<?php declare(strict_types = 1);
/*
** Zabbix
** Copyright (C) 2001-2020 Zabbix SIA
**
** This program is free software; you can redistribute it and/or modify
** it under the terms of the GNU General Public License as published by
** the Free Software Foundation; either version 2 of the License, or
** (at your option) any later version.
**
** This program 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 General Public License for more details.
**
** You should have received a copy of the GNU General Public License
** along with this program; if not, write to the Free Software
** Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
**/


/**
 * The Zabbix autoloader class.
 */
class CAutoloader {

	/**
	 * Registered namespace array. Key is namespace name with trailing '\' and value is array of directories
	 * relative path with trailing '/'.
	 *
	 * @var array
	 */
	protected $namespaces = [];

	/**
	 * Register supported namespace.
	 *
	 * @param string $namespace  Namespace value without trainling '\'.
	 * @param array  $paths      Array of namespace files directory absolute path without trailing '/'.
	 */
	public function addNamespace(string $namespace, array $paths): void {
		foreach ($paths as $path) {
			$path = realpath($path);

			if ($path) {
				$this->namespaces[$namespace][] = $path.'/';
			}
		}
	}

	/**
	 * Add "loadClass" method as an autoload handler.
	 *
	 * @return bool
	 */
	public function register(): bool {
		return spl_autoload_register([$this, 'loadClass']);
	}

	/**
	 * Attempts to find and load the given class.
	 *
	 * @param string $class_name
	 *
	 * @return bool
	 */
	protected function loadClass(string $class_name): bool {
		$chunks = explode('\\', $class_name);
		$file_name = array_pop($chunks).'.php';

		do {
			$namespace = implode('\\', $chunks);

			if (array_key_exists($namespace, $this->namespaces)) {
				foreach ($this->namespaces[$namespace] as $dir) {
					if (is_file($dir.$file_name)) {
						require $dir.$file_name;

						return true;
					}
				}
			}

			if ($chunks) {
				$file_name = strtolower(array_pop($chunks)).'/'.$file_name;
			}
		} while ($chunks);

		return false;
	}
}
