git.squeep.com Git - akkoma/blob - priv/repo/migrations/20190515222404_add_thread_visibility_function.exs

   1 defmodule Pleroma.Repo.Migrations.AddThreadVisibilityFunction do
   2   use Ecto.Migration
   3   @disable_ddl_transaction true
   4
   5   def up do
   6     statement = """
   7     CREATE OR REPLACE FUNCTION thread_visibility(actor varchar, activity_id varchar) RETURNS boolean AS $$
   8     DECLARE
   9       public varchar := 'https://www.w3.org/ns/activitystreams#Public';
  10       child objects%ROWTYPE;
  11       activity activities%ROWTYPE;
  12       actor_user users%ROWTYPE;
  13       author_fa varchar;
  14       valid_recipients varchar[];
  15     BEGIN
  16       --- Fetch our actor.
  17       SELECT * INTO actor_user FROM users WHERE users.ap_id = actor;
  18
  19       --- Fetch our initial activity.
  20       SELECT * INTO activity FROM activities WHERE activities.data->>'id' = activity_id;
  21
  22       LOOP
  23         --- Ensure that we have an activity before continuing.
  24         --- If we don't, the thread is not satisfiable.
  25         IF activity IS NULL THEN
  26           RETURN false;
  27         END IF;
  28
  29         --- We only care about Create activities.
  30         IF activity.data->>'type' != 'Create' THEN
  31           RETURN true;
  32         END IF;
  33
  34         --- Normalize the child object into child.
  35         SELECT * INTO child FROM objects
  36         INNER JOIN activities ON COALESCE(activities.data->'object'->>'id', activities.data->>'object') = objects.data->>'id'
  37         WHERE COALESCE(activity.data->'object'->>'id', activity.data->>'object') = objects.data->>'id';
  38
  39         --- Fetch the author's AS2 following collection.
  40         SELECT COALESCE(users.follower_address, '') INTO author_fa FROM users WHERE users.ap_id = activity.actor;
  41
  42         --- Prepare valid recipients array.
  43         valid_recipients := ARRAY[actor, public];
  44         IF ARRAY[author_fa] && actor_user.following THEN
  45           valid_recipients := valid_recipients || author_fa;
  46         END IF;
  47
  48         --- Check visibility.
  49         IF NOT valid_recipients && activity.recipients THEN
  50           --- activity not visible, break out of the loop
  51           RETURN false;
  52         END IF;
  53
  54         --- If there's a parent, load it and do this all over again.
  55         IF (child.data->'inReplyTo' IS NOT NULL) AND (child.data->'inReplyTo' != 'null'::jsonb) THEN
  56           SELECT * INTO activity FROM activities
  57           INNER JOIN objects ON COALESCE(activities.data->'object'->>'id', activities.data->>'object') = objects.data->>'id'
  58           WHERE child.data->>'inReplyTo' = objects.data->>'id';
  59         ELSE
  60           RETURN true;
  61         END IF;
  62       END LOOP;
  63     END;
  64     $$ LANGUAGE plpgsql IMMUTABLE;
  65     """
  66
  67     execute(statement)
  68   end
  69
  70   def down do
  71     execute("drop function if exists thread_visibility(actor varchar, activity_id varchar)")
  72   end
  73 end