You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: contacts_controller.rb
    path of file: ./repos/diaspora/app/controllers
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

#   Copyright (c) 2010-2011, Dia
    
  def set_up_contacts_mobile
    @contacts = case params[:set]
      when "only_sharing"
        current_user.contacts.only_sharing
      when "all"
        current_user.contacts
      else
        if params[:a_id]
          @aspect = current_user.aspects.find(params[:a_id])
          @aspect.contacts
        else
          current_user.contacts.receiving
        end