

lib/src/proto/api/client_to_server.pbjson.dart

@@ -117,12 +117,13 @@ const ApplicationData$json = {
   '2': [
     {'1': 'textmessage', '3': 1, '4': 1, '5': 11, '6': '.client_to_server.ApplicationData.TextMessage', '9': 0, '10': 'textmessage'},
     {'1': 'getuserbyusername', '3': 2, '4': 1, '5': 11, '6': '.client_to_server.ApplicationData.GetUserByUsername', '9': 0, '10': 'getuserbyusername'},
-    {'1': 'getuserbyid', '3': 6, '4': 1, '5': 11, '6': '.client_to_server.ApplicationData.GetUserById', '9': 0, '10': 'getuserbyid'},
     {'1': 'getprekeysbyuserid', '3': 3, '4': 1, '5': 11, '6': '.client_to_server.ApplicationData.GetPrekeysByUserId', '9': 0, '10': 'getprekeysbyuserid'},
     {'1': 'getuploadtoken', '3': 4, '4': 1, '5': 11, '6': '.client_to_server.ApplicationData.GetUploadToken', '9': 0, '10': 'getuploadtoken'},
     {'1': 'uploaddata', '3': 5, '4': 1, '5': 11, '6': '.client_to_server.ApplicationData.UploadData', '9': 0, '10': 'uploaddata'},
+    {'1': 'getuserbyid', '3': 6, '4': 1, '5': 11, '6': '.client_to_server.ApplicationData.GetUserById', '9': 0, '10': 'getuserbyid'},
+    {'1': 'downloaddata', '3': 7, '4': 1, '5': 11, '6': '.client_to_server.ApplicationData.DownloadData', '9': 0, '10': 'downloaddata'},
   ],
-  '3': [ApplicationData_TextMessage$json, ApplicationData_GetUserByUsername$json, ApplicationData_GetUserById$json, ApplicationData_GetPrekeysByUserId$json, ApplicationData_GetUploadToken$json, ApplicationData_UploadData$json],
+  '3': [ApplicationData_TextMessage$json, ApplicationData_GetUserByUsername$json, ApplicationData_GetUserById$json, ApplicationData_GetPrekeysByUserId$json, ApplicationData_GetUploadToken$json, ApplicationData_UploadData$json, ApplicationData_DownloadData$json],
   '8': [
     {'1': 'ApplicationData'},
   ],
@@ -164,9 +165,6 @@ const ApplicationData_GetPrekeysByUserId$json = {
 @$core.Deprecated('Use applicationDataDescriptor instead')
 const ApplicationData_GetUploadToken$json = {
   '1': 'GetUploadToken',
-  '2': [
-    {'1': 'len', '3': 1, '4': 1, '5': 13, '10': 'len'},
-  ],
 };
 
 @$core.Deprecated('Use applicationDataDescriptor instead')
@@ -179,25 +177,35 @@ const ApplicationData_UploadData$json = {
   ],
 };
 
+@$core.Deprecated('Use applicationDataDescriptor instead')
+const ApplicationData_DownloadData$json = {
+  '1': 'DownloadData',
+  '2': [
+    {'1': 'upload_token', '3': 1, '4': 1, '5': 12, '10': 'uploadToken'},
+  ],
+};
+
 /// Descriptor for `ApplicationData`. Decode as a `google.protobuf.DescriptorProto`.
 final $typed_data.Uint8List applicationDataDescriptor = $convert.base64Decode(
     'Cg9BcHBsaWNhdGlvbkRhdGESUQoLdGV4dG1lc3NhZ2UYASABKAsyLS5jbGllbnRfdG9fc2Vydm'
     'VyLkFwcGxpY2F0aW9uRGF0YS5UZXh0TWVzc2FnZUgAUgt0ZXh0bWVzc2FnZRJjChFnZXR1c2Vy'
     'Ynl1c2VybmFtZRgCIAEoCzIzLmNsaWVudF90b19zZXJ2ZXIuQXBwbGljYXRpb25EYXRhLkdldF'
-    'VzZXJCeVVzZXJuYW1lSABSEWdldHVzZXJieXVzZXJuYW1lElEKC2dldHVzZXJieWlkGAYgASgL'
+    'VzZXJCeVVzZXJuYW1lSABSEWdldHVzZXJieXVzZXJuYW1lEmYKEmdldHByZWtleXNieXVzZXJp'
-    'Mi0uY2xpZW50X3RvX3NlcnZlci5BcHBsaWNhdGlvbkRhdGEuR2V0VXNlckJ5SWRIAFILZ2V0dX'
+    'ZBgDIAEoCzI0LmNsaWVudF90b19zZXJ2ZXIuQXBwbGljYXRpb25EYXRhLkdldFByZWtleXNCeV'
-    'NlcmJ5aWQSZgoSZ2V0cHJla2V5c2J5dXNlcmlkGAMgASgLMjQuY2xpZW50X3RvX3NlcnZlci5B'
+    'VzZXJJZEgAUhJnZXRwcmVrZXlzYnl1c2VyaWQSWgoOZ2V0dXBsb2FkdG9rZW4YBCABKAsyMC5j'
-    'cHBsaWNhdGlvbkRhdGEuR2V0UHJla2V5c0J5VXNlcklkSABSEmdldHByZWtleXNieXVzZXJpZB'
+    'bGllbnRfdG9fc2VydmVyLkFwcGxpY2F0aW9uRGF0YS5HZXRVcGxvYWRUb2tlbkgAUg5nZXR1cG'
-    'JaCg5nZXR1cGxvYWR0b2tlbhgEIAEoCzIwLmNsaWVudF90b19zZXJ2ZXIuQXBwbGljYXRpb25E'
+    'xvYWR0b2tlbhJOCgp1cGxvYWRkYXRhGAUgASgLMiwuY2xpZW50X3RvX3NlcnZlci5BcHBsaWNh'
-    'YXRhLkdldFVwbG9hZFRva2VuSABSDmdldHVwbG9hZHRva2VuEk4KCnVwbG9hZGRhdGEYBSABKA'
+    'dGlvbkRhdGEuVXBsb2FkRGF0YUgAUgp1cGxvYWRkYXRhElEKC2dldHVzZXJieWlkGAYgASgLMi'
-    'syLC5jbGllbnRfdG9fc2VydmVyLkFwcGxpY2F0aW9uRGF0YS5VcGxvYWREYXRhSABSCnVwbG9h'
+    '0uY2xpZW50X3RvX3NlcnZlci5BcHBsaWNhdGlvbkRhdGEuR2V0VXNlckJ5SWRIAFILZ2V0dXNl'
-    'ZGRhdGEaOgoLVGV4dE1lc3NhZ2USFwoHdXNlcl9pZBgBIAEoA1IGdXNlcklkEhIKBGJvZHkYAy'
+    'cmJ5aWQSVAoMZG93bmxvYWRkYXRhGAcgASgLMi4uY2xpZW50X3RvX3NlcnZlci5BcHBsaWNhdG'
-    'ABKAxSBGJvZHkaLwoRR2V0VXNlckJ5VXNlcm5hbWUSGgoIdXNlcm5hbWUYASABKAlSCHVzZXJu'
+    'lvbkRhdGEuRG93bmxvYWREYXRhSABSDGRvd25sb2FkZGF0YRo6CgtUZXh0TWVzc2FnZRIXCgd1'
-    'YW1lGiYKC0dldFVzZXJCeUlkEhcKB3VzZXJfaWQYASABKANSBnVzZXJJZBotChJHZXRQcmVrZX'
+    'c2VyX2lkGAEgASgDUgZ1c2VySWQSEgoEYm9keRgDIAEoDFIEYm9keRovChFHZXRVc2VyQnlVc2'
-    'lzQnlVc2VySWQSFwoHdXNlcl9pZBgBIAEoA1IGdXNlcklkGiIKDkdldFVwbG9hZFRva2VuEhAK'
+    'VybmFtZRIaCgh1c2VybmFtZRgBIAEoCVIIdXNlcm5hbWUaJgoLR2V0VXNlckJ5SWQSFwoHdXNl'
-    'A2xlbhgBIAEoDVIDbGVuGlsKClVwbG9hZERhdGESIQoMdXBsb2FkX3Rva2VuGAEgASgMUgt1cG'
+    'cl9pZBgBIAEoA1IGdXNlcklkGi0KEkdldFByZWtleXNCeVVzZXJJZBIXCgd1c2VyX2lkGAEgAS'
-    'xvYWRUb2tlbhIWCgZvZmZzZXQYAiABKA1SBm9mZnNldBISCgRkYXRhGAMgASgMUgRkYXRhQhEK'
+    'gDUgZ1c2VySWQaEAoOR2V0VXBsb2FkVG9rZW4aWwoKVXBsb2FkRGF0YRIhCgx1cGxvYWRfdG9r'
-    'D0FwcGxpY2F0aW9uRGF0YQ==');
+    'ZW4YASABKAxSC3VwbG9hZFRva2VuEhYKBm9mZnNldBgCIAEoDVIGb2Zmc2V0EhIKBGRhdGEYAy'
+    'ABKAxSBGRhdGEaMQoMRG93bmxvYWREYXRhEiEKDHVwbG9hZF90b2tlbhgBIAEoDFILdXBsb2Fk'
+    'VG9rZW5CEQoPQXBwbGljYXRpb25EYXRh');
 
