3 files changed, 41 insertions, 0 deletions
diff --git a/lib/pleroma/web/activity_pub/activity_pub.ex b/lib/pleroma/web/activity_pub/activity_pub.ex
index eeb826814..532db17c4 100644
--- a/lib/pleroma/web/activity_pub/activity_pub.ex
+++ b/lib/pleroma/web/activity_pub/activity_pub.ex
@@ -312,6 +312,16 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
     end
   end
 
+  def react_with_emoji(user, object, emoji, options \\ []) do
+    with local <- Keyword.get(options, :local, true),
+         activity_id <- Keyword.get(options, :activity_id, nil),
+         is_emoji?(emoji),
+         reaction_data <- make_emoji_reaction_data(user, object, emoji, activity_id),
+         {:ok, activity} <- insert(reaction_data, local) do
+      {:ok, activity, object}
+    end
+  end
+
   # TODO: This is weird, maybe we shouldn't check here if we can make the activity.
   def like(
         %User{ap_id: ap_id} = user,
diff --git a/lib/pleroma/web/activity_pub/transmogrifier.ex b/lib/pleroma/web/activity_pub/transmogrifier.ex
index 36340a3a1..9132df8cb 100644
--- a/lib/pleroma/web/activity_pub/transmogrifier.ex
+++ b/lib/pleroma/web/activity_pub/transmogrifier.ex
@@ -573,6 +573,27 @@ defmodule Pleroma.Web.ActivityPub.Transmogrifier do
   end
 
   def handle_incoming(
+        %{
+          "type" => "EmojiReaction",
+          "object" => object_id,
+          "actor" => _actor,
+          "id" => id,
+          "content" => emoji
+        } = data,
+        _options
+      ) do
+    with actor <- Containment.get_actor(data),
+         {:ok, %User{} = actor} <- User.get_or_fetch_by_ap_id(actor),
+         {:ok, object} <- get_obj_helper(object_id),
+         {:ok, activity, _object} <-
+           ActivityPub.react_with_emoji(actor, object, emoji, activity_id: id, local: false) do
+      {:ok, activity}
+    else
+      _e -> :error
+    end
+  end
+
+  def handle_incoming(
         %{"type" => "Announce", "object" => object_id, "actor" => _actor, "id" => id} = data,
         _options
       ) do
diff --git a/lib/pleroma/web/activity_pub/utils.ex b/lib/pleroma/web/activity_pub/utils.ex
index c9c0c3763..32e22d8d7 100644
--- a/lib/pleroma/web/activity_pub/utils.ex
+++ b/lib/pleroma/web/activity_pub/utils.ex
@@ -277,6 +277,16 @@ defmodule Pleroma.Web.ActivityPub.Utils do
     |> Repo.all()
   end
 
+  def is_emoji?(emoji) do
+    String.length(emoji) == 1
+  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 make_like_data(User.t(), map(), String.t()) :: map()
   def make_like_data(
         %User{ap_id: ap_id} = actor,