ReservationController.cs

 public async Task<ActionResult> Reservee(ReservationRequestModel model)
        {
            // Check if requested space exists
            if (!await _spaceRepository.IsSpaceExistById(model.ReservedSpaceId))
            {
                return NotFound("Space Not Found");
            }

            // Check if requested space is available
            if (!await _reservationRepo.IsSpaceAvailable(model))
            {
                return BadRequest("Space Not Available!");
            }

            // reservation request model -> reservation
            var reservation = _mapper.Map<Reservation>(model);

            // Get requested space and reserved by user
            var space = await _spaceRepository.GetSpaceById(reservation.ReservedSpaceId);
            var user = _mapper.Map<ReservationUserResponseModel>(
                await _userRepository.GetByUsername(
                    await _userRepository.GetUsernameById(model.ReservedByUserId)
                )
            );


            List<ReservationUserResponseModel> inviteesList;

            // Set invitees list based on the invited category (team only, sub-team only or individuals)
            if (model.IsMainTeamOnly)
            {
                inviteesList = (List<ReservationUserResponseModel>)await _userRepository.GetUsersByTeamId(model.ReservedTeamId);
            }
            else if (model.IsSubTeamOnly)
            {
                inviteesList = (List<ReservationUserResponseModel>)await _userRepository.GetUsersBySubTeamId(model.ReservedSubTeamId);
            }
            else
            {
                inviteesList = (List<ReservationUserResponseModel>)model.ReservedUsers;
            }

            reservation.StatusId = 2; // SCHEDULED -> 2
            reservation.InvitedCount = inviteesList.Count;
            reservation.Date = DateTime.Today;

            _reservationRepo.Add(reservation);

            // Add invitees in table after adding reservation
            if (await _reservationRepo.SaveAllAsync())
            {
                // await this.AddInvitees(model, reservation.ReservationId);
                foreach (var invitedUser in inviteesList)
                {
                    var invitee = new Invitee(invitedUser.Username,
                        invitedUser.Email,
                        false,
                        reservation.ReservationTitle,
                        space.SpaceName,
                        space.SpaceCategory.SpaceCategoryName,
                        reservation.StartsAt,
                        reservation.EndsAt,
                        (reservation.EndsAt - reservation.StartsAt).Minutes,
                        $"https://space360.azurewebsites.net/api/reservation/accept-invite?reservartionId={reservation.ReservationId}&userId={invitedUser.UserId}",
                        $"https://space360.azurewebsites.net/api/reservation/decline-invite"
                    );

                    await _inviteeRepo.Add(invitee);
                }
                await _inviteeRepo.SaveAllAsync();
                return Ok(new { message = "Reserved, Mail Has Been Sent" });
            }

            return BadRequest("Something Went Wrong");
        }