```ruby
require 'twilio-ruby'

class InboundMessageProcessor
  def initialize(phone_number, body)
    @phone_number = phone_number
    @body = body
  end

  def process
    if member
      if member.email
        create_attendance_for_current_event
      else
        update_member_email
      end
    else
      create_member
    end
  end

  private
    def member
      @member ||= Member.find_by(phone: @phone_number)
    end

    def event
      @event ||= Event.where(token: event_token).current
    end

    def event_token
      @body.strip.downcase
    end

    def create_attendance_for_current_event
      if event
        unless Attendance.exists?(event: event, member: member)
          Attendance.create(member: member, event: event)
        end

        respond "Welcome to #{event.name}!"
      else
        respond "Invalid event code."
      end
    end

    def update_member_email
      member.update!(email: @body)
      respond "Thanks, #{member.first_name}! Your email was updated to #{@body}."
    end

    def create_member
      Member.create!(phone: @phone_number, name: @body)
      respond "Hey there, #{member.first_name}!  Welcome to Handy.  Please respond with your email address."
    end

    def respond(response)
      Sms::DeliveryJob.perform_later(@phone_number, response)
    end
end
```

Raise an exception if Attendance creation fails in message processing
user
```ruby
require 'twilio-ruby'

class InboundMessageProcessor
  def initialize(phone_number, body)
    @phone_number = phone_number
    @body = body
  end

  def process
    if member
      if member.email
        create_attendance_for_current_event
      else
        update_member_email
      end
    else
      create_member
    end
  end

  private
    def member
      @member ||= Member.find_by(phone: @phone_number)
    end

    def event
      @event ||= Event.where(token: event_token).current
    end

    def event_token
      @body.strip.downcase
    end

    def create_attendance_for_current_event
      if event
        unless Attendance.exists?(event: event, member: member)
          Attendance.create!(member: member, event: event)
        end

        respond "Welcome to #{event.name}!"
      else
        respond "Invalid event code."
      end
    end

    def update_member_email
      member.update!(email: @body)
      respond "Thanks, #{member.first_name}! Your email was updated to #{@body}."
    end

    def create_member
      Member.create!(phone: @phone_number, name: @body)
      respond "Hey there, #{member.first_name}!  Welcome to Handy.  Please respond with your email address."
    end

    def respond(response)
      Sms::DeliveryJob.perform_later(@phone_number, response)
    end
end
```
assistant