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   1 # Pleroma: A lightweight social networking server
   2 # Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/>
   3 # SPDX-License-Identifier: AGPL-3.0-only
   4
   5 defmodule Pleroma.Web.ActivityPub.Transmogrifier do
   6   @moduledoc """
   7   A module to handle coding from internal to wire ActivityPub and back.
   8   """
   9   alias Pleroma.Activity
  10   alias Pleroma.EarmarkRenderer
  11   alias Pleroma.FollowingRelationship
  12   alias Pleroma.Object
  13   alias Pleroma.Object.Containment
  14   alias Pleroma.Repo
  15   alias Pleroma.User
  16   alias Pleroma.Web.ActivityPub.ActivityPub
  17   alias Pleroma.Web.ActivityPub.ObjectValidator
  18   alias Pleroma.Web.ActivityPub.Pipeline
  19   alias Pleroma.Web.ActivityPub.Utils
  20   alias Pleroma.Web.ActivityPub.Visibility
  21   alias Pleroma.Web.Federator
  22   alias Pleroma.Workers.TransmogrifierWorker
  23
  24   import Ecto.Query
  25
  26   require Logger
  27   require Pleroma.Constants
  28
  29   @doc """
  30   Modifies an incoming AP object (mastodon format) to our internal format.
  31   """
  32   def fix_object(object, options \\ []) do
  33     object
  34     |> strip_internal_fields
  35     |> fix_actor
  36     |> fix_url
  37     |> fix_attachments
  38     |> fix_context
  39     |> fix_in_reply_to(options)
  40     |> fix_emoji
  41     |> fix_tag
  42     |> fix_content_map
  43     |> fix_addressing
  44     |> fix_summary
  45     |> fix_type(options)
  46     |> fix_content
  47   end
  48
  49   def fix_summary(%{"summary" => nil} = object) do
  50     Map.put(object, "summary", "")
  51   end
  52
  53   def fix_summary(%{"summary" => _} = object) do
  54     # summary is present, nothing to do
  55     object
  56   end
  57
  58   def fix_summary(object), do: Map.put(object, "summary", "")
  59
  60   def fix_addressing_list(map, field) do
  61     cond do
  62       is_binary(map[field]) ->
  63         Map.put(map, field, [map[field]])
  64
  65       is_nil(map[field]) ->
  66         Map.put(map, field, [])
  67
  68       true ->
  69         map
  70     end
  71   end
  72
  73   def fix_explicit_addressing(
  74         %{"to" => to, "cc" => cc} = object,
  75         explicit_mentions,
  76         follower_collection
  77       ) do
  78     explicit_to = Enum.filter(to, fn x -> x in explicit_mentions end)
  79
  80     explicit_cc = Enum.filter(to, fn x -> x not in explicit_mentions end)
  81
  82     final_cc =
  83       (cc ++ explicit_cc)
  84       |> Enum.reject(fn x -> String.ends_with?(x, "/followers") and x != follower_collection end)
  85       |> Enum.uniq()
  86
  87     object
  88     |> Map.put("to", explicit_to)
  89     |> Map.put("cc", final_cc)
  90   end
  91
  92   def fix_explicit_addressing(object, _explicit_mentions, _followers_collection), do: object
  93
  94   # if directMessage flag is set to true, leave the addressing alone
  95   def fix_explicit_addressing(%{"directMessage" => true} = object), do: object
  96
  97   def fix_explicit_addressing(object) do
  98     explicit_mentions = Utils.determine_explicit_mentions(object)
  99
 100     %User{follower_address: follower_collection} =
 101       object
 102       |> Containment.get_actor()
 103       |> User.get_cached_by_ap_id()
 104
 105     explicit_mentions =
 106       explicit_mentions ++
 107         [
 108           Pleroma.Constants.as_public(),
 109           follower_collection
 110         ]
 111
 112     fix_explicit_addressing(object, explicit_mentions, follower_collection)
 113   end
 114
 115   # if as:Public is addressed, then make sure the followers collection is also addressed
 116   # so that the activities will be delivered to local users.
