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 users%ROWTYPE;
  14       author_fa 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.
  40         SELECT * INTO author FROM users WHERE users.ap_id = activity.actor;
  41
  42         --- Prepare author's AS2 followers collection.
  43         SELECT COALESCE(author.follower_address, '') INTO author_fa;
  44
  45         --- Check visibility.
  46         IF activity.actor = actor THEN
  47           --- activity visible
  48           NULL;
  49         ELSIF ARRAY[public] && activity.recipients THEN
  50           --- activity visible
  51           NULL;
  52         ELSIF ARRAY[author_fa] && activity.recipients AND ARRAY[author_fa] && actor_user.following THEN
  53           --- activity visible
  54           NULL;
  55         ELSIF ARRAY[actor] && activity.recipients THEN
  56           --- activity visible
  57           NULL;
  58         ELSE
  59           --- activity not visible, break out of the loop
  60           RETURN false;
  61         END IF;
  62
  63         --- If there's a parent, load it and do this all over again.
  64         IF (child.data->'inReplyTo' IS NOT NULL) AND (child.data->'inReplyTo' != 'null'::jsonb) THEN
  65           SELECT * INTO activity FROM activities
  66           INNER JOIN objects ON COALESCE(activities.data->'object'->>'id', activities.data->>'object') = objects.data->>'id'
  67           WHERE child.data->>'inReplyTo' = objects.data->>'id';
  68         ELSE
  69           RETURN true;
  70         END IF;
  71       END LOOP;
  72     END;
  73     $$ LANGUAGE plpgsql IMMUTABLE;
  74     """
  75
  76     execute(statement)
  77   end
  78
  79   def down do
  80     execute("drop function thread_visibility(actor varchar, activity_id varchar)")
  81   end
  82 end