3 files changed, 176 insertions, 22 deletions

diff --git a/lib/pleroma/web/activity_pub/builder.ex b/lib/pleroma/web/activity_pub/builder.ex
index 532047599..8eab3a241 100644
--- a/lib/pleroma/web/activity_pub/builder.ex
+++ b/lib/pleroma/web/activity_pub/builder.ex
@@ -16,6 +16,7 @@ defmodule Pleroma.Web.ActivityPub.Builder do
   alias Pleroma.Web.ActivityPub.Utils
   alias Pleroma.Web.ActivityPub.Visibility
   alias Pleroma.Web.CommonAPI.ActivityDraft
+  alias Pleroma.Web.Endpoint
 
   require Pleroma.Constants
 
@@ -54,13 +55,87 @@ defmodule Pleroma.Web.ActivityPub.Builder do
     {:ok, data, []}
   end
 
+  defp unicode_emoji_react(_object, data, emoji) do
+    data
+    |> Map.put("content", emoji)
+    |> Map.put("type", "EmojiReact")
+  end
+
+  defp add_emoji_content(data, emoji, url) do
+    tag = [
+      %{
+        "id" => url,
+        "type" => "Emoji",
+        "name" => Emoji.maybe_quote(emoji),
+        "icon" => %{
+          "type" => "Image",
+          "url" => url
+        }
+      }
+    ]
+
+    data
+    |> Map.put("content", Emoji.maybe_quote(emoji))
+    |> Map.put("type", "EmojiReact")
+    |> Map.put("tag", tag)
+  end
+
+  defp remote_custom_emoji_react(
+         %{data: %{"reactions" => existing_reactions}},
+         data,
+         emoji
+       ) do
+    [emoji_code, instance] = String.split(Emoji.maybe_strip_name(emoji), "@")
+
+    matching_reaction =
+      Enum.find(
+        existing_reactions,
+        fn [name, _, url] ->
+          if url != nil do
+            url = URI.parse(url)
+            url.host == instance && name == emoji_code
+          end
+        end
+      )
+
+    if matching_reaction do
+      [name, _, url] = matching_reaction
+      add_emoji_content(data, name, url)
+    else
+      {:error, "Could not react"}
+    end
+  end
+
+  defp remote_custom_emoji_react(_object, _data, _emoji) do
+    {:error, "Could not react"}
+  end
+
+  defp local_custom_emoji_react(data, emoji) do
+    with %{file: path} = emojo <- Emoji.get(emoji) do
+      url = "#{Endpoint.url()}#{path}"
+      add_emoji_content(data, emojo.code, url)
+    else
+      _ -> {:error, "Emoji does not exist"}
+    end
+  end
+
+  defp custom_emoji_react(object, data, emoji) do
+    if String.contains?(emoji, "@") do
+      remote_custom_emoji_react(object, data, emoji)
+    else
+      local_custom_emoji_react(data, emoji)
+    end
+  end
+
   @spec emoji_react(User.t(), Object.t(), String.t()) :: {:ok, map(), keyword()}
   def emoji_react(actor, object, emoji) do
     with {:ok, data, meta} <- object_action(actor, object) do
       data =
-        data
-        |> Map.put("content", emoji)
-        |> Map.put("type", "EmojiReact")
+        if Emoji.is_unicode_emoji?(emoji) do
+          unicode_emoji_react(object, data, emoji)
+        else
+          custom_emoji_react(object, data, emoji)
+        end
 
       {:ok, data, meta}
     end
diff --git a/lib/pleroma/web/activity_pub/object_validators/emoji_react_validator.ex b/lib/pleroma/web/activity_pub/object_validators/emoji_react_validator.ex
index 0858281e5..a0b82b325 100644
--- a/lib/pleroma/web/activity_pub/object_validators/emoji_react_validator.ex
+++ b/lib/pleroma/web/activity_pub/object_validators/emoji_react_validator.ex
@@ -5,8 +5,10 @@
 defmodule Pleroma.Web.ActivityPub.ObjectValidators.EmojiReactValidator do
   use Ecto.Schema
 
