UIMessage communication. Single instancing for server and re-connection mechanism on suspension.

Wino.BackgroundTasks/SessionConnectedTask.cs

@@ -1,13 +1,4 @@
-using System;
+using Windows.ApplicationModel.Background;
-using Microsoft.Extensions.DependencyInjection;
-using Serilog;
-using Windows.ApplicationModel.Background;
-using Windows.Storage;
-using Wino.Core;
-using Wino.Core.Domain.Interfaces;
-using Wino.Core.Services;
-using Wino.Core.UWP;
-using Wino.Services;
 
 namespace Wino.BackgroundTasks
 {
@@ -17,32 +8,34 @@ namespace Wino.BackgroundTasks
         {
             var def = taskInstance.GetDeferral();
 
-            try
+            //try
-            {
+            //{
-                var services = new ServiceCollection();
+            //    var services = new ServiceCollection();
 
-                services.RegisterCoreServices();
+            //    services.RegisterCoreServices();
-                services.RegisterCoreUWPServices();
+            //    services.RegisterCoreUWPServices();
 
-                var providere = services.BuildServiceProvider();
+            //    var providere = services.BuildServiceProvider();
 
-                var backgroundTaskService = providere.GetService<IBackgroundSynchronizer>();
+            //    var backgroundTaskService = providere.GetService<IBackgroundSynchronizer>();
-                var dbService = providere.GetService<IDatabaseService>();
+            //    var dbService = providere.GetService<IDatabaseService>();
-                var logInitializer = providere.GetService<ILogInitializer>();
+            //    var logInitializer = providere.GetService<ILogInitializer>();
 
-                logInitializer.SetupLogger(ApplicationData.Current.LocalFolder.Path);
+            //    logInitializer.SetupLogger(ApplicationData.Current.LocalFolder.Path);
 
-                await dbService.InitializeAsync();
+            //    await dbService.InitializeAsync();
-                await backgroundTaskService.RunBackgroundSynchronizationAsync(Core.Domain.Enums.BackgroundSynchronizationReason.SessionConnected);
+            //    await backgroundTaskService.RunBackgroundSynchronizationAsync(Core.Domain.Enums.BackgroundSynchronizationReason.SessionConnected);
-            }
+            //}
-            catch (Exception ex)
+            //catch (Exception ex)
-            {
+            //{
-                Log.Error(ex, "Background synchronization failed from background task.");
+            //    Log.Error(ex, "Background synchronization failed from background task.");
-            }
+            //}
-            finally
+            //finally
-            {
+            //{
-                def.Complete();
+            //    def.Complete();
-            }
+            //}
+
+            def.Complete();
         }
     }
 }

Wino.Core.Domain/Interfaces/IServerMessage.cs

@@ -6,5 +6,6 @@
     /// They are sent either from processor or view models to signal some other
     /// parts of the application.
     /// </summary>
+
     public interface IServerMessage;
 }

Wino.Core.Domain/Interfaces/IWinoServerConnectionManager.cs

@@ -1,13 +1,17 @@
-using System.Threading.Tasks;
+using System;
+using System.Threading.Tasks;
 using Wino.Core.Domain.Enums;
 
 namespace Wino.Core.Domain.Interfaces
 {
     public interface IWinoServerConnectionManager
     {
-        WinoServerConnectionStatus Status { get; }
         Task<bool> ConnectAsync();
         Task<bool> DisconnectAsync();
+
+        WinoServerConnectionStatus Status { get; }
+        event EventHandler<WinoServerConnectionStatus> StatusChanged;
+        void DisposeConnection();
     }
 
     public interface IWinoServerConnectionManager<TAppServiceConnection> : IWinoServerConnectionManager, IInitializeAsync

Wino.Core.UWP/CoreUWPContainerSetup.cs

@@ -25,7 +25,6 @@ namespace Wino.Core.UWP
             services.AddTransient<IFileService, FileService>();
             services.AddTransient<IStoreRatingService, StoreRatingService>();
             services.AddTransient<IKeyPressService, KeyPressService>();
-            services.AddTransient<IBackgroundSynchronizer, BackgroundSynchronizer>();
             services.AddTransient<INotificationBuilder, NotificationBuilder>();
             services.AddTransient<IClipboardService, ClipboardService>();
         }

Wino.Core.UWP/Services/BackgroundSynchronizer.cs

@@ -1,144 +0,0 @@
-using System;
-using System.Threading.Tasks;
-using Serilog;
-using Windows.Storage;
-using Wino.Core;
-using Wino.Core.Domain.Enums;
-using Wino.Core.Domain.Exceptions;
-using Wino.Core.Domain.Interfaces;
-using Wino.Core.Domain.Models.Synchronization;
-using Wino.Core.Synchronizers;
-
-namespace Wino.Services
-{
-    public interface IBackgroundSynchronizer
-    {
-        Task RunBackgroundSynchronizationAsync(BackgroundSynchronizationReason reason);
-        void CreateLock();
-        void ReleaseLock();
-        bool IsBackgroundSynchronizationLocked();
-    }
-
-    /// <summary>
-    /// Service responsible for handling background synchronization on timer and session connected events.
-    /// </summary>
-    public class BackgroundSynchronizer : IBackgroundSynchronizer
-    {
-        private const string BackgroundSynchronizationLock = nameof(BackgroundSynchronizationLock);
-
-        private readonly IAccountService _accountService;
-        private readonly IFolderService _folderService;
-        private readonly IWinoSynchronizerFactory _winoSynchronizerFactory;
-
-        public BackgroundSynchronizer(IAccountService accountService,
-                                     IFolderService folderService,
-                                     IWinoSynchronizerFactory winoSynchronizerFactory)
-        {
-            _accountService = accountService;
-            _folderService = folderService;
-            _winoSynchronizerFactory = winoSynchronizerFactory;
-        }
-
-        public void CreateLock() => ApplicationData.Current.LocalSettings.Values[BackgroundSynchronizationLock] = true;
-        public void ReleaseLock() => ApplicationData.Current.LocalSettings.Values[BackgroundSynchronizationLock] = false;
-
-        public bool IsBackgroundSynchronizationLocked()
-            => ApplicationData.Current.LocalSettings.Values.ContainsKey(BackgroundSynchronizationLock)
-            && ApplicationData.Current.LocalSettings.Values[BackgroundSynchronizationLock] is bool boolValue && boolValue;
-
-        public async Task RunBackgroundSynchronizationAsync(BackgroundSynchronizationReason reason)
-        {
-            Log.Information($"{reason} background synchronization is kicked in.");
-
-            // This should never crash.
-            // We might be in-process or out-of-process.
-
-            //if (IsBackgroundSynchronizationLocked())
-            //{
-            //    Log.Warning("Background synchronization is locked. Hence another background synchronization is canceled.");
-            //    return;
-            //}
-
-            try
-            {
-                CreateLock();
-
-                var accounts = await _accountService.GetAccountsAsync();
-
-                foreach (var account in accounts)
-                {
-                    // We can't sync broken account.
-                    if (account.AttentionReason != AccountAttentionReason.None)
-                        continue;
-
-                    // TODO
-                    // We can't synchronize without system folder setup is done.
-                    //var isSystemFolderSetupDone = await _folderService.CheckSystemFolderSetupDoneAsync(account.Id);
-
-                    //// No need to throw here. It's a background process.
-                    //if (!isSystemFolderSetupDone)
-                    //    continue;
-
-                    var synchronizer = _winoSynchronizerFactory.GetAccountSynchronizer(account.Id);
-
-                    if (synchronizer.State != AccountSynchronizerState.Idle)
-                    {
-                        Log.Information("Skipping background synchronization for {Name} since current state is {State}", synchronizer.Account.Name, synchronizer.State);
-
-                        return;
-                    }
-
-                    await HandleSynchronizationAsync(synchronizer, reason);
-                }
-            }
-            catch (Exception ex)
-            {
-                Log.Error($"[BackgroundSynchronization] Failed with message {ex.Message}");
-            }
-            finally
-            {
-                ReleaseLock();
-            }
-        }
-
-        private async Task HandleSynchronizationAsync(IBaseSynchronizer synchronizer, BackgroundSynchronizationReason reason)
-        {
-            if (synchronizer.State != AccountSynchronizerState.Idle) return;
-
-            var account = synchronizer.Account;
-
-            try
-            {
-                // SessionConnected will do Full synchronization for logon, Timer task will do Inbox only.
-
-                var syncType = reason == BackgroundSynchronizationReason.SessionConnected ? SynchronizationType.Full : SynchronizationType.Inbox;
-
-                var options = new SynchronizationOptions()
-                {
-                    AccountId = account.Id,
-                    Type = syncType,
-                };
-
-                await synchronizer.SynchronizeAsync(options);
-            }
-            catch (AuthenticationAttentionException authenticationAttentionException)
-            {
-                Log.Error(authenticationAttentionException, $"[BackgroundSync] Invalid credentials for account {account.Address}");
-
-                account.AttentionReason = AccountAttentionReason.InvalidCredentials;
-                await _accountService.UpdateAccountAsync(account);
-            }
-            catch (SystemFolderConfigurationMissingException configMissingException)
-            {
-                Log.Error(configMissingException, $"[BackgroundSync] Missing system folder configuration for account {account.Address}");
-
-                account.AttentionReason = AccountAttentionReason.MissingSystemFolderConfiguration;
-                await _accountService.UpdateAccountAsync(account);
-            }
-            catch (Exception ex)
-            {
-                Log.Error(ex, "[BackgroundSync] Synchronization failed.");
-            }
-        }
-    }
-}

