X-Git-Url: http://git.squeep.com/?a=blobdiff_plain;f=lib%2Fpleroma%2Fweb%2Factivity_pub%2Futils.ex;h=581b9d1ab3e0f232b4e35e954dd5dbeffb4999a6;hb=8cbad5500cefbba1e0bb67604960fc331b75b498;hp=6a89374d0126d792bd37d18e8a326e60766730cd;hpb=f53dc5ee08b5db336738fa73677533785fb7351f;p=akkoma

diff --git a/lib/pleroma/web/activity_pub/utils.ex b/lib/pleroma/web/activity_pub/utils.ex
index 6a89374d0..cf82d1a9b 100644
--- a/lib/pleroma/web/activity_pub/utils.ex
+++ b/lib/pleroma/web/activity_pub/utils.ex
@@ -3,75 +3,70 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 
 defmodule Pleroma.Web.ActivityPub.Utils do
-  alias Pleroma.Repo
-  alias Pleroma.Web
-  alias Pleroma.Object
+  alias Ecto.Changeset
+  alias Ecto.UUID
   alias Pleroma.Activity
-  alias Pleroma.User
   alias Pleroma.Notification
-  alias Pleroma.Web.Router.Helpers
+  alias Pleroma.Object
+  alias Pleroma.Repo
+  alias Pleroma.User
+  alias Pleroma.Web
+  alias Pleroma.Web.ActivityPub.Visibility
   alias Pleroma.Web.Endpoint
-  alias Ecto.Changeset
-  alias Ecto.UUID
+  alias Pleroma.Web.Router.Helpers
 
   import Ecto.Query
 
   require Logger
+  require Pleroma.Constants
 
-  @supported_object_types ["Article", "Note", "Video", "Page"]
+  @supported_object_types ["Article", "Note", "Video", "Page", "Question", "Answer"]
+  @supported_report_states ~w(open closed resolved)
+  @valid_visibilities ~w(public unlisted private direct)
 
   # Some implementations send the actor URI as the actor field, others send the entire actor object,
   # so figure out what the actor's URI is based on what we have.
-  def get_ap_id(object) do
-    case object do
-      %{"id" => id} -> id
-      id -> id
-    end
-  end
+  def get_ap_id(%{"id" => id} = _), do: id
+  def get_ap_id(id), do: id
 
   def normalize_params(params) do
     Map.put(params, "actor", get_ap_id(params["actor"]))
   end
 
-  def determine_explicit_mentions(%{"tag" => tag} = _object) when is_list(tag) do
-    tag
-    |> Enum.filter(fn x -> is_map(x) end)
-    |> Enum.filter(fn x -> x["type"] == "Mention" end)
-    |> Enum.map(fn x -> x["href"] end)
+  @spec determine_explicit_mentions(map()) :: map()
+  def determine_explicit_mentions(%{"tag" => tag} = _) when is_list(tag) do
+    Enum.flat_map(tag, fn
+      %{"type" => "Mention", "href" => href} -> [href]
+      _ -> []
+    end)
   end
 
   def determine_explicit_mentions(%{"tag" => tag} = object) when is_map(tag) do
-    Map.put(object, "tag", [tag])
+    object
+    |> Map.put("tag", [tag])
     |> determine_explicit_mentions()
   end
 
   def determine_explicit_mentions(_), do: []
 
+  @spec recipient_in_collection(any(), any()) :: boolean()
   defp recipient_in_collection(ap_id, coll) when is_binary(coll), do: ap_id == coll
   defp recipient_in_collection(ap_id, coll) when is_list(coll), do: ap_id in coll
   defp recipient_in_collection(_, _), do: false
 
-  def recipient_in_message(ap_id, params) do
-    cond do
-      recipient_in_collection(ap_id, params["to"]) ->
-        true
-
-      recipient_in_collection(ap_id, params["cc"]) ->
-        true
-
-      recipient_in_collection(ap_id, params["bto"]) ->
-        true
-
-      recipient_in_collection(ap_id, params["bcc"]) ->
-        true
+  @spec recipient_in_message(User.t(), User.t(), map()) :: boolean()
+  def recipient_in_message(%User{ap_id: ap_id} = recipient, %User{} = actor, params) do
+    addresses = [params["to"], params["cc"], params["bto"], params["bcc"]]
 
