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   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.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.FollowingRelationship
  11   alias Pleroma.Object
  12   alias Pleroma.Object.Containment
  13   alias Pleroma.Repo
  14   alias Pleroma.User
  15   alias Pleroma.Web.ActivityPub.ActivityPub
  16   alias Pleroma.Web.ActivityPub.Utils
  17   alias Pleroma.Web.ActivityPub.Visibility
  18   alias Pleroma.Web.Federator
  19   alias Pleroma.Workers.TransmogrifierWorker
  20
  21   import Ecto.Query
  22
  23   require Logger
  24   require Pleroma.Constants
  25
  26   @doc """
  27   Modifies an incoming AP object (mastodon format) to our internal format.
  28   """
  29   def fix_object(object, options \\ []) do
  30     object
  31     |> strip_internal_fields
  32     |> fix_actor
  33     |> fix_url
  34     |> fix_attachments
  35     |> fix_context
  36     |> fix_in_reply_to(options)
  37     |> fix_emoji
  38     |> fix_tag
  39     |> fix_content_map
  40     |> fix_addressing
  41     |> fix_summary
  42     |> fix_type(options)
  43   end
  44
  45   def fix_summary(%{"summary" => nil} = object) do
  46     Map.put(object, "summary", "")
  47   end
  48
  49   def fix_summary(%{"summary" => _} = object) do
  50     # summary is present, nothing to do
  51     object
  52   end
  53
  54   def fix_summary(object), do: Map.put(object, "summary", "")
  55
  56   def fix_addressing_list(map, field) do
  57     cond do
  58       is_binary(map[field]) ->
  59         Map.put(map, field, [map[field]])
  60
  61       is_nil(map[field]) ->
  62         Map.put(map, field, [])
  63
  64       true ->
  65         map
  66     end
  67   end
  68
  69   def fix_explicit_addressing(
  70         %{"to" => to, "cc" => cc} = object,
  71         explicit_mentions,
  72         follower_collection
  73       ) do
  74     explicit_to = Enum.filter(to, fn x -> x in explicit_mentions end)
  75
  76     explicit_cc = Enum.filter(to, fn x -> x not in explicit_mentions end)
  77
  78     final_cc =
  79       (cc ++ explicit_cc)
  80       |> Enum.reject(fn x -> String.ends_with?(x, "/followers") and x != follower_collection end)
  81       |> Enum.uniq()
  82
  83     object
  84     |> Map.put("to", explicit_to)
  85     |> Map.put("cc", final_cc)
  86   end
  87
  88   def fix_explicit_addressing(object, _explicit_mentions, _followers_collection), do: object
  89
  90   # if directMessage flag is set to true, leave the addressing alone
  91   def fix_explicit_addressing(%{"directMessage" => true} = object), do: object
  92
  93   def fix_explicit_addressing(object) do
  94     explicit_mentions = Utils.determine_explicit_mentions(object)
  95
  96     %User{follower_address: follower_collection} =
  97       object
  98       |> Containment.get_actor()
  99       |> User.get_cached_by_ap_id()
 100
 101     explicit_mentions =
 102       explicit_mentions ++
 103         [
 104           Pleroma.Constants.as_public(),
 105           follower_collection
 106         ]
 107
 108     fix_explicit_addressing(object, explicit_mentions, follower_collection)
 109   end
 110
 111   # if as:Public is addressed, then make sure the followers collection is also addressed
 112   # so that the activities will be delivered to local users.
 113   def fix_implicit_addressing(%{"to" => to, "cc" => cc} = object, followers_collection) do
 114     recipients = to ++ cc
 115
 116     if followers_collection not in recipients do
 117       cond do
 118         Pleroma.Constants.as_public() in cc ->
 119           to = to ++ [followers_collection]
 120           Map.put(object, "to", to)
 121
 122         Pleroma.Constants.as_public() in to ->
 123           cc = cc ++ [followers_collection]
 124           Map.put(object, "cc", cc)
 125
 126         true ->
 127           object
 128       end
 129     else
 130       object
 131     end
 132   end
 133
 134   def fix_implicit_addressing(object, _), do: object
 135
 136   def fix_addressing(object) do
 137     {:ok, %User{} = user} = User.get_or_fetch_by_ap_id(object["actor"])
 138     followers_collection = User.ap_followers(user)
 139
 140     object
 141     |> fix_addressing_list("to")
 142     |> fix_addressing_list("cc")
 143     |> fix_addressing_list("bto")
 144     |> fix_addressing_list("bcc")
 145     |> fix_explicit_addressing()
 146     |> fix_implicit_addressing(followers_collection)
 147   end
 148
 149   def fix_actor(%{"attributedTo" => actor} = object) do
 150     Map.put(object, "actor", Containment.get_actor(%{"actor" => actor}))
 151   end
 152
 153   def fix_in_reply_to(object, options \\ [])
 154
 155   def fix_in_reply_to(%{"inReplyTo" => in_reply_to} = object, options)
 156       when not is_nil(in_reply_to) do
 157     in_reply_to_id = prepare_in_reply_to(in_reply_to)
 158     object = Map.put(object, "inReplyToAtomUri", in_reply_to_id)
 159     depth = (options[:depth] || 0) + 1