 @$core.Deprecated('Use responseDescriptor instead')
 const Response$json = {

lib/src/proto/api/server_to_client.pb.dart

@@ -85,6 +85,7 @@ enum V0_Kind {
   response, 
   newMessage, 
   requestNewPreKeys, 
+  downloaddata, 
   notSet
 }
 
@@ -94,6 +95,7 @@ class V0 extends $pb.GeneratedMessage {
     Response? response,
     NewMessage? newMessage,
     $core.bool? requestNewPreKeys,
+    DownloadData? downloaddata,
   }) {
     final $result = create();
     if (seq != null) {
@@ -108,6 +110,9 @@ class V0 extends $pb.GeneratedMessage {
     if (requestNewPreKeys != null) {
       $result.requestNewPreKeys = requestNewPreKeys;
     }
+    if (downloaddata != null) {
+      $result.downloaddata = downloaddata;
+    }
     return $result;
   }
   V0._() : super();
@@ -118,14 +123,16 @@ class V0 extends $pb.GeneratedMessage {
     2 : V0_Kind.response,
     3 : V0_Kind.newMessage,
     4 : V0_Kind.requestNewPreKeys,
+    5 : V0_Kind.downloaddata,
     0 : V0_Kind.notSet
   };
   static final $pb.BuilderInfo _i = $pb.BuilderInfo(_omitMessageNames ? '' : 'V0', package: const $pb.PackageName(_omitMessageNames ? '' : 'server_to_client'), createEmptyInstance: create)
-    ..oo(0, [2, 3, 4])
+    ..oo(0, [2, 3, 4, 5])
     ..a<$fixnum.Int64>(1, _omitFieldNames ? '' : 'seq', $pb.PbFieldType.OU6, defaultOrMaker: $fixnum.Int64.ZERO)
     ..aOM<Response>(2, _omitFieldNames ? '' : 'response', subBuilder: Response.create)
     ..aOM<NewMessage>(3, _omitFieldNames ? '' : 'newMessage', protoName: 'newMessage', subBuilder: NewMessage.create)
     ..aOB(4, _omitFieldNames ? '' : 'RequestNewPreKeys', protoName: 'RequestNewPreKeys')
+    ..aOM<DownloadData>(5, _omitFieldNames ? '' : 'downloaddata', subBuilder: DownloadData.create)
     ..hasRequiredFields = false
   ;
 
@@ -192,6 +199,17 @@ class V0 extends $pb.GeneratedMessage {
   $core.bool hasRequestNewPreKeys() => $_has(3);
   @$pb.TagNumber(4)
   void clearRequestNewPreKeys() => clearField(4);
+
+  @$pb.TagNumber(5)
+  DownloadData get downloaddata => $_getN(4);
+  @$pb.TagNumber(5)
+  set downloaddata(DownloadData v) { setField(5, v); }
+  @$pb.TagNumber(5)
+  $core.bool hasDownloaddata() => $_has(4);
+  @$pb.TagNumber(5)
+  void clearDownloaddata() => clearField(5);
+  @$pb.TagNumber(5)
+  DownloadData ensureDownloaddata() => $_ensure(4);
 }
 
 class NewMessage extends $pb.GeneratedMessage {
@@ -258,6 +276,84 @@ class NewMessage extends $pb.GeneratedMessage {
   void clearFromUserId() => clearField(2);
 }
 
+class DownloadData extends $pb.GeneratedMessage {
+  factory DownloadData({
+    $core.List<$core.int>? uploadToken,
+    $core.int? offset,
+    $core.List<$core.int>? data,
+  }) {
+    final $result = create();
+    if (uploadToken != null) {
+      $result.uploadToken = uploadToken;
+    }
+    if (offset != null) {
+      $result.offset = offset;
+    }
+    if (data != null) {
+      $result.data = data;
+    }
+    return $result;
+  }
+  DownloadData._() : super();
+  factory DownloadData.fromBuffer($core.List<$core.int> i, [$pb.ExtensionRegistry r = $pb.ExtensionRegistry.EMPTY]) => create()..mergeFromBuffer(i, r);
+  factory DownloadData.fromJson($core.String i, [$pb.ExtensionRegistry r = $pb.ExtensionRegistry.EMPTY]) => create()..mergeFromJson(i, r);
+
+  static final $pb.BuilderInfo _i = $pb.BuilderInfo(_omitMessageNames ? '' : 'DownloadData', package: const $pb.PackageName(_omitMessageNames ? '' : 'server_to_client'), createEmptyInstance: create)
+    ..a<$core.List<$core.int>>(1, _omitFieldNames ? '' : 'uploadToken', $pb.PbFieldType.OY)
+    ..a<$core.int>(2, _omitFieldNames ? '' : 'offset', $pb.PbFieldType.OU3)
+    ..a<$core.List<$core.int>>(3, _omitFieldNames ? '' : 'data', $pb.PbFieldType.OY)
+    ..hasRequiredFields = false
+  ;
+
+  @$core.Deprecated(
+  'Using this can add significant overhead to your binary. '
+  'Use [GeneratedMessageGenericExtensions.deepCopy] instead. '
+  'Will be removed in next major version')
+  DownloadData clone() => DownloadData()..mergeFromMessage(this);
+  @$core.Deprecated(
+  'Using this can add significant overhead to your binary. '
+  'Use [GeneratedMessageGenericExtensions.rebuild] instead. '
+  'Will be removed in next major version')
+  DownloadData copyWith(void Function(DownloadData) updates) => super.copyWith((message) => updates(message as DownloadData)) as DownloadData;
+
+  $pb.BuilderInfo get info_ => _i;
+
+  @$core.pragma('dart2js:noInline')
+  static DownloadData create() => DownloadData._();
+  DownloadData createEmptyInstance() => create();
+  static $pb.PbList<DownloadData> createRepeated() => $pb.PbList<DownloadData>();
+  @$core.pragma('dart2js:noInline')
+  static DownloadData getDefault() => _defaultInstance ??= $pb.GeneratedMessage.$_defaultFor<DownloadData>(create);
+  static DownloadData? _defaultInstance;
+
+  @$pb.TagNumber(1)
+  $core.List<$core.int> get uploadToken => $_getN(0);
+  @$pb.TagNumber(1)
+  set uploadToken($core.List<$core.int> v) { $_setBytes(0, v); }
+  @$pb.TagNumber(1)
+  $core.bool hasUploadToken() => $_has(0);
+  @$pb.TagNumber(1)
+  void clearUploadToken() => clearField(1);
+
+  @$pb.TagNumber(2)
+  $core.int get offset => $_getIZ(1);
+  @$pb.TagNumber(2)
+  set offset($core.int v) { $_setUnsignedInt32(1, v); }
+  @$pb.TagNumber(2)
+  $core.bool hasOffset() => $_has(1);
+  @$pb.TagNumber(2)
+  void clearOffset() => clearField(2);
+
+  @$pb.TagNumber(3)
+  $core.List<$core.int> get data => $_getN(2);
+  @$pb.TagNumber(3)
+  set data($core.List<$core.int> v) { $_setBytes(2, v); }
+  @$pb.TagNumber(3)
+  $core.bool hasData() => $_has(2);
+  @$pb.TagNumber(3)
+  void clearData() => clearField(3);
+}
+
 class Response_PreKey extends $pb.GeneratedMessage {
   factory Response_PreKey({
     $fixnum.Int64? id,

lib/src/proto/api/server_to_client.pbjson.dart

@@ -37,6 +37,7 @@ const V0$json = {
     {'1': 'response', '3': 2, '4': 1, '5': 11, '6': '.server_to_client.Response', '9': 0, '10': 'response'},
     {'1': 'newMessage', '3': 3, '4': 1, '5': 11, '6': '.server_to_client.NewMessage', '9': 0, '10': 'newMessage'},
     {'1': 'RequestNewPreKeys', '3': 4, '4': 1, '5': 8, '9': 0, '10': 'RequestNewPreKeys'},
+    {'1': 'downloaddata', '3': 5, '4': 1, '5': 11, '6': '.server_to_client.DownloadData', '9': 0, '10': 'downloaddata'},
   ],
   '8': [
     {'1': 'Kind'},
@@ -48,7 +49,8 @@ final $typed_data.Uint8List v0Descriptor = $convert.base64Decode(
     'CgJWMBIQCgNzZXEYASABKARSA3NlcRI4CghyZXNwb25zZRgCIAEoCzIaLnNlcnZlcl90b19jbG'
     'llbnQuUmVzcG9uc2VIAFIIcmVzcG9uc2USPgoKbmV3TWVzc2FnZRgDIAEoCzIcLnNlcnZlcl90'
     'b19jbGllbnQuTmV3TWVzc2FnZUgAUgpuZXdNZXNzYWdlEi4KEVJlcXVlc3ROZXdQcmVLZXlzGA'
-    'QgASgISABSEVJlcXVlc3ROZXdQcmVLZXlzQgYKBEtpbmQ=');
+    'QgASgISABSEVJlcXVlc3ROZXdQcmVLZXlzEkQKDGRvd25sb2FkZGF0YRgFIAEoCzIeLnNlcnZl'
+    'cl90b19jbGllbnQuRG93bmxvYWREYXRhSABSDGRvd25sb2FkZGF0YUIGCgRLaW5k');
 
