Allow reacting with remote emoji when they exist on the post (#200)

Co-authored-by: FloatingGhost <hannah@coffee-and-dreams.uk>
Reviewed-on: https://akkoma.dev/AkkomaGang/akkoma/pulls/200

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 +55,85 @@ 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
+    data
+    |> Map.put("content", Emoji.maybe_quote(emoji))
+    |> Map.put("type", "EmojiReact")
+    |> Map.put("tag", [
+      %{}
+      |> Map.put("id", url)
+      |> Map.put("type", "Emoji")
+      |> Map.put("name", Emoji.maybe_quote(emoji))
+      |> Map.put(
+        "icon",
+        %{}
+        |> Map.put("type", "Image")
+        |> Map.put("url", url)
+      )
+    ])
+  end
+
+  defp remote_custom_emoji_react(
+         %{data: %{"reactions" => existing_reactions}},
+         data,
+         emoji
+       ) do
+    [emoji_code, instance] = String.split(Emoji.stripped_name(emoji), "@")
+
+    matching_reaction =
+      Enum.find(
+        existing_reactions,
+        fn [name, _, url] ->
+          url = URI.parse(url)
+          url.host == instance && name == emoji_code
+        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 %{} = emojo <- Emoji.get(emoji) do
+      path = emojo |> Map.get(:file)
+      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
+        if Emoji.is_unicode_emoji?(emoji) do
-        |> Map.put("content", emoji)
+          unicode_emoji_react(object, data, emoji)
-        |> Map.put("type", "EmojiReact")
+        else
+          custom_emoji_react(object, data, emoji)
+        end
 
       {:ok, data, meta}
     end

lib/pleroma/web/activity_pub/object_validators/emoji_react_validator.ex

@@ -5,6 +5,7 @@
 defmodule Pleroma.Web.ActivityPub.ObjectValidators.EmojiReactValidator do
   use Ecto.Schema
 
+  alias Pleroma.Emoji
   alias Pleroma.Object
   alias Pleroma.Web.ActivityPub.ObjectValidators.CommonFixes
 
@@ -12,6 +13,7 @@ defmodule Pleroma.Web.ActivityPub.ObjectValidators.EmojiReactValidator do
   import Pleroma.Web.ActivityPub.ObjectValidators.CommonValidations
 
   @primary_key false
+  @emoji_regex ~r/:[A-Za-z0-9_-]+(@.+)?:/
 
   embedded_schema do
     quote do
@@ -19,6 +21,7 @@ defmodule Pleroma.Web.ActivityPub.ObjectValidators.EmojiReactValidator do
         import Elixir.Pleroma.Web.ActivityPub.ObjectValidators.CommonFields
         message_fields()
         activity_fields()
+        tag_fields()
       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 +57,21 @@ defmodule Pleroma.Web.ActivityPub.ObjectValidators.EmojiReactValidator do
       |> CommonFixes.fix_actor()
       |> CommonFixes.fix_activity_addressing()
 
-    with %Object{} = object <- Object.normalize(data["object"]) do
+    data =
-      data
+      if Map.has_key?(data, "tag") do
-      |> CommonFixes.fix_activity_context(object)
+        data
-      |> CommonFixes.fix_object_action_recipients(object)
+      else
-    else
+        Map.put(data, "tag", [])
-      _ -> data
+      end
+
+    case Object.normalize(data["object"]) do
+      %Object{} = object ->
+        data
+        |> CommonFixes.fix_activity_context(object)
+        |> CommonFixes.fix_object_action_recipients(object)
+
+      _ ->
+        data
     end
   end
 
@@ -79,14 +92,37 @@ defmodule Pleroma.Web.ActivityPub.ObjectValidators.EmojiReactValidator do
 
   defp fix_emoji_qualification(data), do: data
 
+  defp matches_shortcode?(nil), do: false
+  defp matches_shortcode?(s), do: Regex.match?(@emoji_regex, s)
+
   defp validate_emoji(cng) do
     content = get_field(cng, :content)
 
-    if Pleroma.Emoji.is_unicode_emoji?(content) do
+    if Emoji.is_unicode_emoji?(content) || matches_shortcode?(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.stripped_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 +133,6 @@ defmodule Pleroma.Web.ActivityPub.ObjectValidators.EmojiReactValidator do
     |> validate_actor_presence()
     |> validate_object_presence()
     |> validate_emoji()
+    |> maybe_validate_tag_presence()
   end
 end

