module RenderMixin

  # shortcut to a template path based on name.
  def template_dir(loc)
    File.expand_path(Merb::Server.config[:merb_root] + "/dist/app/views/#{loc}")
  end  
  
  # returns the current method name. Used for
  # auto discovery of which template to render
  # based on the action name.
  def current_method_name(depth=0)
    caller[depth] =~ /`(.*)'$/; $1
  end
  
  # does a render with no layout. Also sets the
  # content type header to text/javascript and
  # escapes the template for javascript eval on
  # the client
  def render_js(template=current_method_name(1), b=binding)
    headers['Content-Type'] = "text/javascript"
    template = Erubis::Eruby.new(IO.read( template_dir(self.class.name.snake_case) + "/#{template}.merbjs" )) 
    template.result(b)
  end
  
  # set the @layout. Use this right before a render to
  # set the name of the layout to use minus the .rhtml
  def layout(l)
     @layout = l 
  end
  
  def render_nothing(status)
    @status = status
    return ''
  end
  
  # renders the action without wrapping it in a layout.
  def render_no_layout(template=current_method_name(1), b=binding)
    template = Erubis::Eruby.new( IO.read( template_dir(self.class.name.snake_case) + "/#{template}.rhtml" ) ) 
    template.result(b)
  end 
  
  def partial(template)
    template = Erubis::Eruby.new( IO.read( template_dir(self.class.name.snake_case) + "/_#{template}.rhtml" ) ) 
    template.result(binding)
  end 
  
  # renders a template based on the current action name
  # you can pass the name of a template if you want to
  # render a template with a different name then then 
  # current action name. Wraps the rendered template in
  # the layout. Uses layout/application.rhtml unless
  # there is a layout named after the current controller
  # or @layout has been set to another value.
  def render(template=current_method_name(1), b=binding)
    MERB_LOGGER.info("Rendering template: #{template_dir(template)}")
    name = self.class.name.snake_case
    template = Erubis::Eruby.new( IO.read( template_dir(name) + "/#{template}.rhtml" ) ) 
    layout_content = template.result(b)
    return layout_content if (@layout.to_s == 'none')
    if ['application', name].include?(@layout.to_s)
      if File.exist?(template_dir("layout/#{name}.rhtml"))
        layout = name
      else
        layout = 'application'
      end
    else
      layout = @layout.to_s
    end
    MERB_LOGGER.info("With Layout: #{template_dir('layout')}/#{layout}.rhtml")
    @layout_content = layout_content
    layout_tmpl = Erubis::Eruby.new( IO.read( template_dir('layout') + "/#{layout}.rhtml" ) )      
    layout_tmpl.result(b)
  end
  
end