 @$core.Deprecated('Use newMessageDescriptor instead')
 const NewMessage$json = {
@@ -64,6 +66,21 @@ final $typed_data.Uint8List newMessageDescriptor = $convert.base64Decode(
     'CgpOZXdNZXNzYWdlEiAKDGZyb21fdXNlcl9pZBgCIAEoA1IKZnJvbVVzZXJJZBISCgRib2R5GA'
     'EgASgMUgRib2R5');
 
+@$core.Deprecated('Use downloadDataDescriptor instead')
+const DownloadData$json = {
+  '1': 'DownloadData',
+  '2': [
+    {'1': 'upload_token', '3': 1, '4': 1, '5': 12, '10': 'uploadToken'},
+    {'1': 'offset', '3': 2, '4': 1, '5': 13, '10': 'offset'},
+    {'1': 'data', '3': 3, '4': 1, '5': 12, '10': 'data'},
+  ],
+};
+
+/// Descriptor for `DownloadData`. Decode as a `google.protobuf.DescriptorProto`.
+final $typed_data.Uint8List downloadDataDescriptor = $convert.base64Decode(
+    'CgxEb3dubG9hZERhdGESIQoMdXBsb2FkX3Rva2VuGAEgASgMUgt1cGxvYWRUb2tlbhIWCgZvZm'
+    'ZzZXQYAiABKA1SBm9mZnNldBISCgRkYXRhGAMgASgMUgRkYXRh');
+
 @$core.Deprecated('Use responseDescriptor instead')
 const Response$json = {
   '1': 'Response',

lib/src/providers/api/api.dart

@@ -0,0 +1,107 @@
+import 'dart:io';
+import 'package:fixnum/fixnum.dart';
+import 'package:flutter/foundation.dart';
+import 'package:logging/logging.dart';
+import 'package:twonly/main.dart';
+import 'package:twonly/src/model/json/message.dart';
+import 'package:twonly/src/model/messages_model.dart';
+import 'package:twonly/src/proto/api/error.pb.dart';
+import 'package:twonly/src/providers/api/api_utils.dart';
+import 'package:twonly/src/utils/misc.dart';
+// ignore: library_prefixes
+import 'package:twonly/src/utils/signal.dart' as SignalHelper;
+
+// this functions ensures that the message is received by the server and in case of errors will try again later
+Future<Result> encryptAndSendMessage(Int64 userId, Message msg) async {
+  Uint8List? bytes = await SignalHelper.encryptMessage(msg, userId);
+
+  if (bytes == null) {
+    Logger("api.dart").shout("Error encryption message!");
+    return Result.error(ErrorCode.InternalError);
+  }
+
+  Logger("api.dart").shout(
+      "TODO: store encrypted message and send later again. STORE: userId, bytes and messageId");
+
+  Result resp = await apiProvider.sendTextMessage(userId, bytes);
+
+  if (resp.isSuccess) {
+    if (msg.messageId != null) {
+      DbMessages.acknowledgeMessageByServer(msg.messageId!);
+    }
+    // TODO: remove encrypted tmp file
+  } else {
+    // in case of error do nothing. As the message is not removed the app will try again when relaunched
+  }
+
+  return resp;
+}
+
+Future sendImageToSingleTarget(Int64 target, Uint8List imageBytes) async {
+  int? messageId =
+      await DbMessages.insertMyMessage(target.toInt(), MessageKind.image);
+  if (messageId == null) return;
+
+  Result res = await apiProvider.getUploadToken();
+
+  if (res.isError || !res.value.hasUploadtoken()) {
+    Logger("api.dart").shout("Error getting upload token!");
+
+    // TODO store message for later and try again
+
+    return null;
+  }
+
+  List<int> uploadToken = res.value.uploadtoken;
+  Logger("sendImageToSingleTarget").fine("Got token: $uploadToken");
+
+  MessageContent content =
+      MessageContent(text: null, downloadToken: uploadToken);
+
+  Uint8List? encryptBytes = await SignalHelper.encryptBytes(imageBytes, target);
+  if (encryptBytes == null) {
+    await DbMessages.deleteMessageById(messageId);
+    Logger("api.dart").shout("Error encrypting image! Deleting image.");
+    return;
+  }
+
+  List<int>? imageToken =
+      await apiProvider.uploadData(uploadToken, encryptBytes);
+  if (imageToken == null) {
+    Logger("api.dart").shout("handle error uploading like saving...");
+    return;
+  }
+
+  print("TODO: insert into DB and then create this MESSAGE");
+
+  Message msg = Message(
+    kind: MessageKind.image,
+    messageId: messageId,
+    content: content,
+    timestamp: DateTime.now(),
+  );
+
+  await encryptAndSendMessage(target, msg);
+}
+
+Future sendImage(List<Int64> userIds, String imagePath) async {
+  // 1. set notifier provider
+
+  File imageFile = File(imagePath);
+
+  Uint8List? imageBytes = await getCompressedImage(imageFile);
+  if (imageBytes == null) {
+    Logger("api.dart").shout("Error compressing image!");
+    return;
+  }
+
+  for (int i = 0; i < userIds.length; i++) {
+    sendImageToSingleTarget(userIds[i], imageBytes);
+  }
+}
+
+Future tryDownloadMedia(List<int> imageToken, {bool force = false}) async {
+  print("check if free network connection");
+
+  print("Downloading: " + imageToken.toString());
+}

lib/src/providers/api/api_utils.dart

@@ -0,0 +1,42 @@
+import 'package:fixnum/fixnum.dart';
+import 'package:twonly/src/proto/api/client_to_server.pb.dart' as client;
+import 'package:twonly/src/proto/api/client_to_server.pbserver.dart';
+import 'package:twonly/src/proto/api/error.pb.dart';
+import 'package:twonly/src/proto/api/server_to_client.pb.dart' as server;
+
+class Result<T, E> {
+  final T? value;
+  final E? error;
+
+  bool get isSuccess => value != null;
+  bool get isError => error != null;
+
+  Result.success(this.value) : error = null;
+  Result.error(this.error) : value = null;
+}
+
+Result asResult(server.ServerToClient? msg) {
+  if (msg == null) {
+    return Result.error(ErrorCode.InternalError);
+  }
+  if (msg.v0.response.hasOk()) {
+    return Result.success(msg.v0.response.ok);
+  } else {
+    return Result.error(msg.v0.response.error);
+  }
+}
+
+ClientToServer createClientToServerFromHandshake(Handshake handshake) {
+  var v0 = client.V0()
+    ..seq = Int64(0)
+    ..handshake = handshake;
+  return ClientToServer()..v0 = v0;
+}
+
+ClientToServer createClientToServerFromApplicationData(
+    ApplicationData applicationData) {
+  var v0 = client.V0()
+    ..seq = Int64(0)
+    ..applicationdata = applicationData;
+  return ClientToServer()..v0 = v0;
+}

