feat: show vpn start/stop failure in app (#44)

Adds red text that appears when the VPN fails to start or stop. After an
error, any manual start/stop operation will clear the error.

Contributes to #40

Author: deansheather

App/Converters/AgentStatusToColorConverter.cs

@@ -9,7 +9,7 @@ namespace Coder.Desktop.App.Converters;
 public class AgentStatusToColorConverter : IValueConverter
 {
     private static readonly SolidColorBrush Green = new(Color.FromArgb(255, 52, 199, 89));
-    private static readonly SolidColorBrush Yellow = new(Color.FromArgb(255, 204, 1, 0));
+    private static readonly SolidColorBrush Yellow = new(Color.FromArgb(255, 255, 204, 1));
     private static readonly SolidColorBrush Red = new(Color.FromArgb(255, 255, 59, 48));
     private static readonly SolidColorBrush Gray = new(Color.FromArgb(255, 142, 142, 147));
 

App/Converters/InverseBoolToVisibilityConverter.cs

@@ -146,7 +146,8 @@ public async Task Reconnect(CancellationToken ct = default)
             Status = new StatusRequest(),
         }, ct);
         if (statusReply.MsgCase != ServiceMessage.MsgOneofCase.Status)
-            throw new InvalidOperationException($"Unexpected reply message type: {statusReply.MsgCase}");
+            throw new VpnLifecycleException(
+                $"Failed to get VPN status. Unexpected reply message type: {statusReply.MsgCase}");
         ApplyStatusUpdate(statusReply.Status);
     }
 
@@ -172,20 +173,26 @@ public async Task StartVpn(CancellationToken ct = default)
                     ApiToken = credentials.ApiToken,
                 },
             }, ct);
-            if (reply.MsgCase != ServiceMessage.MsgOneofCase.Start)
-                throw new InvalidOperationException($"Unexpected reply message type: {reply.MsgCase}");
         }
         catch (Exception e)
         {
             MutateState(state => { state.VpnLifecycle = VpnLifecycle.Stopped; });
             throw new RpcOperationException("Failed to send start command to service", e);
         }
 
+        if (reply.MsgCase != ServiceMessage.MsgOneofCase.Start)
+        {
+            MutateState(state => { state.VpnLifecycle = VpnLifecycle.Unknown; });
+            throw new VpnLifecycleException($"Failed to start VPN. Unexpected reply message type: {reply.MsgCase}");
+        }
+
         if (!reply.Start.Success)
         {
+            // We use Stopped instead of Unknown here as it's usually the case
+            // that a failed start got cleaned up successfully.
             MutateState(state => { state.VpnLifecycle = VpnLifecycle.Stopped; });
-            throw new VpnLifecycleException("Failed to start VPN",
-                new InvalidOperationException($"Service reported failure: {reply.Start.ErrorMessage}"));
+            throw new VpnLifecycleException(
+                $"Failed to start VPN. Service reported failure: {reply.Start.ErrorMessage}");
         }
 
         MutateState(state => { state.VpnLifecycle = VpnLifecycle.Started; });
@@ -212,16 +219,20 @@ public async Task StopVpn(CancellationToken ct = default)
         }
         finally
         {
-            // Technically the state is unknown now.
-            MutateState(state => { state.VpnLifecycle = VpnLifecycle.Stopped; });
+            MutateState(state => { state.VpnLifecycle = VpnLifecycle.Unknown; });
         }
 
         if (reply.MsgCase != ServiceMessage.MsgOneofCase.Stop)
-            throw new VpnLifecycleException("Failed to stop VPN",
-                new InvalidOperationException($"Unexpected reply message type: {reply.MsgCase}"));
+        {
+            MutateState(state => { state.VpnLifecycle = VpnLifecycle.Unknown; });
+            throw new VpnLifecycleException($"Failed to stop VPN. Unexpected reply message type: {reply.MsgCase}");
+        }
+
         if (!reply.Stop.Success)
-            throw new VpnLifecycleException("Failed to stop VPN",
-                new InvalidOperationException($"Service reported failure: {reply.Stop.ErrorMessage}"));
+        {
+            MutateState(state => { state.VpnLifecycle = VpnLifecycle.Unknown; });
+            throw new VpnLifecycleException($"Failed to stop VPN. Service reported failure: {reply.Stop.ErrorMessage}");
+        }
     }
 
     public async ValueTask DisposeAsync()

App/Converters/VpnLifecycleToVisibilityConverter.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using System.Threading.Tasks;
 using Coder.Desktop.App.Models;
 using Coder.Desktop.App.Services;
 using Coder.Desktop.Vpn.Proto;
@@ -10,6 +11,7 @@
 using Microsoft.UI.Dispatching;
 using Microsoft.UI.Xaml;
 using Microsoft.UI.Xaml.Controls;
+using Exception = System.Exception;
 
 namespace Coder.Desktop.App.ViewModels;
 
@@ -23,22 +25,45 @@ public partial class TrayWindowViewModel : ObservableObject
 
     private DispatcherQueue? _dispatcherQueue;
 
