more fixes for idle timeout

Author: rhamlett

src/PerfProblemSimulator/Hubs/MetricsHub.cs

@@ -153,4 +153,24 @@ public async Task WakeUp()
         };
         await Clients.Caller.ReceiveIdleState(idleData);
     }
+
+    /// <summary>
+    /// Returns the server's current idle state without waking it.
+    /// Called by the client after auto-reconnect to determine whether the
+    /// server is idle (and therefore the client should disconnect again)
+    /// or active (and the client should stay connected).
+    /// </summary>
+    [UsedImplicitly]
+    public IdleStateData GetIdleState()
+    {
+        var isIdle = _idleStateService.IsIdle;
+        return new IdleStateData
+        {
+            IsIdle = isIdle,
+            Message = isIdle
+                ? "Application is idle, no health probes being sent."
+                : "Application is active",
+            Timestamp = DateTimeOffset.UtcNow
+        };
+    }
 }

src/PerfProblemSimulator/wwwroot/js/dashboard.js

@@ -246,17 +246,34 @@ async function initializeSignalR() {
 
     // Handle connection state changes
     state.connection.onreconnecting(error => {
+        // If we intentionally disconnected for idle, suppress reconnect UI
+        if (state.intentionalDisconnect) return;
         updateConnectionStatus('connecting', 'Reconnecting...');
         logEvent('system', 'Connection lost. Attempting to reconnect...');
     });
 
     state.connection.onreconnected(async connectionId => {
-        // Reset intentional disconnect flag - any successful connection means we're active
         state.intentionalDisconnect = false;
-
-        // WS is intentionally closed during idle, so any reconnect means we're active
-        updateConnectionStatus('connected', 'Connected');
         logEvent('system', 'Reconnected to server');
+
+        // After auto-reconnect, check if the server is idle.
+        // The server does NOT send idle state on connect (to avoid a race
+        // with WakeUp on initial page load), so we must query it explicitly.
+        try {
+            const idleData = await state.connection.invoke('GetIdleState');
+            if (idleData.isIdle) {
+                // Server is idle — re-enter idle mode and disconnect
+                handleIdleState(idleData);
+            } else {
+                // Server is active — show connected and resume chart
+                state.isIdle = false;
+                updateConnectionStatus('connected', 'Connected');
+                startLatencyChartUpdates();
+            }
+        } catch (err) {
+            // Query failed — assume connected
+            updateConnectionStatus('connected', 'Connected');
+        }
     });
 
     state.connection.onclose(error => {