Add Windows share target draft attachment flow

Wino.Core.Domain/Interfaces/IShareActivationService.cs

@@ -0,0 +1,14 @@
+#nullable enable
+using System;
+using Wino.Core.Domain.Models.Launch;
+
+namespace Wino.Core.Domain.Interfaces;
+
+public interface IShareActivationService
+{
+    MailShareRequest? PendingShareRequest { get; set; }
+    MailShareRequest? ConsumePendingShareRequest();
+    void ClearPendingShareRequest();
+    void StagePendingComposeShareRequest(Guid draftUniqueId, MailShareRequest shareRequest);
+    MailShareRequest? ConsumePendingComposeShareRequest(Guid draftUniqueId);
+}

Wino.Core.Domain/Models/Launch/MailShareRequest.cs

@@ -0,0 +1,15 @@
+using System;
+using System.Collections.Generic;
+using Wino.Core.Domain.Models.Common;
+
+namespace Wino.Core.Domain.Models.Launch;
+
+public sealed class MailShareRequest
+{
+    public MailShareRequest(IReadOnlyList<SharedFile> files)
+    {
+        Files = files ?? throw new ArgumentNullException(nameof(files));
+    }
+
+    public IReadOnlyList<SharedFile> Files { get; }
+}

Wino.Core.Domain/Models/Launch/PendingComposeMailShareRequest.cs

@@ -0,0 +1,15 @@
+using System;
+
+namespace Wino.Core.Domain.Models.Launch;
+
+public sealed class PendingComposeMailShareRequest
+{
+    public PendingComposeMailShareRequest(Guid draftUniqueId, MailShareRequest shareRequest)
+    {
+        DraftUniqueId = draftUniqueId;
+        ShareRequest = shareRequest ?? throw new ArgumentNullException(nameof(shareRequest));
+    }
+
+    public Guid DraftUniqueId { get; }
+    public MailShareRequest ShareRequest { get; }
+}

Wino.Mail.ViewModels/ComposePageViewModel.cs

@@ -19,6 +19,7 @@ using Wino.Core.Domain.Extensions;
 using Wino.Core.Domain.Interfaces;
 using Wino.Core.Domain.Models.MailItem;
 using Wino.Core.Domain.Models;
+using Wino.Core.Domain.Models.Launch;
 using Wino.Core.Domain.Models.Navigation;
 using Wino.Core.Extensions;
 using Wino.Core.Services;
@@ -159,6 +160,7 @@ public partial class ComposePageViewModel : MailBaseViewModel,
     public readonly IPreferencesService PreferencesService;
     public readonly IContactService ContactService;
     public readonly ISmimeCertificateService _smimeCertificateService;
+    private readonly IShareActivationService _shareActivationService;
 
     public ComposePageViewModel(IMailDialogService dialogService,
                                 IMailService mailService,
@@ -172,7 +174,8 @@ public partial class ComposePageViewModel : MailBaseViewModel,
                                 IContactService contactService,
                                 IFontService fontService,
                                 IPreferencesService preferencesService,
-                                ISmimeCertificateService smimeCertificateService)
+                                ISmimeCertificateService smimeCertificateService,
+                                IShareActivationService shareActivationService)
     {
         NativeAppService = nativeAppService;
         ContactService = contactService;
@@ -188,6 +191,7 @@ public partial class ComposePageViewModel : MailBaseViewModel,
         _emailTemplateService = emailTemplateService;
         _worker = worker;
         _smimeCertificateService = smimeCertificateService;
+        _shareActivationService = shareActivationService;
 
         foreach (var cert in _smimeCertificateService.GetCertificates(emailAddress: SelectedAlias?.AliasAddress))
         {
@@ -752,6 +756,7 @@ public partial class ComposePageViewModel : MailBaseViewModel,
             await LoadAddressInfoAsync(replyingMime.Bcc, BCCItems);
 
