Update thread visibility function

priv/repo/migrations/20220821004840_change_thread_visibility_to_use_new_object_id_index.exs

@@ -0,0 +1,156 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2022 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Repo.Migrations.ChangeThreadVisibilityToUseNewObjectIdIndex do
+  use Ecto.Migration
+
+  def up do
+    execute(update_thread_visibility())
+  end
+
+  def down do
+    execute(restore_thread_visibility())
+  end
+
+  def update_thread_visibility do
+    """
+    CREATE OR REPLACE FUNCTION thread_visibility(actor varchar, activity_id varchar, local_public varchar default '') 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 associated_object_id(activities.data) = objects.data->>'id'
+        WHERE associated_object_id(activity.data) = 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 we specified local public, add it.
+        IF local_public <> '' THEN
+          valid_recipients := valid_recipients || local_public;
+        END IF;
+        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 associated_object_id(activities.data) = objects.data->>'id'
+          WHERE child.data->>'inReplyTo' = objects.data->>'id';
+        ELSE
+          RETURN true;
+        END IF;
+      END LOOP;
+    END;
+    $$ LANGUAGE plpgsql IMMUTABLE;
+    """
+  end
+
+  # priv/repo/migrations/20220509180452_change_thread_visibility_to_be_local_only_aware.exs
+  def restore_thread_visibility do
+    """
+    CREATE OR REPLACE FUNCTION thread_visibility(actor varchar, activity_id varchar, local_public varchar default '') 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 we specified local public, add it.
+        IF local_public <> '' THEN
+          valid_recipients := valid_recipients || local_public;
+        END IF;
+        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;
+    """
+  end
+end