Show the cluster's solar weather in a bandmap status bar

The reader follows N1MM's rules for WWV and WCY lines and the sh/wwv
table. The bar is hidden until the cluster has sent some.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

src/Nonemm.App/AppSession.cs

@@ -914,6 +914,7 @@ public sealed partial class AppSession : IDisposable
     public void ConnectCluster()
     {
         cluster?.Dispose();
+        SetSolar("");
         cluster = new ClusterClient(
             Settings.ClusterHost,
             Settings.ClusterPort,
@@ -923,14 +924,28 @@ public sealed partial class AppSession : IDisposable
             autoLogon: Settings.ClusterAutoLogon,
             keepAliveInterval: TimeSpan.FromMinutes(Math.Max(1, Settings.ClusterKeepAliveMinutes)));
         cluster.SpotArrived += (_, spot) => TakeSpot(spot);
+        cluster.SolarArrived += (_, text) => SetSolar(text);
         cluster.ConnectionChanged += (_, _) => Changed?.Invoke(this, EventArgs.Empty);
         cluster.Start();
     }
 
+    /// The latest solar weather the cluster sent, or empty when it has sent
+    /// none on this connection.
+    public string Solar { get; private set; } = "";
+
+    public event EventHandler? SolarChanged;
+
+    private void SetSolar(string text)
+    {
+        Solar = text;
+        SolarChanged?.Invoke(this, EventArgs.Empty);
+    }
+
     public void DisconnectCluster()
     {
         cluster?.Dispose();
         cluster = null;
+        SetSolar("");
         Changed?.Invoke(this, EventArgs.Empty);
     }
 

src/Nonemm.App/Windows/BandmapWindow.axaml

@@ -8,6 +8,10 @@
       <ComboBox Name="SpanBox" FontSize="11" Width="96" />
       <CheckBox Name="CentreBox" Content="Centre on VFO" FontSize="11" Margin="8,0,0,0" />
     </DockPanel>
+    <Border Name="SolarBar" DockPanel.Dock="Bottom" IsVisible="False" Padding="6,2"
+            BorderThickness="0,1,0,0" BorderBrush="Gray">
+      <TextBlock Name="SolarText" FontSize="11" TextWrapping="Wrap" />
+    </Border>
     <local:BandmapView Name="View" />
   </DockPanel>
 </local:RefreshableWindow>

src/Nonemm.App/Windows/BandmapWindow.axaml.cs

@@ -76,9 +76,21 @@ public sealed partial class BandmapWindow : RefreshableWindow
         };
         View.FrequencyPicked += (_, frequency) => tune(frequency, "");
         session.Bandmap.Changed += (_, _) => Dispatcher.UIThread.Post(Refresh);
+        EventHandler solarChanged = (_, _) => Dispatcher.UIThread.Post(ShowSolar);
+        session.SolarChanged += solarChanged;
+        Closed += (_, _) => session.SolarChanged -= solarChanged;
+        ShowSolar();
         Refresh();
     }
 
+    /// The status bar holds the solar weather the cluster sent, and is hidden
+    /// while there is none.
+    private void ShowSolar()
+    {
+        SolarText.Text = session.Solar;
+        SolarBar.IsVisible = session.Solar.Length > 0;
+    }
+
     private void SaveView()
     {
         session.Save(session.Settings with

src/Nonemm.Spotting/ClusterClient.cs

@@ -29,6 +29,7 @@ public sealed class ClusterClient : IDisposable
     private readonly CancellationTokenSource stopping = new();
     private readonly LineAssembler lines = new();
     private readonly Queue<ClusterLine> recent = new();
+    private readonly SolarReader solar = new();
     private readonly Lock guard = new();
 
     private TcpClient? client;
@@ -80,6 +81,9 @@ public sealed class ClusterClient : IDisposable
 
     public event EventHandler<string>? LineArrived;
 
+    /// The node sent solar weather, as the text to show.
+    public event EventHandler<string>? SolarArrived;
+
     /// What went out to the node, so the telnet window can show the login and
     /// the commands beside the node's answers.
     public event EventHandler<string>? LineSent;
@@ -237,6 +241,10 @@ public sealed class ClusterClient : IDisposable
             Kind = kind;
             ConnectionChanged?.Invoke(this, IsConnected);
         }
+        if (solar.Read(line) is { } weather)
+        {
+            SolarArrived?.Invoke(this, weather);
+        }
         Spot? spot = SpotLine.Parse(line, DateTime.UtcNow);
         if (spot is not null)
         {

src/Nonemm.Spotting/SolarReader.cs

@@ -0,0 +1,60 @@
+using System.Text.RegularExpressions;
+
+namespace Nonemm.Spotting;
+
+/// Picks the solar weather out of a node's traffic, as N1MM does for its Info
+/// window. A node sends it as one line, such as `WWV de VE7CC <18Z> : SFI=140,
+/// A=5, K=2`, or after `sh/wwv` as a header line (`Date Hour SFI A K ...`)
+/// and a line of numbers under it. The text is kept as the node sent it,
+/// without the extra blanks.
+public sealed partial class SolarReader
+{
+    private bool afterHeader;
+
+    /// The text to show when the line carries solar weather, otherwise null.
+    /// A line has to be passed in even when it is not solar weather, because
+    /// a spot between the header and the numbers cancels the header.
+    public string? Read(string line)
+    {
+        string text = Collapse(line);
+        if (text.Length == 0)
+        {
+            return null;
+        }
+        string upper = text.ToUpperInvariant();
+        bool isFromNode = upper.Contains(" DE ", StringComparison.Ordinal);
+        if (upper.StartsWith("DX", StringComparison.Ordinal))
+        {
+            afterHeader = false;
+            return null;
+        }
+        if (upper.StartsWith("WWV:", StringComparison.Ordinal)
+            || upper.StartsWith("WCY:", StringComparison.Ordinal)
+            || upper.Contains("WWV DE", StringComparison.Ordinal)
+            || upper.Contains("WCY DE", StringComparison.Ordinal))
+        {
+            return text;
+        }
+        if (upper.StartsWith("DATE HOUR SFI", StringComparison.Ordinal))
+        {
+            afterHeader = true;
+            return null;
+        }
+        if (afterHeader && !isFromNode)
+        {
+            return "SFI/A/K: " + text;
+        }
+        if (isFromNode)
+        {
+            afterHeader = false;
+        }
+        return null;
+    }
+
+    /// Control characters out, runs of blanks down to one.
+    private static string Collapse(string line) =>
+        Blanks().Replace(new string([.. line.Where(c => !char.IsControl(c) || c == '\t')]), " ").Trim();
+
+    [GeneratedRegex(@"\s+")]
+    private static partial Regex Blanks();
+}