Wino.Core.UWP/Services/WinoServerConnectionManager.cs

@@ -1,18 +1,36 @@
 using System;
+using System.Text.Json;
 using System.Threading.Tasks;
-using CommunityToolkit.Mvvm.ComponentModel;
+using CommunityToolkit.Mvvm.Messaging;
 using Windows.ApplicationModel;
 using Windows.ApplicationModel.AppService;
 using Windows.Foundation.Metadata;
 using Wino.Core.Domain.Enums;
 using Wino.Core.Domain.Interfaces;
+using Wino.Messaging;
+using Wino.Messaging.Enums;
+using Wino.Messaging.Server;
 
 namespace Wino.Core.UWP.Services
 {
-    public partial class WinoServerConnectionManager : ObservableObject, IWinoServerConnectionManager<AppServiceConnection>
+    public class WinoServerConnectionManager : IWinoServerConnectionManager<AppServiceConnection>
     {
+        private WinoServerConnectionStatus status;
+
+        public WinoServerConnectionStatus Status
+        {
+            get { return status; }
+            private set
+            {
+                status = value;
+                StatusChanged?.Invoke(this, value);
+            }
+        }
+
         private AppServiceConnection _connection;
 
+        public event EventHandler<WinoServerConnectionStatus> StatusChanged;
+
         public AppServiceConnection Connection
         {
             get { return _connection; }
@@ -40,9 +58,6 @@ namespace Wino.Core.UWP.Services
             }
         }
 
-        [ObservableProperty]
-        private WinoServerConnectionStatus _status;
-
         public async Task<bool> ConnectAsync()
         {
             if (Status == WinoServerConnectionStatus.Connected) return true;
@@ -87,12 +102,98 @@ namespace Wino.Core.UWP.Services
 
         private void ServerMessageReceived(AppServiceConnection sender, AppServiceRequestReceivedEventArgs args)
         {
-            // TODO: Handle server messsages.
+            if (args.Request.Message.TryGetValue(MessageConstants.MessageTypeKey, out object messageTypeObject) && messageTypeObject is int messageTypeInt)
+            {
+                var messageType = (MessageType)messageTypeInt;
+
+                if (args.Request.Message.TryGetValue(MessageConstants.MessageDataKey, out object messageDataObject) && messageDataObject is string messageJson)
+                {
+                    switch (messageType)
+                    {
+                        case MessageType.UIMessage:
+                            if (args.Request.Message.TryGetValue(MessageConstants.MessageDataTypeKey, out object dataTypeObject) && dataTypeObject is string dataTypeName)
+                            {
+                                HandleUIMessage(messageJson, dataTypeName);
+                            }
+                            else
+                                throw new ArgumentException("Message data type is missing.");
+
+                            break;
+                        case MessageType.ServerAction:
+                            HandleServerAction(messageJson);
+                            break;
+                        default:
+                            break;
+                    }
+                }
+            }
+        }
+
+        private void HandleServerAction(string messageJson)
+        {
+
+        }
+
+        /// <summary>
+        /// Unpacks IServerMessage objects and delegate it to Messenger for UI to process.
+        /// </summary>
+        /// <param name="messageJson">Message data in json format.</param>
+        private void HandleUIMessage(string messageJson, string typeName)
+        {
+            switch (typeName)
+            {
+                case nameof(MailAddedMessage):
+                    WeakReferenceMessenger.Default.Send(JsonSerializer.Deserialize<MailAddedMessage>(messageJson));
+                    break;
+                case nameof(MailDownloadedMessage):
+                    WeakReferenceMessenger.Default.Send(JsonSerializer.Deserialize<MailDownloadedMessage>(messageJson));
+                    break;
+                case nameof(MailRemovedMessage):
+                    WeakReferenceMessenger.Default.Send(JsonSerializer.Deserialize<MailRemovedMessage>(messageJson));
+                    break;
+                case nameof(MailUpdatedMessage):
+                    WeakReferenceMessenger.Default.Send(JsonSerializer.Deserialize<MailUpdatedMessage>(messageJson));
+                    break;
+                case nameof(AccountCreatedMessage):
+                    WeakReferenceMessenger.Default.Send(JsonSerializer.Deserialize<AccountCreatedMessage>(messageJson));
+                    break;
+                case nameof(AccountRemovedMessage):
+                    WeakReferenceMessenger.Default.Send(JsonSerializer.Deserialize<AccountRemovedMessage>(messageJson));
+                    break;
+                case nameof(AccountUpdatedMessage):
+                    WeakReferenceMessenger.Default.Send(JsonSerializer.Deserialize<AccountUpdatedMessage>(messageJson));
+                    break;
+                case nameof(DraftCreated):
+                    WeakReferenceMessenger.Default.Send(JsonSerializer.Deserialize<DraftCreated>(messageJson));
+                    break;
+                case nameof(DraftFailed):
+                    WeakReferenceMessenger.Default.Send(JsonSerializer.Deserialize<DraftFailed>(messageJson));
+                    break;
+                case nameof(DraftMapped):
+                    WeakReferenceMessenger.Default.Send(JsonSerializer.Deserialize<DraftMapped>(messageJson));
+                    break;
+                case nameof(FolderRenamed):
+                    WeakReferenceMessenger.Default.Send(JsonSerializer.Deserialize<FolderRenamed>(messageJson));
+                    break;
+                case nameof(FolderSynchronizationEnabled):
+                    WeakReferenceMessenger.Default.Send(JsonSerializer.Deserialize<FolderSynchronizationEnabled>(messageJson));
+                    break;
+                case nameof(MergedInboxRenamed):
+                    WeakReferenceMessenger.Default.Send(JsonSerializer.Deserialize<MergedInboxRenamed>(messageJson));
+                    break;
+                default:
+                    throw new Exception("Invalid data type name passed to client.");
+            }
         }
 
         private void ServerDisconnected(AppServiceConnection sender, AppServiceClosedEventArgs args)
         {
             // TODO: Handle server disconnection.
         }
+
+        public void DisposeConnection()
+        {
+            if (Connection == null) return;
+        }
     }
 }

