private async Task ExecuteMigration()

in WiMigrator/CommandLine.cs [111:174]
59 lines of code
7 McCabe index (conditional complexity)

        private async Task ExecuteMigration(CommandOption migrate)
        {
            bool showedHelp = false;
            ConfigJson configJson = null;
            try
            {
                string configFileName = migrate.Value();
                ConfigReaderJson configReaderJson = new ConfigReaderJson(configFileName);
                configJson = configReaderJson.Deserialize();

                var validatorContext = new ValidationContext(configJson);
                using (var heartbeat = new ValidationHeartbeatLogger(validatorContext.WorkItemsMigrationState, validatorContext, validatorContext.Config.HeartbeatFrequencyInSeconds))
                {
                    await new Validator(validatorContext).Validate();
                    heartbeat.Beat();
                }

                //TODO: Create a common method to take the validator context and created a migration context
                var migrationContext = new MigrationContext(configJson);

                migrationContext.WorkItemIdsUris = validatorContext.WorkItemIdsUris;
                migrationContext.WorkItemTypes = validatorContext.TargetTypesAndFields;
                migrationContext.IdentityFields = validatorContext.IdentityFields;
                migrationContext.TargetAreaPaths = validatorContext.TargetAreaPaths;
                migrationContext.TargetIterationPaths = validatorContext.TargetIterationPaths;
                migrationContext.WorkItemsMigrationState = validatorContext.WorkItemsMigrationState;
                migrationContext.TargetIdToSourceHyperlinkAttributeId = validatorContext.TargetIdToSourceHyperlinkAttributeId;
                migrationContext.ValidatedWorkItemLinkRelationTypes = validatorContext.ValidatedWorkItemLinkRelationTypes;
                migrationContext.RemoteLinkRelationTypes = validatorContext.RemoteLinkRelationTypes;
                migrationContext.SourceFields = validatorContext.SourceFields;
                migrationContext.FieldsThatRequireSourceProjectToBeReplacedWithTargetProject = validatorContext.FieldsThatRequireSourceProjectToBeReplacedWithTargetProject;

                using (var heartbeat = new MigrationHeartbeatLogger(migrationContext.WorkItemsMigrationState, migrationContext.Config.HeartbeatFrequencyInSeconds))
                {
                    await new Migrator(migrationContext).Migrate();
                    heartbeat.Beat();
                }
            }
            catch (CommandParsingException e)
            {
                Logger.LogError(LogDestination.All, e, "Invalid command line option(s):");
                commandLineApplication.ShowHelp();
                showedHelp = true;
            }
            catch (Exception e) when (e is ValidationException)
            {
                Logger.LogError(LogDestination.All, e, "Validation error:");
            }
            catch (Exception e) when (e is MigrationException)
            {
                Logger.LogError(LogDestination.All, e, "Migration error:");
            }
            catch (Exception e)
            {
                Logger.LogError(LogDestination.All, e, $"Unexpected error: {e}");
            }
            finally
            {
                if (!showedHelp && configJson != null)
                {
                    SendSummaryEmail(configJson);
                }
            }
        }