private void ScheduleTimer()

in src/PatchOrchestrationApplication/NodeAgentNTService/src/Manager/TimerManager.cs [200:305]
89 lines of code
14 McCabe index (conditional complexity)

        private void ScheduleTimer()
        {
            try
            {
                if (!this.CheckApplicationExists())
                {
                    _eventSource.InfoMessage("Application deleted. Removing NT service...");
                    this._windowsUpdateManager.ResetStateMachine();
                    this.RemoveSelf();                    
                    return;
                }

                // If cancellation token is canceled or application is not found
                if (this._cancellationToken.IsCancellationRequested)
                {
                    _eventSource.InfoMessage("Canceled timer.");
                    return;
                }

                NodeAgentSfUtilityExitCodes exitCode = this._nodeAgentSfUtility.GetWuOperationState(
                    TimeSpan.FromMinutes(this._serviceSettings.OperationTimeOutInMinutes));
                _eventSource.InfoMessage("Current Wu state: {0}", exitCode);
                if (exitCode == NodeAgentSfUtilityExitCodes.RestartRequested)
                {                                              
                    _eventSource.ErrorMessage("Not able to restart system.");
                    
                    //wait for sometime before retrying. This delay is recommended if posting health reports.
                    if (this._helper.WaitOnTask(Task.Delay(TimeSpan.FromMinutes(WaitTimeInMinutes)),
                        this._cancellationToken))
                    {
                        this.ScheduleWindowsUpdates();
                        this.ScheduleTimer();
                    }
                    return;
                }
                else if (exitCode == NodeAgentSfUtilityExitCodes.RestartCompleted)
                {
                    this.ScheduleWindowsUpdates();

                    this.CreateNewCheckpointFile();                       

                    this.ScheduleTimer();
                    return;
                }

                CheckpointFileData fileData = this.ReadCheckpointFile();

                if (fileData.rescheduleNeeded)
                {
                    // If total retries are exhausted, schedule the call back for next interval mentioned in Settings.xml.
                    if (this.IncrementRetryCount() == false)
                    {
                        if (this._windowsUpdateManager.ResetStateMachine())
                        {
                            this.UpdateSettingsAndCreateCheckpoint();
                            this.CreateNewCheckpointFile();
                        }
                        else
                        {
                            if (this._helper.WaitOnTask(Task.Delay(TimeSpan.FromMinutes(WaitTimeInMinutes)),
                                this._cancellationToken))
                            {
                                this.ScheduleTimer();
                            }
                            return;
                        }
                    }
                }
                else
                {
                    // Do not update the lastAttemptedTime.
                    this.UpdateSettingsAndCreateCheckpoint(false);                    
                }

                // read checkpoint file after modifications.
                fileData = this.ReadCheckpointFile();

                // Execute call back
                if (this.ScheduleWindowsUpdatesFlag(fileData))
                {
                    bool retryNeeded = this.ScheduleWindowsUpdates();

                    if (retryNeeded)
                    {
                        fileData.rescheduleNeeded = true;
                        this.WriteCheckpointFile(fileData);
                    }
                    else
                    {
                        this.CreateNewCheckpointFile();
                    }

                    this.ScheduleTimer();
                    return;
                }
            }
            catch (Exception e)
            {
                _eventSource.ErrorMessage("ScheduleTimer ended with exception : {0}", e);
            }
            TimeSpan operationTimeSpan = TimeSpan.FromMinutes(WaitTimeInMinutes);
            if (this._helper.WaitOnTask(Task.Delay(operationTimeSpan), this._cancellationToken))
            {
                this.ScheduleTimer();
            }
        }