feat: add support for broadcasting and handling channel deletions across clients

src/EchoHub.Client/AppOrchestrator.cs

@@ -1071,6 +1071,15 @@ public sealed class AppOrchestrator : IDisposable
         _conn.MessageDeleted += (channelName, messageId) =>
             InvokeUI(() => _messageManager.RemoveMessage(channelName, messageId));
 
+        _conn.ChannelDeleted += channelName =>
+        {
+            InvokeUI(() =>
+            {
+                _conn.UntrackChannel(channelName);
+                _mainWindow.RemoveChannel(channelName);
+            });
+        };
+
         _conn.ChannelNuked += channelName =>
         {
             InvokeUI(() =>

src/EchoHub.Client/Services/ConnectionManager.cs

@@ -46,6 +46,7 @@ internal sealed class ConnectionManager : IAsyncDisposable
     public event Action<string, string?>? UserBanned;
     public event Action<string>? ForceDisconnected;
     public event Action<string, Guid>? MessageDeleted;
+    public event Action<string>? ChannelDeleted;
     public event Action<string>? ChannelNuked;
     public event Action<ChannelDto>? ChannelUpdated;
     public event Action<string>? Error;
@@ -300,6 +301,7 @@ internal sealed class ConnectionManager : IAsyncDisposable
         connection.OnUserBanned += (user, reason) => UserBanned?.Invoke(user, reason);
         connection.OnForceDisconnect += reason => ForceDisconnected?.Invoke(reason);
         connection.OnMessageDeleted += (ch, id) => MessageDeleted?.Invoke(ch, id);
+        connection.OnChannelDeleted += ch => ChannelDeleted?.Invoke(ch);
         connection.OnChannelNuked += ch => ChannelNuked?.Invoke(ch);
         connection.OnChannelUpdated += ch =>
         {

src/EchoHub.Client/Services/EchoHubConnection.cs

@@ -58,6 +58,7 @@ public sealed class EchoHubConnection : IAsyncDisposable
     public event Action<string, string, string?>? OnUserKicked;
     public event Action<string, string?>? OnUserBanned;
     public event Action<string, Guid>? OnMessageDeleted;
+    public event Action<string>? OnChannelDeleted;
     public event Action<string>? OnChannelNuked;
     public event Action<string>? OnForceDisconnect;
     public event Action<string>? OnError;
@@ -144,6 +145,11 @@ public sealed class EchoHubConnection : IAsyncDisposable
             OnMessageDeleted?.Invoke(channelName, messageId);
         });
 
+        _connection.On<string>(nameof(Core.Contracts.IEchoHubClient.ChannelDeleted), channelName =>
+        {
+            OnChannelDeleted?.Invoke(channelName);
+        });
+
         _connection.On<string>(nameof(Core.Contracts.IEchoHubClient.ChannelNuked), channelName =>
         {
             OnChannelNuked?.Invoke(channelName);

src/EchoHub.Core/Contracts/IChatBroadcaster.cs

@@ -12,6 +12,7 @@ public interface IChatBroadcaster
     Task SendUserKickedAsync(string channelName, string username, string? reason);
     Task SendUserBannedAsync(string username, string? reason);
     Task SendMessageDeletedAsync(string channelName, Guid messageId);
+    Task SendChannelDeletedAsync(string channelName);
     Task SendChannelNukedAsync(string channelName);
     Task SendErrorAsync(string connectionId, string message);
     Task ForceDisconnectUserAsync(List<string> connectionIds, string reason);

src/EchoHub.Core/Contracts/IChatService.cs

@@ -24,6 +24,7 @@ public interface IChatService
     // Broadcasting (used by controllers and IRC gateway)
     Task BroadcastMessageAsync(string channelName, MessageDto message);
     Task BroadcastChannelUpdatedAsync(ChannelDto channel, string? channelName = null);
+    Task BroadcastChannelDeletedAsync(string channelName);
 
     // Query operations (used by IRC gateway for WHOIS)
     Task<List<string>> GetChannelsForUserAsync(string username);

src/EchoHub.Core/Contracts/IEchoHubClient.cs

@@ -15,6 +15,7 @@ public interface IEchoHubClient
     Task UserKicked(string channelName, string username, string? reason);
     Task UserBanned(string username, string? reason);
     Task MessageDeleted(string channelName, Guid messageId);
+    Task ChannelDeleted(string channelName);
     Task ChannelNuked(string channelName);
     Task ForceDisconnect(string reason);
     Task Error(string message);

src/EchoHub.Server.Irc/IrcBroadcaster.cs

@@ -101,6 +101,14 @@ public class IrcBroadcaster : IChatBroadcaster
         }
     }
 
+    public async Task SendChannelDeletedAsync(string channelName)
+    {
+        foreach (var conn in _gateway.GetConnectionsInChannel(channelName))
+        {
+            await conn.SendAsync($":{_gateway.Options.ServerName} NOTICE {conn.Nickname ?? "*"} :Channel #{channelName} has been deleted");
+        }
+    }
+
     public async Task SendChannelNukedAsync(string channelName)
     {
         foreach (var conn in _gateway.GetConnectionsInChannel(channelName))

src/EchoHub.Server/Controllers/ChannelsController.cs

@@ -162,6 +162,8 @@ public class ChannelsController : ControllerBase
         if (!result.IsSuccess)
             return MapChannelError(result);
 
+        await _chatService.BroadcastChannelDeletedAsync(channel.ToLowerInvariant().Trim());
+
         return NoContent();
     }
 

src/EchoHub.Server/Services/ChatService.cs

@@ -320,6 +320,9 @@ public class ChatService : IChatService
     public Task BroadcastChannelUpdatedAsync(ChannelDto channel, string? channelName = null)
         => BroadcastToAllAsync(b => b.SendChannelUpdatedAsync(channel, channelName));
 
+    public Task BroadcastChannelDeletedAsync(string channelName)
+        => BroadcastToAllAsync(b => b.SendChannelDeletedAsync(channelName));
+
     private async Task BroadcastToAllAsync(Func<IChatBroadcaster, Task> action)
     {
         foreach (var broadcaster in _broadcasters)

src/EchoHub.Server/Services/SignalRBroadcaster.cs

@@ -63,6 +63,9 @@ public class SignalRBroadcaster : IChatBroadcaster
     public Task SendMessageDeletedAsync(string channelName, Guid messageId)
         => HubContext.Clients.Group(channelName).MessageDeleted(channelName, messageId);
 
+    public Task SendChannelDeletedAsync(string channelName)
+        => HubContext.Clients.All.ChannelDeleted(channelName);
+
     public Task SendChannelNukedAsync(string channelName)
         => HubContext.Clients.Group(channelName).ChannelNuked(channelName);
 

src/EchoHub.Tests/Irc/TestHelpers.cs

@@ -212,6 +212,9 @@ internal sealed class FakeChatService : IChatService
     public Task BroadcastChannelUpdatedAsync(ChannelDto channel, string? channelName = null) =>
         Task.CompletedTask;
 
+    public Task BroadcastChannelDeletedAsync(string channelName) =>
+        Task.CompletedTask;
+
     public Task<List<string>> GetChannelsForUserAsync(string username) =>
         Task.FromResult(ChannelsForUserToReturn);
 }