public UpdateAttendedStatusOnParticipantCommandValidator(IInvitationValidator invitationValidator, IRowVersionValidator rowVersionValidator) { CascadeMode = CascadeMode.Stop; RuleFor(command => command) .MustAsync((command, cancellationToken) => BeAnExistingInvitation(command.InvitationId, cancellationToken)) .WithMessage(command => $"Invitation with this ID does not exist! Id={command.InvitationId}") .MustAsync((command, cancellationToken) => NotBeCancelledInvitation(command.InvitationId, cancellationToken)) .WithMessage(command => $"Cannot perform updates on cancelled invitation! Id={command.InvitationId}") .MustAsync((command, cancellationToken) => BeAnExistingParticipant(command.ParticipantId, command.InvitationId, cancellationToken)) .WithMessage(command => $"Participant with ID does not exist on invitation! ParticipantId={command.ParticipantId}") .Must(command => HaveAValidRowVersion(command.RowVersion)) .WithMessage(command => $"Participant doesn't have valid rowVersion! ParticipantRowVersion={command.RowVersion}") .MustAsync((command, cancellationToken) => HavePermissionToEdit(command.ParticipantId, command.InvitationId, cancellationToken)) .WithMessage("The current user does not have sufficient privileges to edit this participant.") .MustAsync((command, cancellationToken) => HaveOppositeAttendedStatusIfTouched(command.ParticipantId, command.InvitationId, command.Attended, cancellationToken)) .WithMessage("Cannot update participant to its current attendedStatus."); async Task <bool> BeAnExistingInvitation(int invitationId, CancellationToken cancellationToken) => await invitationValidator.IpoExistsAsync(invitationId, cancellationToken); async Task <bool> NotBeCancelledInvitation(int invitationId, CancellationToken cancellationToken) => !await invitationValidator.IpoIsInStageAsync(invitationId, IpoStatus.Canceled, cancellationToken); async Task <bool> BeAnExistingParticipant(int participantId, int invitationId, CancellationToken cancellationToken) => await invitationValidator.ParticipantExistsAsync(participantId, invitationId, cancellationToken); async Task <bool> HavePermissionToEdit(int participantId, int invitationId, CancellationToken cancellationToken) => await invitationValidator.HasPermissionToEditParticipantAsync(participantId, invitationId, cancellationToken); async Task <bool> HaveOppositeAttendedStatusIfTouched(int participantId, int invitationId, bool attended, CancellationToken cancellationToken) => await invitationValidator.HasOppositeAttendedStatusIfTouchedAsync(participantId, invitationId, attended, cancellationToken); bool HaveAValidRowVersion(string rowVersion) => rowVersionValidator.IsValid(rowVersion); }