added excel functionality

doesn't work though. the OpenXml library creates a file one parent
above the current working directory, and the excel file is empty

DAL/ExcelDataService.cs

@@ -0,0 +1,86 @@
+using DocumentFormat.OpenXml;
+using DocumentFormat.OpenXml.Packaging;
+using DocumentFormat.OpenXml.Spreadsheet;
+
+public class ExcelDataService : IDataService
+{
+    private SpreadsheetDocument? _xlsxFile;
+    private Workbook? _xlsxWorkbook;
+    private WorkbookPart? _xlsxWorkbookPart;
+    private WorksheetPart? _xlsxWorksheetPart;
+    private Sheets? _xlsxSheets;
+    private Sheet? _xlsxSheet;
+    private Cell? _cell;
+    private string _fileName;
+    private string _pathName;
+    private string _dateTime;
+
+    public ExcelDataService()
+    {
+        _dateTime = DateTime.Now.ToString("yyyyMMdd");
+        _fileName = $"CommitReport-{_dateTime}.xlsx";
+        _pathName = Directory.GetCurrentDirectory() + _fileName;
+        _xlsxFile = SpreadsheetDocument.Create(_pathName, SpreadsheetDocumentType.Workbook);
+        _xlsxWorkbookPart = _xlsxFile.AddWorkbookPart();
+        _xlsxWorkbookPart.Workbook = new Workbook();
+        _xlsxWorksheetPart = _xlsxWorkbookPart.AddNewPart<WorksheetPart>();
+        _xlsxWorksheetPart.Worksheet = new Worksheet(new SheetData());
+        _xlsxSheets = _xlsxFile.WorkbookPart.Workbook.AppendChild<Sheets>(new Sheets());
+        _xlsxSheet = new Sheet() { Id = _xlsxFile.WorkbookPart.GetIdOfPart(_xlsxWorksheetPart), SheetId = 1, Name = "Commit Report" };
+        _xlsxSheets.Append(_xlsxSheet);
+        _xlsxWorkbookPart.Workbook.Save();
+        _xlsxFile.Close();
+    }
+    
+    public void WriteAll(SortedList<string, int> dictResults)
+    {
+        using (SpreadsheetDocument spreadSheet = SpreadsheetDocument.Open(_pathName, true))
+        {
+            WorksheetPart worksheetPart = spreadSheet.WorkbookPart.WorksheetParts.First();
+            
+            foreach (var d in dictResults)
+            {
+                var index = dictResults.GetEnumerator().Current;
+                _cell = InsertCellInWorksheet("A", (index.Value), worksheetPart);
+                _cell.CellValue = new CellValue(d.Key);
+                _cell.DataType = new EnumValue<CellValues>(CellValues.SharedString);
+                worksheetPart.Worksheet.Save();
+                
+                //_cell = InsertCellInWorksheet("B", (index.Value), worksheetPart);
+                //_cell.CellValue = new CellValue(d.Value);
+                //_cell.DataType = new EnumValue<CellValues>(CellValues.SharedString);
+                //worksheetPart.Worksheet.Save();
+            }
+
+
+
+        }
+    }
+
+    private static Cell InsertCellInWorksheet(string columnName, int rowIndex, WorksheetPart worksheetPart)
+    {
+        Worksheet worksheet = worksheetPart.Worksheet;
+        SheetData sheetData = worksheet.GetFirstChild<SheetData>();
+        string cellReference = columnName + rowIndex;
+
+        Row row;
+        if (sheetData.Elements<Row>().Where(r => r.RowIndex == rowIndex).Count() != 0)
+        {
+            row = sheetData.Elements<Row>().Where(r => r.RowIndex == rowIndex).First();
+        }
+        else
+        {
+            row = new Row() { RowIndex = ((uint)rowIndex) };
+            sheetData.Append(row);
+        }
+
+        Cell refCell = row.Descendants<Cell>().LastOrDefault();
+
+        Cell newCell = new Cell() { CellReference = cellReference };
+        row.InsertAfter(newCell, refCell);
+
+        worksheet.Save();
+        return newCell;
+
+    }
+}