defmodule Unfurl.Parser.RelMe do
  import Untangle

  def parse(html, opts \\ [])

  def parse(html_tree, opts) when is_list(html_tree) do
    with rel_me_hrefs when is_list(rel_me_hrefs) and rel_me_hrefs != [] <-
           Floki.attribute(html_tree, "link[rel~=me]", "href") ++
             Floki.attribute(html_tree, "a[rel~=me]", "href") do
      case opts[:rel_me_urls] do
        rel_me_urls when is_list(rel_me_urls) ->
          {:ok,
           %{urls: rel_me_hrefs, verified: Enum.any?(rel_me_hrefs, fn x -> x in rel_me_urls end)}}

        _ ->
          # no url(s) provided to verify against
          {:ok, %{urls: rel_me_hrefs}}
      end
    else
      e ->
        warn(e, "Parsing error with rel=me")
        {:ok, nil}
    end
  end

  def parse(html, opts) when is_list(html) do
    with {:ok, html_tree} <- Floki.parse_document(html) do
      parse(html_tree, opts)
    else
      e ->
        warn(e, "Parsing error with rel=me")
        {:ok, nil}
    end
  end

  def parse(html, opts) do
    warn(html, "Invalid HTML")
    {:ok, nil}
  end
end