Add plugins discovery means

src/mibew/libs/classes/Mibew/Plugin/Utils.php

@@ -0,0 +1,70 @@
+<?php
+/*
+ * This file is a part of Mibew Messenger.
+ *
+ * Copyright 2005-2014 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+namespace Mibew\Plugin;
+
+/**
+ * Contains a set of utility methods.
+ */
+class Utils
+{
+    /**
+     * Gets list of plugins existing in File System.
+     *
+     * @return array List of existing plugins. Each item is a full plugin name
+     *   in "Vendor:Name" format.
+     */
+    public static function discoverPlugins()
+    {
+        $pattern = MIBEW_FS_ROOT . str_replace(
+            '/',
+            DIRECTORY_SEPARATOR,
+            '/plugins/*/Mibew/Plugin/*/Plugin.php'
+        );
+
+        $plugins = array();
+        foreach (glob($pattern) as $plugin_file) {
+            $parts = array_reverse(explode(DIRECTORY_SEPARATOR, $plugin_file));
+            $plugin = $parts[1];
+            $vendor = $parts[4];
+
+            $class_name = '\\' . $vendor . '\\Mibew\\Plugin\\' . $plugin . '\\Plugin';
+
+            // Check plugin class name
+            if (!class_exists($class_name)) {
+                continue;
+            }
+            // Check if plugin implements 'Plugin' interface
+            if (!in_array('Mibew\\Plugin\\PluginInterface', class_implements($class_name))) {
+                continue;
+            }
+
+            $plugins[] = $vendor . ':' . $plugin;
+        }
+
+        return $plugins;
+    }
+
+    /**
+     * This class should not be instantiated
+     */
+    private function __construct()
+    {
+    }
+}