<?php

class stNavigationMenu implements \Iterator, \Countable
{
    /**
     * Elementy menu
     *
     * @var stNavigationMenuItem[]
     */
    private $items = array();

    /**
     * Dodaje elementu menu
     *
     * @param string $id Unikalne id elementu
     * @param string $title Tytuł elementu
     * @param string $url Url elementu
     * @param array $options Dodatkowe opcje elementu (icon, i18n, children)
     * @return stNavigationMenuItem
     */
    public function addItem($id, $title, $url = null, array $options = array())
    {
        $item = new stNavigationMenuItem($title, $url, $options);

        $this->items[$id] = $item;

        return $item;
    }

    /**
     * Zwraca elementu menu o podanym id
     *
     * @param string $id Id elementu menu
     * @return stNavigationMenuItem
     */
    public function getItem($id)
    {
        if (!isset($this->items[$id]))
        {
            throw new Exception(sprintf('Item "%s" does not exist', $id));
        }
        
        return $this->items[$id];
    }

    /**
     * Zwraca tablicę elementów menu
     * 
     * @return stNavigationMenuItem[] 
     */
    public function getItems()
    {
        return $this->items;
    }

    public function current()
    {
        return current($this->items);
    }

    public function next()
    {
        return next($this->items);
    }

    public function key()
    {
        return key($this->items);
    }

    public function valid()
    {
        return null !== $this->key();
    }

    public function rewind()
    {
        return reset($this->items);
    }

    public function count()
    {
        return count($this->items);
    }
}