<?php
/**
 * Zend Framework (http://framework.zend.com/)
 *
 * @link      http://github.com/zendframework/zf2 for the canonical source repository
 * @copyright Copyright (c) 2005-2012 Zend Technologies USA Inc. (http://www.zend.com)
 * @license   http://framework.zend.com/license/new-bsd New BSD License
 * @package   Zend_Feed
 */

namespace Zend\Feed\Writer\Extension\Atom\Renderer;

use DOMDocument;
use DOMElement;
use Zend\Feed\Writer\Extension;

/**
* @category Zend
* @package Zend_Feed_Writer
*/
class Feed extends Extension\AbstractRenderer
{

    /**
     * Set to TRUE if a rendering method actually renders something. This
     * is used to prevent premature appending of a XML namespace declaration
     * until an element which requires it is actually appended.
     *
     * @var bool
     */
    protected $called = false;

    /**
     * Render feed
     *
     * @return void
     */
    public function render()
    {
        /**
         * RSS 2.0 only. Used mainly to include Atom links and
         * Pubsubhubbub Hub endpoint URIs under the Atom namespace
         */
        if (strtolower($this->getType()) == 'atom') {
            return;
        }
        $this->_setFeedLinks($this->dom, $this->base);
        $this->_setHubs($this->dom, $this->base);
        if ($this->called) {
            $this->_appendNamespaces();
        }
    }

    /**
     * Append namespaces to root element of feed
     *
     * @return void
     */
    protected function _appendNamespaces()
    {
        $this->getRootElement()->setAttribute('xmlns:atom',
            'http://www.w3.org/2005/Atom');
    }

    /**
     * Set feed link elements
     *
     * @param  DOMDocument $dom
     * @param  DOMElement $root
     * @return void
     */
    protected function _setFeedLinks(DOMDocument $dom, DOMElement $root)
    {
        $flinks = $this->getDataContainer()->getFeedLinks();
        if (!$flinks || empty($flinks)) {
            return;
        }
        foreach ($flinks as $type => $href) {
            $mime  = 'application/' . strtolower($type) . '+xml';
            $flink = $dom->createElement('atom:link');
            $root->appendChild($flink);
            $flink->setAttribute('rel', 'self');
            $flink->setAttribute('type', $mime);
            $flink->setAttribute('href', $href);
        }
        $this->called = true;
    }

    /**
     * Set PuSH hubs
     *
     * @param  DOMDocument $dom
     * @param  DOMElement $root
     * @return void
     */
    protected function _setHubs(DOMDocument $dom, DOMElement $root)
    {
        $hubs = $this->getDataContainer()->getHubs();
        if (!$hubs || empty($hubs)) {
            return;
        }
        foreach ($hubs as $hubUrl) {
            $hub = $dom->createElement('atom:link');
            $hub->setAttribute('rel', 'hub');
            $hub->setAttribute('href', $hubUrl);
            $root->appendChild($hub);
        }
        $this->called = true;
    }
}