-    [ObservableProperty] public partial VpnLifecycle VpnLifecycle { get; set; } = VpnLifecycle.Unknown;
+    [ObservableProperty]
+    [NotifyPropertyChangedFor(nameof(ShowEnableSection))]
+    [NotifyPropertyChangedFor(nameof(ShowWorkspacesHeader))]
+    [NotifyPropertyChangedFor(nameof(ShowNoAgentsSection))]
+    [NotifyPropertyChangedFor(nameof(ShowAgentsSection))]
+    public partial VpnLifecycle VpnLifecycle { get; set; } = VpnLifecycle.Unknown;
 
     // This is a separate property because we need the switch to be 2-way.
     [ObservableProperty] public partial bool VpnSwitchActive { get; set; } = false;
 
-    [ObservableProperty] public partial string? VpnFailedMessage { get; set; } = null;
+    [ObservableProperty]
+    [NotifyPropertyChangedFor(nameof(ShowEnableSection))]
+    [NotifyPropertyChangedFor(nameof(ShowWorkspacesHeader))]
+    [NotifyPropertyChangedFor(nameof(ShowNoAgentsSection))]
+    [NotifyPropertyChangedFor(nameof(ShowAgentsSection))]
+    [NotifyPropertyChangedFor(nameof(ShowAgentOverflowButton))]
+    [NotifyPropertyChangedFor(nameof(ShowFailedSection))]
+    public partial string? VpnFailedMessage { get; set; } = null;
 
     [ObservableProperty]
-    [NotifyPropertyChangedFor(nameof(NoAgents))]
-    [NotifyPropertyChangedFor(nameof(AgentOverflow))]
     [NotifyPropertyChangedFor(nameof(VisibleAgents))]
+    [NotifyPropertyChangedFor(nameof(ShowNoAgentsSection))]
+    [NotifyPropertyChangedFor(nameof(ShowAgentsSection))]
+    [NotifyPropertyChangedFor(nameof(ShowAgentOverflowButton))]
     public partial List<AgentViewModel> Agents { get; set; } = [];
 
-    public bool NoAgents => Agents.Count == 0;
+    public bool ShowEnableSection => VpnFailedMessage is null && VpnLifecycle is not VpnLifecycle.Started;
+
+    public bool ShowWorkspacesHeader => VpnFailedMessage is null && VpnLifecycle is VpnLifecycle.Started;
+
+    public bool ShowNoAgentsSection =>
+        VpnFailedMessage is null && Agents.Count == 0 && VpnLifecycle is VpnLifecycle.Started;
+
+    public bool ShowAgentsSection =>
+        VpnFailedMessage is null && Agents.Count > 0 && VpnLifecycle is VpnLifecycle.Started;
+
+    public bool ShowFailedSection => VpnFailedMessage is not null;
 
-    public bool AgentOverflow => Agents.Count > MaxAgents;
+    public bool ShowAgentOverflowButton => VpnFailedMessage is null && Agents.Count > MaxAgents;
 
     [ObservableProperty]
     [NotifyPropertyChangedFor(nameof(VisibleAgents))]
@@ -190,24 +215,47 @@ public void VpnSwitch_Toggled(object sender, RoutedEventArgs e)
     {
         if (sender is not ToggleSwitch toggleSwitch) return;
 
-        VpnFailedMessage = "";
+        VpnFailedMessage = null;
+
+        // The start/stop methods will call back to update the state.
+        if (toggleSwitch.IsOn && VpnLifecycle is VpnLifecycle.Stopped)
+            _ = StartVpn(); // in the background
+        else if (!toggleSwitch.IsOn && VpnLifecycle is VpnLifecycle.Started)
+            _ = StopVpn(); // in the background
+        else
+            toggleSwitch.IsOn = VpnLifecycle is VpnLifecycle.Starting or VpnLifecycle.Started;
+    }
+
+    private async Task StartVpn()
+    {
         try
         {
-            // The start/stop methods will call back to update the state.
-            if (toggleSwitch.IsOn && VpnLifecycle is VpnLifecycle.Stopped)
-                _rpcController.StartVpn();
-            else if (!toggleSwitch.IsOn && VpnLifecycle is VpnLifecycle.Started)
-                _rpcController.StopVpn();
-            else
-                toggleSwitch.IsOn = VpnLifecycle is VpnLifecycle.Starting or VpnLifecycle.Started;
+            await _rpcController.StartVpn();
         }
-        catch
+        catch (Exception e)
         {
-            // TODO: display error
-            VpnFailedMessage = e.ToString();
+            VpnFailedMessage = "Failed to start CoderVPN: " + MaybeUnwrapTunnelError(e);
         }
     }
 
+    private async Task StopVpn()
+    {
+        try
+        {
+            await _rpcController.StopVpn();
+        }
+        catch (Exception e)
+        {
+            VpnFailedMessage = "Failed to stop CoderVPN: " + MaybeUnwrapTunnelError(e);
+        }
+    }
+
+    private static string MaybeUnwrapTunnelError(Exception e)
+    {
+        if (e is VpnLifecycleException vpnError) return vpnError.Message;
+        return e.ToString();
+    }
+
     [RelayCommand]
     public void ToggleShowAllAgents()
     {