 160
 161     if Federator.allowed_thread_distance?(depth) do
 162       with {:ok, replied_object} <- get_obj_helper(in_reply_to_id, options),
 163            %Activity{} <- Activity.get_create_by_object_ap_id(replied_object.data["id"]) do
 164         object
 165         |> Map.put("inReplyTo", replied_object.data["id"])
 166         |> Map.put("inReplyToAtomUri", object["inReplyToAtomUri"] || in_reply_to_id)
 167         |> Map.put("conversation", replied_object.data["context"] || object["conversation"])
 168         |> Map.put("context", replied_object.data["context"] || object["conversation"])
 169       else
 170         e ->
 171           Logger.error("Couldn't fetch #{inspect(in_reply_to_id)}, error: #{inspect(e)}")
 172           object
 173       end
 174     else
 175       object
 176     end
 177   end
 178
 179   def fix_in_reply_to(object, _options), do: object
 180
 181   defp prepare_in_reply_to(in_reply_to) do
 182     cond do
 183       is_bitstring(in_reply_to) ->
 184         in_reply_to
 185
 186       is_map(in_reply_to) && is_bitstring(in_reply_to["id"]) ->
 187         in_reply_to["id"]
 188
 189       is_list(in_reply_to) && is_bitstring(Enum.at(in_reply_to, 0)) ->
 190         Enum.at(in_reply_to, 0)
 191
 192       true ->
 193         ""
 194     end
 195   end
 196
 197   def fix_context(object) do
 198     context = object["context"] || object["conversation"] || Utils.generate_context_id()
 199
 200     object
 201     |> Map.put("context", context)
 202     |> Map.put("conversation", context)
 203   end
 204
 205   def fix_attachments(%{"attachment" => attachment} = object) when is_list(attachment) do
 206     attachments =
 207       Enum.map(attachment, fn data ->
 208         media_type = data["mediaType"] || data["mimeType"]
 209         href = data["url"] || data["href"]
 210         url = [%{"type" => "Link", "mediaType" => media_type, "href" => href}]
 211
 212         data
 213         |> Map.put("mediaType", media_type)
 214         |> Map.put("url", url)
 215       end)
 216
 217     Map.put(object, "attachment", attachments)
 218   end
 219
 220   def fix_attachments(%{"attachment" => attachment} = object) when is_map(attachment) do
 221     object
 222     |> Map.put("attachment", [attachment])
 223     |> fix_attachments()
 224   end
 225
 226   def fix_attachments(object), do: object
 227
 228   def fix_url(%{"url" => url} = object) when is_map(url) do
 229     Map.put(object, "url", url["href"])
 230   end
 231
 232   def fix_url(%{"type" => "Video", "url" => url} = object) when is_list(url) do
 233     first_element = Enum.at(url, 0)
 234
 235     link_element = Enum.find(url, fn x -> is_map(x) and x["mimeType"] == "text/html" end)
 236
 237     object
 238     |> Map.put("attachment", [first_element])
 239     |> Map.put("url", link_element["href"])
 240   end
 241
 242   def fix_url(%{"type" => object_type, "url" => url} = object)
 243       when object_type != "Video" and is_list(url) do
 244     first_element = Enum.at(url, 0)
 245
 246     url_string =
 247       cond do
 248         is_bitstring(first_element) -> first_element
 249         is_map(first_element) -> first_element["href"] || ""
 250         true -> ""
 251       end
 252
 253     Map.put(object, "url", url_string)
 254   end
 255
 256   def fix_url(object), do: object
 257
 258   def fix_emoji(%{"tag" => tags} = object) when is_list(tags) do
 259     emoji =
 260       tags
 261       |> Enum.filter(fn data -> data["type"] == "Emoji" and data["icon"] end)
 262       |> Enum.reduce(%{}, fn data, mapping ->
 263         name = String.trim(data["name"], ":")
 264
 265         Map.put(mapping, name, data["icon"]["url"])
 266       end)
 267
 268     # we merge mastodon and pleroma emoji into a single mapping, to allow for both wire formats
 269     emoji = Map.merge(object["emoji"] || %{}, emoji)
 270
 271     Map.put(object, "emoji", emoji)
 272   end
 273
 274   def fix_emoji(%{"tag" => %{"type" => "Emoji"} = tag} = object) do
 275     name = String.trim(tag["name"], ":")
 276     emoji = %{name => tag["icon"]["url"]}
 277
 278     Map.put(object, "emoji", emoji)
 279   end
 280
 281   def fix_emoji(object), do: object
 282
 283   def fix_tag(%{"tag" => tag} = object) when is_list(tag) do
 284     tags =
 285       tag
 286       |> Enum.filter(fn data -> data["type"] == "Hashtag" and data["name"] end)
 287       |> Enum.map(fn data -> String.slice(data["name"], 1..-1) end)
 288
 289     Map.put(object, "tag", tag ++ tags)
 290   end
 291
 292   def fix_tag(%{"tag" => %{"type" => "Hashtag", "name" => hashtag} = tag} = object) do
 293     combined = [tag, String.slice(hashtag, 1..-1)]
 294
 295     Map.put(object, "tag", combined)
 296   end
 297
 298   def fix_tag(%{"tag" => %{} = tag} = object), do: Map.put(object, "tag", [tag])
 299
 300   def fix_tag(object), do: object
 301
 302   # content map usually only has one language so this will do for now.
