require 'sprockets/autoload'

module Sprockets
  # Public: Sass CSS minifier.
  #
  # To accept the default options
  #
  #     environment.register_bundle_processor 'text/css',
  #       Sprockets::SassCompressor
  #
  # Or to pass options to the Sass::Engine class.
  #
  #     environment.register_bundle_processor 'text/css',
  #       Sprockets::SassCompressor.new({ ... })
  #
  class SassCompressor
    VERSION = '1'

    # Public: Return singleton instance with default options.
    #
    # Returns SassCompressor object.
    def self.instance
      @instance ||= new
    end

    def self.call(input)
      instance.call(input)
    end

    def self.cache_key
      instance.cache_key
    end

    attr_reader :cache_key

    def initialize(options = {})
      @options = options
      @cache_key = [
        self.class.name,
        Autoload::Sass::VERSION,
        VERSION,
        options
      ].freeze
    end

    def call(input)
      data = input[:data]
      input[:cache].fetch(@cache_key + [data]) do
        options = {
          syntax: :scss,
          cache: false,
          read_cache: false,
          style: :compressed
        }.merge(@options)
        Autoload::Sass::Engine.new(data, options).render
      end
    end
  end
end