defmodule Frenzy.Pipeline.Extractor.Slate do
  @moduledoc """
  Extractor for https://slate.com
  """

  alias Frenzy.Pipeline.Extractor
  @behaviour Extractor

  @impl Extractor
  def extract(html_tree) do
    case get_article_content(html_tree) do
      nil ->
        {:error, "no matching elements"}

      elem ->
        {:ok, elem}
    end
  end

  defp get_article_content(html_tree) do
    case Floki.find(html_tree, ".article__content") do
      [el] ->
        article_content =
          Floki.filter_out(el, ".slate-ad, .in-article-recirc, .social-share, .newsletter-signup")

        image = Floki.find(html_tree, ".article__top-image img")

        case image do
          [] ->
            article_content

          [image | _] ->
            [image, article_content]
        end

      _ ->
        nil
    end
  end
end