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WebApplication4/Services/WebSocketMessageStore.cs

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+using System;
+using System.Threading;
+
+namespace WebApplication4.Services
+{
+    public class WebSocketMessageStore
+    {
+        private string? _lastMessage;
+        private DateTime? _receivedAtUtc;
+        private readonly object _lock = new();
+
+        public void Set(string message)
+        {
+            if (message == null) return;
+            lock (_lock)
+            {
+                _lastMessage = message;
+                _receivedAtUtc = DateTime.UtcNow;
+            }
+        }
+
+        public (string? Message, DateTime? ReceivedAtUtc) Get()
+        {
+            lock (_lock)
+            {
+                return (_lastMessage, _receivedAtUtc);
+            }
+        }
+    }
+}