             LoadAttachments();
+            ApplyPendingSharedAttachments();
 
             if (replyingMime.Cc.Any() || replyingMime.Bcc.Any())
                 IsCCBCCVisible = true;
@@ -783,6 +788,24 @@ public partial class ComposePageViewModel : MailBaseViewModel,
         }
     }
 
+    private void ApplyPendingSharedAttachments()
+    {
+        var draftUniqueId = CurrentMailDraftItem?.MailCopy?.UniqueId ?? Guid.Empty;
+
+        if (draftUniqueId == Guid.Empty)
+            return;
+
+        var shareRequest = _shareActivationService.ConsumePendingComposeShareRequest(draftUniqueId);
+
+        if (shareRequest?.Files == null || shareRequest.Files.Count == 0)
+            return;
+
+        foreach (var sharedFile in shareRequest.Files)
+        {
+            IncludedAttachments.Add(new MailAttachmentViewModel(sharedFile));
+        }
+    }
+
     private async Task LoadAddressInfoAsync(InternetAddressList list, ObservableCollection<AccountContact> collection)
     {
         foreach (var item in list)

Wino.Mail.ViewModels/MailAppShellViewModel.cs

@@ -15,8 +15,9 @@ using Wino.Core.Domain.Entities.Shared;
 using Wino.Core.Domain.Enums;
 using Wino.Core.Domain.Interfaces;
 using Wino.Core.Domain.MenuItems;
-using Wino.Core.Domain.Models.Folders;
 using Wino.Core.Domain.Models;
+using Wino.Core.Domain.Models.Folders;
+using Wino.Core.Domain.Models.Launch;
 using Wino.Core.Domain.Models.MailItem;
 using Wino.Core.Domain.Models.Navigation;
 using Wino.Core.Domain.Models.Synchronization;
@@ -84,6 +85,7 @@ public partial class MailAppShellViewModel : MailBaseViewModel,
     private readonly IMimeFileService _mimeFileService;
     private readonly IWebView2RuntimeValidatorService _webView2RuntimeValidatorService;
     private readonly IStoreUpdateService _storeUpdateService;
+    private readonly IShareActivationService _shareActivationService;
 
     private readonly INativeAppService _nativeAppService;
     private readonly IMailService _mailService;
@@ -109,7 +111,8 @@ public partial class MailAppShellViewModel : MailBaseViewModel,
                              IConfigurationService configurationService,
                              IStartupBehaviorService startupBehaviorService,
                              IWebView2RuntimeValidatorService webView2RuntimeValidatorService,
-                             IStoreUpdateService storeUpdateService)
+                             IStoreUpdateService storeUpdateService,
+                             IShareActivationService shareActivationService)
     {
         StatePersistenceService = statePersistanceService;
 
@@ -131,6 +134,7 @@ public partial class MailAppShellViewModel : MailBaseViewModel,
         _winoRequestDelegator = winoRequestDelegator;
         _webView2RuntimeValidatorService = webView2RuntimeValidatorService;
         _storeUpdateService = storeUpdateService;
+        _shareActivationService = shareActivationService;
     }
 
     protected override void OnDispatcherAssigned()
@@ -274,6 +278,7 @@ public partial class MailAppShellViewModel : MailBaseViewModel,
         }
 
         await ProcessLaunchOptionsAsync();
+        await HandlePendingShareRequestAsync();
         await ValidateWebView2RuntimeAsync();
 
         if (shouldRunStartupFlows && !Debugger.IsAttached)
@@ -943,6 +948,9 @@ public partial class MailAppShellViewModel : MailBaseViewModel,
     }
 
     public async Task CreateNewMailForAsync(MailAccount account)
+        => await CreateNewMailForAsync(account, null);
+
+    public async Task CreateNewMailForAsync(MailAccount account, MailShareRequest shareRequest)
     {
         if (account == null) return;
 
@@ -974,6 +982,11 @@ public partial class MailAppShellViewModel : MailBaseViewModel,
 
         var (draftMailCopy, draftBase64MimeMessage) = await _mailService.CreateDraftAsync(account.Id, draftOptions).ConfigureAwait(false);
 
