Insert text representation of hashtags into object["hashtags"]

Includes a new mix task: pleroma.database fill_old_hashtags

lib/mix/tasks/pleroma/database.ex

@@ -128,6 +128,49 @@ defmodule Mix.Tasks.Pleroma.Database do
     |> Stream.run()
   end
 
+  def run(["fill_old_hashtags"]) do
+    import Ecto.Query
+
+    start_pleroma()
+
+    from(
+      o in Object,
+      where: fragment("(?)->>'hashtags' is null", o.data),
+      where: fragment("(?)->>'tag' != '[]'", o.data),
+      select: %{id: o.id, tag: fragment("(?)->>'tag'", o.data)},
+      order_by: [:desc, o.id]
+    )
+    |> Pleroma.Repo.chunk_stream(200, :batches)
+    |> Stream.each(fn objects ->
+      Repo.transaction(fn ->
+        objects_first = objects |> List.first()
+        objects_last = objects |> List.last()
+
+        Logger.info(
+          "fill_old_hashtags: #{objects_first.id} (#{objects_first.inserted_at}) -- #{
+            objects_last.id
+          } (#{objects_last.inserted_at})"
+        )
+
+        objects
+        |> Enum.map(fn object ->
+          tags =
+            object.tag
+            |> Jason.decode!()
+            |> Enum.filter(&is_bitstring(&1))
+
+          Object
+          |> where([o], o.id == ^object.id)
+          |> update([o],
+            set: [data: fragment("safe_jsonb_set(?, '{hashtags}', ?, true)", o.data, ^tags)]
+          )
+          |> Repo.update_all([], timeout: :infinity)
+        end)
+      end)
+    end)
+    |> Stream.run()
+  end
+
   def run(["vacuum", args]) do
     start_pleroma()