From 412cdb0dad16b551aea8d597e6f3b39ab50b8714 Mon Sep 17 00:00:00 2001
From: Eoin Motherway <25342760+YuKitsune@users.noreply.github.com>
Date: Sun, 11 Oct 2026 14:18:57 +1000
Subject: [PATCH 1/5] wip: connection request

---
 .../OpenConnectionRequestWindowRequest.cs     | 42 ++++++++++
 .../RebuildCpdlcStatusLabelItemsRequest.cs    | 16 +++-
 .../Messages/SendConnectionRequestRequest.cs  | 26 +++++++
 .../Server/SignalRConnectionManager.cs        | 10 +++
 .../ViewModels/ConnectionRequestViewModel.cs  | 53 +++++++++++++
 .../Windows/ConnectionRequestWindow.xaml      | 78 +++++++++++++++++++
 .../Windows/ConnectionRequestWindow.xaml.cs   | 13 ++++
 source/CPDLCPlugin/Windows/WindowKeys.cs      |  1 +
 .../Mocks/TestClientManager.cs                | 10 +++
 source/CPDLCServer/Clients/ClientManager.cs   | 11 +++
 .../DownlinkReceivedNotificationHandler.cs    |  7 ++
 .../SendConnectionRequestCommandHandler.cs    | 45 +++++++++++
 source/CPDLCServer/Hubs/ControllerHub.cs      | 18 +++++
 .../Messages/SendConnectionRequestCommand.cs  |  8 ++
 source/CPDLCServer/Model/ControlMessages.cs   |  5 ++
 15 files changed, 342 insertions(+), 1 deletion(-)
 create mode 100644 source/CPDLCPlugin/Messages/OpenConnectionRequestWindowRequest.cs
 create mode 100644 source/CPDLCPlugin/Messages/SendConnectionRequestRequest.cs
 create mode 100644 source/CPDLCPlugin/ViewModels/ConnectionRequestViewModel.cs
 create mode 100644 source/CPDLCPlugin/Windows/ConnectionRequestWindow.xaml
 create mode 100644 source/CPDLCPlugin/Windows/ConnectionRequestWindow.xaml.cs
 create mode 100644 source/CPDLCServer/Handlers/SendConnectionRequestCommandHandler.cs
 create mode 100644 source/CPDLCServer/Messages/SendConnectionRequestCommand.cs

diff --git a/source/CPDLCPlugin/Messages/OpenConnectionRequestWindowRequest.cs b/source/CPDLCPlugin/Messages/OpenConnectionRequestWindowRequest.cs
new file mode 100644
index 0000000..27deaed
--- /dev/null
+++ b/source/CPDLCPlugin/Messages/OpenConnectionRequestWindowRequest.cs
@@ -0,0 +1,42 @@
+using CPDLCPlugin.Configuration;
+using CPDLCPlugin.ViewModels;
+using CPDLCPlugin.Windows;
+using MediatR;
+
+namespace CPDLCPlugin.Messages;
+
+public record OpenConnectionRequestWindowRequest(string Callsign) : IRequest;
+
+public class OpenConnectionRequestWindowRequestHandler(
+    WindowManager windowManager,
+    PluginConfiguration pluginConfiguration,
+    IMediator mediator,
+    Plugin plugin,
+    IErrorReporter errorReporter)
+    : IRequestHandler<OpenConnectionRequestWindowRequest>
+{
+    public Task Handle(OpenConnectionRequestWindowRequest request, CancellationToken cancellationToken)
+    {
+        // Each window is specific to a callsign, so we always want a fresh window
+        windowManager.TryRemoveWindow(WindowKeys.ConnectionRequest);
+
+        windowManager.FocusOrCreateWindow(
+            WindowKeys.ConnectionRequest,
+            windowHandle =>
+            {
+                var currentStationIdentifier = plugin.ConnectionManager?.StationIdentifier;
+                var viewModel = new ConnectionRequestViewModel(
+                    mediator,
+                    errorReporter,
+                    windowHandle,
+                    request.Callsign,
+                    pluginConfiguration.Stations,
+                    string.IsNullOrEmpty(currentStationIdentifier) ? pluginConfiguration.Stations.First() : currentStationIdentifier!);
+
+                var control = new ConnectionRequestWindow(viewModel);
+                return control;
+            });
+
+        return Task.CompletedTask;
+    }
+}
diff --git a/source/CPDLCPlugin/Messages/RebuildCpdlcStatusLabelItemsRequest.cs b/source/CPDLCPlugin/Messages/RebuildCpdlcStatusLabelItemsRequest.cs
index ea689f4..feb5399 100644
--- a/source/CPDLCPlugin/Messages/RebuildCpdlcStatusLabelItemsRequest.cs
+++ b/source/CPDLCPlugin/Messages/RebuildCpdlcStatusLabelItemsRequest.cs
@@ -84,7 +84,21 @@ public async Task Handle(RebuildCpdlcStatusLabelItemsRequest request, Cancellati
                     if (isOnAcarsNetwork && connection is null)
                     {
                         text = ".";
-                        // TODO: Left click will initiate a manual connection
+                        onMouseClick = args =>
+                        {
+                            try
+                            {
+                                if (args.Button != CustomLabelItemMouseButton.Left)
+                                    return;
+
+                                mediator.Send(new OpenConnectionRequestWindowRequest(callsign));
+                                args.Handled = true;
+                            }
+                            catch (Exception ex)
+                            {
+                                errorReporter.ReportError(ex, "Error opening CPDLC connection request window");
+                            }
+                        };
                     }
                     else if (connection is not null && connection.DataAuthorityState == DataAuthorityState.NextDataAuthority)
                     {
diff --git a/source/CPDLCPlugin/Messages/SendConnectionRequestRequest.cs b/source/CPDLCPlugin/Messages/SendConnectionRequestRequest.cs
new file mode 100644
index 0000000..a482da2
--- /dev/null
+++ b/source/CPDLCPlugin/Messages/SendConnectionRequestRequest.cs
@@ -0,0 +1,26 @@
+using MediatR;
+using Serilog;
+
+namespace CPDLCPlugin.Messages;
+
+public record SendConnectionRequestRequest(string Callsign, string StationId) : IRequest;
+
+public class SendConnectionRequestRequestHandler(Plugin plugin, ILogger logger)
+    : IRequestHandler<SendConnectionRequestRequest>
+{
+    public async Task Handle(SendConnectionRequestRequest request, CancellationToken cancellationToken)
+    {
+        logger.Information("Sending connection request for {StationId} to {Callsign}", request.StationId, request.Callsign);
+
+        if (plugin.ConnectionManager is null || !plugin.ConnectionManager.IsConnected)
+        {
+            logger.Warning("Not connected to server");
+            return;
+        }
+
+        await plugin.ConnectionManager.RequestConnection(
+            request.Callsign,
+            request.StationId,
+            cancellationToken);
+    }
+}
diff --git a/source/CPDLCPlugin/Server/SignalRConnectionManager.cs b/source/CPDLCPlugin/Server/SignalRConnectionManager.cs
index 618d1fb..ba93224 100644
--- a/source/CPDLCPlugin/Server/SignalRConnectionManager.cs
+++ b/source/CPDLCPlugin/Server/SignalRConnectionManager.cs
@@ -180,6 +180,16 @@ await connection.InvokeAsync<UplinkMessageDto>(
             cancellationToken: cancellationToken);
     }
 