 303   def fix_content_map(%{"contentMap" => content_map} = object) do
 304     content_groups = Map.to_list(content_map)
 305     {_, content} = Enum.at(content_groups, 0)
 306
 307     Map.put(object, "content", content)
 308   end
 309
 310   def fix_content_map(object), do: object
 311
 312   def fix_type(object, options \\ [])
 313
 314   def fix_type(%{"inReplyTo" => reply_id, "name" => _} = object, options)
 315       when is_binary(reply_id) do
 316     with true <- Federator.allowed_thread_distance?(options[:depth]),
 317          {:ok, %{data: %{"type" => "Question"} = _} = _} <- get_obj_helper(reply_id, options) do
 318       Map.put(object, "type", "Answer")
 319     else
 320       _ -> object
 321     end
 322   end
 323
 324   def fix_type(object, _), do: object
 325
 326   defp mastodon_follow_hack(%{"id" => id, "actor" => follower_id}, followed) do
 327     with true <- id =~ "follows",
 328          %User{local: true} = follower <- User.get_cached_by_ap_id(follower_id),
 329          %Activity{} = activity <- Utils.fetch_latest_follow(follower, followed) do
 330       {:ok, activity}
 331     else
 332       _ -> {:error, nil}
 333     end
 334   end
 335
 336   defp mastodon_follow_hack(_, _), do: {:error, nil}
 337
 338   defp get_follow_activity(follow_object, followed) do
 339     with object_id when not is_nil(object_id) <- Utils.get_ap_id(follow_object),
 340          {_, %Activity{} = activity} <- {:activity, Activity.get_by_ap_id(object_id)} do
 341       {:ok, activity}
 342     else
 343       # Can't find the activity. This might a Mastodon 2.3 "Accept"
 344       {:activity, nil} ->
 345         mastodon_follow_hack(follow_object, followed)
 346
 347       _ ->
 348         {:error, nil}
 349     end
 350   end
 351
 352   # Reduce the object list to find the reported user.
 353   defp get_reported(objects) do
 354     Enum.reduce_while(objects, nil, fn ap_id, _ ->
 355       with %User{} = user <- User.get_cached_by_ap_id(ap_id) do
 356         {:halt, user}
 357       else
 358         _ -> {:cont, nil}
 359       end
 360     end)
 361   end
 362
 363   def handle_incoming(data, options \\ [])
 364
 365   # Flag objects are placed ahead of the ID check because Mastodon 2.8 and earlier send them
 366   # with nil ID.
 367   def handle_incoming(%{"type" => "Flag", "object" => objects, "actor" => actor} = data, _options) do
 368     with context <- data["context"] || Utils.generate_context_id(),
 369          content <- data["content"] || "",
 370          %User{} = actor <- User.get_cached_by_ap_id(actor),
 371          # Reduce the object list to find the reported user.
 372          %User{} = account <- get_reported(objects),
 373          # Remove the reported user from the object list.
 374          statuses <- Enum.filter(objects, fn ap_id -> ap_id != account.ap_id end) do
 375       %{
 376         actor: actor,
 377         context: context,
 378         account: account,
 379         statuses: statuses,
 380         content: content,
 381         additional: %{"cc" => [account.ap_id]}
 382       }
 383       |> ActivityPub.flag()
 384     end
 385   end
 386
 387   # disallow objects with bogus IDs
 388   def handle_incoming(%{"id" => nil}, _options), do: :error
 389   def handle_incoming(%{"id" => ""}, _options), do: :error
 390   # length of https:// = 8, should validate better, but good enough for now.
 391   def handle_incoming(%{"id" => id}, _options) when is_binary(id) and byte_size(id) < 8,
 392     do: :error
 393
 394   # TODO: validate those with a Ecto scheme
 395   # - tags
 396   # - emoji
 397   def handle_incoming(
 398         %{"type" => "Create", "object" => %{"type" => objtype} = object} = data,
 399         options
 400       )
 401       when objtype in ["Article", "Event", "Note", "Video", "Page", "Question", "Answer"] do
 402     actor = Containment.get_actor(data)
 403
 404     data =
 405       Map.put(data, "actor", actor)
 406       |> fix_addressing
 407
 408     with nil <- Activity.get_create_by_object_ap_id(object["id"]),
 409          {:ok, %User{} = user} <- User.get_or_fetch_by_ap_id(data["actor"]) do
 410       object = fix_object(object, options)
 411
 412       params = %{
 413         to: data["to"],
 414         object: object,
 415         actor: user,
 416         context: object["conversation"],
 417         local: false,
 418         published: data["published"],
 419         additional:
 420           Map.take(data, [
 421             "cc",
 422             "directMessage",
 423             "id"
 424           ])
 425       }
 426
 427       with {:ok, created_activity} <- ActivityPub.create(params) do
 428         reply_depth = (options[:depth] || 0) + 1
 429
 430         if Federator.allowed_thread_distance?(reply_depth) do
 431           for reply_id <- replies(object) do
 432             Pleroma.Workers.RemoteFetcherWorker.enqueue("fetch_remote", %{
 433               "id" => reply_id,
 434               "depth" => reply_depth
 435             })
 436           end
 437         end
 438
 439         {:ok, created_activity}
 440       end
 441     else
 442       %Activity{} = activity -> {:ok, activity}
 443       _e -> :error
 444     end
 445   end
 446
 447   def handle_incoming(
 448         %{"type" => "Listen", "object" => %{"type" => "Audio"} = object} = data,
 449         options
 450       ) do
 451     actor = Containment.get_actor(data)
 452
 453     data =
 454       Map.put(data, "actor", actor)
 455       |> fix_addressing
 456
