module Middleman::Renderers::Markdown

def registered(app)
  # Set our preference for a markdown engine
  app.config.define_setting :markdown_engine, :kramdown, 'Preferred markdown engine'
  app.config.define_setting :markdown_engine_prefix, ::Tilt, 'The parent module for markdown template engines'
  app.before_configuration do
    template_extensions :markdown => :html,
                        :mdown    => :html,
                        :md       => :html,
                        :mkd      => :html,
                        :mkdn     => :html
  end
  # Once configuration is parsed
  app.after_configuration do
    markdown_exts = %w(markdown mdown md mkd mkdn)
    begin
      # Look for the user's preferred engine
      if config[:markdown_engine] == :redcarpet
        require "middleman-core/renderers/redcarpet"
        ::Tilt.prefer(::Middleman::Renderers::RedcarpetTemplate, *markdown_exts)
        MiddlemanRedcarpetHTML.middleman_app = self
      elsif config[:markdown_engine] == :kramdown
        require "middleman-core/renderers/kramdown"
        ::Tilt.prefer(::Middleman::Renderers::KramdownTemplate, *markdown_exts)
        MiddlemanKramdownHTML.middleman_app = self
      elsif !config[:markdown_engine].nil?
        # Map symbols to classes
        markdown_engine_klass = if config[:markdown_engine].is_a? Symbol
          engine = config[:markdown_engine].to_s
          engine = engine == "rdiscount" ? "RDiscount" : engine.camelize
          config[:markdown_engine_prefix].const_get("#{engine}Template")
        else
          config[:markdown_engine_prefix]
        end
        # Tell tilt to use that engine
        ::Tilt.prefer(markdown_engine_klass, *markdown_exts)
      end
    rescue LoadError
      logger.warn "Requested Markdown engine (#{config[:markdown_engine]}) not found. Maybe the gem needs to be installed and required?"
    end
  end
end