+    cond do
+      Enum.any?(addresses, &recipient_in_collection(ap_id, &1)) -> true
       # if the message is unaddressed at all, then assume it is directly addressed
       # to the recipient
-      !params["to"] && !params["cc"] && !params["bto"] && !params["bcc"] ->
-        true
-
-      true ->
-        false
+      Enum.all?(addresses, &is_nil(&1)) -> true
+      # if the message is sent from somebody the user is following, then assume it
+      # is addressed to the recipient
+      User.following?(recipient, actor) -> true
+      true -> false
     end
   end
 
@@ -98,7 +93,10 @@ defmodule Pleroma.Web.ActivityPub.Utils do
     %{
       "@context" => [
         "https://www.w3.org/ns/activitystreams",
-        "#{Web.base_url()}/schemas/litepub-0.1.jsonld"
+        "#{Web.base_url()}/schemas/litepub-0.1.jsonld",
+        %{
+          "@language" => "und"
+        }
       ]
     }
   end
@@ -140,31 +138,37 @@ defmodule Pleroma.Web.ActivityPub.Utils do
 
   def create_context(context) do
     context = context || generate_id("contexts")
-    changeset = Object.context_mapping(context)
 
-    case Repo.insert(changeset) do
-      {:ok, object} ->
-        object
+    # Ecto has problems accessing the constraint inside the jsonb,
+    # so we explicitly check for the existed object before insert
+    object = Object.get_cached_by_ap_id(context)
 
-      # This should be solved by an upsert, but it seems ecto
-      # has problems accessing the constraint inside the jsonb.
-      {:error, _} ->
-        Object.get_cached_by_ap_id(context)
+    with true <- is_nil(object),
+         changeset <- Object.context_mapping(context),
+         {:ok, inserted_object} <- Repo.insert(changeset) do
+      inserted_object
+    else
+      _ ->
+        object
     end
   end
 
   @doc """
   Enqueues an activity for federation if it's local
   """
+  @spec maybe_federate(any()) :: :ok
   def maybe_federate(%Activity{local: true} = activity) do
-    priority =
-      case activity.data["type"] do
-        "Delete" -> 10
-        "Create" -> 1
-        _ -> 5
-      end
+    if Pleroma.Config.get!([:instance, :federating]) do
+      priority =
+        case activity.data["type"] do
+          "Delete" -> 10
+          "Create" -> 1
+          _ -> 5
+        end
+
+      Pleroma.Web.Federator.publish(activity, priority)
+    end
 
-    Pleroma.Web.Federator.publish(activity, priority)
     :ok
   end
 
@@ -174,148 +178,171 @@ defmodule Pleroma.Web.ActivityPub.Utils do
   Adds an id and a published data if they aren't there,
   also adds it to an included object
   """
-  def lazy_put_activity_defaults(map) do
+  @spec lazy_put_activity_defaults(map(), boolean) :: map()
+  def lazy_put_activity_defaults(map, fake \\ false)
+
+  def lazy_put_activity_defaults(map, true) do
+    map
+    |> Map.put_new("id", "pleroma:fakeid")
+    |> Map.put_new_lazy("published", &make_date/0)
+    |> Map.put_new("context", "pleroma:fakecontext")
+    |> Map.put_new("context_id", -1)
+    |> lazy_put_object_defaults(true)
+  end
+
+  def lazy_put_activity_defaults(map, _fake) do
     %{data: %{"id" => context}, id: context_id} = create_context(map["context"])
 
-    map =
+    map
+    |> Map.put_new_lazy("id", &generate_activity_id/0)
+    |> Map.put_new_lazy("published", &make_date/0)
+    |> Map.put_new("context", context)
+    |> Map.put_new("context_id", context_id)
+    |> lazy_put_object_defaults(false)
+  end
+
+  # Adds an id and published date if they aren't there.
+  #
+  @spec lazy_put_object_defaults(map(), boolean()) :: map()
+  defp lazy_put_object_defaults(%{"object" => map} = activity, true)
+       when is_map(map) do
+    object =
       map
-      |> Map.put_new_lazy("id", &generate_activity_id/0)
+      |> Map.put_new("id", "pleroma:fake_object_id")
       |> Map.put_new_lazy("published", &make_date/0)
-      |> Map.put_new("context", context)
-      |> Map.put_new("context_id", context_id)
+      |> Map.put_new("context", activity["context"])
+      |> Map.put_new("context_id", activity["context_id"])
+      |> Map.put_new("fake", true)
 