 457     with {:ok, %User{} = user} <- User.get_or_fetch_by_ap_id(data["actor"]) do
 458       reply_depth = (options[:depth] || 0) + 1
 459       options = Keyword.put(options, :depth, reply_depth)
 460       object = fix_object(object, options)
 461
 462       params = %{
 463         to: data["to"],
 464         object: object,
 465         actor: user,
 466         context: nil,
 467         local: false,
 468         published: data["published"],
 469         additional: Map.take(data, ["cc", "id"])
 470       }
 471
 472       ActivityPub.listen(params)
 473     else
 474       _e -> :error
 475     end
 476   end
 477
 478   def handle_incoming(
 479         %{"type" => "Follow", "object" => followed, "actor" => follower, "id" => id} = data,
 480         _options
 481       ) do
 482     with %User{local: true} = followed <-
 483            User.get_cached_by_ap_id(Containment.get_actor(%{"actor" => followed})),
 484          {:ok, %User{} = follower} <-
 485            User.get_or_fetch_by_ap_id(Containment.get_actor(%{"actor" => follower})),
 486          {:ok, activity} <- ActivityPub.follow(follower, followed, id, false) do
 487       with deny_follow_blocked <- Pleroma.Config.get([:user, :deny_follow_blocked]),
 488            {_, false} <- {:user_blocked, User.blocks?(followed, follower) && deny_follow_blocked},
 489            {_, false} <- {:user_locked, User.locked?(followed)},
 490            {_, {:ok, follower}} <- {:follow, User.follow(follower, followed)},
 491            {_, {:ok, _}} <-
 492              {:follow_state_update, Utils.update_follow_state_for_all(activity, "accept")},
 493            {:ok, _relationship} <- FollowingRelationship.update(follower, followed, "accept") do
 494         ActivityPub.accept(%{
 495           to: [follower.ap_id],
 496           actor: followed,
 497           object: data,
 498           local: true
 499         })
 500       else
 501         {:user_blocked, true} ->
 502           {:ok, _} = Utils.update_follow_state_for_all(activity, "reject")
 503           {:ok, _relationship} = FollowingRelationship.update(follower, followed, "reject")
 504
 505           ActivityPub.reject(%{
 506             to: [follower.ap_id],
 507             actor: followed,
 508             object: data,
 509             local: true
 510           })
 511
 512         {:follow, {:error, _}} ->
 513           {:ok, _} = Utils.update_follow_state_for_all(activity, "reject")
 514           {:ok, _relationship} = FollowingRelationship.update(follower, followed, "reject")
 515
 516           ActivityPub.reject(%{
 517             to: [follower.ap_id],
 518             actor: followed,
 519             object: data,
 520             local: true
 521           })
 522
 523         {:user_locked, true} ->
 524           {:ok, _relationship} = FollowingRelationship.update(follower, followed, "pending")
 525           :noop
 526       end
 527
 528       {:ok, activity}
 529     else
 530       _e ->
 531         :error
 532     end
 533   end
 534
 535   def handle_incoming(
 536         %{"type" => "Accept", "object" => follow_object, "actor" => _actor, "id" => id} = data,
 537         _options
 538       ) do
 539     with actor <- Containment.get_actor(data),
 540          {:ok, %User{} = followed} <- User.get_or_fetch_by_ap_id(actor),
 541          {:ok, follow_activity} <- get_follow_activity(follow_object, followed),
 542          {:ok, follow_activity} <- Utils.update_follow_state_for_all(follow_activity, "accept"),
 543          %User{local: true} = follower <- User.get_cached_by_ap_id(follow_activity.data["actor"]),
 544          {:ok, _relationship} <- FollowingRelationship.update(follower, followed, "accept") do
 545       ActivityPub.accept(%{
 546         to: follow_activity.data["to"],
 547         type: "Accept",
 548         actor: followed,
 549         object: follow_activity.data["id"],
 550         local: false,
 551         activity_id: id
 552       })
 553     else
 554       _e -> :error
 555     end
 556   end
 557
 558   def handle_incoming(
 559         %{"type" => "Reject", "object" => follow_object, "actor" => _actor, "id" => id} = data,
 560         _options
 561       ) do
 562     with actor <- Containment.get_actor(data),
 563          {:ok, %User{} = followed} <- User.get_or_fetch_by_ap_id(actor),
 564          {:ok, follow_activity} <- get_follow_activity(follow_object, followed),
 565          {:ok, follow_activity} <- Utils.update_follow_state_for_all(follow_activity, "reject"),
 566          %User{local: true} = follower <- User.get_cached_by_ap_id(follow_activity.data["actor"]),
 567          {:ok, _relationship} <- FollowingRelationship.update(follower, followed, "reject"),
 568          {:ok, activity} <-
 569            ActivityPub.reject(%{
 570              to: follow_activity.data["to"],
 571              type: "Reject",
 572              actor: followed,
 573              object: follow_activity.data["id"],
 574              local: false,
 575              activity_id: id
 576            }) do
 577       {:ok, activity}
 578     else
 579       _e -> :error
 580     end
 581   end
 582
 583   @misskey_reactions %{
 584     "like" => "👍",
 585     "love" => "❤️",
 586     "laugh" => "😆",
 587     "hmm" => "🤔",
 588     "surprise" => "😮",
 589     "congrats" => "🎉",
 590     "angry" => "💢",
 591     "confused" => "😥",
 592     "rip" => "😇",
 593     "pudding" => "🍮",
 594     "star" => "⭐"
 595   }
 596
 597   @doc "Rewrite misskey likes into EmojiReacts"
 598   def handle_incoming(
 599         %{
