Merge branch 'activitypub-likes' into 'develop'

Activitypub c2s likes

See merge request pleroma/pleroma!658

lib/pleroma/web/activity_pub/activity_pub_controller.ex

@@ -54,6 +54,36 @@ defmodule Pleroma.Web.ActivityPub.ActivityPubController do
     end
   end
 
+  def object_likes(conn, %{"uuid" => uuid, "page" => page}) do
+    with ap_id <- o_status_url(conn, :object, uuid),
+         %Object{} = object <- Object.get_cached_by_ap_id(ap_id),
+         {_, true} <- {:public?, ActivityPub.is_public?(object)},
+         likes <- Utils.get_object_likes(object) do
+      {page, _} = Integer.parse(page)
+
+      conn
+      |> put_resp_header("content-type", "application/activity+json")
+      |> json(ObjectView.render("likes.json", ap_id, likes, page))
+    else
+      {:public?, false} ->
+        {:error, :not_found}
+    end
+  end
+
+  def object_likes(conn, %{"uuid" => uuid}) do
+    with ap_id <- o_status_url(conn, :object, uuid),
+         %Object{} = object <- Object.get_cached_by_ap_id(ap_id),
+         {_, true} <- {:public?, ActivityPub.is_public?(object)},
+         likes <- Utils.get_object_likes(object) do
+      conn
+      |> put_resp_header("content-type", "application/activity+json")
+      |> json(ObjectView.render("likes.json", ap_id, likes))
+    else
+      {:public?, false} ->
+        {:error, :not_found}
+    end
+  end
+
   def activity(conn, %{"uuid" => uuid}) do
     with ap_id <- o_status_url(conn, :activity, uuid),
          %Activity{} = activity <- Activity.normalize(ap_id),
@@ -204,6 +234,15 @@ defmodule Pleroma.Web.ActivityPub.ActivityPubController do
     end
   end
 
+  def handle_user_activity(user, %{"type" => "Like"} = params) do
+    with %Object{} = object <- Object.normalize(params["object"]),
+         {:ok, activity, _object} <- ActivityPub.like(user, object) do
+      {:ok, activity}
+    else
+      _ -> {:error, "Can't like object"}
+    end
+  end
+
   def handle_user_activity(_, _) do
     {:error, "Unhandled activity type"}
   end

lib/pleroma/web/activity_pub/transmogrifier.ex

@@ -629,6 +629,7 @@ defmodule Pleroma.Web.ActivityPub.Transmogrifier do
     |> add_mention_tags
     |> add_emoji_tags
     |> add_attributed_to
+    |> add_likes
     |> prepare_attachments
     |> set_conversation
     |> set_reply_to_uri
@@ -641,7 +642,7 @@ defmodule Pleroma.Web.ActivityPub.Transmogrifier do
   #  internal -> Mastodon
   #  """
 
-  def prepare_outgoing(%{"type" => "Create", "object" => %{"type" => "Note"} = object} = data) do
+  def prepare_outgoing(%{"type" => "Create", "object" => object} = data) do
     object =
       object
       |> prepare_object
@@ -788,6 +789,22 @@ defmodule Pleroma.Web.ActivityPub.Transmogrifier do
     |> Map.put("attributedTo", attributedTo)
   end
 
+  def add_likes(%{"id" => id, "like_count" => likes} = object) do
+    likes = %{
+      "id" => "#{id}/likes",
+      "first" => "#{id}/likes?page=1",
+      "type" => "OrderedCollection",
+      "totalItems" => likes
+    }
+
+    object
+    |> Map.put("likes", likes)
+  end
+
+  def add_likes(object) do
+    object
+  end
+
   def prepare_attachments(object) do
     attachments =
       (object["attachment"] || [])
@@ -803,7 +820,6 @@ defmodule Pleroma.Web.ActivityPub.Transmogrifier do
   defp strip_internal_fields(object) do
     object
     |> Map.drop([
-      "likes",
       "like_count",
       "announcements",
       "announcement_count",

lib/pleroma/web/activity_pub/utils.ex

@@ -231,6 +231,27 @@ defmodule Pleroma.Web.ActivityPub.Utils do
     Repo.one(query)
   end
 
+  @doc """
+  Returns like activities targeting an object
+  """
+  def get_object_likes(%{data: %{"id" => id}}) do
+    query =
+      from(
+        activity in Activity,
+        # this is to use the index
+        where:
+          fragment(
+            "coalesce((?)->'object'->>'id', (?)->>'object') = ?",
+            activity.data,
+            activity.data,
+            ^id
+          ),
+        where: fragment("(?)->>'type' = 'Like'", activity.data)
+      )
+
+    Repo.all(query)
+  end
+
   def make_like_data(%User{ap_id: ap_id} = actor, %{data: %{"id" => id}} = object, activity_id) do
     data = %{
       "type" => "Like",

lib/pleroma/web/activity_pub/views/object_view.ex

@@ -35,4 +35,38 @@ defmodule Pleroma.Web.ActivityPub.ObjectView do
 
     Map.merge(base, additional)
   end
+
+  def render("likes.json", ap_id, likes, page) do
+    collection(likes, "#{ap_id}/likes", page)
+    |> Map.merge(Pleroma.Web.ActivityPub.Utils.make_json_ld_header())
+  end
+
+  def render("likes.json", ap_id, likes) do
+    %{
+      "id" => "#{ap_id}/likes",
+      "type" => "OrderedCollection",
+      "totalItems" => length(likes),
+      "first" => collection(likes, "#{ap_id}/followers", 1)
+    }
+    |> Map.merge(Pleroma.Web.ActivityPub.Utils.make_json_ld_header())
+  end
+
+  def collection(collection, iri, page) do
+    offset = (page - 1) * 10
+    items = Enum.slice(collection, offset, 10)
+    items = Enum.map(items, fn object -> Transmogrifier.prepare_object(object.data) end)
+    total = length(collection)
+
+    map = %{
+      "id" => "#{iri}?page=#{page}",
+      "type" => "OrderedCollectionPage",
+      "partOf" => iri,
+      "totalItems" => total,
+      "orderedItems" => items
+    }
+
+    if offset < total do
+      Map.put(map, "next", "#{iri}?page=#{page + 1}")
+    end
+  end
 end

lib/pleroma/web/router.ex

@@ -421,6 +421,7 @@ defmodule Pleroma.Web.Router do
     get("/users/:nickname/followers", ActivityPubController, :followers)
     get("/users/:nickname/following", ActivityPubController, :following)
     get("/users/:nickname/outbox", ActivityPubController, :outbox)
+    get("/objects/:uuid/likes", ActivityPubController, :object_likes)
   end
 
   pipeline :activitypub_client do