<?php
/**
 * Zend Framework (http://framework.zend.com/)
 *
 * @link      http://github.com/zendframework/zf2 for the canonical source repository
 * @copyright Copyright (c) 2005-2014 Zend Technologies USA Inc. (http://www.zend.com)
 * @license   http://framework.zend.com/license/new-bsd New BSD License
 */

namespace Zend\Permissions\Rbac;

use RecursiveIterator;

abstract class AbstractIterator implements RecursiveIterator
{
    /**
     * @var int
     */
    protected $index    = 0;
    /**
     * @var array
     */
    protected $children = array();

    /**
     * (PHP 5 &gt;= 5.0.0)<br/>
     * Return the current element
     * @link http://php.net/manual/en/iterator.current.php
     * @return mixed Can return any type.
     */
    public function current()
    {
        return $this->children[$this->index];
    }

    /**
     * (PHP 5 &gt;= 5.0.0)<br/>
     * Move forward to next element
     * @link http://php.net/manual/en/iterator.next.php
     * @return void Any returned value is ignored.
     */
    public function next()
    {
        $this->index++;
    }

    /**
     * (PHP 5 &gt;= 5.0.0)<br/>
     * Return the key of the current element
     * @link http://php.net/manual/en/iterator.key.php
     * @return int|null scalar on success, or null on failure.
     */
    public function key()
    {
        return $this->index;
    }

    /**
     * (PHP 5 &gt;= 5.0.0)<br/>
     * Checks if current position is valid
     * @link http://php.net/manual/en/iterator.valid.php
     * @return bool The return value will be casted to boolean and then evaluated.
     * Returns true on success or false on failure.
     */
    public function valid()
    {
        return isset($this->children[$this->index]);
    }

    /**
     * (PHP 5 &gt;= 5.0.0)<br/>
     * Rewind the Iterator to the first element
     * @link http://php.net/manual/en/iterator.rewind.php
     * @return void Any returned value is ignored.
     */
    public function rewind()
    {
        $this->index = 0;
    }

    /**
     * (PHP 5 &gt;= 5.1.0)<br/>
     * Returns if an iterator can be created fot the current entry.
     * @link http://php.net/manual/en/recursiveiterator.haschildren.php
     * @return bool true if the current entry can be iterated over, otherwise returns false.
     */
    public function hasChildren()
    {
        if ($this->valid() && ($this->current() instanceof RecursiveIterator)) {
            return true;
        }

        return false;
    }

    /**
     * (PHP 5 &gt;= 5.1.0)<br/>
     * Returns an iterator for the current entry.
     * @link http://php.net/manual/en/recursiveiterator.getchildren.php
     * @return RecursiveIterator An iterator for the current entry.
     */
    public function getChildren()
    {
        return $this->children[$this->index];
    }
}
