module Scrivito

class CmsRouting < Struct.new(:request, :main_app)
  LINK_TO_EMPTY_LINKLIST = "#__empty_linklist"
  LINK_TO_EMPTY_BLOB = "#__empty_blob"

  def self.match_protocol(url, request)
    request.ssl? && !url.starts_with?('https') ? url.gsub(/^http/, 'https') : url
  end

  def path_or_url(target, path_or_url, options = {})
    if cms_with_editing_context?(target)
      path_or_url_with_editing_context(target, path_or_url, options)
    else
      path_or_url_without_editing_context(target, path_or_url, options)
    end
  end

  def convert_links(html)
    if html
      html.gsub(%r{\bobjid:([a-f0-9]{16})\b([^"']*)}) do
        if obj = Obj.find_by_id($1)
          options = {}

          if $2.present?
            begin
              uri = URI.parse($2)
              options.merge!(extract_query(uri))
              options['anchor'] = uri.fragment
            rescue
            end
          end

          path_or_url(obj, "path", options)
        else
          "#__target_object_not_reachable"
        end
      end
    end
  end

  private

  def path_or_url_with_editing_context(target, path_or_url, options)
    path_or_url_without_editing_context(target, path_or_url,
        options.merge(editing_context.to_params))
  end

  def path_or_url_without_editing_context(target, path_or_url, options)
    if target.is_a?(Link)
      path_or_url_for_links(target, path_or_url, options)
    elsif target.is_a?(Obj)
      path_or_url_for_objs(target, path_or_url, options)
    elsif target.respond_to?(:first)
      if target.first.is_a?(Link)
        path_or_url_for_links(target.first, path_or_url, options)
      else
        return LINK_TO_EMPTY_LINKLIST
      end
    elsif target.is_a?(Binary)
      target.url
    else
      raise "scrivito_path or scrivito_url was called with an instance of #{target.class}. "+
        "It must only be called with an Obj or a Link or a non-empty LinkList."
    end
  end

  def path_or_url_for_links(link, path_or_url, options = {})
    url = basic_url_or_path_for_link(link, path_or_url,
        Rack::Utils.parse_nested_query(link.query).merge(options))
    url = url + "##{link.fragment}" if link.fragment.present?
    url
  end

  def path_or_url_for_objs(obj, path_or_url, options = {})
    if editing_context.display_mode == "editing"
      return id_path_or_url_for_objs(obj, path_or_url, options)
    end

    permalink = obj.permalink
    if permalink
      main_app.public_send("scrivito_permalink_#{path_or_url}", options.merge(:permalink => permalink))
    elsif obj.homepage?
      main_app.public_send("scrivito_root_#{path_or_url}", options)
    elsif obj.binary?
      if obj.binary_url
        obj.binary_url
      else
        LINK_TO_EMPTY_BLOB
      end
    else
      id_path_or_url_for_objs(obj, path_or_url, options)
    end
  end

  def id_path_or_url_for_objs(obj, path_or_url, options)
    main_app.public_send(
      "cms_id_#{path_or_url}",
      options.merge(
        id: obj.id,
        slug: obj.slug.presence
      )
    )
  end

  def editor_authenticated?
    editing_context.authenticated_editor?
  end

  def editing_context
    EditingContextMiddleware.from_request(request)
  end

  def cms_with_editing_context?(target)
    editor_authenticated? && (!target.is_a?(Link) || target.internal?)
  end

  def basic_url_or_path_for_link(link, path_or_url, options = {})
    if link.internal?
      path_or_url_without_editing_context(link.obj, path_or_url, options)
    else
      url = link.url
      url = merge_options(url, options) if options.any?
      url
    end
  end

  def merge_options(url, options)
    parsed_url = URI.parse(url)

    query = extract_query(parsed_url)
    merged_query = query.merge(options.stringify_keys)
    parsed_url.query = merged_query.to_query

    parsed_url.to_s
  end

  def extract_query(uri)
    Rack::Utils.parse_query(uri.query)
  end
end

end