Wino.Core.UWP/Wino.Core.UWP.csproj

@@ -130,7 +130,6 @@
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="Services\AppInitializerService.cs" />
     <Compile Include="Services\WinoServerConnectionManager.cs" />
-    <Compile Include="Services\BackgroundSynchronizer.cs" />
     <Compile Include="Services\BackgroundTaskService.cs" />
     <Compile Include="Services\ClipboardService.cs" />
     <Compile Include="Services\ConfigurationService.cs" />
@@ -170,6 +169,10 @@
       <Project>{e6b1632a-8901-41e8-9ddf-6793c7698b0b}</Project>
       <Name>Wino.Core</Name>
     </ProjectReference>
+    <ProjectReference Include="..\Wino.Messages\Wino.Messaging.csproj">
+      <Project>{0c307d7e-256f-448c-8265-5622a812fbcc}</Project>
+      <Name>Wino.Messaging</Name>
+    </ProjectReference>
   </ItemGroup>
   <ItemGroup>
     <SDKReference Include="WindowsDesktop, Version=10.0.22621.0">

Wino.Core/Requests/ArchiveRequest.cs

@@ -7,7 +7,7 @@ using Wino.Core.Domain.Entities;
 using Wino.Core.Domain.Enums;
 using Wino.Core.Domain.Interfaces;
 using Wino.Core.Domain.Models.Requests;
-using Wino.Messages.Server;
+using Wino.Messaging.Server;
 
 namespace Wino.Core.Requests
 {

Wino.Core/Requests/ChangeFlagRequest.cs

@@ -7,7 +7,7 @@ using Wino.Core.Domain.Entities;
 using Wino.Core.Domain.Enums;
 using Wino.Core.Domain.Interfaces;
 using Wino.Core.Domain.Models.Requests;
-using Wino.Messages.Server;
+using Wino.Messaging.Server;
 
 namespace Wino.Core.Requests
 {

Wino.Core/Requests/CreateDraftRequest.cs

@@ -7,7 +7,7 @@ using Wino.Core.Domain.Enums;
 using Wino.Core.Domain.Interfaces;
 using Wino.Core.Domain.Models.MailItem;
 using Wino.Core.Domain.Models.Requests;
-using Wino.Messages.Server;
+using Wino.Messaging.Server;
 
 namespace Wino.Core.Requests
 {

Wino.Core/Requests/DeleteRequest.cs

@@ -7,7 +7,7 @@ using Wino.Core.Domain.Entities;
 using Wino.Core.Domain.Enums;
 using Wino.Core.Domain.Interfaces;
 using Wino.Core.Domain.Models.Requests;
-using Wino.Messages.Server;
+using Wino.Messaging.Server;
 
 namespace Wino.Core.Requests
 {

Wino.Core/Requests/EmptyFolderRequest.cs

@@ -5,7 +5,7 @@ using Wino.Core.Domain.Entities;
 using Wino.Core.Domain.Enums;
 using Wino.Core.Domain.Interfaces;
 using Wino.Core.Domain.Models.Requests;
-using Wino.Messages.Server;
+using Wino.Messaging.Server;
 
 namespace Wino.Core.Requests
 {

Wino.Core/Requests/MarkFolderAsReadRequest.cs

@@ -5,7 +5,7 @@ using Wino.Core.Domain.Entities;
 using Wino.Core.Domain.Enums;
 using Wino.Core.Domain.Interfaces;
 using Wino.Core.Domain.Models.Requests;
-using Wino.Messages.Server;
+using Wino.Messaging.Server;
 
 namespace Wino.Core.Requests
 {

Wino.Core/Requests/MarkReadRequest.cs

@@ -7,7 +7,7 @@ using Wino.Core.Domain.Entities;
 using Wino.Core.Domain.Enums;
 using Wino.Core.Domain.Interfaces;
 using Wino.Core.Domain.Models.Requests;
-using Wino.Messages.Server;
+using Wino.Messaging.Server;
 
 namespace Wino.Core.Requests
 {

Wino.Core/Requests/MoveRequest.cs

@@ -7,7 +7,7 @@ using Wino.Core.Domain.Entities;
 using Wino.Core.Domain.Enums;
 using Wino.Core.Domain.Interfaces;
 using Wino.Core.Domain.Models.Requests;
-using Wino.Messages.Server;
+using Wino.Messaging.Server;
 
 namespace Wino.Core.Requests
 {

Wino.Core/Requests/RenameFolderRequest.cs

@@ -2,7 +2,7 @@
 using Wino.Core.Domain.Entities;
 using Wino.Core.Domain.Enums;
 using Wino.Core.Domain.Models.Requests;
-using Wino.Messages.Server;
+using Wino.Messaging.Server;
 
 namespace Wino.Core.Requests
 {

Wino.Core/Requests/SendDraftRequest.cs

@@ -7,7 +7,7 @@ using Wino.Core.Domain.Enums;
 using Wino.Core.Domain.Interfaces;
 using Wino.Core.Domain.Models.MailItem;
 using Wino.Core.Domain.Models.Requests;
-using Wino.Messages.Server;
+using Wino.Messaging.Server;
 
 namespace Wino.Core.Requests
 {

Wino.Core/Services/AccountService.cs

@@ -12,7 +12,7 @@ using Wino.Core.Domain.Enums;
 using Wino.Core.Domain.Interfaces;
 using Wino.Core.Extensions;
 using Wino.Core.Messages.Accounts;
-using Wino.Messages.Server;
+using Wino.Messaging.Server;
 
 namespace Wino.Core.Services
 {

Wino.Core/Services/FolderService.cs

@@ -16,7 +16,7 @@ using Wino.Core.Domain.Models.MailItem;
 using Wino.Core.Domain.Models.Synchronization;
 using Wino.Core.Extensions;
 using Wino.Core.MenuItems;
-using Wino.Messages.Server;
+using Wino.Messaging.Server;
 
 namespace Wino.Core.Services
 {

Wino.Core/Services/MailService.cs

@@ -14,7 +14,7 @@ using Wino.Core.Domain.Interfaces;
 using Wino.Core.Domain.Models.Comparers;
 using Wino.Core.Domain.Models.MailItem;
 using Wino.Core.Extensions;
-using Wino.Messages.Server;
+using Wino.Messaging.Server;
 
 namespace Wino.Core.Services
 {

Wino.Core/Services/WinoRequestDelegator.cs

@@ -20,6 +20,7 @@ namespace Wino.Core.Services
     {
         private readonly IWinoRequestProcessor _winoRequestProcessor;
         private readonly IWinoSynchronizerFactory _winoSynchronizerFactory;
+
         private readonly IFolderService _folderService;
         private readonly IDialogService _dialogService;
         private readonly ILogger _logger = Log.ForContext<WinoRequestDelegator>();

Wino.Core/Wino.Core.csproj

@@ -37,6 +37,6 @@
 
    <ItemGroup>
      <ProjectReference Include="..\Wino.Core.Domain\Wino.Core.Domain.csproj" />
-     <ProjectReference Include="..\Wino.Messages\Wino.Messages.csproj" />
+     <ProjectReference Include="..\Wino.Messages\Wino.Messaging.csproj" />
    </ItemGroup>
 </Project>