+  alias Pleroma.Emoji
   alias Pleroma.Object
   alias Pleroma.Web.ActivityPub.ObjectValidators.CommonFixes
+  alias Pleroma.Web.ActivityPub.ObjectValidators.TagValidator
 
   import Ecto.Changeset
   import Pleroma.Web.ActivityPub.ObjectValidators.CommonValidations
@@ -19,6 +21,7 @@ defmodule Pleroma.Web.ActivityPub.ObjectValidators.EmojiReactValidator do
         import Elixir.Pleroma.Web.ActivityPub.ObjectValidators.CommonFields
         message_fields()
         activity_fields()
+        embeds_many(:tag, TagValidator)
       end
     end
 
@@ -43,7 +46,8 @@ defmodule Pleroma.Web.ActivityPub.ObjectValidators.EmojiReactValidator do
 
   def changeset(struct, data) do
     struct
-    |> cast(data, __schema__(:fields))
+    |> cast(data, __schema__(:fields) -- [:tag])
+    |> cast_embed(:tag)
   end
 
   defp fix(data) do
@@ -53,12 +57,16 @@ defmodule Pleroma.Web.ActivityPub.ObjectValidators.EmojiReactValidator do
       |> CommonFixes.fix_actor()
       |> CommonFixes.fix_activity_addressing()
 
-    with %Object{} = object <- Object.normalize(data["object"]) do
-      data
-      |> CommonFixes.fix_activity_context(object)
-      |> CommonFixes.fix_object_action_recipients(object)
-    else
-      _ -> data
+    data = Map.put_new(data, "tag", [])
+
+    case Object.normalize(data["object"]) do
+      %Object{} = object ->
+        data
+        |> CommonFixes.fix_activity_context(object)
+        |> CommonFixes.fix_object_action_recipients(object)
+
+      _ ->
+        data
     end
   end
 
@@ -82,11 +90,31 @@ defmodule Pleroma.Web.ActivityPub.ObjectValidators.EmojiReactValidator do
   defp validate_emoji(cng) do
     content = get_field(cng, :content)
 
-    if Pleroma.Emoji.is_unicode_emoji?(content) do
+    if Emoji.is_unicode_emoji?(content) || Emoji.is_custom_emoji?(content) do
       cng
     else
       cng
-      |> add_error(:content, "must be a single character emoji")
+      |> add_error(:content, "is not a valid emoji")
+    end
+  end
+
+  defp maybe_validate_tag_presence(cng) do
+    content = get_field(cng, :content)
+
+    if Emoji.is_unicode_emoji?(content) do
+      cng
+    else
+      tag = get_field(cng, :tag)
+      emoji_name = Emoji.maybe_strip_name(content)
+
+      case tag do
+        [%{name: ^emoji_name, type: "Emoji", icon: %{url: _}}] ->
+          cng
+
+        _ ->
+          cng
+          |> add_error(:tag, "does not contain an Emoji tag")
+      end
     end
   end
 
@@ -97,5 +125,6 @@ defmodule Pleroma.Web.ActivityPub.ObjectValidators.EmojiReactValidator do
     |> validate_actor_presence()
     |> validate_object_presence()
     |> validate_emoji()
+    |> maybe_validate_tag_presence()
   end
 end
diff --git a/lib/pleroma/web/activity_pub/utils.ex b/lib/pleroma/web/activity_pub/utils.ex
index b898d6fe8..db7f79dac 100644
--- a/lib/pleroma/web/activity_pub/utils.ex
+++ b/lib/pleroma/web/activity_pub/utils.ex
@@ -325,21 +325,29 @@ defmodule Pleroma.Web.ActivityPub.Utils do
           {:ok, Object.t()} | {:error, Ecto.Changeset.t()}
 
   def add_emoji_reaction_to_object(
-        %Activity{data: %{"content" => emoji, "actor" => actor}},
+        %Activity{data: %{"content" => emoji, "actor" => actor}} = activity,
         object
       ) do
     reactions = get_cached_emoji_reactions(object)
+    emoji = Pleroma.Emoji.maybe_strip_name(emoji)
+    url = maybe_emoji_url(emoji, activity)
 
     new_reactions =
-      case Enum.find_index(reactions, fn [candidate, _] -> emoji == candidate end) do
+      case Enum.find_index(reactions, fn [candidate, _, candidate_url] ->
+             if is_nil(candidate_url) do
+               emoji == candidate
+             else
+               url == candidate_url
+             end
+           end) do
         nil ->
-          reactions ++ [[emoji, [actor]]]
+          reactions ++ [[emoji, [actor], url]]
 
         index ->
           List.update_at(
             reactions,
             index,
-            fn [emoji, users] -> [emoji, Enum.uniq([actor | users])] end
+            fn [emoji, users, url] -> [emoji, Enum.uniq([actor | users]), url] end
           )
       end
 
