112 lines
3.0 KiB
Elixir
112 lines
3.0 KiB
Elixir
# Portions of this file are derived from Pleroma:
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# Pleroma: A lightweight social networking server
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# Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/>
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# SPDX-License-Identifier: AGPL-3.0-only
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defmodule Mobilizon.Service.RichMedia.Parsers.OEmbed do
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@moduledoc """
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Module to parse OEmbed data in HTML pages
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"""
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alias Mobilizon.Service.Formatter.HTML
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require Logger
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@http_options [
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follow_redirect: true,
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ssl: [{:versions, [:"tlsv1.2"]}]
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]
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@spec parse(String.t(), map()) :: {:ok, map()} | {:error, String.t()}
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def parse(html, _data) do
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Logger.debug("Using OEmbed parser")
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with elements = [_ | _] <- get_discovery_data(html),
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{:ok, oembed_url} <- get_oembed_url(elements),
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{:ok, oembed_data} <- get_oembed_data(oembed_url),
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{:ok, oembed_data} <- filter_oembed_data(oembed_data) do
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Logger.debug("Data found with OEmbed parser")
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Logger.debug(inspect(oembed_data))
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{:ok, oembed_data}
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else
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_e ->
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{:error, "No OEmbed data found"}
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end
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end
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defp get_discovery_data(html) do
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with {:ok, document} <- Floki.parse_document(html) do
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Floki.find(document, "link[type='application/json+oembed']")
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end
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end
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defp get_oembed_url(nodes) do
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{"link", attributes, _children} = nodes |> hd()
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{:ok, Enum.into(attributes, %{})["href"]}
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end
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@oembed_allowed_attributes [
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:type,
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:version,
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:html,
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:width,
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:height,
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:title,
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:author_name,
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:author_url,
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:provider_name,
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:provider_url,
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:cache_age,
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:thumbnail_url,
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:thumbnail_width,
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:thumbnail_height,
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:url
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]
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defp get_oembed_data(url) do
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with {:ok, %{body: json}} <- Tesla.get(url, opts: @http_options),
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{:ok, data} <- Jason.decode(json),
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data <-
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data
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|> Map.new(fn {k, v} -> {String.to_existing_atom(k), String.trim(v)} end)
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|> Map.take(@oembed_allowed_attributes) do
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{:ok, data}
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end
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end
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defp filter_oembed_data(data) do
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case Map.get(data, :type) do
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nil ->
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{:error, "No type declared for OEmbed data"}
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"link" ->
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data
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|> Map.put(:image_remote_url, Map.get(data, :thumbnail_url))
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|> (&{:ok, &1}).()
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"photo" ->
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if Map.get(data, :url, "") == "" do
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{:error, "No URL for photo OEmbed data"}
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else
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data
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|> Map.put(:image_remote_url, Map.get(data, :url))
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|> Map.put(:width, Map.get(data, :width, 0))
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|> Map.put(:height, Map.get(data, :height, 0))
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|> (&{:ok, &1}).()
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end
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"video" ->
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{:ok, html} = data |> Map.get(:html, "") |> HTML.filter_tags_for_oembed()
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data
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|> Map.put(:html, html)
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|> Map.put(:width, Map.get(data, :width, 0))
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|> Map.put(:height, Map.get(data, :height, 0))
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|> Map.put(:image_remote_url, Map.get(data, :thumbnail_url))
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|> (&{:ok, &1}).()
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"rich" ->
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{:error, "OEmbed data has rich type, which we don't support"}
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end
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end
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end
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