 600           "type" => "Like",
 601           "_misskey_reaction" => reaction
 602         } = data,
 603         options
 604       ) do
 605     data
 606     |> Map.put("type", "EmojiReact")
 607     |> Map.put("content", @misskey_reactions[reaction] || reaction)
 608     |> handle_incoming(options)
 609   end
 610
 611   def handle_incoming(
 612         %{"type" => "Like", "object" => object_id, "actor" => _actor, "id" => id} = data,
 613         _options
 614       ) do
 615     with actor <- Containment.get_actor(data),
 616          {:ok, %User{} = actor} <- User.get_or_fetch_by_ap_id(actor),
 617          {:ok, object} <- get_obj_helper(object_id),
 618          {:ok, activity, _object} <- ActivityPub.like(actor, object, id, false) do
 619       {:ok, activity}
 620     else
 621       _e -> :error
 622     end
 623   end
 624
 625   def handle_incoming(
 626         %{
 627           "type" => "EmojiReact",
 628           "object" => object_id,
 629           "actor" => _actor,
 630           "id" => id,
 631           "content" => emoji
 632         } = data,
 633         _options
 634       ) do
 635     with actor <- Containment.get_actor(data),
 636          {:ok, %User{} = actor} <- User.get_or_fetch_by_ap_id(actor),
 637          {:ok, object} <- get_obj_helper(object_id),
 638          {:ok, activity, _object} <-
 639            ActivityPub.react_with_emoji(actor, object, emoji, activity_id: id, local: false) do
 640       {:ok, activity}
 641     else
 642       _e -> :error
 643     end
 644   end
 645
 646   def handle_incoming(
 647         %{"type" => "Announce", "object" => object_id, "actor" => _actor, "id" => id} = data,
 648         _options
 649       ) do
 650     with actor <- Containment.get_actor(data),
 651          {:ok, %User{} = actor} <- User.get_or_fetch_by_ap_id(actor),
 652          {:ok, object} <- get_embedded_obj_helper(object_id, actor),
 653          public <- Visibility.is_public?(data),
 654          {:ok, activity, _object} <- ActivityPub.announce(actor, object, id, false, public) do
 655       {:ok, activity}
 656     else
 657       _e -> :error
 658     end
 659   end
 660
 661   def handle_incoming(
 662         %{"type" => "Update", "object" => %{"type" => object_type} = object, "actor" => actor_id} =
 663           data,
 664         _options
 665       )
 666       when object_type in [
 667              "Person",
 668              "Application",
 669              "Service",
 670              "Organization"
 671            ] do
 672     with %User{ap_id: ^actor_id} = actor <- User.get_cached_by_ap_id(object["id"]) do
 673       {:ok, new_user_data} = ActivityPub.user_data_from_user_object(object)
 674
 675       actor
 676       |> User.upgrade_changeset(new_user_data, true)
 677       |> User.update_and_set_cache()
 678
 679       ActivityPub.update(%{
 680         local: false,
 681         to: data["to"] || [],
 682         cc: data["cc"] || [],
 683         object: object,
 684         actor: actor_id,
 685         activity_id: data["id"]
 686       })
 687     else
 688       e ->
 689         Logger.error(e)
 690         :error
 691     end
 692   end
 693
 694   # TODO: We presently assume that any actor on the same origin domain as the object being
 695   # deleted has the rights to delete that object.  A better way to validate whether or not
 696   # the object should be deleted is to refetch the object URI, which should return either
 697   # an error or a tombstone.  This would allow us to verify that a deletion actually took
 698   # place.
 699   def handle_incoming(
 700         %{"type" => "Delete", "object" => object_id, "actor" => actor, "id" => id} = data,
 701         _options
 702       ) do
 703     object_id = Utils.get_ap_id(object_id)
 704
 705     with actor <- Containment.get_actor(data),
 706          {:ok, %User{} = actor} <- User.get_or_fetch_by_ap_id(actor),
 707          {:ok, object} <- get_obj_helper(object_id),
 708          :ok <- Containment.contain_origin(actor.ap_id, object.data),
 709          {:ok, activity} <-
 710            ActivityPub.delete(object, local: false, activity_id: id, actor: actor.ap_id) do
 711       {:ok, activity}
 712     else
 713       nil ->
 714         case User.get_cached_by_ap_id(object_id) do
 715           %User{ap_id: ^actor} = user ->
 716             User.delete(user)
 717
 718           nil ->
 719             :error
 720         end
 721
 722       _e ->
 723         :error
 724     end
 725   end
 726
 727   def handle_incoming(
 728         %{
 729           "type" => "Undo",
 730           "object" => %{"type" => "Announce", "object" => object_id},
 731           "actor" => _actor,
 732           "id" => id
 733         } = data,
 734         _options
 735       ) do
 736     with actor <- Containment.get_actor(data),
 737          {:ok, %User{} = actor} <- User.get_or_fetch_by_ap_id(actor),
 738          {:ok, object} <- get_obj_helper(object_id),
 739          {:ok, activity, _} <- ActivityPub.unannounce(actor, object, id, false) do
 740       {:ok, activity}
 741     else
 742       _e -> :error
 743     end
 744   end
 745
 746   def handle_incoming(
 747         %{
 748           "type" => "Undo",
 749           "object" => %{"type" => "Follow", "object" => followed},
 750           "actor" => follower,
 751           "id" => id
 752         } = _data,
 753         _options
 754       ) do
 755     with %User{local: true} = followed <- User.get_cached_by_ap_id(followed),
 756          {:ok, %User{} = follower} <- User.get_or_fetch_by_ap_id(follower),
