Implement: Remove client from group

Author: Mr-Yavar

Lib.AspNetCore.ServerSentEvents/IServerSentEventsService.cs

@@ -58,6 +58,14 @@ public interface IServerSentEventsService
         /// <param name="client">The client to add to a group.</param>
         /// <returns>The result of operation.</returns>
         ServerSentEventsAddToGroupResult AddToGroup(string groupName, IServerSentEventsClient client);
+        
+        /// <summary>
+        /// removes a client from the specified group.
+        /// </summary>
+        /// <param name="groupName">The group name.</param>
+        /// <param name="client">The client to remove from a group.</param>
+        /// <returns>The result of operation.</returns>
+        ServerSentEventsRemoveFromGroupResult RemoveFromGroup(string groupName, IServerSentEventsClient client);
 
         /// <summary>
         /// Changes the interval after which clients will attempt to reestablish failed connections.

Lib.AspNetCore.ServerSentEvents/ServerSentEventsRemoveFromGroupResult.cs

@@ -0,0 +1,23 @@
+namespace Lib.AspNetCore.ServerSentEvents
+{
+    /// <summary>
+    /// The remove from group results.
+    /// </summary>
+    public enum ServerSentEventsRemoveFromGroupResult
+    {
+        /// <summary>
+        /// The specified group could not be found.
+        /// </summary>
+        NotFoundGroup = 0,
+
+        /// <summary>
+        /// The client has been removed from an existing group.
+        /// </summary>
+        RemovedFromExistingGroup = 1,
+
+        /// <summary>
+        /// The client was not part of the group, so no removal occurred.
+        /// </summary>
+        NotInGroup = 2,
+    }
+}

Lib.AspNetCore.ServerSentEvents/ServerSentEventsService.cs

@@ -129,6 +129,26 @@ public ServerSentEventsAddToGroupResult AddToGroup(string groupName, IServerSent
             return result;
         }
 
+        /// <summary>
+        /// removes a client from the specified group.
+        /// </summary>
+        /// <param name="groupName">The group name.</param>
+        /// /// <param name="client">The client to remove from a group.</param>
+        /// <returns>The task object representing the result of asynchronous operation</returns>
+        public ServerSentEventsRemoveFromGroupResult RemoveFromGroup(string groupName, IServerSentEventsClient client)
+        {
+            ServerSentEventsRemoveFromGroupResult result = ServerSentEventsRemoveFromGroupResult.NotFoundGroup;
+
+            if (_groups.TryGetValue(groupName, out ConcurrentDictionary<Guid, IServerSentEventsClient> group))
+            {
+                result = ServerSentEventsRemoveFromGroupResult.NotInGroup;
+                if (group.TryRemove(client.Id, out _))
+                    result = ServerSentEventsRemoveFromGroupResult.RemovedFromExistingGroup;
+            }
+
+            return result;
+        }
+
         /// <summary>
         /// Changes the interval after which clients will attempt to reestablish failed connections.
         /// </summary>
@@ -138,7 +158,7 @@ public Task ChangeReconnectIntervalAsync(uint reconnectInterval)
         {
             return ChangeReconnectIntervalAsync(reconnectInterval, CancellationToken.None);
         }
-    
+
         /// <summary>
         /// Changes the interval after which clients will attempt to reestablish failed connections.
         /// </summary>