+    public async Task RequestConnection(string callsign, string stationId, CancellationToken cancellationToken)
+    {
+        var connection = GetConnectedOrThrow();
+        await connection.InvokeAsync(
+            "RequestConnection",
+            callsign,
+            stationId,
+            cancellationToken);
+    }
+
     public async Task<AircraftConnectionDto[]> GetConnectedAircraft(CancellationToken cancellationToken)
     {
         var connection = GetConnectedOrThrow();
diff --git a/source/CPDLCPlugin/ViewModels/ConnectionRequestViewModel.cs b/source/CPDLCPlugin/ViewModels/ConnectionRequestViewModel.cs
new file mode 100644
index 0000000..50aaced
--- /dev/null
+++ b/source/CPDLCPlugin/ViewModels/ConnectionRequestViewModel.cs
@@ -0,0 +1,53 @@
+using CommunityToolkit.Mvvm.ComponentModel;
+using CommunityToolkit.Mvvm.Input;
+using CPDLCPlugin.Messages;
+using MediatR;
+
+namespace CPDLCPlugin.ViewModels;
+
+public partial class ConnectionRequestViewModel : ObservableObject
+{
+    readonly IMediator _mediator;
+    readonly IErrorReporter _errorReporter;
+    readonly IWindowHandle _windowHandle;
+
+    [ObservableProperty] string callsign;
+    [ObservableProperty] string[] availableStationIdentifiers;
+    [ObservableProperty] string selectedStationIdentifier;
+
+    public ConnectionRequestViewModel(
+        IMediator mediator,
+        IErrorReporter errorReporter,
+        IWindowHandle windowHandle,
+        string callsign,
+        string[] availableStationIdentifiers,
+        string selectedStationIdentifier)
+    {
+        _mediator = mediator;
+        _errorReporter = errorReporter;
+        _windowHandle = windowHandle;
+        Callsign = callsign;
+        AvailableStationIdentifiers = availableStationIdentifiers;
+        SelectedStationIdentifier = selectedStationIdentifier;
+    }
+
+    [RelayCommand]
+    async Task Confirm()
+    {
+        try
+        {
+            await _mediator.Send(new SendConnectionRequestRequest(Callsign, SelectedStationIdentifier));
+            _windowHandle.Close();
+        }
+        catch (Exception e)
+        {
+            _errorReporter.ReportError(e);
+        }
+    }
+
+    [RelayCommand]
+    void Cancel()
+    {
+        _windowHandle.Close();
+    }
+}
diff --git a/source/CPDLCPlugin/Windows/ConnectionRequestWindow.xaml b/source/CPDLCPlugin/Windows/ConnectionRequestWindow.xaml
new file mode 100644
index 0000000..1e3c123
--- /dev/null
+++ b/source/CPDLCPlugin/Windows/ConnectionRequestWindow.xaml
@@ -0,0 +1,78 @@
+<Window x:Class="CPDLCPlugin.Windows.ConnectionRequestWindow"
+        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+        xmlns:cpdlcPlugin="clr-namespace:CPDLCPlugin"
+        xmlns:viewModels="clr-namespace:CPDLCPlugin.ViewModels"
+        Background="{x:Static cpdlcPlugin:Theme.BackgroundColor}"
+        d:DataContext="{d:DesignInstance Type=viewModels:ConnectionRequestViewModel}"
+        mc:Ignorable="d"
+        Title="CPDLC Connection Request"
+        Width="300"
+        SizeToContent="Height"
+        ResizeMode="NoResize">
+    <Window.Resources>
+        <ResourceDictionary>
+            <ResourceDictionary.MergedDictionaries>
+                <ResourceDictionary Source="/CPDLCPlugin;component/Styles.xaml" />
+            </ResourceDictionary.MergedDictionaries>
+
+            <Style TargetType="Button" BasedOn="{StaticResource ButtonBaseStyle}">
+                <Setter Property="Height" Value="32"/>
+                <Setter Property="MinWidth" Value="80"/>
+            </Style>
+
+            <Style TargetType="TextBlock" BasedOn="{StaticResource GenericTextStyle}" />
+        </ResourceDictionary>
+    </Window.Resources>
+
+    <Grid Margin="16">
+        <Grid.RowDefinitions>
+            <RowDefinition Height="Auto"/>
+            <RowDefinition Height="Auto"/>
+            <RowDefinition Height="16"/>
+            <RowDefinition Height="Auto"/>
+        </Grid.RowDefinitions>
+
+        <TextBlock Grid.Row="0" Margin="0,0,0,8" TextWrapping="Wrap">
+            <Run Text="Send CONNECTION REQUESTED to"/>
+            <Run Text="{Binding Callsign, Mode=OneWay}"/>
+        </TextBlock>
+
+        <!-- ATSU -->
+        <Grid Grid.Row="1">
+            <Grid.RowDefinitions>
+                <RowDefinition Height="Auto"/>
+                <RowDefinition Height="Auto"/>
+            </Grid.RowDefinitions>
+
+            <TextBlock Grid.Row="0" Text="ATSU" Margin="0,0,0,4"/>
+            <ComboBox Grid.Row="1"
+                      ItemsSource="{Binding AvailableStationIdentifiers}"
+                      SelectedItem="{Binding SelectedStationIdentifier}"/>
+        </Grid>
+
+        <!-- Buttons -->
+        <Grid Grid.Row="3">
+            <Grid.ColumnDefinitions>
+                <ColumnDefinition Width="*"/>
+                <ColumnDefinition Width="*"/>
+            </Grid.ColumnDefinitions>
+
+            <Button
+                Grid.Column="0"
+                Content="Send"
+                Command="{Binding ConfirmCommand}"
+                HorizontalAlignment="Stretch"
+                Margin="0,0,4,0"/>
+
+            <Button
+                Grid.Column="1"
+                Content="Cancel"
+                Command="{Binding CancelCommand}"
+                HorizontalAlignment="Stretch"
+                Margin="4,0,0,0"/>
+        </Grid>
+    </Grid>
+</Window>
diff --git a/source/CPDLCPlugin/Windows/ConnectionRequestWindow.xaml.cs b/source/CPDLCPlugin/Windows/ConnectionRequestWindow.xaml.cs
new file mode 100644
index 0000000..6c93d82
--- /dev/null
+++ b/source/CPDLCPlugin/Windows/ConnectionRequestWindow.xaml.cs
@@ -0,0 +1,13 @@
+using System.Windows;
+using CPDLCPlugin.ViewModels;
+
+namespace CPDLCPlugin.Windows;
+
+public partial class ConnectionRequestWindow : Window
+{
+    public ConnectionRequestWindow(ConnectionRequestViewModel viewModel)
+    {
+        InitializeComponent();
+        DataContext = viewModel;
+    }
+}
diff --git a/source/CPDLCPlugin/Windows/WindowKeys.cs b/source/CPDLCPlugin/Windows/WindowKeys.cs
index b1dacf4..3e04d8f 100644
--- a/source/CPDLCPlugin/Windows/WindowKeys.cs
+++ b/source/CPDLCPlugin/Windows/WindowKeys.cs
@@ -7,4 +7,5 @@ public static class WindowKeys
     public const string CurrentMessages = nameof(CurrentMessages);
     public const string History = nameof(History);
     public const string ADSContract = nameof(ADSContract);
+    public const string ConnectionRequest = nameof(ConnectionRequest);
 }
\ No newline at end of file
diff --git a/source/CPDLCServer.Tests/Mocks/TestClientManager.cs b/source/CPDLCServer.Tests/Mocks/TestClientManager.cs
index 48d6328..a2ac026 100644
--- a/source/CPDLCServer.Tests/Mocks/TestClientManager.cs
+++ b/source/CPDLCServer.Tests/Mocks/TestClientManager.cs
@@ -70,6 +70,16 @@ public Task<AcarsConfiguration> GetConfigurationForStation(string stationId, Can
         return Task.FromResult(configuration);
     }
 