Wino.Mail.ViewModels/AccountDetailsPageViewModel.cs

@@ -12,7 +12,7 @@ using Wino.Core.Domain.Interfaces;
 using Wino.Core.Domain.Models.Folders;
 using Wino.Core.Domain.Models.Navigation;
 using Wino.Core.Messages.Navigation;
-using Wino.Messages.Server;
+using Wino.Messaging.Server;
 
 namespace Wino.Mail.ViewModels
 {

Wino.Mail.ViewModels/AccountManagementViewModel.cs

@@ -20,7 +20,7 @@ using Wino.Core.Domain.Models.Synchronization;
 using Wino.Core.Messages.Authorization;
 using Wino.Core.Messages.Navigation;
 using Wino.Mail.ViewModels.Data;
-using Wino.Messages.Server;
+using Wino.Messaging.Server;
 
 namespace Wino.Mail.ViewModels
 {

Wino.Mail.ViewModels/AppShellViewModel.cs

@@ -26,7 +26,7 @@ using Wino.Core.Messages.Navigation;
 using Wino.Core.Messages.Shell;
 using Wino.Core.Messages.Synchronization;
 using Wino.Core.Services;
-using Wino.Messages.Server;
+using Wino.Messaging.Server;
 
 namespace Wino.Mail.ViewModels
 {
@@ -83,6 +83,9 @@ namespace Wino.Mail.ViewModels
 
         private readonly SemaphoreSlim accountInitFolderUpdateSlim = new SemaphoreSlim(1);
 
+        [ObservableProperty]
+        private string _activeConnectionStatus = WinoServerConnectionStatus.None.ToString();
+
         public AppShellViewModel(IDialogService dialogService,
                                  IWinoNavigationService navigationService,
                                  IWinoSynchronizerFactory synchronizerFactory,
@@ -104,6 +107,14 @@ namespace Wino.Mail.ViewModels
             StatePersistenceService = statePersistanceService;
             ServerConnectionManager = serverConnectionManager;
 
+            ServerConnectionManager.StatusChanged += async (sender, status) =>
+            {
+                await ExecuteUIThread(() =>
+                {
+                    ActiveConnectionStatus = status.ToString();
+                });
+            };
+
             PreferencesService = preferencesService;
             NavigationService = navigationService;
 

Wino.Mail.ViewModels/BaseViewModel.cs

@@ -6,7 +6,7 @@ using Wino.Core.Domain.Entities;
 using Wino.Core.Domain.Interfaces;
 using Wino.Core.Domain.Models.Folders;
 using Wino.Core.Domain.Models.Navigation;
-using Wino.Messages.Server;
+using Wino.Messaging.Server;
 
 namespace Wino.Mail.ViewModels
 {
@@ -71,9 +71,7 @@ namespace Wino.Mail.ViewModels
         protected virtual void OnFolderRenamed(IMailItemFolder mailItemFolder) { }
         protected virtual void OnFolderSynchronizationEnabled(IMailItemFolder mailItemFolder) { }
 
-        public void ReportUIChange<TMessage>(TMessage message) where TMessage : class, IServerMessage
+        public void ReportUIChange<TMessage>(TMessage message) where TMessage : class, IServerMessage => Messenger.Send(message);
-            => Messenger.Send(message);
-
         void IRecipient<AccountCreatedMessage>.Receive(AccountCreatedMessage message) => OnAccountCreated(message.Account);
         void IRecipient<AccountRemovedMessage>.Receive(AccountRemovedMessage message) => OnAccountRemoved(message.Account);
         void IRecipient<AccountUpdatedMessage>.Receive(AccountUpdatedMessage message) => OnAccountUpdated(message.Account);

Wino.Mail.ViewModels/MailListPageViewModel.cs

@@ -602,6 +602,8 @@ namespace Wino.Mail.ViewModels
         {
             base.OnMailAdded(addedMail);
 
+            if (addedMail.AssignedAccount == null || addedMail.AssignedFolder == null) return;
+
             try
             {
                 await listManipulationSemepahore.WaitAsync();

Wino.Mail.ViewModels/MergedAccountDetailsPageViewModel.cs

@@ -10,7 +10,7 @@ using Wino.Core.Domain.Interfaces;
 using Wino.Core.Domain.Models.Navigation;
 using Wino.Core.Messages.Navigation;
 using Wino.Mail.ViewModels.Data;
-using Wino.Messages.Server;
+using Wino.Messaging.Server;
 
 namespace Wino.Mail.ViewModels
 {

Wino.Mail.ViewModels/Wino.Mail.ViewModels.csproj

@@ -17,7 +17,7 @@
   <ItemGroup>
     <ProjectReference Include="..\Wino.Core.Domain\Wino.Core.Domain.csproj" />
     <ProjectReference Include="..\Wino.Core\Wino.Core.csproj" />
-    <ProjectReference Include="..\Wino.Messages\Wino.Messages.csproj" />
+    <ProjectReference Include="..\Wino.Messages\Wino.Messaging.csproj" />
   </ItemGroup>
 
 </Project>

Wino.Mail/Activation/BackgroundActivationHandler.cs

@@ -1,18 +1,15 @@
-using System.Diagnostics;
+using System.Threading.Tasks;
-using System.Threading.Tasks;
 using Microsoft.Toolkit.Uwp.Notifications;
 using Serilog;
 using Windows.ApplicationModel.Activation;
 using Windows.ApplicationModel.Background;
 using Windows.UI.Notifications;
-using Wino.Core;
 using Wino.Core.Domain;
 using Wino.Core.Domain.Enums;
 using Wino.Core.Domain.Interfaces;
 using Wino.Core.Domain.Models.MailItem;
 using Wino.Core.Domain.Models.Synchronization;
 using Wino.Core.UWP.Services;
-using Wino.Services;
 
 namespace Wino.Activation
 {
@@ -21,7 +18,6 @@ namespace Wino.Activation
         private const string BackgroundExecutionLogTag = "[BackgroundExecution] ";
 
         private readonly IWinoRequestDelegator _winoRequestDelegator;
-        private readonly IBackgroundSynchronizer _backgroundSynchronizer;
         private readonly INativeAppService _nativeAppService;
         private readonly IWinoRequestProcessor _winoRequestProcessor;
         private readonly IWinoSynchronizerFactory _winoSynchronizerFactory;
@@ -30,14 +26,12 @@ namespace Wino.Activation
 
         BackgroundTaskDeferral _deferral;
         public BackgroundActivationHandler(IWinoRequestDelegator winoRequestDelegator,
-                                           IBackgroundSynchronizer backgroundSynchronizer,
                                            INativeAppService nativeAppService,
                                            IWinoRequestProcessor winoRequestProcessor,
                                            IWinoSynchronizerFactory winoSynchronizerFactory,
                                            IMailService mailService)
         {
             _winoRequestDelegator = winoRequestDelegator;
-            _backgroundSynchronizer = backgroundSynchronizer;
             _nativeAppService = nativeAppService;
             _winoRequestProcessor = winoRequestProcessor;
             _winoSynchronizerFactory = winoSynchronizerFactory;
@@ -104,18 +98,6 @@ namespace Wino.Activation
                     }
                 }
             }
-            else if (taskName == BackgroundTaskService.BackgroundSynchronizationTimerTaskNameEx)
-            {
-                var watch = new Stopwatch();
-                watch.Start();
-
-                // Run timer based background synchronization.
-
-                await _backgroundSynchronizer.RunBackgroundSynchronizationAsync(BackgroundSynchronizationReason.Timer);
-
-                watch.Stop();
-                Log.Information($"{BackgroundExecutionLogTag}Background synchronization is completed in {watch.Elapsed.TotalSeconds} seconds.");
-            }
 
             instance.Canceled -= OnBackgroundExecutionCanceled;
 

