如何更新关联Hall的HallEvent复杂模型？

我有一个表示大厅的Hall模型，当大厅为空时，会通过函数创建一个HallEvent，并关联该大厅对应的区域、排和座位——即创建关联Hall的HallEvent、关联Area的HallEventArea、关联Row的HallEventRow以及关联Seat的HallEventSeat。

当更新Hall（例如添加座位、添加排或删除区域等操作）时，需要同步更新对应的HallEvent及其关联的HallEventArea、HallEventRow和HallEventSeat。此前创建HallEvent时采用自上而下的方式（从HallEvent到HallEventSeat），但现在由于模型间无直接关联，无法沿用该方式。

最终需求是让HallEvent的区域、排、座位与源Hall保持一致，以下是我目前的代码，但尚未找到正确的实现方法：

[HttpPost]
[OutputCache(NoStore = true, Duration = 0, VaryByParam = "None")]
public ActionResult Index(Guid hallId, Guid eventId, RegistrationDetials registrationDetials)
{
    if (hallId == null)
        return RedirectToAction("Index", "Halls");

    if (CustomerId == 0)
    {
        return HttpNotFound();
    }
    int customerId = CustomerId;

    //get hall event if exists
    var hallEventToUpdate = hallEventsRepo.GetByIdAndCustomerId(eventId, customerId);
    Hall hallSource = hallsRepo.GetByIdAndCustomerId(hallId, customerId);
    List<HallEventSeat> eventSeats = hallEventSeatsRepo.GetHallEventSeatsByCustomerId(eventId, customerId);
    //.Select(x => new SeatModel(x))
    //.ToList();
    // comment: if there are no seats for the event we need to create it
    //          else, we need to update statuses for the seats that need to be free.
    
    if(eventSeats.Count != 0)
    {
        foreach(var hallEventAreaToUpdate in hallEventToUpdate.HallEventAreas)
        {
            var area = hallSource.Areas.SingleOrDefault(x=> x.Name == hallEventAreaToUpdate.Name);
            if (area == null)
            {
                continue;
            }

            hallEventAreaToUpdate.Angle = area.Angle;
            hallEventAreaToUpdate.AreaTypeId = area.AreaTypeId;
            hallEventAreaToUpdate.CreatDate = area.CreatDate;
            hallEventAreaToUpdate.Deleted = area.Deleted;
            hallEventAreaToUpdate.CreateUser = area.CreateUser;
            hallEventAreaToUpdate.ModifyDate = DateTime.Now;
            hallEventAreaToUpdate.Height= area.Height;
            hallEventAreaToUpdate.LastUser = area.LastUser;
            hallEventAreaToUpdate.Left = area.Left;

            hallEventAreasRepo.Update(hallEventAreaToUpdate);
            
            if(area.Rows !=null)
            {
                foreach(var row in area.Rows)
                {
                    var hallEventRowToUpdate = hallEventAreaToUpdate.HallEventRows.SingleOrDefault(x=>x.Name== row.Name);
                    if (hallEventRowToUpdate == null)
                    {
                        hallEventRowToUpdate = new HallEventRow()
                        {
                            Angle = row.Angle,
                            Height = row.Height,
                            Left = row.Left,
                            Name = row.Name,
                            Status = row.Status,
                            Top = row.Top,
                            Width = row.Width,
                            CreatDate = row.CreatDate,
                            CreateUser = row.CreateUser,
                            ModifyDate = row.ModifyDate,
                            LastUser = row.LastUser,
                            Deleted = row.Deleted,

                            HallEventAreaId = hallEventAreaToUpdate.Id,
                            HallEventArea = hallEventAreaToUpdate,
                        };
                        hallEventAreaToUpdate.HallEventRows.Add(hallEventRowToUpdate);

                    }
                    hallEventRowToUpdate.Angle = row.Angle;
                    hallEventRowToUpdate.Height = row.Height;
                    hallEventRowToUpdate.Left = row.Left;
                    hallEventRowToUpdate.Name = row.Name;
                    hallEventRowToUpdate.Status = row.Status;
                    hallEventRowToUpdate.Top = row.Top;
                    hallEventRowToUpdate.Width = row.Width;
                    hallEventRowToUpdate.CreatDate = row.CreatDate;
                    hallEventRowToUpdate.CreateUser = row.CreateUser;
                    hallEventRowToUpdate.ModifyDate = row.ModifyDate;
                    hallEventRowToUpdate.LastUser = row.LastUser;
                    hallEventRowToUpdate.Deleted = row.Deleted;
                    hallEventRowToUpdate.HallEventAreaId = hallEventAreaToUpdate.Id;
                    hallEventRowToUpdate.HallEventArea = hallEventAreaToUpdate;
                  
                    hallEventAreasRepo.Update(hallEventAreaToUpdate);
                }
                var rowsToDelete = hallEventAreaToUpdate.HallEventRows
                            .Where(x => !area.Rows.Any(y => y.Id == x.Id));
                //need to delete rows;
        
            }
            if (area.Seats != null)
            {
                foreach(var seat in area.Seats)
                {
                    var HallEventSeatToUpdate = hallEventAreaToUpdate.HallEventSeats.SingleOrDefault(x => x.Id == seat.Id);
                    if (HallEventSeatToUpdate == null)
                    {
                        HallEventSeatToUpdate = new HallEventSeat()
                        {
                            Angle = seat.Angle,
                            Left = seat.Left,
                            Name = seat.Name,
                            Height = seat.Height,
                            Number = seat.Number,
                            SeatId = seat.Id,
                            Status = seat.Status,
                            Top = seat.Top,
                            Width = seat.Width,
                            CreatDate = seat.CreatDate,
                            CreateUser = seat.CreateUser,
                            ModifyDate = seat.ModifyDate,
                            LastUser = seat.LastUser,
                            Deleted = seat.Deleted,

                            //HallEventRowId = HallEventSeat,
                            //HallEventRow = hallEventRows,

                            HallEventAreaId = hallEventAreaToUpdate.Id,
                            HallEventArea = hallEventAreaToUpdate,
                        };
                    }
                    var row = hallEventAreaToUpdate.HallEventRows
                        .SingleOrDefault(x => (x.Id == 0 &&
                                    x.HallEventArea.Id == seat.AreaId &&
                                    x.Name == seat.Row.Name) ||
                                    (x.Id == seat.RowId));

                    HallEventSeatToUpdate.HallEventRowId = row.Id;
                    HallEventSeatToUpdate.HallEventRow = row;

                    if(HallEventSeatToUpdate.Id == 0)
                    {
                        hallEventSeatsRepo.Create(HallEventSeatToUpdate);
                        seat.Id = HallEventSeatToUpdate.Id;
                    }
                    else
                    {
                        hallEventSeatsRepo.Update(HallEventSeatToUpdate);
                    }
                }
                var seatsToDelete = hallEventAreaToUpdate.HallEventSeats
                    .Where(x => !area.Seats.Any(y => y.Id == x.Id))
                    .ToList();

                foreach(var seatToDelete in seatsToDelete)
                {
                    hallEventSeatsRepo.Delete(seatToDelete);
                }
            }

        }
    }
}

内容的提问来源于stack exchange，提问作者Hai Elimelech