+    public Task<string?> FindAcarsClientId(string stationId, CancellationToken cancellationToken)
+    {
+        var acarsClientId = _clients
+            .Where(c => string.Equals(c.Value.StationId, stationId, StringComparison.OrdinalIgnoreCase))
+            .Select(c => c.Key)
+            .FirstOrDefault();
+
+        return Task.FromResult(acarsClientId);
+    }
+
     public bool ClientExists(string acarsClientId)
     {
         return _clients.ContainsKey(acarsClientId);
diff --git a/source/CPDLCServer/Clients/ClientManager.cs b/source/CPDLCServer/Clients/ClientManager.cs
index 6b9a7e8..cf99337 100644
--- a/source/CPDLCServer/Clients/ClientManager.cs
+++ b/source/CPDLCServer/Clients/ClientManager.cs
@@ -12,6 +12,7 @@ public interface IClientManager
     Task<IAcarsClient> GetAcarsClient(string acarsClientId, CancellationToken cancellationToken);
     Task<IAcarsClient> GetAcarsClientForStation(string stationId, CancellationToken cancellationToken);
     Task<AcarsConfiguration> GetConfigurationForStation(string stationId, CancellationToken cancellationToken);
+    Task<string?> FindAcarsClientId(string stationId, CancellationToken cancellationToken);
 }
 