lib/src/providers/api/server_messages.dart

@@ -0,0 +1,99 @@
+import 'dart:convert';
+import 'package:fixnum/fixnum.dart';
+import 'package:flutter/foundation.dart';
+import 'package:libsignal_protocol_dart/libsignal_protocol_dart.dart';
+import 'package:logging/logging.dart';
+import 'package:twonly/main.dart';
+import 'package:twonly/src/model/contacts_model.dart';
+import 'package:twonly/src/model/json/message.dart';
+import 'package:twonly/src/model/messages_model.dart';
+import 'package:twonly/src/proto/api/client_to_server.pb.dart' as client;
+import 'package:twonly/src/proto/api/client_to_server.pbserver.dart';
+import 'package:twonly/src/proto/api/server_to_client.pb.dart' as server;
+import 'package:twonly/src/providers/api/api.dart';
+import 'package:twonly/src/providers/api/api_utils.dart';
+// ignore: library_prefixes
+import 'package:twonly/src/utils/signal.dart' as SignalHelper;
+
+Future handleServerMessage(server.ServerToClient msg) async {
+  client.Response? response;
+
+  if (msg.v0.hasRequestNewPreKeys()) {
+    List<PreKeyRecord> localPreKeys = await SignalHelper.getPreKeys();
+
+    List<client.Response_PreKey> prekeysList = [];
+    for (int i = 0; i < localPreKeys.length; i++) {
+      prekeysList.add(client.Response_PreKey()
+        ..id = Int64(localPreKeys[i].id)
+        ..prekey = localPreKeys[i].getKeyPair().publicKey.serialize());
+    }
+    var prekeys = client.Response_Prekeys(prekeys: prekeysList);
+    var ok = client.Response_Ok()..prekeys = prekeys;
+    response = client.Response()..ok = ok;
+  } else if (msg.v0.hasNewMessage()) {
+    Uint8List body = Uint8List.fromList(msg.v0.newMessage.body);
+    Int64 fromUserId = msg.v0.newMessage.fromUserId;
+    Message? message = await SignalHelper.getDecryptedText(fromUserId, body);
+    if (message != null) {
+      switch (message.kind) {
+        case MessageKind.contactRequest:
+          Result username = await apiProvider.getUsername(fromUserId);
+          if (username.isSuccess) {
+            Uint8List name = username.value.userdata.username;
+            DbContacts.insertNewContact(
+                utf8.decode(name), fromUserId.toInt(), true);
+          }
+          break;
+        case MessageKind.rejectRequest:
+          DbContacts.deleteUser(fromUserId.toInt());
+          break;
+        case MessageKind.acceptRequest:
+          DbContacts.acceptUser(fromUserId.toInt());
+          break;
+        case MessageKind.ack:
+          DbMessages.acknowledgeMessageByUser(
+              fromUserId.toInt(), message.messageId!);
+          break;
+        default:
+          if (message.kind != MessageKind.textMessage &&
+              message.kind != MessageKind.video &&
+              message.kind != MessageKind.image) {
+            Logger("handleServerMessages")
+                .shout("Got unknown MessageKind $message");
+          } else {
+            String content = jsonEncode(message.content!.toJson());
+            await DbMessages.insertOtherMessage(
+                fromUserId.toInt(), message.kind, message.messageId!, content);
+
+            encryptAndSendMessage(
+              fromUserId,
+              Message(
+                kind: MessageKind.ack,
+                messageId: message.messageId!,
+                timestamp: DateTime.now(),
+              ),
+            );
+
+            if (message.kind == MessageKind.video ||
+                message.kind == MessageKind.image) {
+              dynamic content = message.content!;
+              List<int> downloadToken = content.downloadToken;
+              tryDownloadMedia(downloadToken);
+            }
+          }
+      }
+    }
+    var ok = client.Response_Ok()..none = true;
+    response = client.Response()..ok = ok;
+  } else {
+    Logger("handleServerMessage")
+        .shout("Got a new message from the server: $msg");
+    return;
+  }
+
+  var v0 = client.V0()
+    ..seq = msg.v0.seq
+    ..response = response;
+
+  apiProvider.sendResponse(ClientToServer()..v0 = v0);
+}

lib/src/providers/api_provider.dart

@@ -1,18 +1,15 @@
+import 'dart:async';
 import 'dart:collection';
-import 'dart:convert';
 import 'dart:math';
 import 'package:fixnum/fixnum.dart';
 import 'package:flutter/foundation.dart';
-import 'package:libsignal_protocol_dart/libsignal_protocol_dart.dart';
 import 'package:logging/logging.dart';
-import 'package:twonly/src/model/contacts_model.dart';
+import 'package:twonly/src/app.dart';
-import 'package:twonly/src/model/json/message.dart';
-import 'package:twonly/src/model/messages_model.dart';
-import 'package:twonly/src/proto/api/client_to_server.pb.dart' as client;
 import 'package:twonly/src/proto/api/client_to_server.pbserver.dart';
 import 'package:twonly/src/proto/api/error.pb.dart';
 import 'package:twonly/src/proto/api/server_to_client.pb.dart' as server;
-import 'package:twonly/src/utils/api.dart';
+import 'package:twonly/src/providers/api/api_utils.dart';
+import 'package:twonly/src/providers/api/server_messages.dart';
 import 'package:twonly/src/utils/misc.dart';
 import 'package:twonly/src/utils/storage.dart';
 // ignore: library_prefixes
@@ -22,30 +19,21 @@ import 'package:web_socket_channel/io.dart';
 import 'package:libsignal_protocol_dart/src/ecc/ed25519.dart';
 import 'package:web_socket_channel/web_socket_channel.dart';
 
-class Result<T, E> {
+/// The ApiProvider is responsible for communicating with the server.
-  final T? value;
+/// It handles errors and does automatically tries to reconnect on
-  final E? error;
+/// errors or network changes.
-
-  bool get isSuccess => value != null;
-  bool get isError => error != null;
-
-  Result.success(this.value) : error = null;
-  Result.error(this.error) : value = null;
-}
-
 class ApiProvider {
-  ApiProvider({required this.apiUrl, required this.backupApiUrl});
-
   final String apiUrl;
   final String? backupApiUrl;
+  ApiProvider({required this.apiUrl, required this.backupApiUrl});
+
+  final log = Logger("ApiProvider");
+
+  // reconnection params
+  Timer? reconnectionTimer;
   int _reconnectionDelay = 5;
-  bool _tryingToConnect = false;
-  final log = Logger("api_provider");
-  Function(bool)? _connectionStateCallback;
-  Function? _updatedContacts;
 
   final HashMap<Int64, server.ServerToClient?> messagesV0 = HashMap();
-
   IOWebSocketChannel? _channel;
 
   Future<bool> _connectTo(String apiUrl) async {
@@ -68,19 +56,23 @@ class ApiProvider {
     if (_channel != null && _channel!.closeCode != null) {
       return true;
     }
+    // ensure that the connect function is not called again by the timer.
+    if (reconnectionTimer != null) {
+      reconnectionTimer!.cancel();
+    }
 
     log.info("Trying to connect to the backend $apiUrl!");
     if (await _connectTo(apiUrl)) {
       await authenticate();
-      if (_connectionStateCallback != null) _connectionStateCallback!(true);
+      globalCallbackConnectionState(true);
       _reconnectionDelay = 5;
       return true;
     }
     if (backupApiUrl != null) {
       log.info("Trying to connect to the backup backend $backupApiUrl!");
       if (await _connectTo(backupApiUrl!)) {
+        globalCallbackConnectionState(true);
         await authenticate();
-        if (_connectionStateCallback != null) _connectionStateCallback!(true);
         _reconnectionDelay = 5;
         return true;
       }
@@ -91,42 +83,35 @@ class ApiProvider {
   bool get isConnected => _channel != null && _channel!.closeCode != null;
 
   void _onDone() {
-    if (_connectionStateCallback != null) {
+    globalCallbackConnectionState(false);
-      _connectionStateCallback!(false);
-    }
     _channel = null;
     tryToReconnect();
   }
 
   void _onError(dynamic e) {
-    if (_connectionStateCallback != null) {
+    globalCallbackConnectionState(false);
-      _connectionStateCallback!(false);
-    }
     _channel = null;
     tryToReconnect();
   }
 
-  void setConnectionStateCallback(Function(bool) callBack) {
-    _connectionStateCallback = callBack;
-  }
-
-  void setUpdatedContacts(Function callBack) {
-    _updatedContacts = callBack;
-  }
-
   void tryToReconnect() {
-    if (_tryingToConnect) return;
+    if (reconnectionTimer != null) {
-    _tryingToConnect = true;
+      reconnectionTimer!.cancel();
-    Future.delayed(Duration(seconds: _reconnectionDelay)).then(
+    }
-      (value) async {
+
-        _tryingToConnect = false;
+    final int randomDelay = Random().nextInt(20);
-        _reconnectionDelay = _reconnectionDelay + 2;
+    final int delay = _reconnectionDelay + randomDelay;
-        if (_reconnectionDelay > 20) {
+
-          _reconnectionDelay = 20;
+    debugPrint("Delay reconnection $delay");
+
+    reconnectionTimer = Timer(Duration(seconds: delay), () async {
+      // increase delay but set a maximum of 60 seconds (including the random delay)
+      _reconnectionDelay = _reconnectionDelay * 2;
+      if (_reconnectionDelay > 40) {
+        _reconnectionDelay = 40;
       }
       await connect();
-      },
+    });
-    );
   }
 
   void _onData(dynamic msgBuffer) {
@@ -135,103 +120,13 @@ class ApiProvider {
       if (msg.v0.hasResponse()) {
         messagesV0[msg.v0.seq] = msg;
       } else {
-        _handleServerMessage(msg);
+        handleServerMessage(msg);
       }
     } catch (e) {
       log.shout("Error parsing the servers message: $e");
     }
   }
 
