CarrierWave base class - appends digest hash to the original filename

base_uploader.rb

class BaseUploader < CarrierWave::Uploader::Base
  include ::CarrierWave::MimeTypes

  storage Rails.env.development? ? :file : :fog

  process :set_content_type

  # append digests to the original filename so we can validate file uniqueness
  def md5
    @md5 ||= Digest::MD5.hexdigest(model.send(mounted_as).read.to_s)
  end

  def filename
    if original_filename.present? && super.present? && !super.include?("-#{md5}")
      fname = super.split('.')
      ext = fname.pop
      @name ||= "#{fname.join('.')}-#{md5}.#{ext}"
    else
      super
    end
  end
end