- UPDATE
- users
- SET
- following = following_query.following_array,
- updated_at = now()
- FROM (
- SELECT
- follwer.id AS follower_id,
- CASE follwer.local
- WHEN TRUE THEN
- array_prepend(follwer.follower_address, array_agg(following.follower_address))
- ELSE
- array_agg(following.follower_address)
- END AS following_array
- FROM
- following_relationships
- JOIN users AS follwer ON follwer.id = following_relationships.follower_id
- JOIN users AS FOLLOWING ON following.id = following_relationships.following_id
- GROUP BY
- follwer.id) AS following_query
- WHERE
- following_query.follower_id = users.id
+ CREATE OR REPLACE FUNCTION thread_visibility(actor varchar, activity_id varchar) RETURNS boolean AS $$
+ DECLARE
+ public varchar := 'https://www.w3.org/ns/activitystreams#Public';
+ child objects%ROWTYPE;
+ activity activities%ROWTYPE;
+ actor_user users%ROWTYPE;
+ author_fa varchar;
+ valid_recipients varchar[];
+ BEGIN
+ --- Fetch our actor.
+ SELECT * INTO actor_user FROM users WHERE users.ap_id = actor;
+
+ --- Fetch our initial activity.
+ SELECT * INTO activity FROM activities WHERE activities.data->>'id' = activity_id;
+
+ LOOP
+ --- Ensure that we have an activity before continuing.
+ --- If we don't, the thread is not satisfiable.
+ IF activity IS NULL THEN
+ RETURN false;
+ END IF;
+
+ --- We only care about Create activities.
+ IF activity.data->>'type' != 'Create' THEN
+ RETURN true;
+ END IF;
+
+ --- Normalize the child object into child.
+ SELECT * INTO child FROM objects
+ INNER JOIN activities ON COALESCE(activities.data->'object'->>'id', activities.data->>'object') = objects.data->>'id'
+ WHERE COALESCE(activity.data->'object'->>'id', activity.data->>'object') = objects.data->>'id';
+
+ --- Fetch the author's AS2 following collection.
+ SELECT COALESCE(users.follower_address, '') INTO author_fa FROM users WHERE users.ap_id = activity.actor;
+
+ --- Prepare valid recipients array.
+ valid_recipients := ARRAY[actor, public];
+ IF ARRAY[author_fa] && actor_user.following THEN
+ valid_recipients := valid_recipients || author_fa;
+ END IF;
+
+ --- Check visibility.
+ IF NOT valid_recipients && activity.recipients THEN
+ --- activity not visible, break out of the loop
+ RETURN false;
+ END IF;
+
+ --- If there's a parent, load it and do this all over again.
+ IF (child.data->'inReplyTo' IS NOT NULL) AND (child.data->'inReplyTo' != 'null'::jsonb) THEN
+ SELECT * INTO activity FROM activities
+ INNER JOIN objects ON COALESCE(activities.data->'object'->>'id', activities.data->>'object') = objects.data->>'id'
+ WHERE child.data->>'inReplyTo' = objects.data->>'id';
+ ELSE
+ RETURN true;
+ END IF;
+ END LOOP;
+ END;
+ $$ LANGUAGE plpgsql IMMUTABLE;