class ActiveModel::Error

def self.full_message(attribute, message, base) # :nodoc:
  return message if attribute == :base
  base_class = base.class
  attribute = attribute.to_s
  if i18n_customize_full_message && base_class.respond_to?(:i18n_scope)
    attribute = attribute.remove(/\[\d+\]/)
    parts = attribute.split(".")
    attribute_name = parts.pop
    namespace = parts.join("/") unless parts.empty?
    attributes_scope = "#{base_class.i18n_scope}.errors.models"
    if namespace
      defaults = base_class.lookup_ancestors.map do |klass|
        [
          :"#{attributes_scope}.#{klass.model_name.i18n_key}/#{namespace}.attributes.#{attribute_name}.format",
          :"#{attributes_scope}.#{klass.model_name.i18n_key}/#{namespace}.format",
        ]
      end
    else
      defaults = base_class.lookup_ancestors.map do |klass|
        [
          :"#{attributes_scope}.#{klass.model_name.i18n_key}.attributes.#{attribute_name}.format",
          :"#{attributes_scope}.#{klass.model_name.i18n_key}.format",
        ]
      end
    end
    defaults.flatten!
  else
    defaults = []
  end
  defaults << :"errors.format"
  defaults << "%{attribute} %{message}"
  attr_name = attribute.tr(".", "_").humanize
  attr_name = base_class.human_attribute_name(attribute, {
    default: attr_name,
    base: base,
  })
  I18n.t(defaults.shift,
    default:  defaults,
    attribute: attr_name,
    message:   message)
end