-    if is_map(map["object"]) do
-      object = lazy_put_object_defaults(map["object"], map)
-      %{map | "object" => object}
-    else
-      map
-    end
+    %{activity | "object" => object}
   end
 
-  @doc """
-  Adds an id and published date if they aren't there.
-  """
-  def lazy_put_object_defaults(map, activity \\ %{}) do
-    map
-    |> Map.put_new_lazy("id", &generate_object_id/0)
-    |> Map.put_new_lazy("published", &make_date/0)
-    |> Map.put_new("context", activity["context"])
-    |> Map.put_new("context_id", activity["context_id"])
+  defp lazy_put_object_defaults(%{"object" => map} = activity, _)
+       when is_map(map) do
+    object =
+      map
+      |> Map.put_new_lazy("id", &generate_object_id/0)
+      |> Map.put_new_lazy("published", &make_date/0)
+      |> Map.put_new("context", activity["context"])
+      |> Map.put_new("context_id", activity["context_id"])
+
+    %{activity | "object" => object}
   end
 
+  defp lazy_put_object_defaults(activity, _), do: activity
+
   @doc """
   Inserts a full object if it is contained in an activity.
   """
-  def insert_full_object(%{"object" => %{"type" => type} = object_data})
+  def insert_full_object(%{"object" => %{"type" => type} = object_data} = map)
       when is_map(object_data) and type in @supported_object_types do
-    with {:ok, _} <- Object.create(object_data) do
-      :ok
+    with {:ok, object} <- Object.create(object_data) do
+      map =
+        map
+        |> Map.put("object", object.data["id"])
+
+      {:ok, map, object}
     end
   end
 
-  def insert_full_object(_), do: :ok
-
-  def update_object_in_activities(%{data: %{"id" => id}} = object) do
-    # TODO
-    # Update activities that already had this. Could be done in a seperate process.
-    # Alternatively, just don't do this and fetch the current object each time. Most
-    # could probably be taken from cache.
-    relevant_activities = Activity.get_all_create_by_object_ap_id(id)
-
-    Enum.map(relevant_activities, fn activity ->
-      new_activity_data = activity.data |> Map.put("object", object.data)
-      changeset = Changeset.change(activity, data: new_activity_data)
-      Repo.update(changeset)
-    end)
-  end
+  def insert_full_object(map), do: {:ok, map, nil}
 
   #### Like-related helpers
 
   @doc """
   Returns an existing like if a user already liked an object
   """
+  @spec get_existing_like(String.t(), map()) :: Activity.t() | nil
   def get_existing_like(actor, %{data: %{"id" => id}}) do
-    query =
-      from(
-        activity in Activity,
-        where: fragment("(?)->>'actor' = ?", activity.data, ^actor),
-        # this is to use the index
-        where:
-          fragment(
-            "coalesce((?)->'object'->>'id', (?)->>'object') = ?",
-            activity.data,
-            activity.data,
-            ^id
-          ),
-        where: fragment("(?)->>'type' = 'Like'", activity.data)
-      )
-
-    Repo.one(query)
+    actor
+    |> Activity.Queries.by_actor()
+    |> Activity.Queries.by_object_id(id)
+    |> Activity.Queries.by_type("Like")
+    |> Activity.Queries.limit(1)
+    |> Repo.one()
   end
 
   @doc """
   Returns like activities targeting an object
   """
   def get_object_likes(%{data: %{"id" => id}}) do
-    query =
-      from(
-        activity in Activity,
-        # this is to use the index
-        where:
-          fragment(
-            "coalesce((?)->'object'->>'id', (?)->>'object') = ?",
-            activity.data,
-            activity.data,
-            ^id
-          ),
-        where: fragment("(?)->>'type' = 'Like'", activity.data)
-      )
-
-    Repo.all(query)
+    id
+    |> Activity.Queries.by_object_id()
+    |> Activity.Queries.by_type("Like")
+    |> Repo.all()
   end
 