 117   def fix_implicit_addressing(%{"to" => to, "cc" => cc} = object, followers_collection) do
 118     recipients = to ++ cc
 119
 120     if followers_collection not in recipients do
 121       cond do
 122         Pleroma.Constants.as_public() in cc ->
 123           to = to ++ [followers_collection]
 124           Map.put(object, "to", to)
 125
 126         Pleroma.Constants.as_public() in to ->
 127           cc = cc ++ [followers_collection]
 128           Map.put(object, "cc", cc)
 129
 130         true ->
 131           object
 132       end
 133     else
 134       object
 135     end
 136   end
 137
 138   def fix_implicit_addressing(object, _), do: object
 139
 140   def fix_addressing(object) do
 141     {:ok, %User{} = user} = User.get_or_fetch_by_ap_id(object["actor"])
 142     followers_collection = User.ap_followers(user)
 143
 144     object
 145     |> fix_addressing_list("to")
 146     |> fix_addressing_list("cc")
 147     |> fix_addressing_list("bto")
 148     |> fix_addressing_list("bcc")
 149     |> fix_explicit_addressing()
 150     |> fix_implicit_addressing(followers_collection)
 151   end
 152
 153   def fix_actor(%{"attributedTo" => actor} = object) do
 154     Map.put(object, "actor", Containment.get_actor(%{"actor" => actor}))
 155   end
 156
 157   def fix_in_reply_to(object, options \\ [])
 158
 159   def fix_in_reply_to(%{"inReplyTo" => in_reply_to} = object, options)
 160       when not is_nil(in_reply_to) do
 161     in_reply_to_id = prepare_in_reply_to(in_reply_to)
 162     object = Map.put(object, "inReplyToAtomUri", in_reply_to_id)
 163     depth = (options[:depth] || 0) + 1
 164
 165     if Federator.allowed_thread_distance?(depth) do
 166       with {:ok, replied_object} <- get_obj_helper(in_reply_to_id, options),
 167            %Activity{} <- Activity.get_create_by_object_ap_id(replied_object.data["id"]) do
 168         object
 169         |> Map.put("inReplyTo", replied_object.data["id"])
 170         |> Map.put("inReplyToAtomUri", object["inReplyToAtomUri"] || in_reply_to_id)
 171         |> Map.put("conversation", replied_object.data["context"] || object["conversation"])
 172         |> Map.put("context", replied_object.data["context"] || object["conversation"])
 173       else
 174         e ->
 175           Logger.error("Couldn't fetch #{inspect(in_reply_to_id)}, error: #{inspect(e)}")
 176           object
 177       end
 178     else
 179       object
 180     end
 181   end
 182
 183   def fix_in_reply_to(object, _options), do: object
 184
 185   defp prepare_in_reply_to(in_reply_to) do
 186     cond do
 187       is_bitstring(in_reply_to) ->
 188         in_reply_to
 189
 190       is_map(in_reply_to) && is_bitstring(in_reply_to["id"]) ->
 191         in_reply_to["id"]
 192
 193       is_list(in_reply_to) && is_bitstring(Enum.at(in_reply_to, 0)) ->
 194         Enum.at(in_reply_to, 0)
 195
 196       true ->
 197         ""
 198     end
 199   end
 200
 201   def fix_context(object) do
 202     context = object["context"] || object["conversation"] || Utils.generate_context_id()
 203
 204     object
 205     |> Map.put("context", context)
 206     |> Map.put("conversation", context)
 207   end
 208
 209   defp add_if_present(map, _key, nil), do: map
 210
 211   defp add_if_present(map, key, value) do
 212     Map.put(map, key, value)
 213   end
 214
 215   def fix_attachments(%{"attachment" => attachment} = object) when is_list(attachment) do
 216     attachments =
 217       Enum.map(attachment, fn data ->
 218         url =
 219           cond do
 220             is_list(data["url"]) -> List.first(data["url"])
 221             is_map(data["url"]) -> data["url"]
 222             true -> nil
 223           end
 224
 225         media_type =
 226           cond do
 227             is_map(url) && is_binary(url["mediaType"]) -> url["mediaType"]
 228             is_binary(data["mediaType"]) -> data["mediaType"]
 229             is_binary(data["mimeType"]) -> data["mimeType"]
 230             true -> nil
 231           end
 232
 233         href =
 234           cond do
 235             is_map(url) && is_binary(url["href"]) -> url["href"]
 236             is_binary(data["url"]) -> data["url"]
 237             is_binary(data["href"]) -> data["href"]
 238           end
 239
 240         attachment_url =
 241           %{"href" => href}
 242           |> add_if_present("mediaType", media_type)
 243           |> add_if_present("type", Map.get(url || %{}, "type"))
 244
 245         %{"url" => [attachment_url]}
 246         |> add_if_present("mediaType", media_type)
 247         |> add_if_present("type", data["type"])
 248         |> add_if_present("name", data["name"])
 249       end)
 250
 251     Map.put(object, "attachment", attachments)
 252   end
 253
 254   def fix_attachments(%{"attachment" => attachment} = object) when is_map(attachment) do
 255     object
 256     |> Map.put("attachment", [attachment])
 257     |> fix_attachments()
 258   end
 259
 260   def fix_attachments(object), do: object
 261
 262   def fix_url(%{"url" => url} = object) when is_map(url) do
 263     Map.put(object, "url", url["href"])
 264   end
 265
 266   def fix_url(%{"type" => object_type, "url" => url} = object)
 267       when object_type in ["Video", "Audio"] and is_list(url) do
 268     first_element = Enum.at(url, 0)
 269
 270     link_element = Enum.find(url, fn x -> is_map(x) and x["mimeType"] == "text/html" end)
