Add single status fetching to TwAPI.

lib/pleroma/web/twitter_api/twitter_api.ex

@@ -69,9 +69,19 @@ defmodule Pleroma.Web.TwitterAPI.TwitterAPI do
 
   defp activities_to_statuses(activities, opts) do
     Enum.map(activities, fn(activity) ->
-      actor = get_in(activity.data, ["actor"])
-      user = Repo.get_by!(User, ap_id: actor)
-      ActivityRepresenter.to_map(activity, Map.merge(opts, %{user: user}))
+      activity_to_status(activity, opts)
     end)
   end
+
+  defp activity_to_status(activity, opts) do
+    actor = get_in(activity.data, ["actor"])
+    user = Repo.get_by!(User, ap_id: actor)
+    ActivityRepresenter.to_map(activity, Map.merge(opts, %{user: user}))
+  end
+
+  def fetch_status(user, id) do
+    with %Activity{} = activity <- Repo.get(Activity, id) do
+      activity_to_status(activity, %{for: user})
+    end
+  end
 end

lib/pleroma/web/twitter_api/twitter_api_controller.ex

@@ -50,6 +50,13 @@ defmodule Pleroma.Web.TwitterAPI.Controller do
     |> json_reply(200, response)
   end
 
+  def fetch_status(%{assigns: %{user: user}} = conn, %{ "id" => id }) do
+    response = TwitterAPI.fetch_status(user, id) |> Poison.encode!
+
+    conn
+    |> json_reply(200, response)
+  end
+
   defp json_reply(conn, status, json) do
     conn
     |> put_resp_content_type("application/json")