3 files changed, 112 insertions, 6 deletions

diff --git a/lib/pleroma/web/activity_pub/activity_pub.ex b/lib/pleroma/web/activity_pub/activity_pub.ex
index 48eba36fd..a711e6b76 100644
--- a/lib/pleroma/web/activity_pub/activity_pub.ex
+++ b/lib/pleroma/web/activity_pub/activity_pub.ex
@@ -16,9 +16,23 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
     (data["to"] || []) ++ (data["cc"] || [])
   end
 
+  defp check_actor_is_active(actor) do
+    if not is_nil(actor) do
+      with user <- User.get_cached_by_ap_id(actor),
+           nil <- user.info["deactivated"] do
+        :ok
+      else
+        _e -> :reject
+      end
+    else
+      :ok
+    end
+  end
+
   def insert(map, local \\ true) when is_map(map) do
     with nil <- Activity.get_by_ap_id(map["id"]),
          map <- lazy_put_activity_defaults(map),
+         :ok <- check_actor_is_active(map["actor"]),
          {:ok, map} <- MRF.filter(map),
          :ok <- insert_full_object(map) do
       {:ok, activity} =
@@ -117,11 +131,19 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
     end
   end
 
-  def unlike(%User{} = actor, %Object{} = object) do
-    with %Activity{} = activity <- get_existing_like(actor.ap_id, object),
-         {:ok, _activity} <- Repo.delete(activity),
-         {:ok, object} <- remove_like_from_object(activity, object) do
-      {:ok, object}
+  def unlike(
+        %User{} = actor,
+        %Object{} = object,
+        activity_id \\ nil,
+        local \\ true
+      ) do
+    with %Activity{} = like_activity <- get_existing_like(actor.ap_id, object),
+         unlike_data <- make_unlike_data(actor, like_activity, activity_id),
+         {:ok, unlike_activity} <- insert(unlike_data, local),
+         {:ok, _activity} <- Repo.delete(like_activity),
+         {:ok, object} <- remove_like_from_object(like_activity, object),
+         :ok <- maybe_federate(unlike_activity) do
+      {:ok, unlike_activity, like_activity, object}
     else
       _e -> {:ok, object}
     end
@@ -261,6 +283,25 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
     |> Enum.reverse()
   end
 
+  def fetch_user_activities(user, reading_user, params \\ %{}) do
+    params =
+      params
+      |> Map.put("type", ["Create", "Announce"])
+      |> Map.put("actor_id", user.ap_id)
+      |> Map.put("whole_db", true)
+
+    recipients =
+      if reading_user do
+        ["https://www.w3.org/ns/activitystreams#Public"] ++
+          [reading_user.ap_id | reading_user.following]
+      else
+        ["https://www.w3.org/ns/activitystreams#Public"]
+      end
+
+    fetch_activities(recipients, params)
+    |> Enum.reverse()
+  end
+
   defp restrict_since(query, %{"since_id" => since_id}) do
     from(activity in query, where: activity.id > ^since_id)
   end
@@ -424,6 +465,8 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
           "url" => [%{"href" => data["image"]["url"]}]
         }
 
+    data = Transmogrifier.maybe_fix_user_object(data)
+
     user_data = %{
       ap_id: data["id"],
       info: %{
diff --git a/lib/pleroma/web/activity_pub/transmogrifier.ex b/lib/pleroma/web/activity_pub/transmogrifier.ex
index 47b84a469..d92ca9b65 100644
--- a/lib/pleroma/web/activity_pub/transmogrifier.ex
+++ b/lib/pleroma/web/activity_pub/transmogrifier.ex
@@ -273,9 +273,26 @@ defmodule Pleroma.Web.ActivityPub.Transmogrifier do
     end
   end
 
+  def handle_incoming(
+        %{
+          "type" => "Undo",
+          "object" => %{"type" => "Like", "object" => object_id},
+          "actor" => actor,
+          "id" => id
+        } = data
+      ) do
+    with %User{} = actor <- User.get_or_fetch_by_ap_id(actor),
+         {:ok, object} <-
+           get_obj_helper(object_id) || ActivityPub.fetch_object_from_id(object_id),
+         {:ok, activity, _, _} <- ActivityPub.unlike(actor, object, id, false) do
+      {:ok, activity}
+    else
+      e -> :error
+    end
+  end
+
   # TODO
   # Accept
-  # Undo for non-Announce
 
   def handle_incoming(_), do: :error
 
@@ -527,4 +544,17 @@ defmodule Pleroma.Web.ActivityPub.Transmogrifier do
       Repo.delete_all(q)
     end
   end
+
+  def maybe_fix_user_url(data) do
+    if is_map(data["url"]) do
+      data = Map.put(data, "url", data["url"]["href"])
+    end
+
+    data
+  end
+
+  def maybe_fix_user_object(data) do
+    data
+    |> maybe_fix_user_url
+  end
 end
diff --git a/lib/pleroma/web/activity_pub/utils.ex b/lib/pleroma/web/activity_pub/utils.ex
index 846dd97c2..050413d51 100644
--- a/lib/pleroma/web/activity_pub/utils.ex
+++ b/lib/pleroma/web/activity_pub/utils.ex
@@ -5,6 +5,22 @@ defmodule Pleroma.Web.ActivityPub.Utils do
   alias Ecto.{Changeset, UUID}
   import Ecto.Query
 
+  # 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 normalize_actor(actor) do
+    cond do
+      is_binary(actor) ->
+        actor
+
+      is_map(actor) ->
+        actor["id"]
+    end
+  end
+
+  def normalize_params(params) do
+    Map.put(params, "actor", normalize_actor(params["actor"]))
+  end
+
   def make_json_ld_header do
     %{
       "@context" => [
@@ -299,6 +315,23 @@ defmodule Pleroma.Web.ActivityPub.Utils do
     if activity_id, do: Map.put(data, "id", activity_id), else: data
   end
 
+  def make_unlike_data(
+        %User{ap_id: ap_id} = user,
+        %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"],
+      "context" => context
+    }
+
+    if activity_id, do: Map.put(data, "id", activity_id), else: data
+  end
+
   def add_announce_to_object(%Activity{data: %{"actor" => actor}}, object) do
     with announcements <- [actor | object.data["announcements"] || []] |> Enum.uniq() do
       update_element_in_object("announcement", announcements, object)