 271
 272     object
 273     |> Map.put("attachment", [first_element])
 274     |> Map.put("url", link_element["href"])
 275   end
 276
 277   def fix_url(%{"type" => object_type, "url" => url} = object)
 278       when object_type != "Video" and is_list(url) do
 279     first_element = Enum.at(url, 0)
 280
 281     url_string =
 282       cond do
 283         is_bitstring(first_element) -> first_element
 284         is_map(first_element) -> first_element["href"] || ""
 285         true -> ""
 286       end
 287
 288     Map.put(object, "url", url_string)
 289   end
 290
 291   def fix_url(object), do: object
 292
 293   def fix_emoji(%{"tag" => tags} = object) when is_list(tags) do
 294     emoji =
 295       tags
 296       |> Enum.filter(fn data -> data["type"] == "Emoji" and data["icon"] end)
 297       |> Enum.reduce(%{}, fn data, mapping ->
 298         name = String.trim(data["name"], ":")
 299
 300         Map.put(mapping, name, data["icon"]["url"])
 301       end)
 302
 303     # we merge mastodon and pleroma emoji into a single mapping, to allow for both wire formats
 304     emoji = Map.merge(object["emoji"] || %{}, emoji)
 305
 306     Map.put(object, "emoji", emoji)
 307   end
 308
 309   def fix_emoji(%{"tag" => %{"type" => "Emoji"} = tag} = object) do
 310     name = String.trim(tag["name"], ":")
 311     emoji = %{name => tag["icon"]["url"]}
 312
 313     Map.put(object, "emoji", emoji)
 314   end
 315
 316   def fix_emoji(object), do: object
 317
 318   def fix_tag(%{"tag" => tag} = object) when is_list(tag) do
 319     tags =
 320       tag
 321       |> Enum.filter(fn data -> data["type"] == "Hashtag" and data["name"] end)
 322       |> Enum.map(fn data -> String.slice(data["name"], 1..-1) end)
 323
 324     Map.put(object, "tag", tag ++ tags)
 325   end
 326
 327   def fix_tag(%{"tag" => %{"type" => "Hashtag", "name" => hashtag} = tag} = object) do
 328     combined = [tag, String.slice(hashtag, 1..-1)]
 329
 330     Map.put(object, "tag", combined)
 331   end
 332
 333   def fix_tag(%{"tag" => %{} = tag} = object), do: Map.put(object, "tag", [tag])
 334
 335   def fix_tag(object), do: object
 336
 337   # content map usually only has one language so this will do for now.
 338   def fix_content_map(%{"contentMap" => content_map} = object) do
 339     content_groups = Map.to_list(content_map)
 340     {_, content} = Enum.at(content_groups, 0)
 341
 342     Map.put(object, "content", content)
 343   end
 344
 345   def fix_content_map(object), do: object
 346
 347   def fix_type(object, options \\ [])
 348
 349   def fix_type(%{"inReplyTo" => reply_id, "name" => _} = object, options)
 350       when is_binary(reply_id) do
 351     with true <- Federator.allowed_thread_distance?(options[:depth]),
 352          {:ok, %{data: %{"type" => "Question"} = _} = _} <- get_obj_helper(reply_id, options) do
 353       Map.put(object, "type", "Answer")
 354     else
 355       _ -> object
 356     end
 357   end
 358
 359   def fix_type(object, _), do: object
 360
 361   defp fix_content(%{"mediaType" => "text/markdown", "content" => content} = object)
 362        when is_binary(content) do
 363     html_content =
 364       content
 365       |> Earmark.as_html!(%Earmark.Options{renderer: EarmarkRenderer})
 366       |> Pleroma.HTML.filter_tags()
 367
 368     Map.merge(object, %{"content" => html_content, "mediaType" => "text/html"})
 369   end
 370
 371   defp fix_content(object), do: object
 372
 373   defp mastodon_follow_hack(%{"id" => id, "actor" => follower_id}, followed) do
 374     with true <- id =~ "follows",
 375          %User{local: true} = follower <- User.get_cached_by_ap_id(follower_id),
 376          %Activity{} = activity <- Utils.fetch_latest_follow(follower, followed) do
 377       {:ok, activity}
 378     else
 379       _ -> {:error, nil}
 380     end
 381   end
 382
 383   defp mastodon_follow_hack(_, _), do: {:error, nil}
 384
 385   defp get_follow_activity(follow_object, followed) do
 386     with object_id when not is_nil(object_id) <- Utils.get_ap_id(follow_object),
 387          {_, %Activity{} = activity} <- {:activity, Activity.get_by_ap_id(object_id)} do
 388       {:ok, activity}
 389     else
 390       # Can't find the activity. This might a Mastodon 2.3 "Accept"
 391       {:activity, nil} ->
 392         mastodon_follow_hack(follow_object, followed)
 393
 394       _ ->
 395         {:error, nil}
 396     end
 397   end
 398
 399   # Reduce the object list to find the reported user.
 400   defp get_reported(objects) do
 401     Enum.reduce_while(objects, nil, fn ap_id, _ ->
 402       with %User{} = user <- User.get_cached_by_ap_id(ap_id) do
 403         {:halt, user}
 404       else
 405         _ -> {:cont, nil}
 406       end
 407     end)
 408   end
 409
 410   def handle_incoming(data, options \\ [])
 411
 412   # Flag objects are placed ahead of the ID check because Mastodon 2.8 and earlier send them
 413   # with nil ID.
 414   def handle_incoming(%{"type" => "Flag", "object" => objects, "actor" => actor} = data, _options) do
 415     with context <- data["context"] || Utils.generate_context_id(),
 416          content <- data["content"] || "",
 417          %User{} = actor <- User.get_cached_by_ap_id(actor),
 418          # Reduce the object list to find the reported user.
 419          %User{} = account <- get_reported(objects),
 420          # Remove the reported user from the object list.