 757          {:ok, activity} <- ActivityPub.unfollow(follower, followed, id, false) do
 758       User.unfollow(follower, followed)
 759       {:ok, activity}
 760     else
 761       _e -> :error
 762     end
 763   end
 764
 765   def handle_incoming(
 766         %{
 767           "type" => "Undo",
 768           "object" => %{"type" => "EmojiReact", "id" => reaction_activity_id},
 769           "actor" => _actor,
 770           "id" => id
 771         } = data,
 772         _options
 773       ) do
 774     with actor <- Containment.get_actor(data),
 775          {:ok, %User{} = actor} <- User.get_or_fetch_by_ap_id(actor),
 776          {:ok, activity, _} <-
 777            ActivityPub.unreact_with_emoji(actor, reaction_activity_id,
 778              activity_id: id,
 779              local: false
 780            ) do
 781       {:ok, activity}
 782     else
 783       _e -> :error
 784     end
 785   end
 786
 787   def handle_incoming(
 788         %{
 789           "type" => "Undo",
 790           "object" => %{"type" => "Block", "object" => blocked},
 791           "actor" => blocker,
 792           "id" => id
 793         } = _data,
 794         _options
 795       ) do
 796     with %User{local: true} = blocked <- User.get_cached_by_ap_id(blocked),
 797          {:ok, %User{} = blocker} <- User.get_or_fetch_by_ap_id(blocker),
 798          {:ok, activity} <- ActivityPub.unblock(blocker, blocked, id, false) do
 799       User.unblock(blocker, blocked)
 800       {:ok, activity}
 801     else
 802       _e -> :error
 803     end
 804   end
 805
 806   def handle_incoming(
 807         %{"type" => "Block", "object" => blocked, "actor" => blocker, "id" => id} = _data,
 808         _options
 809       ) do
 810     with %User{local: true} = blocked = User.get_cached_by_ap_id(blocked),
 811          {:ok, %User{} = blocker} = User.get_or_fetch_by_ap_id(blocker),
 812          {:ok, activity} <- ActivityPub.block(blocker, blocked, id, false) do
 813       User.unfollow(blocker, blocked)
 814       User.block(blocker, blocked)
 815       {:ok, activity}
 816     else
 817       _e -> :error
 818     end
 819   end
 820
 821   def handle_incoming(
 822         %{
 823           "type" => "Undo",
 824           "object" => %{"type" => "Like", "object" => object_id},
 825           "actor" => _actor,
 826           "id" => id
 827         } = data,
 828         _options
 829       ) do
 830     with actor <- Containment.get_actor(data),
 831          {:ok, %User{} = actor} <- User.get_or_fetch_by_ap_id(actor),
 832          {:ok, object} <- get_obj_helper(object_id),
 833          {:ok, activity, _, _} <- ActivityPub.unlike(actor, object, id, false) do
 834       {:ok, activity}
 835     else
 836       _e -> :error
 837     end
 838   end
 839
 840   # For Undos that don't have the complete object attached, try to find it in our database.
 841   def handle_incoming(
 842         %{
 843           "type" => "Undo",
 844           "object" => object
 845         } = activity,
 846         options
 847       )
 848       when is_binary(object) do
 849     with %Activity{data: data} <- Activity.get_by_ap_id(object) do
 850       activity
 851       |> Map.put("object", data)
 852       |> handle_incoming(options)
 853     else
 854       _e -> :error
 855     end
 856   end
 857
 858   def handle_incoming(
 859         %{
 860           "type" => "Move",
 861           "actor" => origin_actor,
 862           "object" => origin_actor,
 863           "target" => target_actor
 864         },
 865         _options
 866       ) do
 867     with %User{} = origin_user <- User.get_cached_by_ap_id(origin_actor),
 868          {:ok, %User{} = target_user} <- User.get_or_fetch_by_ap_id(target_actor),
 869          true <- origin_actor in target_user.also_known_as do
 870       ActivityPub.move(origin_user, target_user, false)
 871     else
 872       _e -> :error
 873     end
 874   end
 875
 876   def handle_incoming(_, _), do: :error
 877
 878   @spec get_obj_helper(String.t(), Keyword.t()) :: {:ok, Object.t()} | nil
 879   def get_obj_helper(id, options \\ []) do
 880     case Object.normalize(id, true, options) do
 881       %Object{} = object -> {:ok, object}
 882       _ -> nil
 883     end
 884   end
 885
 886   @spec get_embedded_obj_helper(String.t() | Object.t(), User.t()) :: {:ok, Object.t()} | nil
 887   def get_embedded_obj_helper(%{"attributedTo" => attributed_to, "id" => object_id} = data, %User{
 888         ap_id: ap_id
 889       })
 890       when attributed_to == ap_id do
 891     with {:ok, activity} <-
 892            handle_incoming(%{
 893              "type" => "Create",
 894              "to" => data["to"],
 895              "cc" => data["cc"],
 896              "actor" => attributed_to,
 897              "object" => data
 898            }) do
 899       {:ok, Object.normalize(activity)}
 900     else
 901       _ -> get_obj_helper(object_id)
 902     end
 903   end
 904
 905   def get_embedded_obj_helper(object_id, _) do
 906     get_obj_helper(object_id)
 907   end
 908
 909   def set_reply_to_uri(%{"inReplyTo" => in_reply_to} = object) when is_binary(in_reply_to) do
 910     with false <- String.starts_with?(in_reply_to, "http"),
 911          {:ok, %{data: replied_to_object}} <- get_obj_helper(in_reply_to) do
 912       Map.put(object, "inReplyTo", replied_to_object["external_url"] || in_reply_to)
 913     else
 914       _e -> object
 915     end
 916   end
 917
 918   def set_reply_to_uri(obj), do: obj
 919
 920   @doc """
