class ImagesController < ActionController::Base

  after_filter :cache_dynamic_image
  after_filter :run_garbage_collection_for_dynamic_image_controller

  unloadable

  public

    # Return the requested image. Rescale, filter and cache it where appropriate.
    def render_dynamic_image

      render_missing_image and return unless Image.exists?(params[:id])
      image = Image.find(params[:id])

      minTime = Time.rfc2822(request.env["HTTP_IF_MODIFIED_SINCE"]) rescue nil
      if minTime && image.created_at? && image.created_at <= minTime
        render :text => '304 Not Modified', :status => 304
        return
      end

      unless image.data?
        logger.warn "Image #{image.id} exists, but has no data"
        render_missing_image and return
      end

      if size = params[:size]
          if size =~ /^x[\d]+$/ || size =~ /^[\d]+x$/
          if params[:original]
            image.cropped = false
          end
              size = Vector2d.new(size)
            image_size = Vector2d.new(image.size)
            size = image_size.constrain_both(size).round.to_s
        end
          imagedata = image.get_processed(size, params[:filterset])
        else
          imagedata = image
          end

      DynamicImage.dirty_memory = true # Flag memory for GC

      if image
        response.headers['Cache-Control'] = nil
        response.headers['Last-Modified'] = imagedata.created_at.httpdate if imagedata.created_at?
        send_data(
          imagedata.data,
          :filename    => image.filename,
          :type        => image.content_type,
          :disposition => 'inline'
        )
      end

    end

  protected

    def render_missing_image
      if self.respond_to?(:render_error)
        render_error 404
      else
        render :status => 404, :text => "404: Image not found"
      end
    end

    # Enforce caching of dynamic images, even if caching is turned off
    def cache_dynamic_image
      cache_setting = ActionController::Base.perform_caching
      ActionController::Base.perform_caching = true
      cache_page
      ActionController::Base.perform_caching = cache_setting
    end

    # Perform garbage collection if necessary
    def run_garbage_collection_for_dynamic_image_controller
      DynamicImage.clean_dirty_memory
    end

end