-  def make_like_data(%User{ap_id: ap_id} = actor, %{data: %{"id" => id}} = object, activity_id) do
-    data = %{
+  @spec make_like_data(User.t(), map(), String.t()) :: map()
+  def make_like_data(
+        %User{ap_id: ap_id} = actor,
+        %{data: %{"actor" => object_actor_id, "id" => id}} = object,
+        activity_id
+      ) do
+    object_actor = User.get_cached_by_ap_id(object_actor_id)
+
+    to =
+      if Visibility.is_public?(object) do
+        [actor.follower_address, object.data["actor"]]
+      else
+        [object.data["actor"]]
+      end
+
+    cc =
+      (object.data["to"] ++ (object.data["cc"] || []))
+      |> List.delete(actor.ap_id)
+      |> List.delete(object_actor.follower_address)
+
+    %{
       "type" => "Like",
       "actor" => ap_id,
       "object" => id,
-      "to" => [actor.follower_address, object.data["actor"]],
-      "cc" => ["https://www.w3.org/ns/activitystreams#Public"],
+      "to" => to,
+      "cc" => cc,
       "context" => object.data["context"]
     }
-
-    if activity_id, do: Map.put(data, "id", activity_id), else: data
+    |> maybe_put("id", activity_id)
   end
 
+  @spec update_element_in_object(String.t(), list(any), Object.t()) ::
+          {:ok, Object.t()} | {:error, Ecto.Changeset.t()}
   def update_element_in_object(property, element, object) do
-    with new_data <-
-           object.data
-           |> Map.put("#{property}_count", length(element))
-           |> Map.put("#{property}s", element),
-         changeset <- Changeset.change(object, data: new_data),
-         {:ok, object} <- Object.update_and_set_cache(changeset),
-         _ <- update_object_in_activities(object) do
-      {:ok, object}
-    end
-  end
+    data =
+      Map.merge(
+        object.data,
+        %{"#{property}_count" => length(element), "#{property}s" => element}
+      )
 
-  def update_likes_in_object(likes, object) do
-    update_element_in_object("like", likes, object)
+    object
+    |> Changeset.change(data: data)
+    |> Object.update_and_set_cache()
   end
 
+  @spec add_like_to_object(Activity.t(), Object.t()) ::
+          {:ok, Object.t()} | {:error, Ecto.Changeset.t()}
   def add_like_to_object(%Activity{data: %{"actor" => actor}}, object) do
-    likes = if is_list(object.data["likes"]), do: object.data["likes"], else: []
-
-    with likes <- [actor | likes] |> Enum.uniq() do
-      update_likes_in_object(likes, object)
-    end
+    [actor | fetch_likes(object)]
+    |> Enum.uniq()
+    |> update_likes_in_object(object)
   end
 
+  @spec remove_like_from_object(Activity.t(), Object.t()) ::
+          {:ok, Object.t()} | {:error, Ecto.Changeset.t()}
   def remove_like_from_object(%Activity{data: %{"actor" => actor}}, object) do
-    likes = if is_list(object.data["likes"]), do: object.data["likes"], else: []
+    object
+    |> fetch_likes()
+    |> List.delete(actor)
+    |> update_likes_in_object(object)
+  end
 
-    with likes <- likes |> List.delete(actor) do
-      update_likes_in_object(likes, object)
+  defp update_likes_in_object(likes, object) do
+    update_element_in_object("like", likes, object)
+  end
+
+  defp fetch_likes(object) do
+    if is_list(object.data["likes"]) do
+      object.data["likes"]
+    else
+      []
     end
   end
 