 public class ClientManager : BackgroundService, IClientManager
@@ -160,6 +161,16 @@ public Task<AcarsConfiguration> GetConfigurationForStation(string stationId, Can
         return Task.FromResult(configuration);
     }
 
+    public Task<string?> FindAcarsClientId(string stationId, CancellationToken cancellationToken)
+    {
+        var acarsClientId = _clients
+            .Where(c => string.Equals(c.Value.Client.StationId, stationId, StringComparison.OrdinalIgnoreCase))
+            .Select(c => c.Key)
+            .FirstOrDefault();
+
+        return Task.FromResult(acarsClientId);
+    }
+
     async Task<AcarsClientHandle> CreateAcarsClient(string acarsClientId, CancellationToken cancellationToken)
     {
         var configuration = _acarsConfigurations.FirstOrDefault(c => c.ClientId == acarsClientId);
diff --git a/source/CPDLCServer/Handlers/DownlinkReceivedNotificationHandler.cs b/source/CPDLCServer/Handlers/DownlinkReceivedNotificationHandler.cs
index a51f4b5..83997f3 100644
--- a/source/CPDLCServer/Handlers/DownlinkReceivedNotificationHandler.cs
+++ b/source/CPDLCServer/Handlers/DownlinkReceivedNotificationHandler.cs
@@ -23,6 +23,13 @@ public async Task Handle(DownlinkReceivedNotification notification, Cancellation
         var downlink = notification.Downlink;
         logger.Information("Downlink message received from {Callsign}", downlink.Sender);
 
+        // Ignore replies to connection requests to prevent error message loops
+        if (ControlMessages.IsNotCurrentAtsu(downlink))
+        {
+            logger.Information("{Callsign} replied NOT CURRENT ATSU, ignoring downlink", downlink.Sender);
+            return;
+        }
+
         // Scenario 1: Logon request
         if (ControlMessages.IsLogonRequest(downlink))
         {
diff --git a/source/CPDLCServer/Handlers/SendConnectionRequestCommandHandler.cs b/source/CPDLCServer/Handlers/SendConnectionRequestCommandHandler.cs
new file mode 100644
index 0000000..340681d
--- /dev/null
+++ b/source/CPDLCServer/Handlers/SendConnectionRequestCommandHandler.cs
@@ -0,0 +1,45 @@
+using CPDLCServer.Clients;
+using CPDLCServer.Infrastructure;
+using CPDLCServer.Messages;
+using CPDLCServer.Model;
+using CPDLCServer.Services;
+using MediatR;
+
+namespace CPDLCServer.Handlers;
+
+public class SendConnectionRequestCommandHandler(
+    IClientManager clientManager,
+    IMessageIdProvider messageIdProvider,
+    IClock clock,
+    ILogger logger)
+    : IRequestHandler<SendConnectionRequestCommand>
+{
+    public async Task Handle(SendConnectionRequestCommand request, CancellationToken cancellationToken)
+    {
+        var acarsClientId = await clientManager.FindAcarsClientId(request.StationId, cancellationToken);
+        if (acarsClientId is null)
+            throw new Exception($"No ACARS client is configured for {request.StationId}");
+
+        var client = await clientManager.GetAcarsClient(acarsClientId, cancellationToken);
+
+        var messageId = await messageIdProvider.GetNextMessageId(
+            acarsClientId,
+            request.Callsign,
+            cancellationToken);
+
+        // This is a system message. It does not start a dialogue.
+        var uplinkMessage = new UplinkMessage(
+            Guid.Empty,
+            messageId,
+            null,
+            request.Callsign,
+            "SYSTEM",
+            CpdlcUplinkResponseType.NoResponse,
+            AlertType.None,
+            $"CONNECTION REQUESTED @{request.StationId}@",
+            clock.UtcNow());
+
+        await client.Send(uplinkMessage, cancellationToken);
+        logger.Information("Sent connection request for {StationId} to {Callsign}", request.StationId, request.Callsign);
+    }
+}
diff --git a/source/CPDLCServer/Hubs/ControllerHub.cs b/source/CPDLCServer/Hubs/ControllerHub.cs
index 8d59426..c45a8fd 100644
--- a/source/CPDLCServer/Hubs/ControllerHub.cs
+++ b/source/CPDLCServer/Hubs/ControllerHub.cs
@@ -129,6 +129,24 @@ await mediator.Send(new ReplyToDownlinkCommand(
             content));
     }
 
