module Rails::HTML::Concern::Scrubber::SafeList

def self.included(klass)
  class << klass
    attr_accessor :allowed_tags
    attr_accessor :allowed_attributes
  end
  klass.allowed_tags = DEFAULT_ALLOWED_TAGS.dup
  klass.allowed_attributes = DEFAULT_ALLOWED_ATTRIBUTES.dup
end

def allowed_attributes(options)
  options[:attributes] || self.class.allowed_attributes
end

def allowed_tags(options)
  options[:tags] || self.class.allowed_tags
end

def initialize(prune: false)
  @permit_scrubber = PermitScrubber.new(prune: prune)
end

def sanitize_css(style_string)
  Loofah::HTML5::Scrub.scrub_css(style_string)
end

def scrub(fragment, options = {})
  if scrubber = options[:scrubber]
    # No duck typing, Loofah ensures subclass of Loofah::Scrubber
    fragment.scrub!(scrubber)
  elsif allowed_tags(options) || allowed_attributes(options)
    @permit_scrubber.tags = allowed_tags(options)
    @permit_scrubber.attributes = allowed_attributes(options)
    fragment.scrub!(@permit_scrubber)
  else
    fragment.scrub!(:strip)
  end
end