<?php

namespace Providers;

require_once('Provider.php');

abstract class XmlFeed extends \Providers\Provider {

    protected $_feedUrl;
    protected $_feedXml;

    abstract protected function _getFeedUrl($feed);

    public function __construct($feed, $options=[]) {
        parent::__construct($feed, $options);
        $this->_feedUrl = $this->_getFeedUrl($feed);
        if (!$this->_feedUrl) {
            throw new \Exception('XML feed "' . $feed . '" undefined');
        }
    }

    abstract protected function _parseFeedContent($feed);

    protected function _fetchFeedContent($url) {
        $userAgent = file_get_contents('../config/user-agent');
        $context = stream_context_create([
            'http' => [
                'method' => "GET",
                'header' => "Accept: text/html,application/xml,application/xhtml+xml,text/xml\r\nAccept-Language: en;1=0.7\r\nUser-Agent: " . $userAgent,
            ]
        ]);
        return trim(file_get_contents($url, FALSE, $context));
    }

    protected function _fetchItems() {
        $feedContent = $this->_fetchFeedContent($this->_feedUrl);
        $this->_feedXml = new \SimpleXMLElement($feedContent);
        return $this->_parseFeedContent($this->_feedXml);
    }

    protected function _spamFilter($content) {
        return $content;
    }

    protected function _sortContent($content) {
        return $content;
    }

}

?>