class Sprockets::SassTemplate

def self.engine_initialized?
  defined?(::Sass::Engine) && defined?(::Sass::Script::Functions) &&
    ::Sass::Script::Functions < Sprockets::SassFunctions
end

def evaluate(context, locals, &block)
  # Use custom importer that knows about Sprockets Caching
  cache_store = SassCacheStore.new(context.environment)
  options = {
    :filename => eval_file,
    :line => line,
    :syntax => syntax,
    :cache_store => cache_store,
    :importer => SassImporter.new(context.pathname.to_s),
    :load_paths => context.environment.paths.map { |path| SassImporter.new(path.to_s) },
    :sprockets => {
      :context => context,
      :environment => context.environment
    }
  }
  result = ::Sass::Engine.new(data, options).render
  # Track all imported files
  filenames = ([options[:importer].imported_filenames] + options[:load_paths].map(&:imported_filenames)).flatten.uniq
  filenames.each { |filename| context.depend_on(filename) }
  result
rescue ::Sass::SyntaxError => e
  # Annotates exception message with parse line number
  context.__LINE__ = e.sass_backtrace.first[:line]
  raise e
end

def initialize_engine
  # Double check constant to avoid tilt warning
  unless defined? ::Sass
    require_template_library 'sass'
  end
  # Install custom functions. It'd be great if this didn't need to
  # be installed globally, but could be passed into Engine as an
  # option.
  ::Sass::Script::Functions.send :include, Sprockets::SassFunctions
end

def prepare
end

def syntax
  :sass
end