protected virtual async ValueTask DisposeAsyncCore()

in dotnet/src/Azure.Iot.Operations.Protocol/RPC/CommandInvoker.cs [713:771]
51 lines of code
10 McCabe index (conditional complexity)

        protected virtual async ValueTask DisposeAsyncCore(bool disposing)
        {
            if (_isDisposed)
            {
                return;
            }

            _mqttClient.ApplicationMessageReceivedAsync -= MessageReceivedCallbackAsync;

            lock (_requestIdMapLock)
            {
                foreach (KeyValuePair<string, ResponsePromise> responsePromise in _requestIdMap)
                {
                    if (responsePromise.Value != null && responsePromise.Value.CompletionSource != null)
                    {
                        SetCanceledSafe(responsePromise.Value.CompletionSource);
                    }
                }
                _requestIdMap.Clear();
            }

            try
            {
                if (_subscribedTopics.Count > 0)
                {
                    MqttClientUnsubscribeOptions unsubscribeOptions = new();
                    lock (_subscribedTopicsSetLock)
                    {
                        foreach (string subscribedTopic in _subscribedTopics)
                        {
                            unsubscribeOptions.TopicFilters.Add(subscribedTopic);
                        }
                    }

                    MqttClientUnsubscribeResult unsubAck = await _mqttClient.UnsubscribeAsync(unsubscribeOptions, CancellationToken.None).ConfigureAwait(false);
                    if (!unsubAck.IsUnsubAckSuccessful())
                    {
                        Trace.TraceError($"Failed to unsubscribe from the topic(s) for the command invoker of '{_commandName}'.");
                    }
                }
            }
            catch (Exception e)
            {
                Trace.TraceWarning("Encountered an error while unsubscribing during disposal {0}", e);
            }

            lock (_subscribedTopicsSetLock)
            {
                _subscribedTopics.Clear();
            }

            if (disposing)
            {
                // This will disconnect and dispose the client if necessary
                await _mqttClient.DisposeAsync();
            }

            _isDisposed = true;
        }