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.stripped_name(emoji)
+    url = 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 emoji_url(
+         name,
+         %Activity{
+           data: %{
+             "tag" => [
+               %{"type" => "Emoji", "name" => name, "icon" => %{"url" => url}}
+             ]
+           }
+         }
+       ),
+       do: url
+
+  defp 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.stripped_name(emoji)
     reactions = get_cached_emoji_reactions(object)
+    url = 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.stripped_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 """

lib/pleroma/web/mastodon_api/views/status_view.ex

@@ -340,8 +340,8 @@ defmodule Pleroma.Web.MastodonAPI.StatusView do
         opts[:for],
         Map.get(opts, :with_muted, false)
       )
-      |> Stream.map(fn {emoji, users} ->
+      |> Stream.map(fn {emoji, users, url} ->
-        build_emoji_map(emoji, users, opts[:for])
+        build_emoji_map(emoji, users, url, opts[:for])
       end)
       |> Enum.to_list()
 
@@ -702,11 +702,13 @@ defmodule Pleroma.Web.MastodonAPI.StatusView do
     end
   end
 
-  defp build_emoji_map(emoji, users, current_user) do
+  defp build_emoji_map(emoji, users, url, current_user) do
     %{
-      name: emoji,
+      name: Pleroma.Web.PleromaAPI.EmojiReactionView.emoji_name(emoji, url),
       count: length(users),
-      me: !!(current_user && current_user.ap_id in users)
+      url: MediaProxy.url(url),
+      me: !!(current_user && current_user.ap_id in users),
+      account_ids: Enum.map(users, fn user -> User.get_cached_by_ap_id(user).id end)
     }
   end
 

lib/pleroma/web/pleroma_api/controllers/emoji_reaction_controller.ex

@@ -50,29 +50,35 @@ defmodule Pleroma.Web.PleromaAPI.EmojiReactionController do
           if not with_muted, do: User.cached_muted_users_ap_ids(user), else: []
       end
 
-    filter_emoji = fn emoji, users ->
+    filter_emoji = fn emoji, users, url ->
       case Enum.reject(users, &(&1 in exclude_ap_ids)) do
         [] -> nil
-        users -> {emoji, users}
+        users -> {emoji, users, url}
       end
     end
 
     reactions
     |> Stream.map(fn
-      [emoji, users] when is_list(users) -> filter_emoji.(emoji, users)
+      [emoji, users, url] when is_list(users) -> filter_emoji.(emoji, users, url)
-      {emoji, users} when is_list(users) -> filter_emoji.(emoji, users)
+      {emoji, users, url} when is_list(users) -> filter_emoji.(emoji, users, url)
+      {emoji, users} when is_list(users) -> filter_emoji.(emoji, users, nil)
       _ -> nil
     end)
     |> Stream.reject(&is_nil/1)
   end
 
   defp filter(reactions, %{emoji: emoji}) when is_binary(emoji) do
-    Enum.filter(reactions, fn [e, _] -> e == emoji end)
+    Enum.filter(reactions, fn [e, _, _] -> e == emoji end)
   end
 
   defp filter(reactions, _), do: reactions
 
   def create(%{assigns: %{user: user}} = conn, %{id: activity_id, emoji: emoji}) do
+    emoji =
+      emoji
+      |> Pleroma.Emoji.fully_qualify_emoji()
+      |> Pleroma.Emoji.maybe_quote()
+
     with {:ok, _activity} <- CommonAPI.react_with_emoji(activity_id, user, emoji) do
       activity = Activity.get_by_id(activity_id)
 
@@ -83,6 +89,11 @@ defmodule Pleroma.Web.PleromaAPI.EmojiReactionController do
   end
 
   def delete(%{assigns: %{user: user}} = conn, %{id: activity_id, emoji: emoji}) do
+    emoji =
+      emoji
+      |> Pleroma.Emoji.fully_qualify_emoji()
+      |> Pleroma.Emoji.maybe_quote()
+
     with {:ok, _activity} <- CommonAPI.unreact_with_emoji(activity_id, user, emoji) do
       activity = Activity.get_by_id(activity_id)
 

lib/pleroma/web/pleroma_api/views/emoji_reaction_view.ex

@@ -7,17 +7,31 @@ defmodule Pleroma.Web.PleromaAPI.EmojiReactionView do
 
   alias Pleroma.Web.MastodonAPI.AccountView
 
+  def emoji_name(emoji, nil), do: emoji
+  alias Pleroma.Web.MediaProxy
+
+  def emoji_name(emoji, url) do
+    url = URI.parse(url)
+
+    if url.host == Pleroma.Web.Endpoint.host() do
+      emoji
+    else
+      "#{emoji}@#{url.host}"
+    end
+  end
+
   def render("index.json", %{emoji_reactions: emoji_reactions} = opts) do
     render_many(emoji_reactions, __MODULE__, "show.json", opts)
   end
 
