<?php
/**
 * Smarty Autoloader
 *
 * @package    Smarty
 */

/**
 * Smarty Autoloader
 *
 * @package    Smarty
 * @author     Uwe Tews
 *
 *             Usage:
 *             include '...path/Autoloader.php';
 *             Smarty_Autoloader::register();
 *             $smarty = new Smarty();
 *
 *             Note:       This autoloader is not needed if you use Composer.
 *             Composer will automatically add the classes of the Smarty package to it common autoloader.
 */
class Smarty_Autoloader
{
    /**
     * Filepath to Smarty root
     *
     * @var string
     */
    public static $SMARTY_DIR = '';
    /**
     * Filepath to Smarty internal plugins
     *
     * @var string
     */
    public static $SMARTY_SYSPLUGINS_DIR = '';
    /**
     * Array of not existing classes to avoid is_file calls for  already tested classes
     *
     * @var array
     */
    public static $unknown = array();
    /**
     * Array with Smarty core classes and their filename
     *
     * @var array
     */
    public static $rootClasses = array('Smarty'   => 'Smarty.class.php',
                                       'SmartyBC' => 'SmartyBC.class.php',
    );

    /**
     * Registers Smarty_Autoloader backward compatible to older installations.
     *
     * @param bool $prepend Whether to prepend the autoloader or not.
     */
    public static function registerBC($prepend = false)
    {
        /**
         * register the class autoloader
         */
        if (!defined('SMARTY_SPL_AUTOLOAD')) {
            define('SMARTY_SPL_AUTOLOAD', 0);
        }
        if (SMARTY_SPL_AUTOLOAD && set_include_path(get_include_path() . PATH_SEPARATOR . SMARTY_SYSPLUGINS_DIR) !== false) {
            $registeredAutoLoadFunctions = spl_autoload_functions();
            if (!isset($registeredAutoLoadFunctions['spl_autoload'])) {
                spl_autoload_register();
            }
        } else {
            self::register($prepend);
        }
    }

    /**
     * Registers Smarty_Autoloader as an SPL autoloader.
     *
     * @param bool $prepend Whether to prepend the autoloader or not.
     */
    public static function register($prepend = false)
    {
        self::$SMARTY_DIR = defined('SMARTY_DIR') ? SMARTY_DIR : dirname(__FILE__) . '/';
        self::$SMARTY_SYSPLUGINS_DIR = defined('SMARTY_SYSPLUGINS_DIR') ? SMARTY_SYSPLUGINS_DIR : self::$SMARTY_DIR . 'sysplugins/';
        if (version_compare(phpversion(), '5.3.0', '>=')) {
            spl_autoload_register(array(__CLASS__, 'autoload'), true, $prepend);
        } else {
            spl_autoload_register(array(__CLASS__, 'autoload'));
        }
    }

    /**
     * Handles autoloading of classes.
     *
     * @param string $class A class name.
     */
    public static function autoload($class)
    {
        // Request for Smarty or already unknown class
        if (0 !== strpos($class, 'Smarty') || isset(self::$unknown[$class])) {
            return;
        }
        if (isset(self::$rootClasses[$class]) && is_file($file = self::$SMARTY_DIR . self::$rootClasses[$class])) {
            require $file;
            return;
        }
        $_class = strtolower($class);
        if (is_file($file = self::$SMARTY_SYSPLUGINS_DIR . $_class . '.php')) {
            require $file;
        } else {
            self::$unknown[$class] = true;
        }
    }
}