migrations: add migration to fill in recipients_to/recipients_cc fields

priv/repo/migrations/20180829082743_fill_recipients_to_and_cc_fields_in_activities.exs

@@ -0,0 +1,25 @@
+defmodule Pleroma.Repo.Migrations.FillRecipientsToAndCcFieldsInActivities do
+  use Ecto.Migration
+  alias Pleroma.{Repo, Activity}
+
+  def up do
+    max = Repo.aggregate(Activity, :max, :id)
+    if max do
+      IO.puts("#{max} activities")
+      chunks = 0..(round(max / 10_000))
+
+      Enum.each(chunks, fn (i) ->
+        min = i * 10_000
+        max = min + 10_000
+        execute("""
+        update activities set recipients_to = array(select jsonb_array_elements_text(data->'to')) where id > #{min} and id <= #{max} and jsonb_typeof(data->'to') = 'array';
+        """)
+        |> IO.inspect
+        execute("""
+        update activities set recipients_cc = array(select jsonb_array_elements_text(data->'cc')) where id > #{min} and id <= #{max} and jsonb_typeof(data->'cc') = 'array';
+        """)
+        |> IO.inspect
+      end)
+    end
+  end
+end