[CORE][UTIL] Moved classes from util to core

And splitted up Common

src/Core/ModulesManager.php

@@ -0,0 +1,64 @@
+<?php
+
+/*
+ * This file is part of GNU social - https://www.gnu.org/software/social
+ *
+ * GNU social is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * GNU social is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with GNU social.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/**
+ * Module and plugin loader code, one of the main features of GNU social
+ *
+ * Loads plugins from `plugins/enabled`, instances them
+ * and hooks its events
+ *
+ * @package   GNUsocial
+ * @category  Modules
+ *
+ * @author    Hugo Sales <hugo@fc.up.pt>
+ * @copyright 2020 Free Software Foundation, Inc http://www.fsf.org
+ * @license   https://www.gnu.org/licenses/agpl.html GNU AGPL v3 or later
+ */
+
+namespace App\Core;
+
+use Functional as F;
+use GSEvent as Event;
+
+abstract class ModulesManager
+{
+    public static array $modules = [];
+
+    public static function loadModules()
+    {
+        $plugins_paths = glob(INSTALLDIR . '/plugins/*');
+
+        foreach ($plugins_paths as $plugin_path) {
+            $class_name = basename($plugin_path);
+            $qualified  = 'Plugin\\' . $class_name . '\\' . $class_name;
+
+            require_once $plugin_path . '/' . $class_name . '.php';
+            $class           = new $qualified;
+            self::$modules[] = $class;
+
+            // Register event handlers
+            $methods = get_class_methods($class);
+            $events  = F\select($methods, F\partial_right('App\Util\Formatting::startsWith', 'on'));
+            F\map($events,
+                function (string $m) use ($class) {
+                    Event::addHandler(substr($m, 2), [$class, $m]);
+                });
+        }
+    }
+}