+        if (shareRequest?.Files?.Count > 0)
+        {
+            _shareActivationService.StagePendingComposeShareRequest(draftMailCopy.UniqueId, shareRequest);
+        }
+
         var draftPreparationRequest = new DraftPreparationRequest(account, draftMailCopy, draftBase64MimeMessage, draftOptions.Reason);
         await _winoRequestDelegator.ExecuteAsync(draftPreparationRequest);
     }
@@ -1034,6 +1047,35 @@ public partial class MailAppShellViewModel : MailBaseViewModel,
         await CreateNewMailForAsync(targetAccount);
     }
 
+    public async Task HandlePendingShareRequestAsync()
+    {
+        var shareRequest = _shareActivationService.ConsumePendingShareRequest();
+
+        if (shareRequest?.Files == null || shareRequest.Files.Count == 0)
+            return;
+
+        var accounts = await _accountService.GetAccountsAsync();
+
+        if (!accounts.Any())
+            return;
+
+        MailAccount targetAccount = null;
+
+        if (accounts.Count == 1)
+        {
+            targetAccount = accounts[0];
+        }
+        else
+        {
+            targetAccount = await _dialogService.ShowAccountPickerDialogAsync(accounts);
+        }
+
+        if (targetAccount == null)
+            return;
+
+        await CreateNewMailForAsync(targetAccount, shareRequest);
+    }
+
     private async Task RecreateMenuItemsAsync()
     {
         await _menuRefreshSemaphore.WaitAsync().ConfigureAwait(false);

Wino.Mail.WinUI/App.xaml.cs

@@ -15,6 +15,9 @@ using Microsoft.Windows.AppLifecycle;
 using Microsoft.Windows.AppNotifications;
 using MimeKit.Cryptography;
 using Windows.ApplicationModel.Activation;
+using Windows.ApplicationModel.DataTransfer;
+using Windows.ApplicationModel.DataTransfer.ShareTarget;
+using Windows.Storage;
 using Wino.Calendar.ViewModels;
 using Wino.Calendar.ViewModels.Interfaces;
 using Wino.Core;
@@ -22,6 +25,8 @@ using Wino.Core.Domain;
 using Wino.Core.Domain.Enums;
 using Wino.Core.Domain.Interfaces;
 using Wino.Core.Domain.Models.Calendar;
+using Wino.Core.Domain.Models.Common;
+using Wino.Core.Domain.Models.Launch;
 using Wino.Core.Domain.Models.MailItem;
 using Wino.Core.Domain.Models.Navigation;
 using Wino.Core.Domain.Models.Synchronization;
@@ -30,6 +35,7 @@ using Wino.Mail.Services;
 using Wino.Mail.ViewModels;
 using Wino.Mail.ViewModels.Data;
 using Wino.Mail.WinUI.Activation;
+using Wino.Mail.WinUI.Extensions;
 using Wino.Mail.WinUI.Interfaces;
 using Wino.Mail.WinUI.Models;
 using Wino.Mail.WinUI.Services;
@@ -61,6 +67,7 @@ public partial class App : WinoApplication,
     private bool _isExiting;
     private bool _activationInfrastructureInitialized;
     private int _initialNotificationActivationHandled;
+    private int _initialShareActivationHandled;
     private CancellationTokenSource? _autoSynchronizationLoopCts;
     private readonly SemaphoreSlim _autoSynchronizationSemaphore = new(1, 1);
     private readonly SemaphoreSlim _activationInfrastructureSemaphore = new(1, 1);
@@ -446,12 +453,26 @@ public partial class App : WinoApplication,
     private bool TryMarkInitialNotificationActivationHandled()
         => Interlocked.Exchange(ref _initialNotificationActivationHandled, 1) == 0;
 
+    private bool TryMarkInitialShareActivationHandled()
+        => Interlocked.Exchange(ref _initialShareActivationHandled, 1) == 0;
+
     protected override async void OnLaunched(Microsoft.UI.Xaml.LaunchActivatedEventArgs args)
     {
         base.OnLaunched(args);
 
         await EnsureActivationInfrastructureAsync();
 