@@ -348,18 +356,40 @@ defmodule Pleroma.Web.ActivityPub.Utils do
     update_element_in_object("reaction", new_reactions, object, count)
   end
 
+  defp maybe_emoji_url(
+         name,
+         %Activity{
+           data: %{
+             "tag" => [
+               %{"type" => "Emoji", "name" => name, "icon" => %{"url" => url}}
+             ]
+           }
+         }
+       ),
+       do: url
+
+  defp maybe_emoji_url(_, _), do: nil
+
   def emoji_count(reactions_list) do
-    Enum.reduce(reactions_list, 0, fn [_, users], acc -> acc + length(users) end)
+    Enum.reduce(reactions_list, 0, fn [_, users, _], acc -> acc + length(users) end)
   end
 
   def remove_emoji_reaction_from_object(
-        %Activity{data: %{"content" => emoji, "actor" => actor}},
+        %Activity{data: %{"content" => emoji, "actor" => actor}} = activity,
         object
       ) do
+    emoji = Pleroma.Emoji.maybe_strip_name(emoji)
     reactions = get_cached_emoji_reactions(object)
+    url = maybe_emoji_url(emoji, activity)
 
     new_reactions =
-      case Enum.find_index(reactions, fn [candidate, _] -> emoji == candidate end) do
+      case Enum.find_index(reactions, fn [candidate, _, candidate_url] ->
+             if is_nil(candidate_url) do
+               emoji == candidate
+             else
+               url == candidate_url
+             end
+           end) do
         nil ->
           reactions
 
@@ -367,9 +397,9 @@ defmodule Pleroma.Web.ActivityPub.Utils do
           List.update_at(
             reactions,
             index,
-            fn [emoji, users] -> [emoji, List.delete(users, actor)] end
+            fn [emoji, users, url] -> [emoji, List.delete(users, actor), url] end
           )
-          |> Enum.reject(fn [_, users] -> Enum.empty?(users) end)
+          |> Enum.reject(fn [_, users, _] -> Enum.empty?(users) end)
       end
 
     count = emoji_count(new_reactions)
@@ -489,17 +519,37 @@ defmodule Pleroma.Web.ActivityPub.Utils do
 
   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)
+    emoji = Pleroma.Emoji.maybe_quote(emoji)
 
     "EmojiReact"
     |> Activity.Queries.by_type()
     |> where(actor: ^ap_id)
-    |> where([activity], fragment("?->>'content' = ?", activity.data, ^emoji))
+    |> custom_emoji_discriminator(emoji)
     |> Activity.Queries.by_object_id(object_ap_id)
     |> order_by([activity], fragment("? desc nulls last", activity.id))
     |> limit(1)
     |> Repo.one()
   end
 
+  defp custom_emoji_discriminator(query, emoji) do
+    if String.contains?(emoji, "@") do
+      stripped = Pleroma.Emoji.maybe_strip_name(emoji)
+      [name, domain] = String.split(stripped, "@")
+      domain_pattern = "%/" <> domain <> "/%"
+      emoji_pattern = Pleroma.Emoji.maybe_quote(name)
+
+      query
+      |> where([activity], fragment("?->>'content' = ?
+        AND EXISTS (
+          SELECT FROM jsonb_array_elements(?->'tag') elem
+          WHERE elem->>'id' ILIKE ?
+        )", activity.data, ^emoji_pattern, activity.data, ^domain_pattern))
+    else
+      query
+      |> where([activity], fragment("?->>'content' = ?", activity.data, ^emoji))
+    end
+  end
+
   #### Announce-related helpers
 
   @doc """