-  Future _handleServerMessage(server.ServerToClient msg) async {
-    client.Response? response;
-
-    if (msg.v0.hasRequestNewPreKeys()) {
-      List<PreKeyRecord> localPreKeys = await SignalHelper.getPreKeys();
-
-      List<client.Response_PreKey> prekeysList = [];
-      for (int i = 0; i < localPreKeys.length; i++) {
-        prekeysList.add(client.Response_PreKey()
-          ..id = Int64(localPreKeys[i].id)
-          ..prekey = localPreKeys[i].getKeyPair().publicKey.serialize());
-      }
-      var prekeys = client.Response_Prekeys(prekeys: prekeysList);
-      var ok = client.Response_Ok()..prekeys = prekeys;
-      response = client.Response()..ok = ok;
-    } else if (msg.v0.hasNewMessage()) {
-      Uint8List body = Uint8List.fromList(msg.v0.newMessage.body);
-      Int64 fromUserId = msg.v0.newMessage.fromUserId;
-      Message? message = await SignalHelper.getDecryptedText(fromUserId, body);
-      if (message != null) {
-        switch (message.kind) {
-          case MessageKind.contactRequest:
-            Result username = await getUsername(fromUserId);
-            if (username.isSuccess) {
-              Uint8List name = username.value.userdata.username;
-              DbContacts.insertNewContact(
-                  utf8.decode(name), fromUserId.toInt(), true);
-            }
-            break;
-          case MessageKind.rejectRequest:
-            DbContacts.deleteUser(fromUserId.toInt());
-            break;
-          case MessageKind.acceptRequest:
-            DbContacts.acceptUser(fromUserId.toInt());
-            break;
-          case MessageKind.ack:
-            DbMessages.acknowledgeMessage(
-                fromUserId.toInt(), message.messageId!);
-            break;
-          default:
-            if (message.kind != MessageKind.textMessage &&
-                message.kind != MessageKind.video &&
-                message.kind != MessageKind.image) {
-              log.shout("Got unknown MessageKind $message");
-            } else {
-              String content = jsonEncode(message.content!.toJson());
-              await DbMessages.insertOtherMessage(fromUserId.toInt(),
-                  message.kind, message.messageId!, content);
-
-              encryptAndSendMessage(
-                fromUserId,
-                Message(
-                  kind: MessageKind.ack,
-                  messageId: message.messageId!,
-                  timestamp: DateTime.now(),
-                ),
-              );
-
-              if (message.kind == MessageKind.video ||
-                  message.kind == MessageKind.image) {
-                dynamic content = message.content!;
-                List<int> downloadToken = content.downloadToken;
-                tryDownloadMedia(downloadToken);
-              }
-            }
-        }
-      }
-      updateNotifier();
-      var ok = client.Response_Ok()..none = true;
-      response = client.Response()..ok = ok;
-    } else {
-      log.shout("Got a new message from the server: $msg");
-      return;
-    }
-
-    var v0 = client.V0()
-      ..seq = msg.v0.seq
-      ..response = response;
-    var res = ClientToServer()..v0 = v0;
-
-    final resBytes = res.writeToBuffer();
-    _channel!.sink.add(resBytes);
-  }
-
-  Future updateNotifier() async {
-    if (_updatedContacts != null) {
-      _updatedContacts!();
-    }
-  }
-
   Future<server.ServerToClient?> _waitForResponse(Int64 seq) async {
     final startTime = DateTime.now();
 
@@ -251,9 +146,13 @@ class ApiProvider {
     }
   }
 
-  Future<server.ServerToClient?> _sendRequestV0(ClientToServer request) async {
+  Future sendResponse(ClientToServer response) async {
+    _channel!.sink.add(response.writeToBuffer());
+  }
+
+  Future<Result> _sendRequestV0(ClientToServer request) async {
     if (_channel == null) {
-      return null;
+      return Result.error(ErrorCode.InternalError);
     }
     var seq = Int64(Random().nextInt(4294967296));
     while (messagesV0.containsKey(seq)) {
@@ -265,30 +164,7 @@ class ApiProvider {
 
     _channel!.sink.add(requestBytes);
 
-    return await _waitForResponse(seq);
+    return asResult(await _waitForResponse(seq));
-  }
-
-  ClientToServer createClientToServerFromHandshake(Handshake handshake) {
-    var v0 = client.V0()
-      ..seq = Int64(0)
-      ..handshake = handshake;
-    return ClientToServer()..v0 = v0;
-  }
-
-  ClientToServer createClientToServerFromApplicationData(
-      ApplicationData applicationData) {
-    var v0 = client.V0()
-      ..seq = Int64(0)
-      ..applicationdata = applicationData;
-    return ClientToServer()..v0 = v0;
-  }
-
-  Result _asResult(server.ServerToClient msg) {
-    if (msg.v0.response.hasOk()) {
-      return Result.success(msg.v0.response.ok);
-    } else {
-      return Result.error(msg.v0.response.error);
-    }
   }
 
   Future authenticate() async {
@@ -299,12 +175,7 @@ class ApiProvider {
     var handshake = Handshake()..getchallenge = Handshake_GetChallenge();
     var req = createClientToServerFromHandshake(handshake);
 
-    final resp = await _sendRequestV0(req);
+    final result = await _sendRequestV0(req);
-    if (resp == null) {
-      log.shout("Server is not reachable!");
-      return;
-    }
-    final result = _asResult(resp);
     if (result.isError) {
       log.shout(result);
       return;
@@ -328,12 +199,7 @@ class ApiProvider {
 
     var req2 = createClientToServerFromHandshake(opensession);
 
-    final resp2 = await _sendRequestV0(req2);
+    final result2 = await _sendRequestV0(req2);
-    if (resp2 == null) {
-      log.shout("Server is not reachable!");
-      return;
-    }
-    final result2 = _asResult(resp2);
     if (result2.isError) {
       log.shout(result2);
       return;
@@ -370,33 +236,21 @@ class ApiProvider {
     var handshake = Handshake()..register = register;
     var req = createClientToServerFromHandshake(handshake);
 
-    final resp = await _sendRequestV0(req);
+    return await _sendRequestV0(req);
-    if (resp == null) {
-      return Result.error(ErrorCode.InternalError);
-    }
-    return _asResult(resp);
   }
 
   Future<Result> getUsername(Int64 userId) async {
     var get = ApplicationData_GetUserById()..userId = userId;
     var appData = ApplicationData()..getuserbyid = get;
     var req = createClientToServerFromApplicationData(appData);
-    final resp = await _sendRequestV0(req);
+    return await _sendRequestV0(req);
-    if (resp == null) {
-      return Result.error(ErrorCode.InternalError);
-    }
-    return _asResult(resp);
   }
 
-  Future<Result> getUploadToken(int size) async {
+  Future<Result> getUploadToken() async {
-    var get = ApplicationData_GetUploadToken()..len = size;
+    var get = ApplicationData_GetUploadToken();
     var appData = ApplicationData()..getuploadtoken = get;
     var req = createClientToServerFromApplicationData(appData);
-    final resp = await _sendRequestV0(req);
+    return await _sendRequestV0(req);
-    if (resp == null) {
-      return Result.error(ErrorCode.InternalError);
-    }
-    return _asResult(resp);
   }
 
   Future<List<int>?> uploadData(List<int> uploadToken, Uint8List data) async {
@@ -409,23 +263,15 @@ class ApiProvider {
 
     var appData = ApplicationData()..uploaddata = get;
     var req = createClientToServerFromApplicationData(appData);
-    final resp = await _sendRequestV0(req);
+    final result = await _sendRequestV0(req);
-    if (resp == null) {
+    return result.isSuccess ? uploadToken : null;
-      return null;
-    }
-    return _asResult(resp).isSuccess ? uploadToken : null;
   }
 
   Future<Result> getUserData(String username) async {
     var get = ApplicationData_GetUserByUsername()..username = username;
     var appData = ApplicationData()..getuserbyusername = get;
     var req = createClientToServerFromApplicationData(appData);
-
+    return await _sendRequestV0(req);
-    final resp = await _sendRequestV0(req);
-    if (resp == null) {
-      return Result.error(ErrorCode.InternalError);
-    }
-    return _asResult(resp);
   }
 
   Future<Result> sendTextMessage(Int64 target, Uint8List msg) async {
@@ -436,10 +282,6 @@ class ApiProvider {
     var appData = ApplicationData()..textmessage = testMessage;
     var req = createClientToServerFromApplicationData(appData);
 
-    final resp = await _sendRequestV0(req);
+    return await _sendRequestV0(req);
-    if (resp == null) {
-      return Result.error(ErrorCode.InternalError);
-    }
-    return _asResult(resp);
   }
 }

lib/src/providers/contacts_change_provider.dart

@@ -1,50 +1,26 @@
-import 'dart:collection';
-
-import 'package:fixnum/fixnum.dart';
 import 'package:flutter/foundation.dart';
 import 'package:twonly/src/model/contacts_model.dart';
 import 'package:twonly/src/model/messages_model.dart';
 
-/// Mix-in [DiagnosticableTreeMixin] to have access to [debugFillProperties] for the devtool
+// This provider will update the UI on changes in the contact list
-// ignore: prefer_mixin
+class ContactChangeProvider with ChangeNotifier, DiagnosticableTreeMixin {
-class NotifyProvider with ChangeNotifier, DiagnosticableTreeMixin {
   // The page index of the HomeView widget
-  int _activePageIdx = 0;
+  // int _activePageIdx = 0;
 
   List<Contact> _allContacts = [];
   final Map<int, DbMessage> _lastMessagesGroupedByUser = <int, DbMessage>{};
 