+        var activationArgs = AppInstance.GetCurrent().GetActivatedEventArgs();
+
+        if (activationArgs.Kind == ExtendedActivationKind.ShareTarget &&
+            TryMarkInitialShareActivationHandled())
+        {
+            LogActivation("Processing share target activation from OnLaunched.");
+
+            if (await HandleShareTargetActivationAsync(activationArgs, activateWindow: true))
+                return;
+        }
+
         var hasAnyAccount = _hasConfiguredAccounts;
         if (!IsStartupTaskLaunch() && !hasAnyAccount)
         {
@@ -635,6 +656,89 @@ public partial class App : WinoApplication,
         return HandleToastActivationAsync(toastArguments, userInput);
     }
 
+    private async Task<bool> HandleShareTargetActivationAsync(AppActivationArguments activationArgs, bool activateWindow)
+    {
+        if (activationArgs.Kind != ExtendedActivationKind.ShareTarget ||
+            activationArgs.Data is not ShareTargetActivatedEventArgs shareTargetArgs)
+        {
+            return false;
+        }
+
+        var shareRequest = await ExtractMailShareRequestAsync(shareTargetArgs);
+
+        if (shareRequest?.Files == null || shareRequest.Files.Count == 0)
+        {
+            Services.GetRequiredService<IShareActivationService>().ClearPendingShareRequest();
+            return false;
+        }
+
+        var shareActivationService = Services.GetRequiredService<IShareActivationService>();
+        shareActivationService.PendingShareRequest = shareRequest;
+
+        if (!_hasConfiguredAccounts)
+        {
+            shareActivationService.ClearPendingShareRequest();
+            return false;
+        }
+
+        var shellWindowAlreadyExists = HasShellWindow();
+
+        await EnsureShellWindowAsync(WinoApplicationMode.Mail, activateWindow, suppressStartupFlows: true);
+
+        if (shellWindowAlreadyExists)
+        {
+            await Services.GetRequiredService<MailAppShellViewModel>().HandlePendingShareRequestAsync();
+        }
+
+        return true;
+    }
+
+    private async Task<MailShareRequest?> ExtractMailShareRequestAsync(ShareTargetActivatedEventArgs shareTargetArgs)
+    {
+        var shareOperation = shareTargetArgs.ShareOperation;
+
+        try
+        {
+            shareOperation.ReportStarted();
+
+            if (!shareOperation.Data.Contains(StandardDataFormats.StorageItems))
+            {
+                shareOperation.ReportCompleted();
+                return null;
+            }
+
+            var storageItems = await shareOperation.Data.GetStorageItemsAsync();
+            List<SharedFile> sharedFiles = [];
+
+            foreach (var storageFile in storageItems.OfType<StorageFile>())
+            {
+                sharedFiles.Add(await storageFile.ToSharedFileAsync());
+            }
+
+            shareOperation.ReportDataRetrieved();
+            shareOperation.ReportCompleted();
+
+            return sharedFiles.Count == 0
+                ? null
+                : new MailShareRequest(sharedFiles);
+        }
+        catch (Exception ex)
+        {
+            LogActivation($"Failed to extract share target payload: {ex.GetType().Name} - {ex.Message}");
+
+            try
+            {
+                shareOperation.ReportError(ex.Message);
+            }
+            catch
+            {
+                // Ignore share reporting failures and fall back to normal launch flow.
+            }
+
+            return null;
+        }
+    }
+
     private async Task<IWinoShellWindow?> EnsureShellWindowAsync(WinoApplicationMode mode, bool activateWindow, bool suppressStartupFlows = true)
     {
         var windowManager = Services.GetRequiredService<IWinoWindowManager>();
@@ -1446,6 +1550,11 @@ public partial class App : WinoApplication,
                 LogActivation($"Processing redirected notification activation. Arguments: {toastArgs.Argument}");
                 _ = HandleToastActivationAsync(toastArgs.Argument, toastArgs.UserInput);
             }
+            else if (args.Kind == ExtendedActivationKind.ShareTarget)
+            {
+                LogActivation("Processing redirected share target activation.");
+                await HandleShareTargetActivationAsync(args, activateWindow: true);
+            }
             else
             {
                 var shouldActivateWindow = true;
@@ -1527,6 +1636,12 @@ public partial class App : WinoApplication,
 