-  def render("show.json", %{emoji_reaction: {emoji, user_ap_ids}, user: user}) do
+  def render("show.json", %{emoji_reaction: {emoji, user_ap_ids, url}, user: user}) do
     users = fetch_users(user_ap_ids)
 
     %{
-      name: emoji,
+      name: emoji_name(emoji, url),
       count: length(users),
       accounts: render(AccountView, "index.json", users: users, for: user),
+      url: MediaProxy.url(url),
       me: !!(user && user.ap_id in user_ap_ids)
     }
   end

test/pleroma/web/pleroma_api/controllers/emoji_reaction_controller_test.exs

@@ -17,23 +17,101 @@ defmodule Pleroma.Web.PleromaAPI.EmojiReactionControllerTest do
     user = insert(:user)
     other_user = insert(:user)
 
-    {:ok, activity} = CommonAPI.post(user, %{status: "#cofe"})
+    note = insert(:note, user: user, data: %{"reactions" => [["👍", [other_user.ap_id], nil]]})
+    activity = insert(:note_activity, note: note, user: user)
 
     result =
       conn
       |> assign(:user, other_user)
       |> assign(:token, insert(:oauth_token, user: other_user, scopes: ["write:statuses"]))
-      |> put("/api/v1/pleroma/statuses/#{activity.id}/reactions/☕")
+      |> put("/api/v1/pleroma/statuses/#{activity.id}/reactions/\u26A0")
       |> json_response_and_validate_schema(200)
 
-    # We return the status, but this our implementation detail.
     assert %{"id" => id} = result
     assert to_string(activity.id) == id
 
     assert result["pleroma"]["emoji_reactions"] == [
-             %{"name" => "☕", "count" => 1, "me" => true}
+             %{
+               "name" => "👍",
+               "count" => 1,
+               "me" => true,
+               "url" => nil,
+               "account_ids" => [other_user.id]
+             },
+             %{
+               "name" => "\u26A0\uFE0F",
+               "count" => 1,
+               "me" => true,
+               "url" => nil,
+               "account_ids" => [other_user.id]
+             }
            ]
 
+    {:ok, activity} = CommonAPI.post(user, %{status: "#cofe"})
+
+    ObanHelpers.perform_all()
+
+    # Reacting with a custom emoji
+    result =
+      conn
+      |> assign(:user, other_user)
+      |> assign(:token, insert(:oauth_token, user: other_user, scopes: ["write:statuses"]))
+      |> put("/api/v1/pleroma/statuses/#{activity.id}/reactions/:dinosaur:")
+      |> json_response_and_validate_schema(200)
+
+    assert %{"id" => id} = result
+    assert to_string(activity.id) == id
+
+    assert result["pleroma"]["emoji_reactions"] == [
+             %{
+               "name" => "dinosaur",
+               "count" => 1,
+               "me" => true,
+               "url" => "http://localhost:4001/emoji/dino walking.gif",
+               "account_ids" => [other_user.id]
+             }
+           ]
+
+    # Reacting with a remote emoji
+    note =
+      insert(:note,
+        user: user,
+        data: %{"reactions" => [["wow", [other_user.ap_id], "https://remote/emoji/wow"]]}
+      )
+
+    activity = insert(:note_activity, note: note, user: user)
+
+    result =
+      conn
+      |> assign(:user, user)
+      |> assign(:token, insert(:oauth_token, user: user, scopes: ["write:statuses"]))
+      |> put("/api/v1/pleroma/statuses/#{activity.id}/reactions/:wow@remote:")
+      |> json_response(200)
+
+    assert result["pleroma"]["emoji_reactions"] == [
+             %{
+               "name" => "wow@remote",
+               "count" => 2,
+               "me" => true,
+               "url" => "https://remote/emoji/wow",
+               "account_ids" => [user.id, other_user.id]
+             }
+           ]
+
+    # Reacting with a remote custom emoji that hasn't been reacted with yet
+    note =
+      insert(:note,
+        user: user
+      )
+
+    activity = insert(:note_activity, note: note, user: user)
+
+    assert conn
+           |> assign(:user, user)
+           |> assign(:token, insert(:oauth_token, user: user, scopes: ["write:statuses"]))
+           |> put("/api/v1/pleroma/statuses/#{activity.id}/reactions/:wow@remote:")
+           |> json_response(400)
+
     # Reacting with a non-emoji
     assert conn
            |> assign(:user, other_user)
@@ -46,8 +124,21 @@ defmodule Pleroma.Web.PleromaAPI.EmojiReactionControllerTest do
     user = insert(:user)
     other_user = insert(:user)
 