 421          statuses <- Enum.filter(objects, fn ap_id -> ap_id != account.ap_id end) do
 422       %{
 423         actor: actor,
 424         context: context,
 425         account: account,
 426         statuses: statuses,
 427         content: content,
 428         additional: %{"cc" => [account.ap_id]}
 429       }
 430       |> ActivityPub.flag()
 431     end
 432   end
 433
 434   # disallow objects with bogus IDs
 435   def handle_incoming(%{"id" => nil}, _options), do: :error
 436   def handle_incoming(%{"id" => ""}, _options), do: :error
 437   # length of https:// = 8, should validate better, but good enough for now.
 438   def handle_incoming(%{"id" => id}, _options) when is_binary(id) and byte_size(id) < 8,
 439     do: :error
 440
 441   # TODO: validate those with a Ecto scheme
 442   # - tags
 443   # - emoji
 444   def handle_incoming(
 445         %{"type" => "Create", "object" => %{"type" => objtype} = object} = data,
 446         options
 447       )
 448       when objtype in ["Article", "Event", "Note", "Video", "Page", "Question", "Answer", "Audio"] do
 449     actor = Containment.get_actor(data)
 450
 451     data =
 452       Map.put(data, "actor", actor)
 453       |> fix_addressing
 454
 455     with nil <- Activity.get_create_by_object_ap_id(object["id"]),
 456          {:ok, %User{} = user} <- User.get_or_fetch_by_ap_id(data["actor"]) do
 457       object = fix_object(object, options)
 458
 459       params = %{
 460         to: data["to"],
 461         object: object,
 462         actor: user,
 463         context: object["conversation"],
 464         local: false,
 465         published: data["published"],
 466         additional:
 467           Map.take(data, [
 468             "cc",
 469             "directMessage",
 470             "id"
 471           ])
 472       }
 473
 474       with {:ok, created_activity} <- ActivityPub.create(params) do
 475         reply_depth = (options[:depth] || 0) + 1
 476
 477         if Federator.allowed_thread_distance?(reply_depth) do
 478           for reply_id <- replies(object) do
 479             Pleroma.Workers.RemoteFetcherWorker.enqueue("fetch_remote", %{
 480               "id" => reply_id,
 481               "depth" => reply_depth
 482             })
 483           end
 484         end
 485
 486         {:ok, created_activity}
 487       end
 488     else
 489       %Activity{} = activity -> {:ok, activity}
 490       _e -> :error
 491     end
 492   end
 493
 494   def handle_incoming(
 495         %{"type" => "Listen", "object" => %{"type" => "Audio"} = object} = data,
 496         options
 497       ) do
 498     actor = Containment.get_actor(data)
 499
 500     data =
 501       Map.put(data, "actor", actor)
 502       |> fix_addressing
 503
 504     with {:ok, %User{} = user} <- User.get_or_fetch_by_ap_id(data["actor"]) do
 505       reply_depth = (options[:depth] || 0) + 1
 506       options = Keyword.put(options, :depth, reply_depth)
 507       object = fix_object(object, options)
 508
 509       params = %{
 510         to: data["to"],
 511         object: object,
 512         actor: user,
 513         context: nil,
 514         local: false,
 515         published: data["published"],
 516         additional: Map.take(data, ["cc", "id"])
 517       }
 518
 519       ActivityPub.listen(params)
 520     else
 521       _e -> :error
 522     end
 523   end
 524
 525   def handle_incoming(
 526         %{"type" => "Follow", "object" => followed, "actor" => follower, "id" => id} = data,
 527         _options
 528       ) do
 529     with %User{local: true} = followed <-
 530            User.get_cached_by_ap_id(Containment.get_actor(%{"actor" => followed})),
 531          {:ok, %User{} = follower} <-
 532            User.get_or_fetch_by_ap_id(Containment.get_actor(%{"actor" => follower})),
 533          {:ok, activity} <- ActivityPub.follow(follower, followed, id, false) do
 534       with deny_follow_blocked <- Pleroma.Config.get([:user, :deny_follow_blocked]),
 535            {_, false} <- {:user_blocked, User.blocks?(followed, follower) && deny_follow_blocked},
 536            {_, false} <- {:user_locked, User.locked?(followed)},
 537            {_, {:ok, follower}} <- {:follow, User.follow(follower, followed)},
 538            {_, {:ok, _}} <-
 539              {:follow_state_update, Utils.update_follow_state_for_all(activity, "accept")},
 540            {:ok, _relationship} <-
 541              FollowingRelationship.update(follower, followed, :follow_accept) do
 542         ActivityPub.accept(%{
 543           to: [follower.ap_id],
 544           actor: followed,
 545           object: data,
 546           local: true
 547         })
 548       else
 549         {:user_blocked, true} ->
 550           {:ok, _} = Utils.update_follow_state_for_all(activity, "reject")
 551           {:ok, _relationship} = FollowingRelationship.update(follower, followed, :follow_reject)
 552
 553           ActivityPub.reject(%{
 554             to: [follower.ap_id],
 555             actor: followed,
 556             object: data,
 557             local: true
 558           })
 559
 560         {:follow, {:error, _}} ->
 561           {:ok, _} = Utils.update_follow_state_for_all(activity, "reject")
 562           {:ok, _relationship} = FollowingRelationship.update(follower, followed, :follow_reject)
 563
 564           ActivityPub.reject(%{
 565             to: [follower.ap_id],
 566             actor: followed,
 567             object: data,
 568             local: true
 569           })
 570
 571         {:user_locked, true} ->
 572           {:ok, _relationship} = FollowingRelationship.update(follower, followed, :follow_pending)
 573           :noop
 574       end
 575
 576       {:ok, activity}
 577     else
 578       _e ->
 579         :error
 580     end
 581   end
 582
 583   def handle_incoming(
 584         %{"type" => "Accept", "object" => follow_object, "actor" => _actor, "id" => id} = data,
 585         _options
 586       ) do
 587     with actor <- Containment.get_actor(data),
