class PageSweeper < ActionController::Caching::Sweeper
  observe Page, Version
  
  def after_create(record)
    case record
      when Page:
        # TODO: Only expire pages that link to this page
        expire_pages(record.book)
        expire_indexes(record.book)
      when Version:
        controller.class.expire_page(page_path(record.page))
    end
  end
  
  def after_pages_show
    controller.class.cache_page(controller.response.body, page_path(page)) if page
  end
  
  private
    def page_path(page)
      page.title == "Home Page" ? "/#{page.book.url_name}.html" : "/#{page.book.url_name}/pages/#{page.title}.html"
    end
  
    def page
      controller.instance_variable_get("@page")
    end
    
    def expire_pages(book)
      logger.info "Expired pages"
      FileUtils.rm_rf(Dir.glob(RAILS_ROOT + "/public/#{book.url_name}/pages/*.html"))
      FileUtils.rm_rf(RAILS_ROOT + "/public/#{book.url_name}.html")
    end
    
    def expire_indexes(book)
      logger.info "Expired indexes"
      FileUtils.rm_rf(RAILS_ROOT + "/public/#{book.url_name}/pages.html")
      FileUtils.rm_rf(RAILS_ROOT + "/public/#{book.url_name}/recent.html")
    end
end