fixes for STT

OpenJibo/src/Jibo.Cloud/dotnet/src/Jibo.Cloud.Application/Services/WebSocketTurnFinalizationService.cs

@@ -15,6 +15,7 @@ public sealed class WebSocketTurnFinalizationService(
 {
     private const int AutoFinalizeMinBufferedAudioBytes = 12000;
     private const int AutoFinalizeMinBufferedAudioChunks = 5;
+    private static readonly TimeSpan AutoFinalizeMinTurnAge = TimeSpan.FromMilliseconds(1800);
 
     public async Task<IReadOnlyList<WebSocketReply>> HandleBinaryAudioAsync(
         CloudSession session,
@@ -119,10 +120,28 @@ public sealed class WebSocketTurnFinalizationService(
             return turn;
         }
 
+        ISttStrategy? strategy = null;
+        try
+        {
+            strategy = await sttStrategySelector.SelectAsync(turn, cancellationToken);
+        }
+        catch (InvalidOperationException ex) when (string.Equals(ex.Message, "No STT strategy can handle the current turn.", StringComparison.Ordinal))
+        {
+            return turn;
+        }
+        catch (Exception ex)
+        {
+            session.TurnState.LastSttError = ex.Message;
+            session.TurnState.LastSttErrorUtc = DateTimeOffset.UtcNow;
+            await sink.RecordTranscriptError(ex, "Error during STT processing", cancellationToken);
+            return turn;
+        }
+
         try
         {
-            var strategy = await sttStrategySelector.SelectAsync(turn, cancellationToken);
             var sttResult = await strategy.TranscribeAsync(turn, cancellationToken);
+            session.TurnState.LastSttError = null;
+            session.TurnState.LastSttErrorUtc = null;
 
             var attributes = new Dictionary<string, object?>(turn.Attributes, StringComparer.OrdinalIgnoreCase)
             {
@@ -160,6 +179,8 @@ public sealed class WebSocketTurnFinalizationService(
         }
         catch (Exception ex)
         {
+            session.TurnState.LastSttError = ex.Message;
+            session.TurnState.LastSttErrorUtc = DateTimeOffset.UtcNow;
             await sink.RecordTranscriptError(ex, "Error during STT processing", cancellationToken);
             return turn;
         }
@@ -229,6 +250,8 @@ public sealed class WebSocketTurnFinalizationService(
     {
         session.TurnState.BufferedAudioBytes = 0;
         session.TurnState.BufferedAudioChunkCount = 0;
+        session.TurnState.LastSttError = null;
+        session.TurnState.LastSttErrorUtc = null;
         session.TurnState.FirstAudioReceivedUtc = null;
         session.TurnState.LastAudioReceivedUtc = null;
         session.TurnState.BufferedAudioFrames.Clear();
@@ -241,6 +264,8 @@ public sealed class WebSocketTurnFinalizationService(
         turnState.TransId = transId;
         turnState.ContextPayload = null;
         turnState.AudioTranscriptHint = null;
+        turnState.LastSttError = null;
+        turnState.LastSttErrorUtc = null;
         turnState.FirstAudioReceivedUtc = null;
         turnState.LastAudioReceivedUtc = null;
         turnState.BufferedAudioChunkCount = 0;
@@ -272,7 +297,9 @@ public sealed class WebSocketTurnFinalizationService(
                 turnState.FinalizeAttemptCount += 1;
             }
 
-            if (allowFallbackOnMissingTranscript && turnState.BufferedAudioBytes >= AutoFinalizeMinBufferedAudioBytes)
+            if (allowFallbackOnMissingTranscript &&
+                turnState.BufferedAudioBytes >= AutoFinalizeMinBufferedAudioBytes &&
+                string.IsNullOrWhiteSpace(turnState.LastSttError))
             {
                 turnState.AwaitingTurnCompletion = false;
                 session.LastTranscript = string.Empty;
@@ -331,12 +358,16 @@ public sealed class WebSocketTurnFinalizationService(
     private static bool ShouldAutoFinalize(CloudSession session)
     {
         var turnState = session.TurnState;
+        var turnAge = turnState.FirstAudioReceivedUtc.HasValue
+            ? DateTimeOffset.UtcNow - turnState.FirstAudioReceivedUtc.Value
+            : TimeSpan.Zero;
         return turnState.AwaitingTurnCompletion &&
                turnState is
                {
                    SawListen: true, SawContext: true, BufferedAudioChunkCount: >= AutoFinalizeMinBufferedAudioChunks,
                    BufferedAudioBytes: >= AutoFinalizeMinBufferedAudioBytes
-               };
+               } &&
+               turnAge >= AutoFinalizeMinTurnAge;
     }
 
     private static string? ExtractDataPayload(string? text)

