copy_course.rb

class CloneCourse < ActiveJob::Base
  def perform(course)
    ActiveRecord::Base.transaction do
      @new_course = course.dup
      @new_course.save!

      course.materials.each do |material|
        @new_material = material.dup
        @new_material.course = @new_course
        @new_material.save!

        copy_file(material, @new_material)
      end
    end
  end

  private

  def copy_file(material, new_material)
    s3 = AWS::S3.new(material.file.s3_credentials)
    s3_file = s3.buckets[material.file.s3_credentials[:bucket]].objects.first
    s3_file.copy_to(new_material.file.s3_object)
  end
end