 588          {:ok, %User{} = followed} <- User.get_or_fetch_by_ap_id(actor),
 589          {:ok, follow_activity} <- get_follow_activity(follow_object, followed),
 590          {:ok, follow_activity} <- Utils.update_follow_state_for_all(follow_activity, "accept"),
 591          %User{local: true} = follower <- User.get_cached_by_ap_id(follow_activity.data["actor"]),
 592          {:ok, _relationship} <- FollowingRelationship.update(follower, followed, :follow_accept) do
 593       ActivityPub.accept(%{
 594         to: follow_activity.data["to"],
 595         type: "Accept",
 596         actor: followed,
 597         object: follow_activity.data["id"],
 598         local: false,
 599         activity_id: id
 600       })
 601     else
 602       _e -> :error
 603     end
 604   end
 605
 606   def handle_incoming(
 607         %{"type" => "Reject", "object" => follow_object, "actor" => _actor, "id" => id} = data,
 608         _options
 609       ) do
 610     with actor <- Containment.get_actor(data),
 611          {:ok, %User{} = followed} <- User.get_or_fetch_by_ap_id(actor),
 612          {:ok, follow_activity} <- get_follow_activity(follow_object, followed),
 613          {:ok, follow_activity} <- Utils.update_follow_state_for_all(follow_activity, "reject"),
 614          %User{local: true} = follower <- User.get_cached_by_ap_id(follow_activity.data["actor"]),
 615          {:ok, _relationship} <- FollowingRelationship.update(follower, followed, :follow_reject),
 616          {:ok, activity} <-
 617            ActivityPub.reject(%{
 618              to: follow_activity.data["to"],
 619              type: "Reject",
 620              actor: followed,
 621              object: follow_activity.data["id"],
 622              local: false,
 623              activity_id: id
 624            }) do
 625       {:ok, activity}
 626     else
 627       _e -> :error
 628     end
 629   end
 630
 631   @misskey_reactions %{
 632     "like" => "👍",
 633     "love" => "❤️",
 634     "laugh" => "😆",
 635     "hmm" => "🤔",
 636     "surprise" => "😮",
 637     "congrats" => "🎉",
 638     "angry" => "💢",
 639     "confused" => "😥",
 640     "rip" => "😇",
 641     "pudding" => "🍮",
 642     "star" => "⭐"
 643   }
 644
 645   @doc "Rewrite misskey likes into EmojiReacts"
 646   def handle_incoming(
 647         %{
 648           "type" => "Like",
 649           "_misskey_reaction" => reaction
 650         } = data,
 651         options
 652       ) do
 653     data
 654     |> Map.put("type", "EmojiReact")
 655     |> Map.put("content", @misskey_reactions[reaction] || reaction)
 656     |> handle_incoming(options)
 657   end
 658
 659   def handle_incoming(%{"type" => type} = data, _options) when type in ["Like", "EmojiReact"] do
 660     with :ok <- ObjectValidator.fetch_actor_and_object(data),
 661          {:ok, activity, _meta} <-
 662            Pipeline.common_pipeline(data, local: false) do
 663       {:ok, activity}
 664     else
 665       e -> {:error, e}
 666     end
 667   end
 668
 669   def handle_incoming(
 670         %{"type" => "Announce", "object" => object_id, "actor" => _actor, "id" => id} = data,
 671         _options
 672       ) do
 673     with actor <- Containment.get_actor(data),
 674          {:ok, %User{} = actor} <- User.get_or_fetch_by_ap_id(actor),
 675          {:ok, object} <- get_embedded_obj_helper(object_id, actor),
 676          public <- Visibility.is_public?(data),
 677          {:ok, activity, _object} <- ActivityPub.announce(actor, object, id, false, public) do
 678       {:ok, activity}
 679     else
 680       _e -> :error
 681     end
 682   end
 683
 684   def handle_incoming(
 685         %{"type" => "Update", "object" => %{"type" => object_type} = object, "actor" => actor_id} =
 686           data,
 687         _options
 688       )
 689       when object_type in [
 690              "Person",
 691              "Application",
 692              "Service",
 693              "Organization"
 694            ] do
 695     with %User{ap_id: ^actor_id} = actor <- User.get_cached_by_ap_id(object["id"]) do
 696       {:ok, new_user_data} = ActivityPub.user_data_from_user_object(object)
 697
 698       actor
 699       |> User.remote_user_changeset(new_user_data)
 700       |> User.update_and_set_cache()
 701
 702       ActivityPub.update(%{
 703         local: false,
 704         to: data["to"] || [],
 705         cc: data["cc"] || [],
 706         object: object,
 707         actor: actor_id,
 708         activity_id: data["id"]
 709       })
 710     else
 711       e ->
 712         Logger.error(e)
 713         :error
 714     end
 715   end
 716
 717   def handle_incoming(
 718         %{"type" => "Delete"} = data,
 719         _options
 720       ) do
 721     with {:ok, activity, _} <- Pipeline.common_pipeline(data, local: false) do
 722       {:ok, activity}
 723     end
 724   end
 725
 726   def handle_incoming(
 727         %{
 728           "type" => "Undo",
 729           "object" => %{"type" => "Follow", "object" => followed},
 730           "actor" => follower,
 731           "id" => id
 732         } = _data,
 733         _options
 734       ) do
 735     with %User{local: true} = followed <- User.get_cached_by_ap_id(followed),
 736          {:ok, %User{} = follower} <- User.get_or_fetch_by_ap_id(follower),
 737          {:ok, activity} <- ActivityPub.unfollow(follower, followed, id, false) do
 738       User.unfollow(follower, followed)
 739       {:ok, activity}
 740     else
 741       _e -> :error
 742     end
 743   end
 744
 745   def handle_incoming(
 746         %{
 747           "type" => "Undo",
 748           "object" => %{"type" => type}
 749         } = data,
 750         _options
 751       )
 752       when type in ["Like", "EmojiReact", "Announce", "Block"] do
 753     with {:ok, activity, _} <- Pipeline.common_pipeline(data, local: false) do
 754       {:ok, activity}
 755     end
 756   end
 757
 758   # For Undos that don't have the complete object attached, try to find it in our database.