@@ -324,31 +351,41 @@ defmodule Pleroma.Web.ActivityPub.Utils do
   @doc """
   Updates a follow activity's state (for locked accounts).
   """
-  def update_follow_state(
-        %Activity{data: %{"actor" => actor, "object" => object, "state" => "pending"}} = activity,
+  @spec update_follow_state_for_all(Activity.t(), String.t()) :: {:ok, Activity} | {:error, any()}
+  def update_follow_state_for_all(
+        %Activity{data: %{"actor" => actor, "object" => object}} = activity,
         state
       ) do
-    try do
-      Ecto.Adapters.SQL.query!(
-        Repo,
-        "UPDATE activities SET data = jsonb_set(data, '{state}', $1) WHERE data->>'type' = 'Follow' AND data->>'actor' = $2 AND data->>'object' = $3 AND data->>'state' = 'pending'",
-        [state, actor, object]
+    query =
+      from(activity in Activity,
+        where: fragment("data->>'type' = 'Follow'"),
+        where: fragment("data->>'state' = 'pending'"),
+        where: fragment("data->>'actor' = ?", ^actor),
+        where: fragment("data->>'object' = ?", ^object),
+        update: [
+          set: [
+            data: fragment("jsonb_set(data, '{state}', ?)", ^state)
+          ]
+        ]
       )
 
-      activity = Repo.get(Activity, activity.id)
+    with {_, _} <- Repo.update_all(query, []),
+         {_, _} <- User.set_follow_state_cache(actor, object, state),
+         %Activity{} = activity <- Activity.get_by_id(activity.id) do
       {:ok, activity}
-    rescue
-      e ->
-        {:error, e}
+    else
+      e -> {:error, e}
     end
   end
 
-  def update_follow_state(%Activity{} = activity, state) do
-    with new_data <-
-           activity.data
-           |> Map.put("state", state),
+  def update_follow_state(
+        %Activity{data: %{"actor" => actor, "object" => object}} = activity,
+        state
+      ) do
+    with new_data <- Map.put(activity.data, "state", state),
          changeset <- Changeset.change(activity, data: new_data),
-         {:ok, activity} <- Repo.update(changeset) do
+         {:ok, activity} <- Repo.update(changeset),
+         _ <- User.set_follow_state_cache(actor, object, state) do
       {:ok, activity}
     end
   end
@@ -361,41 +398,30 @@ defmodule Pleroma.Web.ActivityPub.Utils do
         %User{ap_id: followed_id} = _followed,
         activity_id
       ) do
-    data = %{
+    %{
       "type" => "Follow",
       "actor" => follower_id,
       "to" => [followed_id],
-      "cc" => ["https://www.w3.org/ns/activitystreams#Public"],
+      "cc" => [Pleroma.Constants.as_public()],
       "object" => followed_id,
       "state" => "pending"
     }
-
-    data = if activity_id, do: Map.put(data, "id", activity_id), else: data
-
-    data
+    |> maybe_put("id", activity_id)
   end
 
   def fetch_latest_follow(%User{ap_id: follower_id}, %User{ap_id: followed_id}) do
     query =
-      from(
-        activity in Activity,
-        where:
-          fragment(
-            "? ->> 'type' = 'Follow'",
-            activity.data
-          ),
-        where: activity.actor == ^follower_id,
-        where:
-          fragment(
-            "? @> ?",
-            activity.data,
-            ^%{object: followed_id}
-          ),
-        order_by: [desc: :id],
-        limit: 1
-      )
+      follower_id
+      |> Activity.Queries.by_actor()
+      |> Activity.Queries.by_type("Follow")
+      |> Activity.Queries.by_object_id(followed_id)
+      |> Activity.Queries.limit(1)
 
-    Repo.one(query)
+    from(
+      activity in query,
+      order_by: [fragment("? desc nulls last", activity.id)]
+    )
+    |> Repo.one()
   end
 
   #### Announce-related helpers
@@ -403,23 +429,14 @@ defmodule Pleroma.Web.ActivityPub.Utils do
   @doc """
   Retruns an existing announce activity if the notice has already been announced
   """
+  @spec get_existing_announce(String.t(), map()) :: Activity.t() | nil
   def get_existing_announce(actor, %{data: %{"id" => id}}) do
-    query =
-      from(
-        activity in Activity,
-        where: activity.actor == ^actor,
-        # this is to use the index
-        where:
-          fragment(
-            "coalesce((?)->'object'->>'id', (?)->>'object') = ?",
-            activity.data,
-            activity.data,
-            ^id
-          ),
-        where: fragment("(?)->>'type' = 'Announce'", activity.data)
-      )
-
-    Repo.one(query)
+    actor
+    |> Activity.Queries.by_actor()
+    |> Activity.Queries.by_type("Announce")
+    |> Activity.Queries.by_object_id(id)
+    |> Activity.Queries.limit(1)
+    |> Repo.one()
   end
 
