- INSERT INTO
- following_relationships (
- follower_id,
- following_id,
- state,
- inserted_at,
- updated_at
- )
- SELECT
- followers.id,
- following.id,
- activities.data ->> 'state',
- (activities.data ->> 'published') :: timestamp,
- now()
- FROM
- activities
- JOIN users AS followers ON (activities.actor = followers.ap_id)
- JOIN users AS following ON (activities.data ->> 'object' = following.ap_id)
- WHERE
- activities.data ->> 'type' = 'Follow'
- AND activities.data ->> 'state' IN ('accept', 'pending', 'reject') ON CONFLICT DO NOTHING
+ 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;
+ author_fa varchar;
+ valid_recipients varchar[];
+ actor_user_following varchar[];
+ BEGIN
+ --- Fetch actor following
+ SELECT array_agg(following.follower_address) INTO actor_user_following FROM following_relationships
+ JOIN users ON users.id = following_relationships.follower_id
+ JOIN users AS following ON following.id = following_relationships.following_id
+ 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;