1 files changed, 92 insertions, 1 deletions

diff --git a/lib/pleroma/web/activity_pub/utils.ex b/lib/pleroma/web/activity_pub/utils.ex
index d812fd734..91cfa2194 100644
--- a/lib/pleroma/web/activity_pub/utils.ex
+++ b/lib/pleroma/web/activity_pub/utils.ex
@@ -255,6 +255,16 @@ defmodule Pleroma.Web.ActivityPub.Utils do
     |> Repo.one()
   end
 
+  @doc """
+  Returns like activities targeting an object
+  """
+  def get_object_likes(%{data: %{"id" => id}}) do
+    id
+    |> Activity.Queries.by_object_id()
+    |> Activity.Queries.by_type("Like")
+    |> Repo.all()
+  end
+
   @spec make_like_data(User.t(), map(), String.t()) :: map()
   def make_like_data(
         %User{ap_id: ap_id} = actor,
@@ -286,13 +296,30 @@ defmodule Pleroma.Web.ActivityPub.Utils do
     |> maybe_put("id", activity_id)
   end
 
+  def make_emoji_reaction_data(user, object, emoji, activity_id) do
+    make_like_data(user, object, activity_id)
+    |> Map.put("type", "EmojiReaction")
+    |> Map.put("content", emoji)
+  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
+    length =
+      if is_map(element) do
+        element
+        |> Map.values()
+        |> List.flatten()
+        |> length()
+      else
+        element
+        |> length()
+      end
+
     data =
       Map.merge(
         object.data,
-        %{"#{property}_count" => length(element), "#{property}s" => element}
+        %{"#{property}_count" => length, "#{property}s" => element}
       )
 
     object
@@ -300,6 +327,38 @@ defmodule Pleroma.Web.ActivityPub.Utils do
     |> Object.update_and_set_cache()
   end
 
+  @spec add_emoji_reaction_to_object(Activity.t(), Object.t()) ::
+          {:ok, Object.t()} | {:error, Ecto.Changeset.t()}
+
+  def add_emoji_reaction_to_object(
+        %Activity{data: %{"content" => emoji, "actor" => actor}},
+        object
+      ) do
+    reactions = object.data["reactions"] || %{}
+    emoji_actors = reactions[emoji] || []
+    new_emoji_actors = [actor | emoji_actors] |> Enum.uniq()
+    new_reactions = Map.put(reactions, emoji, new_emoji_actors)
+    update_element_in_object("reaction", new_reactions, object)
+  end
+
+  def remove_emoji_reaction_from_object(
+        %Activity{data: %{"content" => emoji, "actor" => actor}},
+        object
+      ) do
+    reactions = object.data["reactions"] || %{}
+    emoji_actors = reactions[emoji] || []
+    new_emoji_actors = List.delete(emoji_actors, actor)
+
+    new_reactions =
+      if new_emoji_actors == [] do
+        Map.delete(reactions, emoji)
+      else
+        Map.put(reactions, emoji, new_emoji_actors)
+      end
+
+    update_element_in_object("reaction", new_reactions, object)
+  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
@@ -397,6 +456,19 @@ defmodule Pleroma.Web.ActivityPub.Utils do
     |> Repo.one()
   end
 
+  def get_latest_reaction(internal_activity_id, %{ap_id: ap_id}, emoji) do
+    %{data: %{"object" => object_ap_id}} = Activity.get_by_id(internal_activity_id)
+
+    "EmojiReaction"
+    |> Activity.Queries.by_type()
+    |> where(actor: ^ap_id)
+    |> where([activity], fragment("?->>'content' = ?", activity.data, ^emoji))
+    |> Activity.Queries.by_object_id(object_ap_id)
+    |> order_by([activity], fragment("? desc nulls last", activity.id))
+    |> limit(1)
+    |> Repo.one()
+  end
+
   #### Announce-related helpers
 
   @doc """
@@ -489,6 +561,25 @@ defmodule Pleroma.Web.ActivityPub.Utils do
     |> maybe_put("id", activity_id)
   end
 
+  def make_undo_data(
+        %User{ap_id: actor, follower_address: follower_address},
+        %Activity{
+          data: %{"id" => undone_activity_id, "context" => context},
+          actor: undone_activity_actor
+        },
+        activity_id \\ nil
+      ) do
+    %{
+      "type" => "Undo",
+      "actor" => actor,
+      "object" => undone_activity_id,
+      "to" => [follower_address, undone_activity_actor],
+      "cc" => [Pleroma.Constants.as_public()],
+      "context" => context
+    }
+    |> 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(