module Middleman
  module CoreExtensions

    # Forward the settings on config.rb and the result of registered
    # extensions to Compass
    module Compass

      # Extension registered
      class << self

        # Once registered
        def registered(app)
          # Require the library
          require "compass"

          # Hooks to manually update the compass config after we're
          # done with it
          app.define_hook :compass_config

          # Location of SASS/SCSS files external to source directory.
          # @return [Array]
          #   set :sass_assets_paths, ["#{root}/assets/sass/", "/path/2/external/sass/repository/"]
          app.set :sass_assets_paths, []

          app.after_configuration do
            ::Compass.configuration do |config|
              config.project_path    = source_dir
              config.environment     = :development
              config.cache_path      = sass_cache_path
              config.sass_dir        = css_dir
              config.css_dir         = css_dir
              config.javascripts_dir = js_dir
              config.fonts_dir       = fonts_dir
              config.images_dir      = images_dir
              config.http_path       = http_prefix

              sass_assets_paths.each do |path|
                config.add_import_path path
              end

              # Disable this initially, the cache_buster extension will
              # re-enable it if requested.
              config.asset_cache_buster :none

              # Disable this initially, the relative_assets extension will
              # re-enable it if requested.
              config.relative_assets = false

              # Default output style
              config.output_style = :nested

              # No line-comments in test mode (changing paths mess with sha1)
              config.line_comments = false if ENV["TEST"]

              if respond_to?(:asset_host) && asset_host.is_a?(Proc)
                config.asset_host(&asset_host)
              end
            end

            # Call hook
            run_hook :compass_config, ::Compass.configuration

            # Tell Tilt to use it as well (for inline sass blocks)
            ::Tilt.register 'sass', CompassSassTemplate
            ::Tilt.prefer(CompassSassTemplate)

            # Tell Tilt to use it as well (for inline scss blocks)
            ::Tilt.register 'scss', CompassScssTemplate
            ::Tilt.prefer(CompassScssTemplate)
          end
        end
        alias :included :registered
      end

    end

    # A Compass Sass template for Tilt, adding our options in
    class CompassSassTemplate < ::Middleman::Renderers::Sass::SassPlusCSSFilenameTemplate
      def sass_options
        super.merge(::Compass.configuration.to_sass_engine_options)
      end
    end

    # A Compass Scss template for Tilt, adding our options in
    class CompassScssTemplate < ::Middleman::Renderers::Sass::ScssPlusCSSFilenameTemplate
      def sass_options
        super.merge(::Compass.configuration.to_sass_engine_options)
      end
    end

  end
end