Wino.Mail/App.xaml.cs

@@ -66,6 +66,8 @@ namespace Wino
             UnhandledException += OnAppUnhandledException;
             EnteredBackground += OnEnteredBackground;
             LeavingBackground += OnLeavingBackground;
+
+            Resuming += OnResuming;
             Suspending += OnSuspending;
 
             Services = ConfigureServices();
@@ -87,6 +89,15 @@ namespace Wino
             Encoding.RegisterProvider(CodePagesEncodingProvider.Instance);
         }
 
+        private async void OnResuming(object sender, object e)
+        {
+            // App Service connection was lost on suspension.
+            // We must restore it.
+            // Server might be running already, but re-launching it will trigger a new connection attempt.
+
+            await _appServiceConnectionManager.ConnectAsync();
+        }
+
         private void OnSuspending(object sender, SuspendingEventArgs e)
         {
             var deferral = e.SuspendingOperation.GetDeferral();
@@ -328,10 +339,12 @@ namespace Wino
             yield return Services.GetService<FileActivationHandler>();
         }
 
-        public void OnBackgroundTaskCanceled(IBackgroundTaskInstance sender, BackgroundTaskCancellationReason reason)
+        public async void OnBackgroundTaskCanceled(IBackgroundTaskInstance sender, BackgroundTaskCancellationReason reason)
         {
             Log.Information($"Background task {sender.Task.Name} was canceled. Reason: {reason}");
 
+            await _appServiceConnectionManager.DisconnectAsync();
+
             backgroundTaskDeferral?.Complete();
             backgroundTaskDeferral = null;
 

Wino.Mail/AppShell.xaml

@@ -521,7 +521,7 @@
                     Padding="14"
                     HorizontalAlignment="Right"
                     VerticalAlignment="Bottom">
-                    <TextBlock Text="{x:Bind ViewModel.ServerConnectionManager.Status, Mode=OneWay}" />
+                    <TextBlock Text="{x:Bind ViewModel.ActiveConnectionStatus, Mode=OneWay}" />
                 </Grid>
             </Grid>
         </muxc:NavigationView>

Wino.Mail/Services/DialogService.cs

@@ -20,7 +20,7 @@ using Wino.Core.Messages.Shell;
 using Wino.Core.Messages.Synchronization;
 using Wino.Core.UWP.Extensions;
 using Wino.Dialogs;
-using Wino.Messages.Server;
+using Wino.Messaging.Server;
 
 namespace Wino.Services
 {

Wino.Mail/Views/NewAccountManagementPage.xaml.cs

@@ -8,7 +8,7 @@ using Windows.UI.Xaml.Navigation;
 using Wino.Core.Domain.Enums;
 using Wino.Core.Messages.Navigation;
 using Wino.Mail.ViewModels.Data;
-using Wino.Messages.Server;
+using Wino.Messaging.Server;
 using Wino.Views.Abstract;
 using Wino.Views.Account;
 using Wino.Views.Settings;

Wino.Mail/Wino.Mail.csproj

@@ -801,9 +801,9 @@
       <Project>{d62f1c03-da57-4709-a640-0283296a8e66}</Project>
       <Name>Wino.Mail.ViewModels</Name>
     </ProjectReference>
-    <ProjectReference Include="..\Wino.Messages\Wino.Messages.csproj">
+    <ProjectReference Include="..\Wino.Messages\Wino.Messaging.csproj">
       <Project>{0c307d7e-256f-448c-8265-5622a812fbcc}</Project>
-      <Name>Wino.Messages</Name>
+      <Name>Wino.Messaging</Name>
     </ProjectReference>
   </ItemGroup>
   <ItemGroup>
@@ -811,9 +811,7 @@
       <Name>Windows Desktop Extensions for the UWP</Name>
     </SDKReference>
   </ItemGroup>
-  <ItemGroup>
+  <ItemGroup />
-    <Folder Include="Server\" />
-  </ItemGroup>
   <PropertyGroup Condition=" '$(VisualStudioVersion)' == '' or '$(VisualStudioVersion)' &lt; '14.0' ">
     <VisualStudioVersion>14.0</VisualStudioVersion>
   </PropertyGroup>

Wino.Messages/Client/Accounts/AccountMenuItemExtended.cs

@@ -1,7 +1,7 @@
 using System;
 using Wino.Core.Domain.Models.MailItem;
 
-namespace Wino.Messages.Client.Accounts
+namespace Wino.Messaging.Client.Accounts
 {
     /// <summary>
     /// When menu item for the account is requested to be extended.

Wino.Messages/Client/Accounts/AccountMenuItemsReordered.cs

@@ -1,7 +1,7 @@
 using System;
 using System.Collections.Generic;
 
-namespace Wino.Messages.Client.Accounts
+namespace Wino.Messaging.Client.Accounts
 {
     /// <summary>
     /// Emitted when account menu items are reordered.

Wino.Messages/Client/Accounts/AccountsMenuRefreshRequested.cs

@@ -1,4 +1,4 @@
-namespace Wino.Messages.Client.Accounts
+namespace Wino.Messaging.Client.Accounts
 {
     /// <summary>
     /// When a full menu refresh for accounts menu is requested.

Wino.Messages/Client/Authorization/ProtocolAuthorizationCallbackReceived.cs

@@ -1,6 +1,6 @@
 using System;
 
-namespace Wino.Messages.Client.Authorization
+namespace Wino.Messaging.Client.Authorization
 {
     /// <summary>
     /// When Google authentication makes a callback to the app via protocol activation to the app.

Wino.Messages/Client/Mails/CancelRenderingContentRequested.cs

@@ -1,4 +1,4 @@
-namespace Wino.Messages.Client.Mails
+namespace Wino.Messaging.Client.Mails
 {
     /// <summary>
     /// When rendered html is requested to cancel.

Wino.Messages/Client/Mails/ClearMailSelectionsRequested.cs

@@ -1,4 +1,4 @@
-namespace Wino.Messages.Client.Mails
+namespace Wino.Messaging.Client.Mails
 {
     /// <summary>
     /// When reset all mail selections requested.

Wino.Messages/Client/Mails/CreateNewComposeMailRequested.cs

@@ -1,6 +1,6 @@
 using Wino.Core.Domain.Models.Reader;
 
-namespace Wino.Messages.Client.Mails
+namespace Wino.Messaging.Client.Mails
 {
     /// <summary>
     /// When a new composing requested.

Wino.Messages/Client/Mails/DisposeRenderingFrameRequested.cs

@@ -1,4 +1,4 @@
-namespace Wino.Messages.Client.Mails
+namespace Wino.Messaging.Client.Mails
 {
     /// <summary>
     /// When rendering frame should be disposed.

Wino.Messages/Client/Mails/HtmlRenderingRequested.cs

@@ -1,4 +1,4 @@
-namespace Wino.Messages.Client.Mails
+namespace Wino.Messaging.Client.Mails
 {
     /// <summary>
     /// When existing a new html is requested to be rendered due to mail selection or signature.

Wino.Messages/Client/Mails/ImapSetupBackNavigationRequested.cs

@@ -1,6 +1,6 @@
 using System;
 
-namespace Wino.Messages.Client.Mails
+namespace Wino.Messaging.Client.Mails
 {
     /// <summary>
     /// When IMAP setup dialog requestes back breadcrumb navigation.

