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