 759   def handle_incoming(
 760         %{
 761           "type" => "Undo",
 762           "object" => object
 763         } = activity,
 764         options
 765       )
 766       when is_binary(object) do
 767     with %Activity{data: data} <- Activity.get_by_ap_id(object) do
 768       activity
 769       |> Map.put("object", data)
 770       |> handle_incoming(options)
 771     else
 772       _e -> :error
 773     end
 774   end
 775
 776   def handle_incoming(
 777         %{"type" => "Block", "object" => blocked, "actor" => blocker, "id" => id} = _data,
 778         _options
 779       ) do
 780     with %User{local: true} = blocked = User.get_cached_by_ap_id(blocked),
 781          {:ok, %User{} = blocker} = User.get_or_fetch_by_ap_id(blocker),
 782          {:ok, activity} <- ActivityPub.block(blocker, blocked, id, false) do
 783       User.unfollow(blocker, blocked)
 784       User.block(blocker, blocked)
 785       {:ok, activity}
 786     else
 787       _e -> :error
 788     end
 789   end
 790
 791   def handle_incoming(
 792         %{
 793           "type" => "Move",
 794           "actor" => origin_actor,
 795           "object" => origin_actor,
 796           "target" => target_actor
 797         },
 798         _options
 799       ) do
 800     with %User{} = origin_user <- User.get_cached_by_ap_id(origin_actor),
 801          {:ok, %User{} = target_user} <- User.get_or_fetch_by_ap_id(target_actor),
 802          true <- origin_actor in target_user.also_known_as do
 803       ActivityPub.move(origin_user, target_user, false)
 804     else
 805       _e -> :error
 806     end
 807   end
 808
 809   def handle_incoming(_, _), do: :error
 810
 811   @spec get_obj_helper(String.t(), Keyword.t()) :: {:ok, Object.t()} | nil
 812   def get_obj_helper(id, options \\ []) do
 813     case Object.normalize(id, true, options) do
 814       %Object{} = object -> {:ok, object}
 815       _ -> nil
 816     end
 817   end
 818
 819   @spec get_embedded_obj_helper(String.t() | Object.t(), User.t()) :: {:ok, Object.t()} | nil
 820   def get_embedded_obj_helper(%{"attributedTo" => attributed_to, "id" => object_id} = data, %User{
 821         ap_id: ap_id
 822       })
 823       when attributed_to == ap_id do
 824     with {:ok, activity} <-
 825            handle_incoming(%{
 826              "type" => "Create",
 827              "to" => data["to"],
 828              "cc" => data["cc"],
 829              "actor" => attributed_to,
 830              "object" => data
 831            }) do
 832       {:ok, Object.normalize(activity)}
 833     else
 834       _ -> get_obj_helper(object_id)
 835     end
 836   end
 837
 838   def get_embedded_obj_helper(object_id, _) do
 839     get_obj_helper(object_id)
 840   end
 841
 842   def set_reply_to_uri(%{"inReplyTo" => in_reply_to} = object) when is_binary(in_reply_to) do
 843     with false <- String.starts_with?(in_reply_to, "http"),
 844          {:ok, %{data: replied_to_object}} <- get_obj_helper(in_reply_to) do
 845       Map.put(object, "inReplyTo", replied_to_object["external_url"] || in_reply_to)
 846     else
 847       _e -> object
 848     end
 849   end
 850
 851   def set_reply_to_uri(obj), do: obj
 852
 853   @doc """