+    public async Task RequestConnection(string callsign, string stationId)
+    {
+        var controller = await controllerRepository.FindByConnectionId(Context.ConnectionId, CancellationToken.None);
+        if (controller is null)
+        {
+            _logger.Warning("Controller not found for connection {ConnectionId}", Context.ConnectionId);
+            throw new InvalidOperationException($"Controller not found for connection {Context.ConnectionId}");
+        }
+
+        await mediator.Send(new SendConnectionRequestCommand(callsign, stationId));
+
+        _logger.Information(
+            "Controller {Callsign} requested a connection between {AircraftCallsign} and {StationId}",
+            controller.Callsign,
+            callsign,
+            stationId);
+    }
+
     public async Task<AircraftConnectionDto[]> GetConnectedAircraft()
     {
         var controller = await controllerRepository.FindByConnectionId(Context.ConnectionId, CancellationToken.None);
diff --git a/source/CPDLCServer/Messages/SendConnectionRequestCommand.cs b/source/CPDLCServer/Messages/SendConnectionRequestCommand.cs
new file mode 100644
index 0000000..17e9a06
--- /dev/null
+++ b/source/CPDLCServer/Messages/SendConnectionRequestCommand.cs
@@ -0,0 +1,8 @@
+using MediatR;
+
+namespace CPDLCServer.Messages;
+
+public record SendConnectionRequestCommand(
+    string Callsign,
+    string StationId)
+    : IRequest;
diff --git a/source/CPDLCServer/Model/ControlMessages.cs b/source/CPDLCServer/Model/ControlMessages.cs
index 9b97271..51af778 100644
--- a/source/CPDLCServer/Model/ControlMessages.cs
+++ b/source/CPDLCServer/Model/ControlMessages.cs
@@ -21,4 +21,9 @@ public static bool IsNotCurrentDataAuthority(ReceivedDownlink downlink)
     {
         return downlink.Content.Contains("NOT CURRENT DATA AUTHORITY");
     }
+
+    public static bool IsNotCurrentAtsu(ReceivedDownlink downlink)
+    {
+        return downlink.Content.Contains("NOT CURRENT ATSU");
+    }
 }

From f5c85d11c446c17dd01b6e37c5a827ac4153ac62 Mon Sep 17 00:00:00 2001
From: Eoin Motherway <25342760+YuKitsune@users.noreply.github.com>
Date: Sun, 11 Oct 2026 14:29:26 +1000
Subject: [PATCH 2/5] Remove unused method

---
 .../Handlers/DownlinkReceivedNotificationHandler.cs        | 7 -------
 source/CPDLCServer/Model/ControlMessages.cs                | 5 -----
 2 files changed, 12 deletions(-)

diff --git a/source/CPDLCServer/Handlers/DownlinkReceivedNotificationHandler.cs b/source/CPDLCServer/Handlers/DownlinkReceivedNotificationHandler.cs
index 83997f3..a51f4b5 100644
--- a/source/CPDLCServer/Handlers/DownlinkReceivedNotificationHandler.cs
+++ b/source/CPDLCServer/Handlers/DownlinkReceivedNotificationHandler.cs
@@ -23,13 +23,6 @@ public async Task Handle(DownlinkReceivedNotification notification, Cancellation
         var downlink = notification.Downlink;
         logger.Information("Downlink message received from {Callsign}", downlink.Sender);
 
-        // Ignore replies to connection requests to prevent error message loops
-        if (ControlMessages.IsNotCurrentAtsu(downlink))
-        {
-            logger.Information("{Callsign} replied NOT CURRENT ATSU, ignoring downlink", downlink.Sender);
-            return;
-        }
-
         // Scenario 1: Logon request
         if (ControlMessages.IsLogonRequest(downlink))
         {
diff --git a/source/CPDLCServer/Model/ControlMessages.cs b/source/CPDLCServer/Model/ControlMessages.cs
index 51af778..9b97271 100644
--- a/source/CPDLCServer/Model/ControlMessages.cs
+++ b/source/CPDLCServer/Model/ControlMessages.cs
@@ -21,9 +21,4 @@ public static bool IsNotCurrentDataAuthority(ReceivedDownlink downlink)
     {
         return downlink.Content.Contains("NOT CURRENT DATA AUTHORITY");
     }
-
-    public static bool IsNotCurrentAtsu(ReceivedDownlink downlink)
-    {
-        return downlink.Content.Contains("NOT CURRENT ATSU");
-    }
 }

