No reference to business logic from api controller?

Question

The following code is a function that I wrote in my API controller to call my business logic:

    [HttpGet]
    [Route("api/file/{id}")]
    public async Task<HttpResponseMessage> GetSysMaintExcelFile(int id)
    {
        var wb = await rbs.GetSystemMaintenanceExcelFile(id);
        return CreateFileResponse(rbs.GetSystemMaintenanceExcelFile(id));
    }

The business logic that I wanted to call is as follows:

public async Task<byte[]> GetSystemMaintenanceExcelFile(int id)
{
    Systems sysRec = await dataAccess.GetSystemById(id);
    return BuildSysMaintExcelFile(sysRec);
}

What is confusing me is on the HTTPGET function does not have a connected reference to the business logic function I am trying to call. Am I missing something with this? I have the proper using statement needed to connect the business logic file. And I did add a reference to the API project as well for my business.

---

Edit

The purpose of these two functions were to start the build of an excel file through functions built with closedXML. The entire closedXML function through my Business logic function is as follow:

 public class ReportBS : IReportsBS
{
    private IAppDataAccess dataAccess;
    private IAuthManager authManager;

    #region Constructor
    public ReportBS(IAppDataAccess da, IAuthManager am)
    {
        this.dataAccess = da;
        this.authManager = am;
    }
    #endregion

    #region System Maintenance Reports
    public async Task<byte[]> GetSystemMaintenanceExcelFile(int id)
    {
        Systems sysRec = await dataAccess.GetSystemById(id);
        return BuildSysMaintExcelFile(sysRec);
    }

    public byte[] BuildSysMaintExcelFile(Systems dataRec)
    {
        //Creating the workbook
        const int dataRowStart = 3;
        string templateName = "~/App_Data/SystemMaintenance_Template.xlsx";
        var workbook = new XLWorkbook(templateName);
        var worksheet = workbook.Worksheet(1);
        string folderPath = @"~\Downloads\";
        if (!Directory.Exists(folderPath))
        {
            Directory.CreateDirectory(folderPath);
        }
        string fileName = templateName + folderPath + "SystemMaintenance_" + DateTime.Now.ToString("yyyyMMddHHmm") + ".xlsx";
        var dt = BuildSysDetailLoaExcelTable(dataRec, fileName);
        worksheet.Cell(dataRowStart, 3).InsertData(dt.AsEnumerable());
        workbook.SaveAs(fileName);

        using (var ms = new MemoryStream())
        {
            workbook.SaveAs(fileName);
            return ms.ToArray();
        }
    }

    //Building the tables
    private DataTable BuildSysDetailLoaExcelTable(Systems record, string fileName)
    {
        DataTable dt = new DataTable(fileName);

        dt.Columns.Add("systemName", typeof(string));
        dt.Columns.Add("isActive", typeof(bool));
        dt.Columns.Add("localIAO", typeof(bool));
        dt.Columns.Add("localStaff", typeof(bool));
        dt.Columns.Add("informationOfficerRequired", typeof(bool));
        dt.Columns.Add("iaoRequired", typeof(bool));
        dt.Columns.Add("IAOs", typeof(string));
        dt.Columns.Add("StaffProcessors", typeof(string));
        dt.Columns.Add("StaffRevalidators", typeof(string));

        var dr = dt.NewRow();
        dr[0] = record.systemName;
        dr[1] = record.isActive;
        dr[2] = record.localIAO;
        dr[3] = record.localStaff;
        dr[4] = record.informationOfficerRequired;
        dr[5] = record.iaoRequired;
        dr[6] = record.IAOs;
        dr[9] = record.StaffProcessors;
        dr[11] = record.StaffRevalidators;

        return dt;

    }

    #endregion
}

Thanks for any help

Answer 1

These lines don't seem to be correct

    var wb = await rbs.GetSystemMaintenanceExcelFile(id);
    return CreateFileResponse(rbs.GetSystemMaintenanceExcelFile(id));

First line calls the async function, waits till it returns and stores the results in the local variable wb. Second line calls this async function again, but this time does not wait for the result, and just returns immediately.

I suspect you just wanted this:

    var wbTask = rbs.GetSystemMaintenanceExcelFile(id);
    var wb = await wbTask;
    return CreateFileResponse(wb);

Although it is not clear how it is going to benefit from asynchronous call, because there is no other work done in foreground.