 854   Serialized Mastodon-compatible `replies` collection containing _self-replies_.
 855   Based on Mastodon's ActivityPub::NoteSerializer#replies.
 856   """
 857   def set_replies(obj_data) do
 858     replies_uris =
 859       with limit when limit > 0 <-
 860              Pleroma.Config.get([:activitypub, :note_replies_output_limit], 0),
 861            %Object{} = object <- Object.get_cached_by_ap_id(obj_data["id"]) do
 862         object
 863         |> Object.self_replies()
 864         |> select([o], fragment("?->>'id'", o.data))
 865         |> limit(^limit)
 866         |> Repo.all()
 867       else
 868         _ -> []
 869       end
 870
 871     set_replies(obj_data, replies_uris)
 872   end
 873
 874   defp set_replies(obj, []) do
 875     obj
 876   end
 877
 878   defp set_replies(obj, replies_uris) do
 879     replies_collection = %{
 880       "type" => "Collection",
 881       "items" => replies_uris
 882     }
 883
 884     Map.merge(obj, %{"replies" => replies_collection})
 885   end
 886
 887   def replies(%{"replies" => %{"first" => %{"items" => items}}}) when not is_nil(items) do
 888     items
 889   end
 890
 891   def replies(%{"replies" => %{"items" => items}}) when not is_nil(items) do
 892     items
 893   end
 894
 895   def replies(_), do: []
 896
 897   # Prepares the object of an outgoing create activity.
 898   def prepare_object(object) do
 899     object
 900     |> set_sensitive
 901     |> add_hashtags
 902     |> add_mention_tags
 903     |> add_emoji_tags
 904     |> add_attributed_to
 905     |> prepare_attachments
 906     |> set_conversation
 907     |> set_reply_to_uri
 908     |> set_replies
 909     |> strip_internal_fields
 910     |> strip_internal_tags
 911     |> set_type
 912   end
 913
 914   #  @doc
 915   #  """
 916   #  internal -> Mastodon
 917   #  """
 918
 919   def prepare_outgoing(%{"type" => activity_type, "object" => object_id} = data)
 920       when activity_type in ["Create", "Listen"] do
 921     object =
 922       object_id
 923       |> Object.normalize()
 924       |> Map.get(:data)
 925       |> prepare_object
 926
 927     data =
 928       data
 929       |> Map.put("object", object)
 930       |> Map.merge(Utils.make_json_ld_header())
 931       |> Map.delete("bcc")
 932
 933     {:ok, data}
 934   end
 935
 936   def prepare_outgoing(%{"type" => "Announce", "actor" => ap_id, "object" => object_id} = data) do
 937     object =
 938       object_id
 939       |> Object.normalize()
 940
 941     data =
 942       if Visibility.is_private?(object) && object.data["actor"] == ap_id do
 943         data |> Map.put("object", object |> Map.get(:data) |> prepare_object)
 944       else
 945         data |> maybe_fix_object_url
 946       end
 947
 948     data =
 949       data
 950       |> strip_internal_fields
 951       |> Map.merge(Utils.make_json_ld_header())
 952       |> Map.delete("bcc")
 953
 954     {:ok, data}
 955   end
 956
 957   # Mastodon Accept/Reject requires a non-normalized object containing the actor URIs,
 958   # because of course it does.
 959   def prepare_outgoing(%{"type" => "Accept"} = data) do
 960     with follow_activity <- Activity.normalize(data["object"]) do
 961       object = %{
 962         "actor" => follow_activity.actor,
 963         "object" => follow_activity.data["object"],
 964         "id" => follow_activity.data["id"],
 965         "type" => "Follow"
 966       }
 967
 968       data =
 969         data
 970         |> Map.put("object", object)
 971         |> Map.merge(Utils.make_json_ld_header())
 972
 973       {:ok, data}
 974     end
 975   end
 976
 977   def prepare_outgoing(%{"type" => "Reject"} = data) do
 978     with follow_activity <- Activity.normalize(data["object"]) do
 979       object = %{
 980         "actor" => follow_activity.actor,
 981         "object" => follow_activity.data["object"],
 982         "id" => follow_activity.data["id"],
 983         "type" => "Follow"
 984       }
 985
 986       data =
 987         data
 988         |> Map.put("object", object)
 989         |> Map.merge(Utils.make_json_ld_header())
 990
 991       {:ok, data}
 992     end
 993   end
 994
 995   def prepare_outgoing(%{"type" => _type} = data) do
 996     data =
 997       data
 998       |> strip_internal_fields
 999       |> maybe_fix_object_url
1000       |> Map.merge(Utils.make_json_ld_header())
1001
1002     {:ok, data}
1003   end
1004
1005   def maybe_fix_object_url(%{"object" => object} = data) when is_binary(object) do
1006     with false <- String.starts_with?(object, "http"),
1007          {:fetch, {:ok, relative_object}} <- {:fetch, get_obj_helper(object)},
1008          %{data: %{"external_url" => external_url}} when not is_nil(external_url) <-
1009            relative_object do
1010       Map.put(data, "object", external_url)
1011     else
1012       {:fetch, e} ->
1013         Logger.error("Couldn't fetch #{object} #{inspect(e)}")
1014         data
1015
1016       _ ->
1017         data
1018     end
1019   end
1020
1021   def maybe_fix_object_url(data), do: data
1022
1023   def add_hashtags(object) do
1024     tags =
1025       (object["tag"] || [])
1026       |> Enum.map(fn
1027         # Expand internal representation tags into AS2 tags.
