<?php

/**
 *    Copyright (C) 2015 Deciso B.V.
 *
 *    All rights reserved.
 *
 *    Redistribution and use in source and binary forms, with or without
 *    modification, are permitted provided that the following conditions are met:
 *
 *    1. Redistributions of source code must retain the above copyright notice,
 *       this list of conditions and the following disclaimer.
 *
 *    2. Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *
 *    THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
 *    INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
 *    AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 *    AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
 *    OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 *    SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 *    INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 *    CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 *    ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 *    POSSIBILITY OF SUCH DAMAGE.
 *
 */
namespace OPNsense\Base\Menu;

/**
 * Class MenuSystem
 * @package OPNsense\Base\Menu
 */
class MenuSystem
{
    /**
     * @var null|MenuItem root node
     */
    private $root = null ;

    /**
     * add menu structure to root
     * @param string $filename menu xml filename
     * @throws MenuInitException unloadable menu xml
     */
    private function addXML($filename)
    {
        // load and validate menu xml
        if (!file_exists($filename)) {
            throw new MenuInitException('Menu xml '.$filename.' missing') ;
        }
        $menuXml = simplexml_load_file($filename);
        if ($menuXml === false) {
            throw new MenuInitException('Menu xml '.$filename.' not valid') ;
        }
        if ($menuXml->getName() != "menu") {
            throw new MenuInitException('Menu xml '.$filename.' seems to be of wrong type') ;
        }

        // traverse items
        foreach ($menuXml as $key => $node) {
            $this->root->addXmlNode($node);
        }
    }

    /**
     * append menu item to existing root
     * @param string $root xpath expression
     * @param string $id item if (tag name)
     * @param array $properties properties
     * @return null|MenuItem
     */
    public function appendItem($root, $id, $properties)
    {
        $node = $this->root;
        foreach (explode(".", $root) as $key) {
            $node = $node->findNodeById($key);
            if ($node == null) {
                return null;
            }
        }

        return $node->append($id, $properties);
    }

    /**
     * construct a new menu
     * @throws MenuInitException
     */
    public function __construct()
    {
        $this->root = new MenuItem("root");
        // crawl all vendors and modules and add menu definitions
        foreach (glob(__DIR__.'/../../../*') as $vendor) {
            foreach (glob($vendor.'/*') as $module) {
                $menu_cfg_xml = $module.'/Menu/Menu.xml';
                if (file_exists($menu_cfg_xml)) {
                    $this->addXML($menu_cfg_xml);
                }
            }
        }
    }

    /**
     * return full menu system including selected items
     * @param string $url current location
     * @return array
     */
    public function getItems($url)
    {
        $this->root->toggleSelected($url);
        $menu = $this->root->getChildren();

        return $menu;
    }

    /**
     * return the currently selected page's breadcrumbs
     * @return array
     */
    public function getBreadcrumbs()
    {
        $nodes = $this->root->getChildren();
        $breadcrumbs = array();

        while ($nodes != null) {
            $next = null;
            foreach ($nodes as $node) {
                if ($node->Selected) {
                    $breadcrumbs[] = array('name' => $node->VisibleName);
                    /* only go as far as the first reachable URL */
                    $next = empty($node->Url) ? $node->Children : null;
                    break;
                }
            }
            $nodes = $next;
        }

        return $breadcrumbs;
    }
}