 921   Serialized Mastodon-compatible `replies` collection containing _self-replies_.
 922   Based on Mastodon's ActivityPub::NoteSerializer#replies.
 923   """
 924   def set_replies(obj_data) do
 925     replies_uris =
 926       with limit when limit > 0 <-
 927              Pleroma.Config.get([:activitypub, :note_replies_output_limit], 0),
 928            %Object{} = object <- Object.get_cached_by_ap_id(obj_data["id"]) do
 929         object
 930         |> Object.self_replies()
 931         |> select([o], fragment("?->>'id'", o.data))
 932         |> limit(^limit)
 933         |> Repo.all()
 934       else
 935         _ -> []
 936       end
 937
 938     set_replies(obj_data, replies_uris)
 939   end
 940
 941   defp set_replies(obj, []) do
 942     obj
 943   end
 944
 945   defp set_replies(obj, replies_uris) do
 946     replies_collection = %{
 947       "type" => "Collection",
 948       "items" => replies_uris
 949     }
 950
 951     Map.merge(obj, %{"replies" => replies_collection})
 952   end
 953
 954   def replies(%{"replies" => %{"first" => %{"items" => items}}}) when not is_nil(items) do
 955     items
 956   end
 957
 958   def replies(%{"replies" => %{"items" => items}}) when not is_nil(items) do
 959     items
 960   end
 961
 962   def replies(_), do: []
 963
 964   # Prepares the object of an outgoing create activity.
 965   def prepare_object(object) do
 966     object
 967     |> set_sensitive
 968     |> add_hashtags
 969     |> add_mention_tags
 970     |> add_emoji_tags
 971     |> add_attributed_to
 972     |> prepare_attachments
 973     |> set_conversation
 974     |> set_reply_to_uri
 975     |> set_replies
 976     |> strip_internal_fields
 977     |> strip_internal_tags
 978     |> set_type
 979   end
 980
 981   #  @doc
 982   #  """
 983   #  internal -> Mastodon
 984   #  """
 985
 986   def prepare_outgoing(%{"type" => activity_type, "object" => object_id} = data)
 987       when activity_type in ["Create", "Listen"] do
 988     object =
 989       object_id
 990       |> Object.normalize()
 991       |> Map.get(:data)
 992       |> prepare_object
 993
 994     data =
 995       data
 996       |> Map.put("object", object)
 997       |> Map.merge(Utils.make_json_ld_header())
 998       |> Map.delete("bcc")
 999
1000     {:ok, data}
1001   end
1002
1003   def prepare_outgoing(%{"type" => "Announce", "actor" => ap_id, "object" => object_id} = data) do
1004     object =
1005       object_id
1006       |> Object.normalize()
1007
1008     data =
1009       if Visibility.is_private?(object) && object.data["actor"] == ap_id do
1010         data |> Map.put("object", object |> Map.get(:data) |> prepare_object)
1011       else
1012         data |> maybe_fix_object_url
1013       end
1014
1015     data =
1016       data
1017       |> strip_internal_fields
1018       |> Map.merge(Utils.make_json_ld_header())
1019       |> Map.delete("bcc")
1020
1021     {:ok, data}
1022   end
1023
1024   # Mastodon Accept/Reject requires a non-normalized object containing the actor URIs,
1025   # because of course it does.
1026   def prepare_outgoing(%{"type" => "Accept"} = data) do
1027     with follow_activity <- Activity.normalize(data["object"]) do
1028       object = %{
1029         "actor" => follow_activity.actor,
1030         "object" => follow_activity.data["object"],
1031         "id" => follow_activity.data["id"],
1032         "type" => "Follow"
1033       }
1034
1035       data =
1036         data
1037         |> Map.put("object", object)
1038         |> Map.merge(Utils.make_json_ld_header())
1039
1040       {:ok, data}
1041     end
1042   end
1043
1044   def prepare_outgoing(%{"type" => "Reject"} = data) do
1045     with follow_activity <- Activity.normalize(data["object"]) do
1046       object = %{
1047         "actor" => follow_activity.actor,
1048         "object" => follow_activity.data["object"],
1049         "id" => follow_activity.data["id"],
1050         "type" => "Follow"
1051       }
1052
1053       data =
1054         data
1055         |> Map.put("object", object)
1056         |> Map.merge(Utils.make_json_ld_header())
1057
1058       {:ok, data}
1059     end
1060   end
1061
1062   def prepare_outgoing(%{"type" => _type} = data) do
1063     data =
1064       data
1065       |> strip_internal_fields
1066       |> maybe_fix_object_url
1067       |> Map.merge(Utils.make_json_ld_header())
1068
1069     {:ok, data}
1070   end
1071
1072   def maybe_fix_object_url(%{"object" => object} = data) when is_binary(object) do
1073     with false <- String.starts_with?(object, "http"),
1074          {:fetch, {:ok, relative_object}} <- {:fetch, get_obj_helper(object)},
1075          %{data: %{"external_url" => external_url}} when not is_nil(external_url) <-
1076            relative_object do
1077       Map.put(data, "object", external_url)
1078     else
1079       {:fetch, e} ->
1080         Logger.error("Couldn't fetch #{object} #{inspect(e)}")
1081         data
1082
1083       _ ->
1084         data
1085     end
1086   end
1087
1088   def maybe_fix_object_url(data), do: data
1089
1090   def add_hashtags(object) do
1091     tags =
1092       (object["tag"] || [])
1093       |> Enum.map(fn
1094         # Expand internal representation tags into AS2 tags.