Wino.Messages/Client/Mails/ImapSetupDismissRequested.cs

@@ -1,6 +1,6 @@
 using Wino.Core.Domain.Entities;
 
-namespace Wino.Messages.Client.Mails
+namespace Wino.Messaging.Client.Mails
 {
     /// <summary>
     /// When user asked to dismiss IMAP setup dialog.

Wino.Messages/Client/Mails/ImapSetupNavigationRequested.cs

@@ -1,6 +1,6 @@
 using System;
 
-namespace Wino.Messages.Client.Mails
+namespace Wino.Messaging.Client.Mails
 {
     /// <summary>
     /// When IMAP setup dialog breadcrumb navigation requested.

Wino.Messages/Client/Mails/MailItemNavigationRequested.cs

@@ -1,6 +1,6 @@
 using System;
 
-namespace Wino.Messages.Client.Mails
+namespace Wino.Messaging.Client.Mails
 {
     /// <summary>
     /// When a IMailItem needs to be navigated (or selected)

Wino.Messages/Client/Mails/NavigateMailFolderEvent.cs

@@ -2,7 +2,7 @@
 using Wino.Core.Domain.Interfaces;
 using Wino.Core.Domain.Models.Navigation;
 
-namespace Wino.Messages.Client.Mails
+namespace Wino.Messaging.Client.Mails
 {
     /// <summary>
     /// Selects the given FolderMenuItem in the shell folders list.

Wino.Messages/Client/Mails/RefreshUnreadCountsMessage.cs

@@ -1,6 +1,6 @@
 using System;
 
-namespace Wino.Messages.Client.Mails
+namespace Wino.Messaging.Client.Mails
 {
     public record RefreshUnreadCountsMessage(Guid AccountId);
 }

Wino.Messages/Client/Mails/SaveAsPDFRequested.cs

@@ -2,7 +2,7 @@
 using System.Collections.Generic;
 using System.Text;
 
-namespace Wino.Messages.Client.Mails
+namespace Wino.Messaging.Client.Mails
 {
     /// <summary>
     /// When mail save as PDF requested.

Wino.Messages/Client/Mails/SelectedMailItemsChanged.cs

@@ -1,4 +1,4 @@
-namespace Wino.Messages.Client.Mails
+namespace Wino.Messaging.Client.Mails
 {
     /// <summary>
     /// When selected mail count is changed.

Wino.Messages/Client/Navigation/BackBreadcrumNavigationRequested.cs

@@ -1,4 +1,4 @@
-namespace Wino.Messages.Client.Navigation
+namespace Wino.Messaging.Client.Navigation
 {
     /// <summary>
     /// When back navigation is requested for breadcrumb pages.

Wino.Messages/Client/Navigation/BreadcrumbNavigationRequested.cs

@@ -1,6 +1,6 @@
 using Wino.Core.Domain.Enums;
 
-namespace Wino.Messages.Client.Navigation
+namespace Wino.Messaging.Client.Navigation
 {
     /// <summary>
     /// When Breadcrumb control navigation requested.

Wino.Messages/Client/Navigation/NavigateSettingsRequested.cs

@@ -1,4 +1,4 @@
-namespace Wino.Messages.Client.Navigation
+namespace Wino.Messaging.Client.Navigation
 {
     /// <summary>
     /// Navigates to settings page.

Wino.Messages/Client/Shell/ApplicationThemeChanged.cs

@@ -1,4 +1,4 @@
-namespace Wino.Messages.Client.Shell
+namespace Wino.Messaging.Client.Shell
 {
     /// <summary>
     /// When the application theme changed.

Wino.Messages/Client/Shell/CreateNewMailWithMultipleAccountsRequested.cs

@@ -1,7 +1,7 @@
 using System.Collections.Generic;
 using Wino.Core.Domain.Entities;
 
-namespace Wino.Messages.Client.Shell
+namespace Wino.Messaging.Client.Shell
 {
     /// <summary>
     /// When 

Wino.Messages/Client/Shell/InfoBarMessageRequested.cs

@@ -1,7 +1,7 @@
 using System;
 using Wino.Core.Domain.Enums;
 
-namespace Wino.Messages.Client.Shell
+namespace Wino.Messaging.Client.Shell
 {
     /// <summary>
     /// For displaying right sliding notification message in shell.

Wino.Messages/Client/Shell/LanguageChanged.cs

@@ -1,4 +1,4 @@
-namespace Wino.Messages.Client.Shell
+namespace Wino.Messaging.Client.Shell
 {
     /// <summary>
     /// When application language is updated.

Wino.Messages/Client/Shell/MailtoProtocolMessageRequested.cs

@@ -1,4 +1,4 @@
-namespace Wino.Messages.Client.Shell
+namespace Wino.Messaging.Client.Shell
 {
     public class MailtoProtocolMessageRequested { }
 }

Wino.Messages/Client/Shell/NavigationPaneModeChanged.cs

@@ -1,6 +1,6 @@
 using Wino.Core.Domain.Enums;
 
-namespace Wino.Messages.Client.Shell
+namespace Wino.Messaging.Client.Shell
 {
     /// <summary>
     /// When navigation pane mode is changed.

Wino.Messages/Client/Shell/ShellStateUpdated.cs

@@ -1,4 +1,4 @@
-namespace Wino.Messages.Client.Shell
+namespace Wino.Messaging.Client.Shell
 {
     /// <summary>
     /// When reading mail state or reader pane narrowed state is changed.

Wino.Messages/Client/Synchronization/AccountSynchronizationCompleted.cs

@@ -1,7 +1,7 @@
 using System;
 using Wino.Core.Domain.Enums;
 
-namespace Wino.Messages.Client.Synchronization
+namespace Wino.Messaging.Client.Synchronization
 {
     public record AccountSynchronizationCompleted(Guid AccountId, SynchronizationCompletedState Result, Guid? SynchronizationTrackingId);
 }

Wino.Messages/Client/Synchronization/AccountSynchronizerStateChanged.cs

@@ -1,7 +1,7 @@
 using Wino.Core.Domain.Enums;
 using Wino.Core.Domain.Interfaces;
 
-namespace Wino.Messages.Client.Synchronization
+namespace Wino.Messaging.Client.Synchronization
 {
     /// <summary>
     /// Emitted when synchronizer state is updated.

Wino.Messages/Client/Synchronization/NewSynchronizationRequested.cs

@@ -1,6 +1,6 @@
 using Wino.Core.Domain.Models.Synchronization;
 
-namespace Wino.Messages.Client.Synchronization
+namespace Wino.Messaging.Client.Synchronization
 {
     /// <summary>
     /// Triggers a new synchronization if possible.

