private async Task MigratePhase3()

in Common/Migration/Migrator.cs [115:159]
37 lines of code
9 McCabe index (conditional complexity)

        private async Task MigratePhase3()
        {
            IEnumerable<IPhase3Processor> phase3Processors = ClientHelpers.GetProcessorInstances<IPhase3Processor>(context.Config);
            if (phase3Processors != null && !phase3Processors.Any())
            {
                // nothing to do if no phase 3 processors are enabled
                return;
            }

            // Phase1 or Phase2 have completed, and FailureReason == None
            IEnumerable<WorkItemMigrationState> successfullyMigratedWorkItemMigrationStates = context.WorkItemsMigrationState.Where(w => (w.MigrationCompleted.HasFlag(WorkItemMigrationState.MigrationCompletionStatus.Phase1) || w.MigrationCompleted.HasFlag(WorkItemMigrationState.MigrationCompletionStatus.Phase2)) && w.FailureReason == FailureReason.None);
            var phase3WorkItemsToUpdateCount = successfullyMigratedWorkItemMigrationStates.Count();
            var totalNumberOfBatches = ClientHelpers.GetBatchCount(phase3WorkItemsToUpdateCount, Constants.BatchSize);

            if (phase3WorkItemsToUpdateCount == 0)
            {
                return;
            }

            await successfullyMigratedWorkItemMigrationStates.Batch(Constants.BatchSize).ForEachAsync(context.Config.Parallelism, async (workItemMigrationStateBatch, batchId) =>
            {
                IBatchMigrationContext batchContext = new BatchMigrationContext(batchId, workItemMigrationStateBatch);
                IList<(int SourceId, WitBatchRequest WitBatchRequest)> sourceIdToWitBatchRequests = new List<(int SourceId, WitBatchRequest WitBatchRequest)>();
                IList<WorkItem> sourceWorkItemsInBatch = await WorkItemTrackingHelpers.GetWorkItemsAsync(context.SourceClient.WorkItemTrackingHttpClient, workItemMigrationStateBatch.Select(a => a.SourceId).ToList(), expand: WorkItemExpand.All);

                foreach (WorkItem sourceWorkItem in sourceWorkItemsInBatch)
                {
                    IList<JsonPatchOperation> jsonPatchOperations = new List<JsonPatchOperation>();
                    foreach (IPhase3Processor processor in phase3Processors)
                    {
                        IEnumerable<JsonPatchOperation> processorJsonPatchOperations = await processor.Process(context, null, sourceWorkItem, null);
                        jsonPatchOperations.AddRange(processorJsonPatchOperations);
                    }

                    if (jsonPatchOperations.Any())
                    {
                        WitBatchRequest witBatchRequest = GenerateWitBatchRequestFromJsonPatchOperations(jsonPatchOperations, sourceWorkItem.Id.Value);
                        sourceIdToWitBatchRequests.Add((sourceWorkItem.Id.Value, witBatchRequest));
                    }
                }

                var phase3ApiWrapper = new Phase3ApiWrapper();
                await phase3ApiWrapper.ExecuteWitBatchRequests(sourceIdToWitBatchRequests, context, batchContext);
            });
        }