-    {:ok, activity} = CommonAPI.post(user, %{status: "#cofe"})
+    note =
+      insert(:note,
+        user: user,
+        data: %{"reactions" => [["wow", [user.ap_id], "https://remote/emoji/wow"]]}
+      )
+
+    activity = insert(:note_activity, note: note, user: user)
+
+    ObanHelpers.perform_all()
+
     {:ok, _reaction_activity} = CommonAPI.react_with_emoji(activity.id, other_user, "☕")
+    {:ok, _reaction_activity} = CommonAPI.react_with_emoji(activity.id, other_user, ":dinosaur:")
+
+    {:ok, _reaction_activity} =
+      CommonAPI.react_with_emoji(activity.id, other_user, ":wow@remote:")
 
     ObanHelpers.perform_all()
 
@@ -60,11 +151,47 @@ defmodule Pleroma.Web.PleromaAPI.EmojiReactionControllerTest do
     assert %{"id" => id} = json_response_and_validate_schema(result, 200)
     assert to_string(activity.id) == id
 
+    # Remove custom emoji
+
+    result =
+      conn
+      |> assign(:user, other_user)
+      |> assign(:token, insert(:oauth_token, user: other_user, scopes: ["write:statuses"]))
+      |> delete("/api/v1/pleroma/statuses/#{activity.id}/reactions/:dinosaur:")
+
+    assert %{"id" => id} = json_response_and_validate_schema(result, 200)
+    assert to_string(activity.id) == id
+
     ObanHelpers.perform_all()
 
     object = Object.get_by_ap_id(activity.data["object"])
 
-    assert object.data["reaction_count"] == 0
+    assert object.data["reaction_count"] == 2
+
+    # Remove custom remote emoji
+    result =
+      conn
+      |> assign(:user, other_user)
+      |> assign(:token, insert(:oauth_token, user: other_user, scopes: ["write:statuses"]))
+      |> delete("/api/v1/pleroma/statuses/#{activity.id}/reactions/:wow@remote:")
+      |> json_response(200)
+
+    assert result["pleroma"]["emoji_reactions"] == [
+             %{
+               "name" => "wow@remote",
+               "count" => 1,
+               "me" => false,
+               "url" => "https://remote/emoji/wow",
+               "account_ids" => [user.id]
+             }
+           ]
+
+    # Remove custom remote emoji that hasn't been reacted with yet
+    assert conn
+           |> assign(:user, other_user)
+           |> assign(:token, insert(:oauth_token, user: other_user, scopes: ["write:statuses"]))
+           |> delete("/api/v1/pleroma/statuses/#{activity.id}/reactions/:zoop@remote:")
+           |> json_response(400)
   end
 
   test "GET /api/v1/pleroma/statuses/:id/reactions", %{conn: conn} do
@@ -181,7 +308,15 @@ defmodule Pleroma.Web.PleromaAPI.EmojiReactionControllerTest do
     {:ok, _} = CommonAPI.react_with_emoji(activity.id, other_user, "🎅")
     {:ok, _} = CommonAPI.react_with_emoji(activity.id, other_user, "☕")
 
-    assert [%{"name" => "🎅", "count" => 1, "accounts" => [represented_user], "me" => false}] =
+    assert [
+             %{
+               "name" => "🎅",
+               "count" => 1,
+               "accounts" => [represented_user],
+               "me" => false,
+               "url" => nil
+             }
+           ] =
              conn
              |> get("/api/v1/pleroma/statuses/#{activity.id}/reactions/🎅")
              |> json_response_and_validate_schema(200)