<?php

/*
 * This file is part of Cachet.
 *
 * (c) Alt Three Services Limited
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

namespace CachetHQ\Cachet\Integrations\Core;

use CachetHQ\Cachet\Integrations\Contracts\Feed as FeedContract;
use Exception;
use GuzzleHttp\Client;
use Illuminate\Contracts\Cache\Repository;

/**
 * This is the feed class.
 *
 * @author James Brooks <james@alt-three.com>
 */
class Feed implements FeedContract
{
    /**
     * The default url.
     *
     * @var string
     */
    const URL = 'https://alt-three.com/tag/cachet/rss';

    /**
     * The failed status indicator.
     *
     * @var int
     */
    const FAILED = 1;

    /**
     * The cache repository instance.
     *
     * @var \Illuminate\Contracts\Cache\Repository
     */
    protected $cache;

    /**
     * The url to use.
     *
     * @var string|null
     */
    protected $url;

    /**
     * Creates a new feed instance.
     *
     * @param \Illuminate\Contracts\Cache\Repository $cache
     * @param string|null                            $url
     *
     * @return void
     */
    public function __construct(Repository $cache, $url = null)
    {
        $this->cache = $cache;
        $this->url = $url ?: static::URL;
    }

    /**
     * Returns the latest entries.
     *
     * @return array|null
     */
    public function latest()
    {
        $result = $this->cache->remember('feeds', 720, function () {
            try {
                $xml = simplexml_load_string((new Client())->get($this->url, [
                    'headers' => ['Accept' => 'application/rss+xml', 'User-Agent' => defined('CACHET_VERSION') ? 'cachet/'.constant('CACHET_VERSION') : 'cachet'],
                ])->getBody()->getContents(), null, LIBXML_NOCDATA);

                return json_decode(json_encode($xml));
            } catch (Exception $e) {
                return self::FAILED;
            }
        });

        return $result === self::FAILED ? null : $result;
    }
}