   @doc """
@@ -432,7 +449,7 @@ defmodule Pleroma.Web.ActivityPub.Utils do
         activity_id,
         false
       ) do
-    data = %{
+    %{
       "type" => "Announce",
       "actor" => ap_id,
       "object" => id,
@@ -440,8 +457,7 @@ defmodule Pleroma.Web.ActivityPub.Utils do
       "cc" => [],
       "context" => object.data["context"]
     }
-
-    if activity_id, do: Map.put(data, "id", activity_id), else: data
+    |> maybe_put("id", activity_id)
   end
 
   def make_announce_data(
@@ -450,16 +466,15 @@ defmodule Pleroma.Web.ActivityPub.Utils do
         activity_id,
         true
       ) do
-    data = %{
+    %{
       "type" => "Announce",
       "actor" => ap_id,
       "object" => id,
       "to" => [user.follower_address, object.data["actor"]],
-      "cc" => ["https://www.w3.org/ns/activitystreams#Public"],
+      "cc" => [Pleroma.Constants.as_public()],
       "context" => object.data["context"]
     }
-
-    if activity_id, do: Map.put(data, "id", activity_id), else: data
+    |> maybe_put("id", activity_id)
   end
 
   @doc """
@@ -470,16 +485,15 @@ defmodule Pleroma.Web.ActivityPub.Utils do
         %Activity{data: %{"context" => context}} = activity,
         activity_id
       ) do
-    data = %{
+    %{
       "type" => "Undo",
       "actor" => ap_id,
       "object" => activity.data,
       "to" => [user.follower_address, activity.data["actor"]],
-      "cc" => ["https://www.w3.org/ns/activitystreams#Public"],
+      "cc" => [Pleroma.Constants.as_public()],
       "context" => context
     }
-
-    if activity_id, do: Map.put(data, "id", activity_id), else: data
+    |> maybe_put("id", activity_id)
   end
 
   def make_unlike_data(
@@ -487,100 +501,93 @@ defmodule Pleroma.Web.ActivityPub.Utils do
         %Activity{data: %{"context" => context}} = activity,
         activity_id
       ) do
-    data = %{
+    %{
       "type" => "Undo",
       "actor" => ap_id,
       "object" => activity.data,
       "to" => [user.follower_address, activity.data["actor"]],
-      "cc" => ["https://www.w3.org/ns/activitystreams#Public"],
+      "cc" => [Pleroma.Constants.as_public()],
       "context" => context
     }
-
-    if activity_id, do: Map.put(data, "id", activity_id), else: data
+    |> maybe_put("id", activity_id)
   end
 
+  @spec add_announce_to_object(Activity.t(), Object.t()) ::
+          {:ok, Object.t()} | {:error, Ecto.Changeset.t()}
   def add_announce_to_object(
-        %Activity{
-          data: %{"actor" => actor, "cc" => ["https://www.w3.org/ns/activitystreams#Public"]}
-        },
+        %Activity{data: %{"actor" => actor, "cc" => [Pleroma.Constants.as_public()]}},
         object
       ) do
-    announcements =
-      if is_list(object.data["announcements"]), do: object.data["announcements"], else: []
+    announcements = fetch_announcements(object)
 
-    with announcements <- [actor | announcements] |> Enum.uniq() do
+    with announcements <- Enum.uniq([actor | announcements]) do
       update_element_in_object("announcement", announcements, object)
     end
   end
 
   def add_announce_to_object(_, object), do: {:ok, object}
 
+  @spec remove_announce_from_object(Activity.t(), Object.t()) ::
+          {:ok, Object.t()} | {:error, Ecto.Changeset.t()}
   def remove_announce_from_object(%Activity{data: %{"actor" => actor}}, object) do
-    announcements =
-      if is_list(object.data["announcements"]), do: object.data["announcements"], else: []
-
-    with announcements <- announcements |> List.delete(actor) do
+    with announcements <- List.delete(fetch_announcements(object), actor) do
       update_element_in_object("announcement", announcements, object)
     end
   end
 