1028         tag when is_binary(tag) ->
1029           %{
1030             "href" => Pleroma.Web.Endpoint.url() <> "/tags/#{tag}",
1031             "name" => "##{tag}",
1032             "type" => "Hashtag"
1033           }
1034
1035         # Do not process tags which are already AS2 tag objects.
1036         tag when is_map(tag) ->
1037           tag
1038       end)
1039
1040     Map.put(object, "tag", tags)
1041   end
1042
1043   def add_mention_tags(object) do
1044     {enabled_receivers, disabled_receivers} = Utils.get_notified_from_object(object)
1045     potential_receivers = enabled_receivers ++ disabled_receivers
1046     mentions = Enum.map(potential_receivers, &build_mention_tag/1)
1047
1048     tags = object["tag"] || []
1049     Map.put(object, "tag", tags ++ mentions)
1050   end
1051
1052   defp build_mention_tag(%{ap_id: ap_id, nickname: nickname} = _) do
1053     %{"type" => "Mention", "href" => ap_id, "name" => "@#{nickname}"}
1054   end
1055
1056   def take_emoji_tags(%User{emoji: emoji}) do
1057     emoji
1058     |> Map.to_list()
1059     |> Enum.map(&build_emoji_tag/1)
1060   end
1061
1062   # TODO: we should probably send mtime instead of unix epoch time for updated
1063   def add_emoji_tags(%{"emoji" => emoji} = object) do
1064     tags = object["tag"] || []
1065
1066     out = Enum.map(emoji, &build_emoji_tag/1)
1067
1068     Map.put(object, "tag", tags ++ out)
1069   end
1070
1071   def add_emoji_tags(object), do: object
1072
1073   defp build_emoji_tag({name, url}) do
1074     %{
1075       "icon" => %{"url" => url, "type" => "Image"},
1076       "name" => ":" <> name <> ":",
1077       "type" => "Emoji",
1078       "updated" => "1970-01-01T00:00:00Z",
1079       "id" => url
1080     }
1081   end
1082
1083   def set_conversation(object) do
1084     Map.put(object, "conversation", object["context"])
1085   end
1086
1087   def set_sensitive(%{"sensitive" => true} = object) do
1088     object
1089   end
1090
1091   def set_sensitive(object) do
1092     tags = object["tag"] || []
1093     Map.put(object, "sensitive", "nsfw" in tags)
1094   end
1095
1096   def set_type(%{"type" => "Answer"} = object) do
1097     Map.put(object, "type", "Note")
1098   end
1099
1100   def set_type(object), do: object
1101
1102   def add_attributed_to(object) do
1103     attributed_to = object["attributedTo"] || object["actor"]
1104     Map.put(object, "attributedTo", attributed_to)
1105   end
1106
1107   def prepare_attachments(object) do
1108     attachments =
1109       object
1110       |> Map.get("attachment", [])
1111       |> Enum.map(fn data ->
1112         [%{"mediaType" => media_type, "href" => href} | _] = data["url"]
1113
1114         %{
1115           "url" => href,
1116           "mediaType" => media_type,
1117           "name" => data["name"],
1118           "type" => "Document"
1119         }
1120       end)
1121
1122     Map.put(object, "attachment", attachments)
1123   end
1124
1125   def strip_internal_fields(object) do
1126     Map.drop(object, Pleroma.Constants.object_internal_fields())
1127   end
1128
1129   defp strip_internal_tags(%{"tag" => tags} = object) do
1130     tags = Enum.filter(tags, fn x -> is_map(x) end)
1131
1132     Map.put(object, "tag", tags)
1133   end
1134
1135   defp strip_internal_tags(object), do: object
1136
1137   def perform(:user_upgrade, user) do
1138     # we pass a fake user so that the followers collection is stripped away
1139     old_follower_address = User.ap_followers(%User{nickname: user.nickname})
1140
1141     from(
1142       a in Activity,
1143       where: ^old_follower_address in a.recipients,
1144       update: [
1145         set: [
1146           recipients:
1147             fragment(
1148               "array_replace(?,?,?)",
1149               a.recipients,
1150               ^old_follower_address,
1151               ^user.follower_address
1152             )
1153         ]
1154       ]
1155     )
1156     |> Repo.update_all([])
1157   end
1158
1159   def upgrade_user_from_ap_id(ap_id) do
1160     with %User{local: false} = user <- User.get_cached_by_ap_id(ap_id),
1161          {:ok, data} <- ActivityPub.fetch_and_prepare_user_from_ap_id(ap_id),
1162          {:ok, user} <- update_user(user, data) do
1163       TransmogrifierWorker.enqueue("user_upgrade", %{"user_id" => user.id})
1164       {:ok, user}
1165     else
1166       %User{} = user -> {:ok, user}
1167       e -> e
1168     end
1169   end
1170
1171   defp update_user(user, data) do
1172     user
1173     |> User.remote_user_changeset(data)
1174     |> User.update_and_set_cache()
1175   end
1176
1177   def maybe_fix_user_url(%{"url" => url} = data) when is_map(url) do
1178     Map.put(data, "url", url["href"])
1179   end
1180
1181   def maybe_fix_user_url(data), do: data
1182
1183   def maybe_fix_user_object(data), do: maybe_fix_user_url(data)
1184 end