-  final List<Int64> _sendingCurrentlyTo = [];
-
   int get newContactRequests => _allContacts
       .where((contact) => !contact.accepted && contact.requested)
       .length;
   List<Contact> get allContacts => _allContacts;
-  Map<int, DbMessage> get lastMessagesGroupedByUser =>
-      _lastMessagesGroupedByUser;
-  HashSet<Int64> get sendingCurrentlyTo =>
-      HashSet<Int64>.from(_sendingCurrentlyTo);
 
-  int get activePageIdx => _activePageIdx;
+  // int get activePageIdx => _activePageIdx;
 
-  void setActivePageIdx(int idx) {
+  // void setActivePageIdx(int idx) {
-    _activePageIdx = idx;
+  //   _activePageIdx = idx;
-    notifyListeners();
+  //   notifyListeners();
-  }
+  // }
-
-  void addSendingTo(Int64 user) {
-    _sendingCurrentlyTo.add(user);
-    notifyListeners();
-  }
-
-  // removes the first occurrence of the user
-  void removeSendingTo(Int64 user) {
-    int index = _sendingCurrentlyTo.indexOf(user);
-    if (index != -1) {
-      _sendingCurrentlyTo.removeAt(index);
-    }
-    notifyListeners();
-  }
 
   void update() async {
     _allContacts = await DbContacts.getUsers();

lib/src/providers/messages_change_provider.dart

@@ -0,0 +1,31 @@
+import 'package:flutter/foundation.dart';
+import 'package:twonly/src/model/contacts_model.dart';
+import 'package:twonly/src/model/messages_model.dart';
+
+/// This provider does always contains the latest messages send or received
+/// for every contact.
+class MessagesChangeProvider with ChangeNotifier, DiagnosticableTreeMixin {
+  final Map<int, DbMessage> _lastMessage = <int, DbMessage>{};
+
+  Map<int, DbMessage> get lastMessage => _lastMessage;
+
+  void updateLastMessageFor(int targetUserId) async {
+    DbMessage? last =
+        await DbMessages.getLastMessagesForPreviewForUser(targetUserId);
+    if (last != null) {
+      _lastMessage[last.otherUserId] = last;
+    }
+  }
+
+  void init() async {
+    // load everything from the database
+    List<Contact> allContacts = await DbContacts.getUsers();
+    for (Contact contact in allContacts) {
+      DbMessage? last = await DbMessages.getLastMessagesForPreviewForUser(
+          contact.userId.toInt());
+      if (last != null) {
+        _lastMessage[last.otherUserId] = last;
+      }
+    }
+  }
+}

lib/src/utils/api.dart

@@ -1,169 +0,0 @@
-import 'dart:convert';
-import 'dart:io';
-import 'package:fixnum/fixnum.dart';
-import 'package:flutter/foundation.dart';
-import 'package:flutter/material.dart';
-import 'package:logging/logging.dart';
-import 'package:provider/provider.dart';
-import 'package:twonly/main.dart';
-import 'package:twonly/src/app.dart';
-import 'package:twonly/src/model/contacts_model.dart';
-import 'package:twonly/src/model/json/message.dart';
-import 'package:twonly/src/model/messages_model.dart';
-import 'package:twonly/src/proto/api/error.pb.dart';
-import 'package:twonly/src/providers/api_provider.dart';
-import 'package:twonly/src/providers/notify_provider.dart';
-import 'package:twonly/src/utils/misc.dart';
-// ignore: library_prefixes
-import 'package:twonly/src/utils/signal.dart' as SignalHelper;
-import 'package:twonly/src/model/json/user_data.dart';
-
-Future<bool> addNewContact(String username) async {
-  final res = await apiProvider.getUserData(username);
-
-  if (res.isSuccess) {
-    bool added = await DbContacts.insertNewContact(
-        username, res.value.userdata.userId.toInt(), false);
-
-    if (!added) {
-      print("RETURN FALSE HIER!!!");
-      return false;
-    }
-
-    if (await SignalHelper.addNewContact(res.value.userdata)) {
-      Message msg =
-          Message(kind: MessageKind.contactRequest, timestamp: DateTime.now());
-
-      Uint8List? bytes =
-          await SignalHelper.encryptMessage(msg, res.value.userdata.userId);
-
-      if (bytes == null) {
-        Logger("utils/api").shout("Error encryption message!");
-        return res.error(ErrorCode.InternalError);
-      }
-
-      Result resp =
-          await apiProvider.sendTextMessage(res.value.userdata.userId, bytes);
-
-      return resp.isSuccess;
-    }
-  }
-  return res.isSuccess;
-}
-
-Future<Result> encryptAndSendMessage(Int64 userId, Message msg) async {
-  Uint8List? bytes = await SignalHelper.encryptMessage(msg, userId);
-
-  if (bytes == null) {
-    Logger("utils/api").shout("Error encryption message!");
-    return Result.error(ErrorCode.InternalError);
-  }
-
-  Result resp = await apiProvider.sendTextMessage(userId, bytes);
-
-  if (resp.isError) {
-    // TODO:
-    Logger("encryptAndSendMessage")
-        .shout("handle errors here and store them in the database");
-  }
-
-  return resp;
-}
-
-Future<Result> rejectUserRequest(Int64 userId) async {
-  Message msg =
-      Message(kind: MessageKind.rejectRequest, timestamp: DateTime.now());
-  return encryptAndSendMessage(userId, msg);
-}
-
-Future<Result> acceptUserRequest(Int64 userId) async {
-  Message msg =
-      Message(kind: MessageKind.acceptRequest, timestamp: DateTime.now());
-  return encryptAndSendMessage(userId, msg);
-}
-
-Future<Result> createNewUser(String username, String inviteCode) async {
-  final storage = getSecureStorage();
-
-  await SignalHelper.createIfNotExistsSignalIdentity();
-
-  final res = await apiProvider.register(username, inviteCode);
-
-  if (res.isSuccess) {
-    Logger("create_new_user").info("Got user_id ${res.value} from server");
-    final userData = UserData(
-        userId: res.value.userid, username: username, displayName: username);
-    storage.write(key: "user_data", value: jsonEncode(userData));
-  }
-
-  return res;
-}
-
-Future sendImageToSingleTarget(
-    BuildContext context, Int64 target, Uint8List encryptBytes) async {
-  Result res = await apiProvider.getUploadToken(encryptBytes.length);
-
-  if (res.isError || !res.value.hasUploadtoken()) {
-    Logger("api.dart").shout("Error getting upload token!");
-    return null;
-  }
-  List<int> uploadToken = res.value.uploadtoken;
-  Logger("sendImageToSingleTarget").info("Got token: $uploadToken");
-
-  MessageContent content =
-      MessageContent(text: null, downloadToken: uploadToken);
-  int? messageId = await DbMessages.insertMyMessage(
-      target.toInt(), MessageKind.image, jsonEncode(content.toJson()));
-  if (messageId == null) return;
-
-  updateNotifyProvider();
-
-  List<int>? imageToken =
-      await apiProvider.uploadData(uploadToken, encryptBytes);
-  if (imageToken == null) {
-    Logger("api.dart").shout("handle error uploading like saving...");
-    return;
-  }
-
-  print("TODO: insert into DB and then create this MESSAGE");
-
-  Message msg = Message(
-    kind: MessageKind.image,
-    messageId: messageId,
-    content: content,
-    timestamp: DateTime.now(),
-  );
-
-  await encryptAndSendMessage(target, msg);
-  removeSendingTo(target);
-}
-
-Future sendImage(
-    BuildContext context, List<Contact> users, String imagePath) async {
-  // 1. set notifier provider
-
-  File imageFile = File(imagePath);
-
-  Uint8List? imageBytes = await getCompressedImage(imageFile);
-  if (imageBytes == null) {
-    Logger("api.dart").shout("Error compressing image!");
-    return;
-  }
-
-  for (int i = 0; i < users.length; i++) {
-    Int64 target = users[i].userId;
-    Uint8List? encryptedImage =
-        await SignalHelper.encryptBytes(imageBytes, target);
-    if (encryptedImage == null) {
-      Logger("api.dart").shout("Error encrypting image!");
-      continue;
-    }
-    sendImageToSingleTarget(context, target, encryptedImage);
-  }
-}
-
-Future tryDownloadMedia(List<int> imageToken, {bool force = false}) async {
-  print("check if free network connection");
-
-  print("Downloading: " + imageToken.toString());
-}

lib/src/utils/misc.dart

@@ -1,11 +1,9 @@
 import 'dart:io';
 import 'dart:math';
 import 'dart:typed_data';
-import 'dart:ui';
 import 'package:flutter/material.dart';
 import 'package:flutter_image_compress/flutter_image_compress.dart';
 import 'package:gal/gal.dart';
-import 'package:image/image.dart';
 import 'package:logging/logging.dart';
 import 'package:path_provider/path_provider.dart';
 import 'package:flutter_secure_storage/flutter_secure_storage.dart';
@@ -127,7 +125,5 @@ Future<Uint8List?> getCompressedImage(File file) async {
     file.absolute.path,
     quality: 90,
   );
-  print(file.lengthSync());
-  print(result!.length);
   return result;
 }