+  defp fetch_announcements(%{data: %{"announcements" => announcements}} = _)
+       when is_list(announcements),
+       do: announcements
+
+  defp fetch_announcements(_), do: []
+
   #### Unfollow-related helpers
 
   def make_unfollow_data(follower, followed, follow_activity, activity_id) do
-    data = %{
+    %{
       "type" => "Undo",
       "actor" => follower.ap_id,
       "to" => [followed.ap_id],
       "object" => follow_activity.data
     }
-
-    if activity_id, do: Map.put(data, "id", activity_id), else: data
+    |> maybe_put("id", activity_id)
   end
 
   #### Block-related helpers
+  @spec fetch_latest_block(User.t(), User.t()) :: Activity.t() | nil
   def fetch_latest_block(%User{ap_id: blocker_id}, %User{ap_id: blocked_id}) do
     query =
-      from(
-        activity in Activity,
-        where:
-          fragment(
-            "? ->> 'type' = 'Block'",
-            activity.data
-          ),
-        where: activity.actor == ^blocker_id,
-        where:
-          fragment(
-            "? @> ?",
-            activity.data,
-            ^%{object: blocked_id}
-          ),
-        order_by: [desc: :id],
-        limit: 1
-      )
+      blocker_id
+      |> Activity.Queries.by_actor()
+      |> Activity.Queries.by_type("Block")
+      |> Activity.Queries.by_object_id(blocked_id)
+      |> Activity.Queries.limit(1)
 
-    Repo.one(query)
+    from(
+      activity in query,
+      order_by: [fragment("? desc nulls last", activity.id)]
+    )
+    |> Repo.one()
   end
 
   def make_block_data(blocker, blocked, activity_id) do
-    data = %{
+    %{
       "type" => "Block",
       "actor" => blocker.ap_id,
       "to" => [blocked.ap_id],
       "object" => blocked.ap_id
     }
-
-    if activity_id, do: Map.put(data, "id", activity_id), else: data
+    |> maybe_put("id", activity_id)
   end
 
   def make_unblock_data(blocker, blocked, block_activity, activity_id) do
-    data = %{
+    %{
       "type" => "Undo",
       "actor" => blocker.ap_id,
       "to" => [blocked.ap_id],
       "object" => block_activity.data
     }
-
-    if activity_id, do: Map.put(data, "id", activity_id), else: data
+    |> maybe_put("id", activity_id)
   end
 