Wino.Messages/Enums/MessageType.cs

@@ -0,0 +1,8 @@
+namespace Wino.Messaging.Enums
+{
+    public enum MessageType
+    {
+        UIMessage, // For database changes that needs to be reflected in the UI. 
+        ServerAction, // 
+    }
+}

Wino.Messages/MessageConstants.cs

@@ -0,0 +1,9 @@
+namespace Wino.Messaging
+{
+    public static class MessageConstants
+    {
+        public const string MessageTypeKey = "MessageType";
+        public const string MessageDataKey = "MessageData";
+        public const string MessageDataTypeKey = "MessageDataType";
+    }
+}

Wino.Messages/Server/AccountCreatedMessage.cs

@@ -1,7 +1,6 @@
 using Wino.Core.Domain.Entities;
-using Wino.Core.Domain.Interfaces;
 
-namespace Wino.Messages.Server
+namespace Wino.Messaging.Server
 {
-    public record AccountCreatedMessage(MailAccount Account) : IServerMessage;
+    public record AccountCreatedMessage(MailAccount Account) : ServerMessageBase<AccountCreatedMessage>;
 }

Wino.Messages/Server/AccountRemovedMessage.cs

@@ -1,7 +1,6 @@
 using Wino.Core.Domain.Entities;
-using Wino.Core.Domain.Interfaces;
 
-namespace Wino.Messages.Server
+namespace Wino.Messaging.Server
 {
-    public record AccountRemovedMessage(MailAccount Account) : IServerMessage;
+    public record AccountRemovedMessage(MailAccount Account) : ServerMessageBase<AccountRemovedMessage>;
 }

Wino.Messages/Server/AccountUpdatedMessage.cs

@@ -1,7 +1,6 @@
 using Wino.Core.Domain.Entities;
-using Wino.Core.Domain.Interfaces;
 
-namespace Wino.Messages.Server
+namespace Wino.Messaging.Server
 {
-    public record AccountUpdatedMessage(MailAccount Account) : IServerMessage;
+    public record AccountUpdatedMessage(MailAccount Account) : ServerMessageBase<AccountUpdatedMessage>;
 }

Wino.Messages/Server/DraftCreated.cs

@@ -1,7 +1,6 @@
 using Wino.Core.Domain.Entities;
-using Wino.Core.Domain.Interfaces;
 
-namespace Wino.Messages.Server
+namespace Wino.Messaging.Server
 {
-    public record DraftCreated(MailCopy DraftMail, MailAccount Account) : IServerMessage;
+    public record DraftCreated(MailCopy DraftMail, MailAccount Account) : ServerMessageBase<DraftCreated>;
 }

Wino.Messages/Server/DraftFailed.cs

@@ -1,7 +1,6 @@
 using Wino.Core.Domain.Entities;
-using Wino.Core.Domain.Interfaces;
 
-namespace Wino.Messages.Server
+namespace Wino.Messaging.Server
 {
-    public record DraftFailed(MailCopy DraftMail, MailAccount Account) : IServerMessage;
+    public record DraftFailed(MailCopy DraftMail, MailAccount Account) : ServerMessageBase<DraftFailed>;
 }

Wino.Messages/Server/DraftMapped.cs

@@ -1,6 +1,4 @@
-using Wino.Core.Domain.Interfaces;
+namespace Wino.Messaging.Server
-
-namespace Wino.Messages.Server
 {
-    public record DraftMapped(string LocalDraftCopyId, string RemoteDraftCopyId) : IServerMessage;
+    public record DraftMapped(string LocalDraftCopyId, string RemoteDraftCopyId) : ServerMessageBase<DraftMapped>;
 }

Wino.Messages/Server/FolderRenamed.cs

@@ -1,7 +1,6 @@
-using Wino.Core.Domain.Interfaces;
+using Wino.Core.Domain.Models.Folders;
-using Wino.Core.Domain.Models.Folders;
 
-namespace Wino.Messages.Server
+namespace Wino.Messaging.Server
 {
-    public record FolderRenamed(IMailItemFolder MailItemFolder) : IServerMessage;
+    public record FolderRenamed(IMailItemFolder MailItemFolder) : ServerMessageBase<FolderRenamed>;
 }

Wino.Messages/Server/FolderSynchronizationEnabled.cs

@@ -1,7 +1,6 @@
-using Wino.Core.Domain.Interfaces;
+using Wino.Core.Domain.Models.Folders;
-using Wino.Core.Domain.Models.Folders;
 
-namespace Wino.Messages.Server
+namespace Wino.Messaging.Server
 {
-    public record FolderSynchronizationEnabled(IMailItemFolder MailItemFolder) : IServerMessage;
+    public record FolderSynchronizationEnabled(IMailItemFolder MailItemFolder) : ServerMessageBase<FolderSynchronizationEnabled>;
 }

Wino.Messages/Server/MailAddedMessage.cs

@@ -1,7 +1,6 @@
 using Wino.Core.Domain.Entities;
-using Wino.Core.Domain.Interfaces;
 
-namespace Wino.Messages.Server
+namespace Wino.Messaging.Server
 {
-    public record MailAddedMessage(MailCopy AddedMail) : IServerMessage;
+    public record MailAddedMessage(MailCopy AddedMail) : ServerMessageBase<MailAddedMessage>;
 }

Wino.Messages/Server/MailDownloadedMessage.cs

@@ -1,7 +1,6 @@
 using Wino.Core.Domain.Entities;
-using Wino.Core.Domain.Interfaces;
 
-namespace Wino.Messages.Server
+namespace Wino.Messaging.Server
 {
-    public record MailDownloadedMessage(MailCopy DownloadedMail) : IServerMessage;
+    public record MailDownloadedMessage(MailCopy DownloadedMail) : ServerMessageBase<MailDownloadedMessage>;
 }

Wino.Messages/Server/MailRemovedMessage.cs

@@ -1,7 +1,6 @@
 using Wino.Core.Domain.Entities;
-using Wino.Core.Domain.Interfaces;
 
-namespace Wino.Messages.Server
+namespace Wino.Messaging.Server
 {
-    public record MailRemovedMessage(MailCopy RemovedMail) : IServerMessage;
+    public record MailRemovedMessage(MailCopy RemovedMail) : ServerMessageBase<MailRemovedMessage>;
 }

Wino.Messages/Server/MailUpdatedMessage.cs

@@ -1,7 +1,6 @@
 using Wino.Core.Domain.Entities;
-using Wino.Core.Domain.Interfaces;
 
-namespace Wino.Messages.Server
+namespace Wino.Messaging.Server
 {
-    public record MailUpdatedMessage(MailCopy UpdatedMail) : IServerMessage;
+    public record MailUpdatedMessage(MailCopy UpdatedMail) : ServerMessageBase<MailUpdatedMessage>;
 }

Wino.Messages/Server/MergedInboxRenamed.cs

@@ -1,7 +1,6 @@
 using System;
-using Wino.Core.Domain.Interfaces;
 
-namespace Wino.Messages.Server
+namespace Wino.Messaging.Server
 {
-    public record MergedInboxRenamed(Guid MergedInboxId, string NewName) : IServerMessage;
+    public record MergedInboxRenamed(Guid MergedInboxId, string NewName) : ServerMessageBase<MergedInboxRenamed>;
 }

Wino.Messages/Server/ServerMessageBase.cs

@@ -0,0 +1,6 @@
+using Wino.Core.Domain.Interfaces;
+
+namespace Wino.Messaging.Server
+{
+    public record ServerMessageBase<T> : IServerMessage { }
+}

Wino.Messages/Wino.Messaging.csproj

@@ -14,6 +14,7 @@
 			<PrivateAssets>all</PrivateAssets>
 			<IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
 		</PackageReference>
+		<PackageReference Include="System.Text.Json" Version="8.0.4" />
 	</ItemGroup>
 
 </Project>

Wino.Server/App.xaml.cs

@@ -1,18 +1,70 @@
-using System.Windows;
+using System.Threading;
+using System.Windows;
 using H.NotifyIcon;
 
 namespace Wino.Server
 {
+    /// <summary>
+    /// Single instance Wino Server.
+    /// Instancing is done using Mutex.
+    /// App will not start if another instance is already running.
+    /// App will let running server know that server execution is triggered, which will
+    /// led server to start new connection to requesting UWP app.
+    /// </summary>
     public partial class App : Application
     {
+        private const string WinoServerAppName = "Wino.Server";
+        private const string WinoServerActiatedName = "Wino.Server.Activated";
+
         private TaskbarIcon? notifyIcon;
+        private static Mutex _mutex = null;
+        private EventWaitHandle _eventWaitHandle;
 
         protected override void OnStartup(StartupEventArgs e)
         {
-            base.OnStartup(e);
+            bool isCreatedNew;
 
