<?php

/**
 * XML feed export
 *
 * @license    GPL 2 (http://www.gnu.org/licenses/gpl.html)
 * @author     Andreas Gohr <andi@splitbrain.org>
 *
 * @global array $conf
 * @global Input $INPUT
 */

use dokuwiki\Feed\FeedCreator;
use dokuwiki\Feed\FeedCreatorOptions;
use dokuwiki\Cache\Cache;
use dokuwiki\ChangeLog\MediaChangeLog;
use dokuwiki\ChangeLog\PageChangeLog;
use dokuwiki\Extension\AuthPlugin;
use dokuwiki\Extension\Event;

if (!defined('DOKU_INC')) define('DOKU_INC', __DIR__ . '/');
require_once(DOKU_INC . 'inc/init.php');

//close session
session_write_close();

//feed disabled?
if (!actionOK('rss')) {
    http_status(404);
    echo '<error>RSS feed is disabled.</error>';
    exit;
}

$options = new FeedCreatorOptions();

// we only cache the recent cache, but do so based on dynamic parameters
// other modes are never cached and always created on the fly
$cache = null;
$cacheKey = $options->getCacheKey([
    $INPUT->server->str('REMOTE_USER'),
    $INPUT->server->str('HTTP_HOST'),
    $INPUT->server->str('SERVER_PORT'),
]);
if ($cacheKey !== null) {
    $cache = new Cache($cacheKey, '.feed');

    // prepare cache depends
    $depends['files'] = getConfigFiles('main');
    $depends['age'] = $conf['rss_update'];
    $depends['purge'] = $INPUT->bool('purge');
}

// check cacheage and deliver if nothing has changed since last
// time or the update interval has not passed, also handles conditional requests
header('Cache-Control: must-revalidate, post-check=0, pre-check=0');
header('Pragma: public');
header('Content-Type: ' . $options->getMimeType());
header('X-Robots-Tag: noindex');
if ($cache?->useCache($depends)) {
    http_conditionalRequest($cache->getTime());
    if ($conf['allowdebug']) header("X-CacheUsed: $cache->cache");
    echo $cache->retrieveCache();
    exit;
} else {
    http_conditionalRequest(time());
}

// create new feed
try {
    $feed = (new FeedCreator($options))->build();
    $cache?->storeCache($feed);
    echo $feed;
} catch (Exception $e) {
    http_status(500);
    echo '<error>' . hsc($e->getMessage()) . '</error>';
    exit;
}