   #### Create-related helpers
@@ -598,4 +605,164 @@ defmodule Pleroma.Web.ActivityPub.Utils do
     }
     |> Map.merge(additional)
   end
+
+  #### Flag-related helpers
+  @spec make_flag_data(map(), map()) :: map()
+  def make_flag_data(%{actor: actor, context: context, content: content} = params, additional) do
+    %{
+      "type" => "Flag",
+      "actor" => actor.ap_id,
+      "content" => content,
+      "object" => build_flag_object(params),
+      "context" => context,
+      "state" => "open"
+    }
+    |> Map.merge(additional)
+  end
+
+  def make_flag_data(_, _), do: %{}
+
+  defp build_flag_object(%{account: account, statuses: statuses} = _) do
+    [account.ap_id] ++
+      Enum.map(statuses || [], fn
+        %Activity{} = act -> act.data["id"]
+        act when is_map(act) -> act["id"]
+        act when is_binary(act) -> act
+      end)
+  end
+
+  defp build_flag_object(_), do: []
+
+  @doc """
+  Fetches the OrderedCollection/OrderedCollectionPage from `from`, limiting the amount of pages fetched after
+  the first one to `pages_left` pages.
+  If the amount of pages is higher than the collection has, it returns whatever was there.
+  """
+  def fetch_ordered_collection(from, pages_left, acc \\ []) do
+    with {:ok, response} <- Tesla.get(from),
+         {:ok, collection} <- Jason.decode(response.body) do
+      case collection["type"] do
+        "OrderedCollection" ->
+          # If we've encountered the OrderedCollection and not the page,
+          # just call the same function on the page address
+          fetch_ordered_collection(collection["first"], pages_left)
+
+        "OrderedCollectionPage" ->
+          if pages_left > 0 do
+            # There are still more pages
+            if Map.has_key?(collection, "next") do
+              # There are still more pages, go deeper saving what we have into the accumulator
+              fetch_ordered_collection(
+                collection["next"],
+                pages_left - 1,
+                acc ++ collection["orderedItems"]
+              )
+            else
+              # No more pages left, just return whatever we already have
+              acc ++ collection["orderedItems"]
+            end
+          else
+            # Got the amount of pages needed, add them all to the accumulator
+            acc ++ collection["orderedItems"]
+          end
+
+        _ ->
+          {:error, "Not an OrderedCollection or OrderedCollectionPage"}
+      end
+    end
+  end
+
+  #### Report-related helpers
+
+  def update_report_state(%Activity{} = activity, state) when state in @supported_report_states do
+    with new_data <- Map.put(activity.data, "state", state),
+         changeset <- Changeset.change(activity, data: new_data),
+         {:ok, activity} <- Repo.update(changeset) do
+      {:ok, activity}
+    end
+  end
+
+  def update_report_state(_, _), do: {:error, "Unsupported state"}
+
+  def update_activity_visibility(activity, visibility) when visibility in @valid_visibilities do
+    [to, cc, recipients] =
+      activity
+      |> get_updated_targets(visibility)
+      |> Enum.map(&Enum.uniq/1)
+
+    object_data =
+      activity.object.data
+      |> Map.put("to", to)
+      |> Map.put("cc", cc)
+
+    {:ok, object} =
+      activity.object
+      |> Object.change(%{data: object_data})
+      |> Object.update_and_set_cache()
+
+    activity_data =
+      activity.data
+      |> Map.put("to", to)
+      |> Map.put("cc", cc)
+
+    activity
+    |> Map.put(:object, object)
+    |> Activity.change(%{data: activity_data, recipients: recipients})
+    |> Repo.update()
+  end
+
+  def update_activity_visibility(_, _), do: {:error, "Unsupported visibility"}
+
+  defp get_updated_targets(
+         %Activity{data: %{"to" => to} = data, recipients: recipients},
+         visibility
+       ) do
+    cc = Map.get(data, "cc", [])
+    follower_address = User.get_cached_by_ap_id(data["actor"]).follower_address
+    public = Pleroma.Constants.as_public()
+
+    case visibility do
+      "public" ->
+        to = [public | List.delete(to, follower_address)]
+        cc = [follower_address | List.delete(cc, public)]
+        recipients = [public | recipients]
+        [to, cc, recipients]
+
+      "private" ->
+        to = [follower_address | List.delete(to, public)]
+        cc = List.delete(cc, public)
+        recipients = List.delete(recipients, public)
+        [to, cc, recipients]
+
+      "unlisted" ->
+        to = [follower_address | List.delete(to, public)]
+        cc = [public | List.delete(cc, follower_address)]
+        recipients = recipients ++ [follower_address, public]
+        [to, cc, recipients]
+
+      _ ->
+        [to, cc, recipients]
+    end
+  end
+
+  def get_existing_votes(actor, %{data: %{"id" => id}}) do
+    query =
+      from(
+        [activity, object: object] in Activity.with_preloaded_object(Activity),
+        where: fragment("(?)->>'type' = 'Create'", activity.data),
+        where: fragment("(?)->>'actor' = ?", activity.data, ^actor),
+        where:
+          fragment(
+            "(?)->>'inReplyTo' = ?",
+            object.data,
+            ^to_string(id)
+          ),
+        where: fragment("(?)->>'type' = 'Answer'", object.data)
+      )
+
+    Repo.all(query)
+  end
+
+  defp maybe_put(map, _key, nil), do: map
+  defp maybe_put(map, key, value), do: Map.put(map, key, value)
 end