         }
 
+        if (activationArgs.Kind == ExtendedActivationKind.ShareTarget)
+        {
+            mode = WinoApplicationMode.Mail;
+            return true;
+        }
+
         if (activationArgs.Kind == ExtendedActivationKind.File &&
             activationArgs.Data is IFileActivatedEventArgs fileArgs)
         {

Wino.Mail.WinUI/Package.appxmanifest

@@ -97,6 +97,15 @@
 				</uap:Protocol>
 			</uap:Extension>
 
+			<!-- Share target activation -->
+			<uap:Extension Category="windows.shareTarget">
+				<uap:ShareTarget>
+					<uap:SupportedFileTypes>
+						<uap:SupportsAnyFileType />
+					</uap:SupportedFileTypes>
+				</uap:ShareTarget>
+			</uap:Extension>
+
 			<!-- File Assosication: EML -->
 			<uap:Extension Category="windows.fileTypeAssociation">
 				<uap:FileTypeAssociation Name="eml">

Wino.Services/ServicesContainerSetup.cs

@@ -13,6 +13,7 @@ public static class ServicesContainerSetup
         services.AddSingleton<IApplicationConfiguration, ApplicationConfiguration>();
         services.AddSingleton<IWinoLogger, WinoLogger>();
         services.AddSingleton<ILaunchProtocolService, LaunchProtocolService>();
+        services.AddSingleton<IShareActivationService, ShareActivationService>();
         services.AddSingleton<IMimeFileService, MimeFileService>();
         services.AddSingleton<ICalendarIcsFileService, CalendarIcsFileService>();
         services.AddTransient<IMimeStorageService, MimeStorageService>();

Wino.Services/ShareActivationService.cs

@@ -0,0 +1,70 @@
+#nullable enable
+using System;
+using Wino.Core.Domain.Interfaces;
+using Wino.Core.Domain.Models.Launch;
+
+namespace Wino.Services;
+
+public class ShareActivationService : IShareActivationService
+{
+    private readonly object _syncRoot = new();
+    private MailShareRequest? _pendingShareRequest;
+    private PendingComposeMailShareRequest? _pendingComposeShareRequest;
+
+    public MailShareRequest? PendingShareRequest
+    {
+        get
+        {
+            lock (_syncRoot)
+            {
+                return _pendingShareRequest;
+            }
+        }
+        set
+        {
+            lock (_syncRoot)
+            {
+                _pendingShareRequest = value;
+            }
+        }
+    }
+
+    public MailShareRequest? ConsumePendingShareRequest()
+    {
+        lock (_syncRoot)
+        {
+            var pendingRequest = _pendingShareRequest;
+            _pendingShareRequest = null;
+            return pendingRequest;
+        }
+    }
+
+    public void ClearPendingShareRequest()
+    {
+        lock (_syncRoot)
+        {
+            _pendingShareRequest = null;
+        }
+    }
+
+    public void StagePendingComposeShareRequest(Guid draftUniqueId, MailShareRequest shareRequest)
+    {
+        lock (_syncRoot)
+        {
+            _pendingComposeShareRequest = new PendingComposeMailShareRequest(draftUniqueId, shareRequest);
+        }
+    }
+
+    public MailShareRequest? ConsumePendingComposeShareRequest(Guid draftUniqueId)
+    {
+        lock (_syncRoot)
+        {
+            if (_pendingComposeShareRequest?.DraftUniqueId != draftUniqueId)
+                return null;
+
+            var pendingRequest = _pendingComposeShareRequest.ShareRequest;
+            _pendingComposeShareRequest = null;
+            return pendingRequest;
+        }
+    }
+}