From c4ef196194093546d081c9f7eb729ed87ece8e91 Mon Sep 17 00:00:00 2001
From: Eoin Motherway <25342760+YuKitsune@users.noreply.github.com>
Date: Sun, 11 Oct 2026 15:05:01 +1000
Subject: [PATCH 3/5] Add tests

---
 ...endConnectionRequestCommandHandlerTests.cs | 103 ++++++++++++++++++
 1 file changed, 103 insertions(+)
 create mode 100644 source/CPDLCServer.Tests/Handlers/SendConnectionRequestCommandHandlerTests.cs

diff --git a/source/CPDLCServer.Tests/Handlers/SendConnectionRequestCommandHandlerTests.cs b/source/CPDLCServer.Tests/Handlers/SendConnectionRequestCommandHandlerTests.cs
new file mode 100644
index 0000000..d091993
--- /dev/null
+++ b/source/CPDLCServer.Tests/Handlers/SendConnectionRequestCommandHandlerTests.cs
@@ -0,0 +1,103 @@
+using CPDLCServer.Handlers;
+using CPDLCServer.Messages;
+using CPDLCServer.Model;
+using CPDLCServer.Tests.Mocks;
+using Serilog.Core;
+
+namespace CPDLCServer.Tests.Handlers;
+
+public class SendConnectionRequestCommandHandlerTests
+{
+    [Fact]
+    public async Task Handle_SendsConnectionRequestUplink()
+    {
+        // Arrange
+        var clientManager = new TestClientManager();
+        var messageIdProvider = new TestMessageIdProvider();
+        messageIdProvider.SetNextId(5);
+        var clock = new TestClock();
+
+        var handler = new SendConnectionRequestCommandHandler(clientManager, messageIdProvider, clock, Logger.None);
+
+        var command = new SendConnectionRequestCommand("UAL123", "YBBB");
+
+        // Act
+        await handler.Handle(command, CancellationToken.None);
+
+        // Assert
+        var client = (TestAcarsClient)await clientManager.GetAcarsClient("hoppies-ybbb", CancellationToken.None);
+        var uplink = Assert.Single(client.SentMessages);
+        Assert.Equal("UAL123", uplink.Recipient);
+        Assert.Equal("CONNECTION REQUESTED @YBBB@", uplink.Content);
+        Assert.Equal(5, uplink.MessageId);
+        Assert.Null(uplink.MessageReference);
+        Assert.Equal(CpdlcUplinkResponseType.NoResponse, uplink.ResponseType);
+        Assert.Equal(clock.UtcNow(), uplink.Sent);
+    }
+
+    [Fact]
+    public async Task Handle_SendsUplinkViaClientForSelectedStation()
+    {
+        // The uplink must go through the ACARS client of the selected ATSU, not another client.
+        // Arrange
+        var clientManager = new TestClientManager();
+        var messageIdProvider = new TestMessageIdProvider();
+        var clock = new TestClock();
+
+        var handler = new SendConnectionRequestCommandHandler(clientManager, messageIdProvider, clock, Logger.None);
+
+        var command = new SendConnectionRequestCommand("UAL123", "YMMM");
+
+        // Act
+        await handler.Handle(command, CancellationToken.None);
+
+        // Assert
+        var ymmmClient = (TestAcarsClient)await clientManager.GetAcarsClient("hoppies-ymmm", CancellationToken.None);
+        var ybbbClient = (TestAcarsClient)await clientManager.GetAcarsClient("hoppies-ybbb", CancellationToken.None);
+
+        var uplink = Assert.Single(ymmmClient.SentMessages);
+        Assert.Equal("CONNECTION REQUESTED @YMMM@", uplink.Content);
+        Assert.Empty(ybbbClient.SentMessages);
+    }
+
+    [Fact]
+    public async Task Handle_MatchesStationIdIgnoringCase()
+    {
+        // Arrange
+        var clientManager = new TestClientManager();
+        var messageIdProvider = new TestMessageIdProvider();
+        var clock = new TestClock();
+
+        var handler = new SendConnectionRequestCommandHandler(clientManager, messageIdProvider, clock, Logger.None);
+
+        var command = new SendConnectionRequestCommand("UAL123", "ybbb");
+
+        // Act
+        await handler.Handle(command, CancellationToken.None);
+
+        // Assert
+        var client = (TestAcarsClient)await clientManager.GetAcarsClient("hoppies-ybbb", CancellationToken.None);
+        Assert.Single(client.SentMessages);
+    }
+
+    [Fact]
+    public async Task Handle_ThrowsWhenNoClientForStation()
+    {
+        // Arrange
+        var clientManager = new TestClientManager();
+        var messageIdProvider = new TestMessageIdProvider();
+        var clock = new TestClock();
+
+        var handler = new SendConnectionRequestCommandHandler(clientManager, messageIdProvider, clock, Logger.None);
+
+        var command = new SendConnectionRequestCommand("UAL123", "YPPP");
+
+        // Act & Assert
+        await Assert.ThrowsAnyAsync<Exception>(() => handler.Handle(command, CancellationToken.None));
+
+        var ybbbClient = (TestAcarsClient)await clientManager.GetAcarsClient("hoppies-ybbb", CancellationToken.None);
+        var ymmmClient = (TestAcarsClient)await clientManager.GetAcarsClient("hoppies-ymmm", CancellationToken.None);
+        Assert.Empty(ybbbClient.SentMessages);
+        Assert.Empty(ymmmClient.SentMessages);
+    }
+}

