public async Task ChangeSubscriptionQuantity()

in src/CustomerSite/Controllers/HomeController.cs [754:832]
67 lines of code
14 McCabe index (conditional complexity)

    public async Task<IActionResult> ChangeSubscriptionQuantity(SubscriptionResult subscriptionDetail)
    {
        this.logger.Info(HttpUtility.HtmlEncode($"Home Controller / ChangeSubscriptionPlan  subscriptionDetail:{JsonSerializer.Serialize(subscriptionDetail)}"));
        if (this.User.Identity.IsAuthenticated)
        {
            try
            {
                if (subscriptionDetail != null && subscriptionDetail.Id != default && subscriptionDetail.Quantity > 0)
                {
                    try
                    {
                        //initiate change quantity
                        var currentUserId = this.userService.GetUserIdFromEmailAddress(this.CurrentUserEmailAddress);
                        
                        if (this.subscriptionService.GetPartnerSubscription(this.CurrentUserEmailAddress, subscriptionDetail.Id).FirstOrDefault() == null)
                        {
                            this.logger.LogError($"Cannot find subscription or subscription associated to the current user");
                            return this.RedirectToAction(nameof(this.Index));
                        }

                        var jsonResult = await this.apiService.ChangeQuantityForSubscriptionAsync(subscriptionDetail.Id, subscriptionDetail.Quantity).ConfigureAwait(false);
                        var changeQuantityOperationStatus = OperationStatusEnum.InProgress;
                        if (jsonResult != null && jsonResult.OperationId != default)
                        {
                            int _counter = 0;

                            while (OperationStatusEnum.InProgress.Equals(changeQuantityOperationStatus) || OperationStatusEnum.NotStarted.Equals(changeQuantityOperationStatus))
                            {
                                //loop untill the operation status has moved away from inprogress or notstarted, generally this will be the result of webhooks' action aganist this operation
                                var changeQuantityOperationResult = await this.apiService.GetOperationStatusResultAsync(subscriptionDetail.Id, jsonResult.OperationId).ConfigureAwait(false);
                                changeQuantityOperationStatus = changeQuantityOperationResult.Status;

                                this.logger.Info(HttpUtility.HtmlEncode($"Quantity Change Progress. SubscriptionId: {subscriptionDetail.Id} ToQuantity: {subscriptionDetail.Quantity} UserId: **** OperationId: {jsonResult.OperationId} Operationstatus: { changeQuantityOperationStatus }."));
                                await this.applicationLogService.AddApplicationLog($"Quantity Change Progress. SubscriptionId: {subscriptionDetail.Id} ToQuantity: {subscriptionDetail.Quantity} UserId: {currentUserId} OperationId: {jsonResult.OperationId} Operationstatus: { changeQuantityOperationStatus }.").ConfigureAwait(false);

                                //wait and check every 5secs
                                await Task.Delay(5000);
                                _counter++;
                                if (_counter > 100)
                                {
                                    //if loop has been executed for more than 100 times then break, to avoid infinite loop just in case
                                    break;
                                }
                            }

                            if (changeQuantityOperationStatus == OperationStatusEnum.Succeeded)
                            {
                                this.logger.Info(HttpUtility.HtmlEncode($"Quantity Change Success. SubscriptionId: {subscriptionDetail.Id} ToQuantity: {subscriptionDetail.Quantity} UserId: ***** OperationId: {jsonResult.OperationId}."));
                                await this.applicationLogService.AddApplicationLog($"Quantity Change Success. SubscriptionId: {subscriptionDetail.Id} ToQuantity: {subscriptionDetail.Quantity} UserId: {currentUserId} OperationId: {jsonResult.OperationId}.").ConfigureAwait(false);
                            }
                            else
                            {
                                this.logger.Info(HttpUtility.HtmlEncode($"Quantity Change Failed. SubscriptionId: {subscriptionDetail.Id} ToQuantity: {subscriptionDetail.Quantity} UserId: ***** OperationId: {jsonResult.OperationId} Operationstatus: { changeQuantityOperationStatus }."));
                                await this.applicationLogService.AddApplicationLog($"Quantity Change Failed. SubscriptionId: {subscriptionDetail.Id} ToQuantity: {subscriptionDetail.Quantity} UserId: {currentUserId} OperationId: {jsonResult.OperationId} Operationstatus: { changeQuantityOperationStatus }.").ConfigureAwait(false);
                                    
                                throw new MarketplaceException($"Quantity Change operation failed with operation status {changeQuantityOperationStatus}.");
                            }
                        }
                    }
                    catch (MarketplaceException fex)
                    {
                        this.TempData["ErrorMsg"] = fex.Message;
                        this.logger.LogError($"Message:{fex.Message} :: {fex.InnerException}   ");
                    }
                }

                return this.RedirectToAction(nameof(this.Subscriptions));
            }
            catch (Exception ex)
            {
                this.logger.LogError($"Message:{ex.Message} :: {ex.InnerException}   ");
                return this.View("Error", ex);
            }
        }
        else
        {
            return this.RedirectToAction(nameof(this.Index));
        }
    }