1095         tag when is_binary(tag) ->
1096           %{
1097             "href" => Pleroma.Web.Endpoint.url() <> "/tags/#{tag}",
1098             "name" => "##{tag}",
1099             "type" => "Hashtag"
1100           }
1101
1102         # Do not process tags which are already AS2 tag objects.
1103         tag when is_map(tag) ->
1104           tag
1105       end)
1106
1107     Map.put(object, "tag", tags)
1108   end
1109
1110   def add_mention_tags(object) do
1111     mentions =
1112       object
1113       |> Utils.get_notified_from_object()
1114       |> Enum.map(&build_mention_tag/1)
1115
1116     tags = object["tag"] || []
1117
1118     Map.put(object, "tag", tags ++ mentions)
1119   end
1120
1121   defp build_mention_tag(%{ap_id: ap_id, nickname: nickname} = _) do
1122     %{"type" => "Mention", "href" => ap_id, "name" => "@#{nickname}"}
1123   end
1124
1125   def take_emoji_tags(%User{emoji: emoji}) do
1126     emoji
1127     |> Enum.flat_map(&Map.to_list/1)
1128     |> Enum.map(&build_emoji_tag/1)
1129   end
1130
1131   # TODO: we should probably send mtime instead of unix epoch time for updated
1132   def add_emoji_tags(%{"emoji" => emoji} = object) do
1133     tags = object["tag"] || []
1134
1135     out = Enum.map(emoji, &build_emoji_tag/1)
1136
1137     Map.put(object, "tag", tags ++ out)
1138   end
1139
1140   def add_emoji_tags(object), do: object
1141
1142   defp build_emoji_tag({name, url}) do
1143     %{
1144       "icon" => %{"url" => url, "type" => "Image"},
1145       "name" => ":" <> name <> ":",
1146       "type" => "Emoji",
1147       "updated" => "1970-01-01T00:00:00Z",
1148       "id" => url
1149     }
1150   end
1151
1152   def set_conversation(object) do
1153     Map.put(object, "conversation", object["context"])
1154   end
1155
1156   def set_sensitive(object) do
1157     tags = object["tag"] || []
1158     Map.put(object, "sensitive", "nsfw" in tags)
1159   end
1160
1161   def set_type(%{"type" => "Answer"} = object) do
1162     Map.put(object, "type", "Note")
1163   end
1164
1165   def set_type(object), do: object
1166
1167   def add_attributed_to(object) do
1168     attributed_to = object["attributedTo"] || object["actor"]
1169     Map.put(object, "attributedTo", attributed_to)
1170   end
1171
1172   def prepare_attachments(object) do
1173     attachments =
1174       (object["attachment"] || [])
1175       |> Enum.map(fn data ->
1176         [%{"mediaType" => media_type, "href" => href} | _] = data["url"]
1177         %{"url" => href, "mediaType" => media_type, "name" => data["name"], "type" => "Document"}
1178       end)
1179
1180     Map.put(object, "attachment", attachments)
1181   end
1182
1183   def strip_internal_fields(object) do
1184     object
1185     |> Map.drop(Pleroma.Constants.object_internal_fields())
1186   end
1187
1188   defp strip_internal_tags(%{"tag" => tags} = object) do
1189     tags = Enum.filter(tags, fn x -> is_map(x) end)
1190
1191     Map.put(object, "tag", tags)
1192   end
1193
1194   defp strip_internal_tags(object), do: object
1195
1196   def perform(:user_upgrade, user) do
1197     # we pass a fake user so that the followers collection is stripped away
1198     old_follower_address = User.ap_followers(%User{nickname: user.nickname})
1199
1200     from(
1201       a in Activity,
1202       where: ^old_follower_address in a.recipients,
1203       update: [
1204         set: [
1205           recipients:
1206             fragment(
1207               "array_replace(?,?,?)",
1208               a.recipients,
1209               ^old_follower_address,
1210               ^user.follower_address
1211             )
1212         ]
1213       ]
1214     )
1215     |> Repo.update_all([])
1216   end
1217
1218   def upgrade_user_from_ap_id(ap_id) do
1219     with %User{local: false} = user <- User.get_cached_by_ap_id(ap_id),
1220          {:ok, data} <- ActivityPub.fetch_and_prepare_user_from_ap_id(ap_id),
1221          already_ap <- User.ap_enabled?(user),
1222          {:ok, user} <- upgrade_user(user, data) do
1223       if not already_ap do
1224         TransmogrifierWorker.enqueue("user_upgrade", %{"user_id" => user.id})
1225       end
1226
1227       {:ok, user}
1228     else
1229       %User{} = user -> {:ok, user}
1230       e -> e
1231     end
1232   end
1233
1234   defp upgrade_user(user, data) do
1235     user
1236     |> User.upgrade_changeset(data, true)
1237     |> User.update_and_set_cache()
1238   end
1239
1240   def maybe_fix_user_url(%{"url" => url} = data) when is_map(url) do
1241     Map.put(data, "url", url["href"])
1242   end
1243
1244   def maybe_fix_user_url(data), do: data
1245
1246   def maybe_fix_user_object(data), do: maybe_fix_user_url(data)
1247 end