-            notifyIcon = (TaskbarIcon)FindResource("NotifyIcon");
+            _mutex = new Mutex(true, WinoServerAppName, out isCreatedNew);
-            notifyIcon.ForceCreate(enablesEfficiencyMode: true);
+            _eventWaitHandle = new EventWaitHandle(false, EventResetMode.AutoReset, WinoServerActiatedName);
+
+            if (isCreatedNew)
+            {
+                // Spawn a thread which will be waiting for our event
+                var thread = new Thread(() =>
+                {
+                    while (_eventWaitHandle.WaitOne())
+                    {
+                        if (notifyIcon == null) return;
+
+                        Current.Dispatcher.BeginInvoke(() =>
+                        {
+                            if (notifyIcon.DataContext is TrayIconViewModel trayIconViewModel)
+                            {
+                                trayIconViewModel.Reconnect();
+                            }
+                        });
+                    }
+                });
+
+                // It is important mark it as background otherwise it will prevent app from exiting.
+                thread.IsBackground = true;
+
+                thread.Start();
+
+                base.OnStartup(e);
+
+                // Create taskbar icon for the new server.
+                notifyIcon = (TaskbarIcon)FindResource("NotifyIcon");
+                notifyIcon.ForceCreate(enablesEfficiencyMode: true);
+            }
+            else
+            {
+                // Notify other instance so it could bring itself to foreground.
+                _eventWaitHandle.Set();
+
+                // Terminate this instance.
+                Shutdown();
+            }
         }
 
         protected override void OnExit(ExitEventArgs e)

Wino.Server/ServerContext.cs

@@ -1,12 +1,21 @@
 using System;
+using System.Text.Json;
+using System.Threading.Tasks;
 using Windows.ApplicationModel;
 using Windows.ApplicationModel.AppService;
 using Windows.Foundation.Collections;
+using Wino.Core.Domain.Entities;
+using Wino.Core.Domain.Interfaces;
+using Wino.Messaging;
+using Wino.Messaging.Enums;
+using Wino.Messaging.Server;
 
 namespace Wino.Server
 {
     public class ServerContext
     {
+        private static object connectionLock = new object();
+
         private AppServiceConnection connection = null;
 
         public ServerContext()
@@ -14,15 +23,33 @@ namespace Wino.Server
             InitializeAppServiceConnection();
         }
 
+        private string GetAppPackagFamilyName()
+        {
+            // If running as a standalone app, Package will throw exception.
+            // Return hardcoded value for debugging purposes.
+            // Connection will not be available in this case.
+
+            try
+            {
+                return Package.Current.Id.FamilyName;
+            }
+            catch (Exception)
+            {
+                return "Debug.Wino.Server.FamilyName";
+            }
+        }
+
         /// <summary>
         /// Open connection to UWP app service
         /// </summary>
         public async void InitializeAppServiceConnection()
         {
+            if (connection != null) DisposeConnection();
+
             connection = new AppServiceConnection
             {
                 AppServiceName = "WinoInteropService",
-                PackageFamilyName = Package.Current.Id.FamilyName
+                PackageFamilyName = GetAppPackagFamilyName()
             };
 
             connection.RequestReceived += OnWinRTMessageReceived;
@@ -33,13 +60,33 @@ namespace Wino.Server
             if (status != AppServiceConnectionStatus.Success)
             {
                 // TODO: Handle connection error
+
+                DisposeConnection();
             }
         }
 
-        public async void SendMessage()
+        public Task SendTestMessageAsync()
         {
-            var set = new ValueSet();
+            var message = new MailAddedMessage(new MailCopy());
-            set.Add("Hello", "World");
+            return SendMessageAsync(MessageType.UIMessage, message);
+        }
+
+        private async Task SendMessageAsync(MessageType messageType, object message)
+        {
+            if (connection == null) return;
+
+            if (message is not IServerMessage serverMessage)
+                throw new ArgumentException("Server message must be a type of IServerMessage");
+
+            string json = JsonSerializer.Serialize(message);
+
+            var set = new ValueSet
+            {
+                { MessageConstants.MessageTypeKey, (int)messageType },
+                { MessageConstants.MessageDataKey, json },
+                { MessageConstants.MessageDataTypeKey, message.GetType().Name }
+            };
+
             await connection.SendMessageAsync(set);
         }
 
@@ -47,12 +94,30 @@ namespace Wino.Server
         {
             // TODO: Handle connection closed.
 
-            // UWP app might've been terminated.
+            // UWP app might've been terminated or suspended.
+            // At this point, we must keep active synchronizations going, but connection is lost.
+            // As long as this process is alive, database will be kept updated, but no messages will be sent.
+
+            DisposeConnection();
         }
 
         private void OnWinRTMessageReceived(AppServiceConnection sender, AppServiceRequestReceivedEventArgs args)
         {
             // TODO: Handle incoming messages from UWP/WINUI Application.
         }
+
+        private void DisposeConnection()
+        {
+            lock (connectionLock)
+            {
+                if (connection == null) return;
+
+                connection.RequestReceived -= OnWinRTMessageReceived;
+                connection.ServiceClosed -= OnConnectionClosed;
+
+                connection.Dispose();
+                connection = null;
+            }
+        }
     }
 }

Wino.Server/TrayIconViewModel.cs

@@ -11,7 +11,7 @@ namespace Wino.Server
         [RelayCommand]
         public void LaunchWino()
         {
-            _context.SendMessage();
+            _context.SendTestMessageAsync();
         }
 
         /// <summary>
@@ -24,5 +24,7 @@ namespace Wino.Server
 
             Application.Current.Shutdown();
         }
+
+        public void Reconnect() => _context.InitializeAppServiceConnection();
     }
 }

Wino.Server/Wino.Server.csproj

@@ -25,6 +25,6 @@
 	<ItemGroup>
 	  <ProjectReference Include="..\Wino.Core.Domain\Wino.Core.Domain.csproj" />
 	  <ProjectReference Include="..\Wino.Core\Wino.Core.csproj" />
-	  <ProjectReference Include="..\Wino.Messages\Wino.Messages.csproj" />
+	  <ProjectReference Include="..\Wino.Messages\Wino.Messaging.csproj" />
 	</ItemGroup>
 </Project>

Wino.sln

@@ -15,11 +15,11 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Wino.BackgroundTasks", "Win
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Wino.Mail.ViewModels", "Wino.Mail.ViewModels\Wino.Mail.ViewModels.csproj", "{D62F1C03-DA57-4709-A640-0283296A8E66}"
 EndProject
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Wino.Messages", "Wino.Messages\Wino.Messages.csproj", "{0C307D7E-256F-448C-8265-5622A812FBCC}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Wino.Messaging", "Wino.Messages\Wino.Messaging.csproj", "{0C307D7E-256F-448C-8265-5622A812FBCC}"
 EndProject
 Project("{C7167F0D-BC9F-4E6E-AFE1-012C56B48DB5}") = "Wino.Packaging", "Wino.Packaging\Wino.Packaging.wapproj", "{760F5F31-8EE3-4B83-80F3-0E4FFBCC737C}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Wino.Server", "Wino.Server\Wino.Server.csproj", "{3D1942E5-1A3B-4062-B4BB-156A40DA47FE}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Wino.Server", "Wino.Server\Wino.Server.csproj", "{3D1942E5-1A3B-4062-B4BB-156A40DA47FE}"
 EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution