slarny4/Demo1/UI/ExcelExporter.cs

using ClosedXML.Excel;
using Demo.Domain.Models;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;

namespace Demo.UI
{
    public class ExcelExporter
    {
        public void ExportGroupInfoToExcel(Group group, List<User> users, List<Presence> presence, string filePath)
        {
            using (var workbook = new XLWorkbook())
            {
                var worksheet = workbook.Worksheets.Add("Group Info");

                worksheet.Cell(1, 1).Value = "Group Name";
                worksheet.Cell(1, 2).Value = group.Name;

                worksheet.Cell(3, 1).Value = "Student Name";
                worksheet.Cell(3, 2).Value = "Attended Lessons";
                worksheet.Cell(3, 3).Value = "Missed Lessons";
                worksheet.Cell(3, 4).Value = "Attendance Percentage";

                int row = 4;
                foreach (var user in users)
                {
                    var userPresence = presence.Where(p => p.UserId == user.Id).ToList();
                    int attended = userPresence.Count(p => p.IsAttendance);
                    int missed = userPresence.Count(p => !p.IsAttendance);

                    // Проверка на ноль перед вычислением процента посещаемости
                    double percentage = (attended + missed) == 0 ? 0 : (attended * 100.0) / (attended + missed);

                    worksheet.Cell(row, 1).Value = user.FIO;
                    worksheet.Cell(row, 2).SetValue(attended).Style.NumberFormat.Format = "0"; // Устанавливаем формат числа
                    worksheet.Cell(row, 3).SetValue(missed).Style.NumberFormat.Format = "0"; // Устанавливаем формат числа
                    worksheet.Cell(row, 4).SetValue(percentage).Style.NumberFormat.Format = "0.00"; // Устанавливаем формат числа

                    if (percentage < 40)
                    {
                        worksheet.Row(row).Style.Fill.BackgroundColor = XLColor.Red;
                    }

                    row++;
                }

                workbook.SaveAs(filePath);
            }

            Console.WriteLine($"Отчёт экспортирован в Excel: {filePath}");
        }

        // Реализация метода для DAO моделей
        internal void ExportGroupInfoToExcel(Data.RemoteData.RemoteDataBase.DAO.Group groupForExport, List<Data.RemoteData.RemoteDataBase.DAO.User> usersForExport, List<Presence> presenceForExport, string filePath)
        {
            using (var workbook = new XLWorkbook())
            {
                var worksheet = workbook.Worksheets.Add("Group Info DAO");

                worksheet.Cell(1, 1).Value = "Group Name";
                worksheet.Cell(1, 2).Value = groupForExport.Name;

                worksheet.Cell(3, 1).Value = "Student Name";
                worksheet.Cell(3, 2).Value = "Attended Lessons";
                worksheet.Cell(3, 3).Value = "Missed Lessons";
                worksheet.Cell(3, 4).Value = "Attendance Percentage";

                int row = 4;
                foreach (var user in usersForExport)
                {
                    var userPresence = presenceForExport.Where(p => p.UserId == user.Id).ToList();
                    int attended = userPresence.Count(p => p.IsAttendance);
                    int missed = userPresence.Count(p => !p.IsAttendance);

                    // Проверка на ноль перед вычислением процента посещаемости
                    double percentage = (attended + missed) == 0 ? 0 : (attended * 100.0) / (attended + missed);

                    worksheet.Cell(row, 1).Value = user.FIO;
                    worksheet.Cell(row, 2).SetValue(attended).Style.NumberFormat.Format = "0"; // Устанавливаем формат числа
                    worksheet.Cell(row, 3).SetValue(missed).Style.NumberFormat.Format = "0"; // Устанавливаем формат числа
                    worksheet.Cell(row, 4).SetValue(percentage).Style.NumberFormat.Format = "0.00"; // Устанавливаем формат числа

                    if (percentage < 40)
                    {
                        worksheet.Row(row).Style.Fill.BackgroundColor = XLColor.Red;
                    }

                    row++;
                }

                workbook.SaveAs(filePath);
            }

            Console.WriteLine($"Отчёт экспортирован в Excel: {filePath}");
        }
    }
}