lib/src/views/chat_list_view.dart

@@ -1,6 +1,3 @@
-import 'dart:collection';
-
-import 'package:fixnum/fixnum.dart';
 import 'package:provider/provider.dart';
 import 'package:twonly/src/components/initialsavatar.dart';
 import 'package:twonly/src/components/message_send_state_icon.dart';
@@ -8,13 +5,14 @@ import 'package:twonly/src/components/notification_badge.dart';
 import 'package:twonly/src/components/user_context_menu.dart';
 import 'package:twonly/src/model/contacts_model.dart';
 import 'package:twonly/src/model/messages_model.dart';
-import 'package:twonly/src/providers/notify_provider.dart';
+import 'package:twonly/src/providers/contacts_change_provider.dart';
+import 'package:twonly/src/providers/messages_change_provider.dart';
 import 'package:twonly/src/utils/misc.dart';
 import 'package:twonly/src/views/chat_item_details_view.dart';
+import 'package:twonly/src/views/home_view.dart';
 import 'package:twonly/src/views/search_username_view.dart';
 import 'package:flutter_gen/gen_l10n/app_localizations.dart';
 import 'package:flutter/material.dart';
-import 'dart:async';
 
 class ChatItem {
   const ChatItem(
@@ -42,22 +40,20 @@ class _ChatListViewState extends State<ChatListView> {
   @override
   Widget build(BuildContext context) {
     Map<int, DbMessage> lastMessages =
-        context.watch<NotifyProvider>().lastMessagesGroupedByUser;
+        context.watch<MessagesChangeProvider>().lastMessage;
 
-    HashSet<Int64> sendingCurrentlyTo =
+    List<Contact> allUsers = context.read<ContactChangeProvider>().allContacts;
-        context.watch<NotifyProvider>().sendingCurrentlyTo;
 
-    List<Contact> activeUsers = context
+    List<Contact> activeUsers = allUsers
-        .read<NotifyProvider>()
-        .allContacts
         .where((x) => lastMessages.containsKey(x.userId.toInt()))
         .toList();
+
     return Scaffold(
       appBar: AppBar(
         title: Text(AppLocalizations.of(context)!.chatsTitle),
         actions: [
           NotificationBadge(
-              count: context.watch<NotifyProvider>().newContactRequests,
+            count: context.watch<ContactChangeProvider>().newContactRequests,
             child: IconButton(
               icon: Icon(Icons.person_add),
               onPressed: () {
@@ -72,37 +68,32 @@ class _ChatListViewState extends State<ChatListView> {
           )
         ],
       ),
-        body: Column(
+      body: (activeUsers.isEmpty)
-          children: [
+          ? Center(
-            // if (sendingCurrentlyTo.isNotEmpty)
+              child: Padding(
-            //   Container(
+                padding: const EdgeInsets.all(10),
-            //     padding: EdgeInsets.symmetric(vertical: 10, horizontal: 10),
+                child: OutlinedButton.icon(
-            //     child: ListTile(
+                    icon: Icon((allUsers.isEmpty)
-            //       leading: Stack(
+                        ? Icons.person_add
-            //         // child: Stack(
+                        : Icons.camera_alt),
-            //         alignment: Alignment.center,
+                    onPressed: () {
-            //         children: [
+                      (allUsers.isEmpty)
-            //           CircularProgressIndicator(
+                          ? Navigator.push(
-            //             strokeWidth: 1,
+                              context,
-            //           ),
+                              MaterialPageRoute(
-            //           Icon(
+                                builder: (context) => SearchUsernameView(),
-            //             Icons.send, // Replace with your desired icon
+                              ),
-            //             color: Theme.of(context).colorScheme.primary,
+                            )
-            //             size: 20, // Adjust the size as needed
+                          : globalUpdateOfHomeViewPageIndex(1);
-            //           ),
+                    },
-            //         ],
+                    label: Text((allUsers.isEmpty)
-            //         // ),
+                        ? AppLocalizations.of(context)!
-            //       ),
+                            .chatListViewSearchUserNameBtn
-            //       title: Text(sendingCurrentlyTo
+                        : AppLocalizations.of(context)!
-            //           .map((e) => _activeUsers
+                            .chatListViewSendFirstTwonly)),
-            //               .where((c) => c.userId == e)
+              ),
-            //               .map((c) => c.displayName))
+            )
-            //           .toList()
+          : ListView.builder(
-            //           .join(", ")),
-            //     ),
-            // ), //
-            Expanded(
-              child: ListView.builder(
               restorationId: 'chat_list_view',
               itemCount: activeUsers.length,
               itemBuilder: (BuildContext context, int index) {
@@ -110,25 +101,20 @@ class _ChatListViewState extends State<ChatListView> {
                 return UserListItem(
                   user: user,
                   lastMessage: lastMessages[user.userId.toInt()]!,
-                    isSending: sendingCurrentlyTo.contains(user.userId),
                 );
               },
             ),
-            )
+    );
-          ],
-        ));
   }
 }
 
 class UserListItem extends StatefulWidget {
   final Contact user;
   final DbMessage lastMessage;
-  final bool isSending;
 
   const UserListItem({
     super.key,
     required this.user,
-    required this.isSending,
     required this.lastMessage,
   });
 
@@ -146,11 +132,11 @@ class _UserListItem extends State<UserListItem> {
     //_loadAsync();
   }
 
-  Future _loadAsync() async {
+  // Future _loadAsync() async {
   // flames = await widget.user.getFlames();
   // lastMessageInSeconds = await widget.user.getLastMessageInSeconds();
-    setState(() {});
+  //   setState(() {});
-  }
+  // }
 
   @override
   Widget build(BuildContext context) {
@@ -161,7 +147,7 @@ class _UserListItem extends State<UserListItem> {
         .difference(widget.lastMessage.sendOrReceivedAt)
         .inSeconds;
 
-    if (widget.isSending) {
+    if (!widget.lastMessage.messageAcknowledgeByServer) {
       state = MessageSendState.sending;
     } else {
       if (widget.lastMessage.messageOtherId == null) {

lib/src/views/home_view.dart

@@ -1,14 +1,11 @@
 import 'package:pie_menu/pie_menu.dart';
-import 'package:provider/provider.dart';
-import 'package:twonly/src/providers/notify_provider.dart';
-
 import 'camera_preview_view.dart';
 import 'chat_list_view.dart';
 import 'profile_view.dart';
 import '../settings/settings_controller.dart';
 import 'package:flutter/material.dart';
 
-final PageController homeViewPageController = PageController(initialPage: 0);
+Function(int) globalUpdateOfHomeViewPageIndex = (a) {};
 
 class HomeView extends StatefulWidget {
   const HomeView({super.key, required this.settingsController});
@@ -19,6 +16,27 @@ class HomeView extends StatefulWidget {
 }
 
 class HomeViewState extends State<HomeView> {
+  int activePageIdx = 0;
+  final PageController homeViewPageController = PageController(initialPage: 0);
+
+  @override
+  void initState() {
+    super.initState();
+    globalUpdateOfHomeViewPageIndex = (index) {
+      homeViewPageController.jumpToPage(index);
+      setState(() {
+        activePageIdx = index;
+      });
+    };
+  }
+
+  @override
+  void dispose() {
+    // disable globalCallbacks to the flutter tree
+    globalUpdateOfHomeViewPageIndex = (a) {};
+    super.dispose();
+  }
+
   @override
   Widget build(BuildContext context) {
     return PieCanvas(
@@ -47,7 +65,7 @@ class HomeViewState extends State<HomeView> {
         body: PageView(
           controller: homeViewPageController,
           onPageChanged: (index) {
-            context.read<NotifyProvider>().setActivePageIdx(index);
+            activePageIdx = index;
           },
           children: [
             ChatListView(),
@@ -69,14 +87,16 @@ class HomeViewState extends State<HomeView> {
             BottomNavigationBarItem(icon: Icon(Icons.verified_user), label: ""),
           ],
           onTap: (int index) {
-            context.read<NotifyProvider>().setActivePageIdx(index);
+            activePageIdx = index;
             setState(() {
-              homeViewPageController.animateToPage(index,
+              homeViewPageController.animateToPage(
+                index,
                 duration: const Duration(milliseconds: 100),
-                  curve: Curves.bounceIn);
+                curve: Curves.bounceIn,
+              );
             });
           },
-          currentIndex: context.watch<NotifyProvider>().activePageIdx,
+          currentIndex: activePageIdx,
         ),
       ),
     );

lib/src/views/register_view.dart

@@ -1,9 +1,12 @@
+import 'dart:convert';
+import 'package:logging/logging.dart';
 import 'package:twonly/main.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter_gen/gen_l10n/app_localizations.dart';
-import 'package:twonly/src/utils/api.dart';
+import 'package:twonly/src/model/json/user_data.dart';
 import 'package:twonly/src/utils/misc.dart';
+import 'package:twonly/src/utils/signal.dart';
 
 class RegisterView extends StatefulWidget {
   const RegisterView({super.key, required this.callbackOnSuccess});
@@ -19,6 +22,41 @@ class _RegisterViewState extends State<RegisterView> {
 
   bool _isTryingToRegister = false;
 
