mysociety/alaveteli

##
# Controller to process FoiAttachment objects before being served publicly by
# applying masks and censor rules.
#
class AttachmentMasksController < ApplicationController
  before_action :set_no_crawl_headers
  before_action :decode_referer, :ensure_referer
  before_action :find_attachment, :ensure_attachment

  def wait
    if @attachment.masked?
      redirect_to @referer and return if refered_from_show_as_html?

      redirect_to done_attachment_mask_path(
        id: @attachment.to_signed_global_id,
        referer: verifier.generate(@referer)
      )

    else
      FoiAttachmentMaskJob.perform_later(@attachment)
    end
  end

  def done
    unless @attachment.masked?
      redirect_to wait_for_attachment_mask_path(
        id: @attachment.to_signed_global_id,
        referer: verifier.generate(@referer)
      )
    end
  end

  private

  def set_no_crawl_headers
    headers['X-Robots-Tag'] = 'noindex'
  end

  def decode_referer
    @referer = verifier.verified(params[:referer])
  end

  def find_attachment
    @attachment = GlobalID::Locator.locate_signed(params[:id])
  rescue ActiveRecord::RecordNotFound
  end

  def ensure_referer
    raise RouteNotFound unless @referer
  end

  def ensure_attachment
    redirect_to(@referer) unless @attachment
  end

  def verifier
    Rails.application.message_verifier('AttachmentsController')
  end

  def refered_from_show_as_html?
    @referer =~ %r(/request/\d+/response/\d+/attach/html/)
  end
end