From eb22b67f3feecc3ae8d19972266692f629e35a50 Mon Sep 17 00:00:00 2001
From: Eoin Motherway <25342760+YuKitsune@users.noreply.github.com>
Date: Sat, 17 Oct 2026 14:47:10 +1000
Subject: [PATCH 4/5] Use vatSys form for the connection request window

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
---
 .../Messages/OpenConnectionRequestWindowRequest.cs  | 10 +++++++++-
 ...equestWindow.xaml => ConnectionRequestView.xaml} | 13 +++++--------
 .../Windows/ConnectionRequestView.xaml.cs           | 13 +++++++++++++
 .../Windows/ConnectionRequestWindow.xaml.cs         | 13 -------------
 4 files changed, 27 insertions(+), 22 deletions(-)
 rename source/CPDLCPlugin/Windows/{ConnectionRequestWindow.xaml => ConnectionRequestView.xaml} (91%)
 create mode 100644 source/CPDLCPlugin/Windows/ConnectionRequestView.xaml.cs
 delete mode 100644 source/CPDLCPlugin/Windows/ConnectionRequestWindow.xaml.cs

diff --git a/source/CPDLCPlugin/Messages/OpenConnectionRequestWindowRequest.cs b/source/CPDLCPlugin/Messages/OpenConnectionRequestWindowRequest.cs
index 27deaed..2d705f2 100644
--- a/source/CPDLCPlugin/Messages/OpenConnectionRequestWindowRequest.cs
+++ b/source/CPDLCPlugin/Messages/OpenConnectionRequestWindowRequest.cs
@@ -22,6 +22,7 @@ public Task Handle(OpenConnectionRequestWindowRequest request, CancellationToken
 
         windowManager.FocusOrCreateWindow(
             WindowKeys.ConnectionRequest,
+            "CPDLC Connection Request",
             windowHandle =>
             {
                 var currentStationIdentifier = plugin.ConnectionManager?.StationIdentifier;
@@ -33,8 +34,15 @@ public Task Handle(OpenConnectionRequestWindowRequest request, CancellationToken
                     pluginConfiguration.Stations,
                     string.IsNullOrEmpty(currentStationIdentifier) ? pluginConfiguration.Stations.First() : currentStationIdentifier!);
 
-                var control = new ConnectionRequestWindow(viewModel);
+                var control = new ConnectionRequestView(viewModel);
                 return control;
+            },
+            configureForm: form =>
+            {
+                form.HasMinimizeButton = false;
+                form.MinimizeBox = false;
+                form.HasCloseButton = false;
+                form.HasSendBackButton = false;
             });
 
         return Task.CompletedTask;
diff --git a/source/CPDLCPlugin/Windows/ConnectionRequestWindow.xaml b/source/CPDLCPlugin/Windows/ConnectionRequestView.xaml
similarity index 91%
rename from source/CPDLCPlugin/Windows/ConnectionRequestWindow.xaml
rename to source/CPDLCPlugin/Windows/ConnectionRequestView.xaml
index 1e3c123..fb80673 100644
--- a/source/CPDLCPlugin/Windows/ConnectionRequestWindow.xaml
+++ b/source/CPDLCPlugin/Windows/ConnectionRequestView.xaml
@@ -1,4 +1,4 @@
-<Window x:Class="CPDLCPlugin.Windows.ConnectionRequestWindow"
+<UserControl x:Class="CPDLCPlugin.Windows.ConnectionRequestView"
         xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
         xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
@@ -8,11 +8,8 @@
         Background="{x:Static cpdlcPlugin:Theme.BackgroundColor}"
         d:DataContext="{d:DesignInstance Type=viewModels:ConnectionRequestViewModel}"
         mc:Ignorable="d"
-        Title="CPDLC Connection Request"
-        Width="300"
-        SizeToContent="Height"
-        ResizeMode="NoResize">
-    <Window.Resources>
+        Width="300">
+    <UserControl.Resources>
         <ResourceDictionary>
             <ResourceDictionary.MergedDictionaries>
                 <ResourceDictionary Source="/CPDLCPlugin;component/Styles.xaml" />
@@ -25,7 +22,7 @@
 
             <Style TargetType="TextBlock" BasedOn="{StaticResource GenericTextStyle}" />
         </ResourceDictionary>
-    </Window.Resources>
+    </UserControl.Resources>
 
