git.squeep.com Git - akkoma/blob - lib/pleroma/web/rich_media/parser.ex

   1 # Pleroma: A lightweight social networking server
   2 # Copyright © 2017-2019 Pleroma Authors <https://pleroma.social/>
   3 # SPDX-License-Identifier: AGPL-3.0-only
   4
   5 defmodule Pleroma.Web.RichMedia.Parser do
   6   @parsers [
   7     Pleroma.Web.RichMedia.Parsers.OGP,
   8     Pleroma.Web.RichMedia.Parsers.TwitterCard,
   9     Pleroma.Web.RichMedia.Parsers.OEmbed
  10   ]
  11
  12   def parse(nil), do: {:error, "No URL provided"}
  13
  14   if Mix.env() == :test do
  15     def parse(url), do: parse_url(url)
  16   else
  17     def parse(url) do
  18       with {:ok, data} <- Cachex.fetch(:rich_media_cache, url, fn _ -> parse_url(url) end) do
  19         data
  20       else
  21         _e ->
  22           {:error, "Parsing error"}
  23       end
  24     end
  25   end
  26
  27   defp parse_url(url) do
  28     try do
  29       {:ok, %Tesla.Env{body: html}} = Pleroma.HTTP.get(url)
  30
  31       html |> maybe_parse() |> get_parsed_data()
  32     rescue
  33       _e ->
  34         {:error, "Parsing error"}
  35     end
  36   end
  37
  38   defp maybe_parse(html) do
  39     Enum.reduce_while(@parsers, %{}, fn parser, acc ->
  40       case parser.parse(html, acc) do
  41         {:ok, data} -> {:halt, data}
  42         {:error, _msg} -> {:cont, acc}
  43       end
  44     end)
  45   end
  46
  47   defp get_parsed_data(data) when data == %{} do
  48     {:error, "No metadata found"}
  49   end
  50
  51   defp get_parsed_data(data) do
  52     {:ok, data}
  53   end
  54 end