+  Future createNewUser() async {
+    String username = usernameController.text;
+    String inviteCode = inviteCodeController.text;
+    setState(() {
+      _isTryingToRegister = true;
+    });
+
+    final storage = getSecureStorage();
+
+    await createIfNotExistsSignalIdentity();
+
+    final res = await apiProvider.register(username, inviteCode);
+
+    if (res.isSuccess) {
+      Logger("create_new_user").info("Got user_id ${res.value} from server");
+      final userData = UserData(
+          userId: res.value.userid, username: username, displayName: username);
+      storage.write(key: "user_data", value: jsonEncode(userData));
+    }
+
+    setState(() {
+      _isTryingToRegister = false;
+    });
+
+    if (res.isSuccess) {
+      apiProvider.authenticate();
+      widget.callbackOnSuccess();
+      return;
+    }
+
+    if (context.mounted) {
+      showAlertDialog(context, "Oh no!", errorCodeToText(context, res.error));
+    }
+  }
+
   @override
   Widget build(BuildContext context) {
     InputDecoration getInputDecoration(hintText) {
@@ -117,23 +155,7 @@ class _RegisterViewState extends State<RegisterView> {
                           )
                         : Icon(Icons.group),
                     onPressed: () async {
-                      setState(() {
+                      createNewUser();
-                        _isTryingToRegister = true;
-                      });
-                      final res = await createNewUser(
-                          usernameController.text, inviteCodeController.text);
-                      setState(() {
-                        _isTryingToRegister = false;
-                        apiProvider.authenticate();
-                      });
-                      if (res.isSuccess) {
-                        widget.callbackOnSuccess();
-                        return;
-                      }
-                      if (context.mounted) {
-                        final errMsg = errorCodeToText(context, res.error);
-                        showAlertDialog(context, "Oh no!", errMsg);
-                      }
                     },
                     style: ButtonStyle(
                         padding: WidgetStateProperty.all<EdgeInsets>(

lib/src/views/search_username_view.dart

@@ -2,12 +2,16 @@ import 'dart:async';
 import 'package:flutter/material.dart';
 import 'package:flutter_gen/gen_l10n/app_localizations.dart';
 import 'package:provider/provider.dart';
+import 'package:twonly/main.dart';
 import 'package:twonly/src/components/headline.dart';
 import 'package:twonly/src/components/initialsavatar.dart';
 import 'package:twonly/src/model/contacts_model.dart';
-import 'package:twonly/src/providers/notify_provider.dart';
+import 'package:twonly/src/model/json/message.dart';
-import 'package:twonly/src/utils/api.dart';
+import 'package:twonly/src/providers/contacts_change_provider.dart';
+import 'package:twonly/src/providers/api/api.dart';
 import 'package:twonly/src/views/register_view.dart';
+// ignore: library_prefixes
+import 'package:twonly/src/utils/signal.dart' as SignalHelper;
 
 class SearchUsernameView extends StatefulWidget {
   const SearchUsernameView({super.key});
@@ -25,24 +29,30 @@ class _SearchUsernameView extends State<SearchUsernameView> {
       _isLoading = true;
     });
 
-    final status = await addNewContact(searchUserName.text);
+    final res = await apiProvider.getUserData(searchUserName.text);
 
+    if (res.isSuccess) {
+      bool added = await DbContacts.insertNewContact(
+        searchUserName.text,
+        res.value.userdata.userId.toInt(),
+        false,
+      );
+
+      if (added) {
+        if (await SignalHelper.addNewContact(res.value.userdata)) {
+          encryptAndSendMessage(
+            res.value.userdata.userId,
+            Message(
+              kind: MessageKind.contactRequest,
+              timestamp: DateTime.now(),
+            ),
+          );
+        }
+      }
+    }
     setState(() {
       _isLoading = false;
     });
-
-    if (context.mounted) {
-      if (status) {
-        context.read<NotifyProvider>().update();
-      } else if (context.mounted) {
-        showAlertDialog(
-            context,
-            AppLocalizations.of(context)!.searchUsernameNotFound,
-            AppLocalizations.of(context)!
-                .searchUsernameNotFoundLong(searchUserName.text));
-      }
-    }
-    return status;
   }
 
   @override
@@ -94,7 +104,7 @@ class _SearchUsernameView extends State<SearchUsernameView> {
             ),
             SizedBox(height: 30),
             if (context
-                .read<NotifyProvider>()
+                .read<ContactChangeProvider>()
                 .allContacts
                 .where((contact) => !contact.accepted)
                 .isNotEmpty)
@@ -122,6 +132,8 @@ class _SearchUsernameView extends State<SearchUsernameView> {
 }
 
 class ContactsListView extends StatefulWidget {
+  const ContactsListView({super.key});
+
   @override
   State<ContactsListView> createState() => _ContactsListViewState();
 }
@@ -130,7 +142,7 @@ class _ContactsListViewState extends State<ContactsListView> {
   @override
   Widget build(BuildContext context) {
     List<Contact> contacts = context
-        .read<NotifyProvider>()
+        .read<ContactChangeProvider>()
         .allContacts
         .where((contact) => !contact.accepted)
         .toList();
@@ -143,9 +155,9 @@ class _ContactsListViewState extends State<ContactsListView> {
           leading: InitialsAvatar(displayName: contact.displayName),
           trailing: Row(
             mainAxisSize: MainAxisSize.min,
-            children: (!contact.requested)
+            children: [
-                ? [Text('Pending')]
+              if (!contact.requested) Text('Pending'),
-                : [
+              if (contact.requested) ...[
                 Tooltip(
                   message: "Block the user without informing.",
                   child: IconButton(
@@ -153,9 +165,6 @@ class _ContactsListViewState extends State<ContactsListView> {
                         color: const Color.fromARGB(164, 244, 67, 54)),
                     onPressed: () async {
                       await DbContacts.blockUser(contact.userId.toInt());
-                          if (context.mounted) {
-                            context.read<NotifyProvider>().update();
-                          }
                     },
                   ),
                 ),
@@ -165,10 +174,13 @@ class _ContactsListViewState extends State<ContactsListView> {
                     icon: Icon(Icons.close, color: Colors.red),
                     onPressed: () async {
                       await DbContacts.deleteUser(contact.userId.toInt());
-                          if (context.mounted) {
+                      encryptAndSendMessage(
-                            context.read<NotifyProvider>().update();
+                        contact.userId,
-                          }
+                        Message(
-                          rejectUserRequest(contact.userId);
+                          kind: MessageKind.rejectRequest,
+                          timestamp: DateTime.now(),
+                        ),
+                      );
                     },
                   ),
                 ),
@@ -176,13 +188,17 @@ class _ContactsListViewState extends State<ContactsListView> {
                   icon: Icon(Icons.check, color: Colors.green),
                   onPressed: () async {
                     await DbContacts.acceptUser(contact.userId.toInt());
-                        if (context.mounted) {
+                    encryptAndSendMessage(
-                          context.read<NotifyProvider>().update();
+                      contact.userId,
-                        }
+                      Message(
-                        acceptUserRequest(contact.userId);
+                        kind: MessageKind.acceptRequest,
+                        timestamp: DateTime.now(),
+                      ),
+                    );
                   },
                 ),
               ],
+            ],
           ),
         );
       },

lib/src/views/share_image_view.dart

@@ -2,14 +2,11 @@ import 'dart:collection';
 import 'package:fixnum/fixnum.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_gen/gen_l10n/app_localizations.dart';
-import 'package:provider/provider.dart';
-import 'package:twonly/src/app.dart';
 import 'package:twonly/src/components/best_friends_selector.dart';
 import 'package:twonly/src/components/headline.dart';
 import 'package:twonly/src/components/initialsavatar.dart';
 import 'package:twonly/src/model/contacts_model.dart';
-import 'package:twonly/src/providers/notify_provider.dart';
+import 'package:twonly/src/providers/api/api.dart';
-import 'package:twonly/src/utils/api.dart';
 import 'package:twonly/src/utils/misc.dart';
 import 'package:twonly/src/views/home_view.dart';
 
@@ -112,21 +109,12 @@ class _ShareImageView extends State<ShareImageView> {
               FilledButton.icon(
                 icon: Icon(Icons.send),
                 onPressed: () async {
-                  for (Int64 a in _selectedUserIds) {
+                  sendImage(_selectedUserIds.toList(), widget.image);
-                    addSendingTo(a);
-                  }
-
-                  sendImage(
-                      context,
-                      _users
-                          .where((c) => _selectedUserIds.contains(c.userId))
-                          .toList(),
-                      widget.image);
 
+                  // TODO: pop back to the HomeView page popUntil did not work. check later how to improve in case of pushing more then 2
                   Navigator.pop(context);
                   Navigator.pop(context);
-                  context.read<NotifyProvider>().setActivePageIdx(0);
+                  globalUpdateOfHomeViewPageIndex(0);
-                  homeViewPageController.jumpToPage(0);
                 },
                 style: ButtonStyle(
                   padding: WidgetStateProperty.all<EdgeInsets>(