     <Grid Margin="16">
         <Grid.RowDefinitions>
@@ -75,4 +72,4 @@
                 Margin="4,0,0,0"/>
         </Grid>
     </Grid>
-</Window>
+</UserControl>
diff --git a/source/CPDLCPlugin/Windows/ConnectionRequestView.xaml.cs b/source/CPDLCPlugin/Windows/ConnectionRequestView.xaml.cs
new file mode 100644
index 0000000..69a3a15
--- /dev/null
+++ b/source/CPDLCPlugin/Windows/ConnectionRequestView.xaml.cs
@@ -0,0 +1,13 @@
+using System.Windows.Controls;
+using CPDLCPlugin.ViewModels;
+
+namespace CPDLCPlugin.Windows;
+
+public partial class ConnectionRequestView : UserControl
+{
+    public ConnectionRequestView(ConnectionRequestViewModel viewModel)
+    {
+        InitializeComponent();
+        DataContext = viewModel;
+    }
+}
diff --git a/source/CPDLCPlugin/Windows/ConnectionRequestWindow.xaml.cs b/source/CPDLCPlugin/Windows/ConnectionRequestWindow.xaml.cs
deleted file mode 100644
index 6c93d82..0000000
--- a/source/CPDLCPlugin/Windows/ConnectionRequestWindow.xaml.cs
+++ /dev/null
@@ -1,13 +0,0 @@
-using System.Windows;
-using CPDLCPlugin.ViewModels;
-
-namespace CPDLCPlugin.Windows;
-
-public partial class ConnectionRequestWindow : Window
-{
-    public ConnectionRequestWindow(ConnectionRequestViewModel viewModel)
-    {
-        InitializeComponent();
-        DataContext = viewModel;
-    }
-}

From d6101ab19e728ba07cd9ec422191dc5d063a2061 Mon Sep 17 00:00:00 2001
From: Eoin Motherway <25342760+YuKitsune@users.noreply.github.com>
Date: Sat, 17 Oct 2026 14:54:31 +1000
Subject: [PATCH 5/5] Fix layout

---
 .../ViewModels/ConnectionRequestViewModel.cs  |  8 ++++++++
 .../Windows/ConnectionRequestView.xaml        | 20 +++++++++----------
 2 files changed, 18 insertions(+), 10 deletions(-)

diff --git a/source/CPDLCPlugin/ViewModels/ConnectionRequestViewModel.cs b/source/CPDLCPlugin/ViewModels/ConnectionRequestViewModel.cs
index 50aaced..f570ca2 100644
--- a/source/CPDLCPlugin/ViewModels/ConnectionRequestViewModel.cs
+++ b/source/CPDLCPlugin/ViewModels/ConnectionRequestViewModel.cs
@@ -15,6 +15,14 @@ public partial class ConnectionRequestViewModel : ObservableObject
     [ObservableProperty] string[] availableStationIdentifiers;
     [ObservableProperty] string selectedStationIdentifier;
 
+    // Example data for the XAML designer. Do not use at runtime.
+    public ConnectionRequestViewModel()
+    {
+        Callsign = "QFA123AB";
+        AvailableStationIdentifiers = ["YBBB", "YMMM"];
+        SelectedStationIdentifier = "YBBB";
+    }
+
     public ConnectionRequestViewModel(
         IMediator mediator,
         IErrorReporter errorReporter,
diff --git a/source/CPDLCPlugin/Windows/ConnectionRequestView.xaml b/source/CPDLCPlugin/Windows/ConnectionRequestView.xaml
index fb80673..8bd5696 100644
--- a/source/CPDLCPlugin/Windows/ConnectionRequestView.xaml
+++ b/source/CPDLCPlugin/Windows/ConnectionRequestView.xaml
@@ -8,7 +8,7 @@
         Background="{x:Static cpdlcPlugin:Theme.BackgroundColor}"
         d:DataContext="{d:DesignInstance Type=viewModels:ConnectionRequestViewModel}"
         mc:Ignorable="d"
-        Width="300">
+        Width="400">
     <UserControl.Resources>
         <ResourceDictionary>
             <ResourceDictionary.MergedDictionaries>
@@ -28,24 +28,24 @@
         <Grid.RowDefinitions>
             <RowDefinition Height="Auto"/>
             <RowDefinition Height="Auto"/>
-            <RowDefinition Height="16"/>
+            <RowDefinition Height="Auto"/>
             <RowDefinition Height="Auto"/>
         </Grid.RowDefinitions>
 
         <TextBlock Grid.Row="0" Margin="0,0,0,8" TextWrapping="Wrap">
-            <Run Text="Send CONNECTION REQUESTED to"/>
+            <Run Text="Send connection request to "/>
             <Run Text="{Binding Callsign, Mode=OneWay}"/>
         </TextBlock>
 
         <!-- ATSU -->
-        <Grid Grid.Row="1">
-            <Grid.RowDefinitions>
-                <RowDefinition Height="Auto"/>
-                <RowDefinition Height="Auto"/>
-            </Grid.RowDefinitions>
+        <Grid Grid.Row="1" Margin="0,0,0,8">
+            <Grid.ColumnDefinitions>
+                <ColumnDefinition Width="Auto"/>
+                <ColumnDefinition Width="*"/>
+            </Grid.ColumnDefinitions>
 
-            <TextBlock Grid.Row="0" Text="ATSU" Margin="0,0,0,4"/>
-            <ComboBox Grid.Row="1"
+            <TextBlock Grid.Column="0" Text="ATSU" Margin="0,0,8,0"/>
+            <ComboBox Grid.Column="1"
                       ItemsSource="{Binding AvailableStationIdentifiers}"
                       SelectedItem="{Binding SelectedStationIdentifier}"/>
         </Grid>