OpenJibo/src/Jibo.Cloud/dotnet/src/Jibo.Cloud.Domain/Models/WebSocketTurnState.cs

@@ -5,6 +5,8 @@ public sealed class WebSocketTurnState
     public string? TransId { get; set; }
     public string? ContextPayload { get; set; }
     public string? AudioTranscriptHint { get; set; }
+    public string? LastSttError { get; set; }
+    public DateTimeOffset? LastSttErrorUtc { get; set; }
     public DateTimeOffset? FirstAudioReceivedUtc { get; set; }
     public DateTimeOffset? LastAudioReceivedUtc { get; set; }
     public int BufferedAudioChunkCount { get; set; }

OpenJibo/tests/Jibo.Cloud.Tests/Turn/FileTurnTelemetrySinkTests.cs

@@ -29,4 +29,42 @@ public sealed class FileTurnTelemetrySinkTests
 
         sink.Verify(s => s.RecordTranscriptError(It.IsAny<Exception>(), It.IsAny<string>(), It.IsAny<CancellationToken>()), Times.Once());
     }
-}
+
+    [Fact]
+    public async Task AutoFinalize_DoesNotFallbackImmediately_WhenSttThrows()
+    {
+        var sink = new Mock<ITurnTelemetrySink>();
+        var sttStrategySelector = new Mock<ISttStrategySelector>();
+        sttStrategySelector.Setup(s => s.SelectAsync(It.IsAny<TurnContext>(), It.IsAny<CancellationToken>()))
+            .ThrowsAsync(new InvalidOperationException("ffmpeg failed"));
+
+        var turnService = new WebSocketTurnFinalizationService(
+            new ProtocolToTurnContextMapper(),
+            Mock.Of<IConversationBroker>(),
+            new ResponsePlanToSocketMessagesMapper(),
+            sttStrategySelector.Object,
+            sink.Object
+        );
+
+        var session = new CloudSession();
+        session.TurnState.AwaitingTurnCompletion = true;
+        session.TurnState.SawListen = true;
+        session.TurnState.SawContext = true;
+        session.TurnState.BufferedAudioBytes = 12000;
+        session.TurnState.BufferedAudioChunkCount = 5;
+        session.TurnState.FirstAudioReceivedUtc = DateTimeOffset.UtcNow - TimeSpan.FromSeconds(2);
+
+        var replies = await turnService.HandleContextAsync(
+            session,
+            new WebSocketMessageEnvelope { Text = """{"type":"CONTEXT","data":{"topic":"conversation"}}""" },
+            CancellationToken.None);
+
+        Assert.Single(replies);
+        using var payload = System.Text.Json.JsonDocument.Parse(replies[0].Text!);
+        Assert.Equal("OPENJIBO_TURN_PENDING", payload.RootElement.GetProperty("type").GetString());
+        Assert.Equal(12000, session.TurnState.BufferedAudioBytes);
+        Assert.Equal("ffmpeg failed", session.TurnState.LastSttError);
+
+        sink.Verify(s => s.RecordTranscriptError(It.IsAny<Exception>(), It.IsAny<string>(), It.IsAny<CancellationToken>()), Times.Once());
+    }
+}

OpenJibo/tests/Jibo.Cloud.Tests/WebSockets/JiboWebSocketServiceTests.cs

@@ -135,6 +135,10 @@ public sealed class JiboWebSocketServiceTests
             Assert.Equal("OPENJIBO_AUDIO_RECEIVED", ReadReplyType(replies[0]));
         }
 
+        var session = _store.FindSessionByToken("hub-auto-finalize-token");
+        Assert.NotNull(session);
+        session.TurnState.FirstAudioReceivedUtc = DateTimeOffset.UtcNow - TimeSpan.FromSeconds(2);
+
         replies = await _service.HandleMessageAsync(new WebSocketMessageEnvelope
         {
             HostName = "neo-hub.jibo.com",
@@ -192,6 +196,10 @@ public sealed class JiboWebSocketServiceTests
             Assert.Equal("OPENJIBO_AUDIO_RECEIVED", ReadReplyType(replies[0]));
         }
 
+        var session = _store.FindSessionByToken("hub-auto-fallback-token");
+        Assert.NotNull(session);
+        session.TurnState.FirstAudioReceivedUtc = DateTimeOffset.UtcNow - TimeSpan.FromSeconds(2);
+
         replies = await _service.HandleMessageAsync(new WebSocketMessageEnvelope
         {
             HostName = "neo-hub.jibo.com",