<?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\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', dirname(__FILE__) . '/');
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;
}

// get params
$opt = rss_parseOptions();

// the feed is dynamic - we need a cache for each combo
// (but most people just use the default feed so it's still effective)
$key   = join('', array_values($opt)) . '$' . $INPUT->server->str('REMOTE_USER')
    . '$' . $INPUT->server->str('HTTP_HOST') . $INPUT->server->str('SERVER_PORT');
$cache = new Cache($key, '.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: application/xml; charset=utf-8');
header('X-Robots-Tag: noindex');
if ($cache->useCache($depends)) {
    http_conditionalRequest($cache->getTime());
    if ($conf['allowdebug']) header("X-CacheUsed: $cache->cache");
    print $cache->retrieveCache();
    exit;
} else {
    http_conditionalRequest(time());
}

// create new feed
$rss                 = new UniversalFeedCreator();
$rss->title          = $conf['title'] . (($opt['namespace']) ? ' ' . $opt['namespace'] : '');
$rss->link           = DOKU_URL;
$rss->syndicationURL = DOKU_URL . 'feed.php';
$rss->cssStyleSheet  = DOKU_URL . 'lib/exe/css.php?s=feed';

$image        = new FeedImage();
$image->title = $conf['title'];
$image->url   = tpl_getMediaFile([':wiki:favicon.ico', ':favicon.ico', 'images/favicon.ico'], true);
$image->link  = DOKU_URL;
$rss->image   = $image;

$data  = null;
$modes = [
    'list'   => 'rssListNamespace',
    'search' => 'rssSearch',
    'recent' => 'rssRecentChanges'
];

if (isset($modes[$opt['feed_mode']])) {
    $data = $modes[$opt['feed_mode']]($opt);
} else {
    $eventData = [
        'opt'  => &$opt,
        'data' => &$data,
    ];
    $event     = new Event('FEED_MODE_UNKNOWN', $eventData);
    if ($event->advise_before(true)) {
        echo sprintf('<error>Unknown feed mode %s</error>', hsc($opt['feed_mode']));
        exit;
    }
    $event->advise_after();
}

rss_buildItems($rss, $data, $opt);
$feed = $rss->createFeed($opt['feed_type']);

// save cachefile
$cache->storeCache($feed);

// finally deliver
print $feed;

// ---------------------------------------------------------------- //

/**
 * Get URL parameters and config options and return an initialized option array
 *
 * @author Andreas Gohr <andi@splitbrain.org>
 */
function rss_parseOptions()
{
    global $conf;
    global $INPUT;

    $opt = [];

    foreach (
        [
            // Basic feed properties
            // Plugins may probably want to add new values to these
            // properties for implementing own feeds

            // One of: list, search, recent
            'feed_mode'    => ['str', 'mode', 'recent'],
            // One of: diff, page, rev, current
            'link_to'      => ['str', 'linkto', $conf['rss_linkto']],
            // One of: abstract, diff, htmldiff, html
            'item_content' => ['str', 'content', $conf['rss_content']],

            // Special feed properties
            // These are only used by certain feed_modes

            // String, used for feed title, in list and rc mode
            'namespace'    => ['str', 'ns', null],
            // Positive integer, only used in rc mode
            'items'        => ['int', 'num', $conf['recent']],
            // Boolean, only used in rc mode
            'show_minor'   => ['bool', 'minor', false],
            // Boolean, only used in rc mode
            'only_new'     => ['bool', 'onlynewpages', false],
            // String, only used in list mode
            'sort'         => ['str', 'sort', 'natural'],
            // String, only used in search mode
            'search_query' => ['str', 'q', null],
            // One of: pages, media, both
            'content_type' => ['str', 'view', $conf['rss_media']]

        ] as $name => $val
    ) {
        $opt[$name] = $INPUT->{$val[0]}($val[1], $val[2], true);
    }

    $opt['items']      = max(0, (int) $opt['items']);
    $opt['show_minor'] = (bool) $opt['show_minor'];
    $opt['only_new']   = (bool) $opt['only_new'];
    $opt['sort']       = valid_input_set('sort', ['default' => 'natural', 'date'], $opt);

    $opt['guardmail'] = ($conf['mailguard'] != '' && $conf['mailguard'] != 'none');

    $type = $INPUT->valid(
        'type',
        ['rss', 'rss2', 'atom', 'atom1', 'rss1'],
        $conf['rss_type']
    );
    switch ($type) {
        case 'rss':
            $opt['feed_type'] = 'RSS0.91';
            $opt['mime_type'] = 'text/xml';
            break;
        case 'rss2':
            $opt['feed_type'] = 'RSS2.0';
            $opt['mime_type'] = 'text/xml';
            break;
        case 'atom':
            $opt['feed_type'] = 'ATOM0.3';
            $opt['mime_type'] = 'application/xml';
            break;
        case 'atom1':
            $opt['feed_type'] = 'ATOM1.0';
            $opt['mime_type'] = 'application/atom+xml';
            break;
        default:
            $opt['feed_type'] = 'RSS1.0';
            $opt['mime_type'] = 'application/xml';
    }

    $eventData = [
        'opt' => &$opt,
    ];
    Event::createAndTrigger('FEED_OPTS_POSTPROCESS', $eventData);
    return $opt;
}

/**
 * Add recent changed pages to a feed object
 *
 * @param FeedCreator $rss  the FeedCreator Object
 * @param array       $data the items to add
 * @param array       $opt  the feed options
 * @author Andreas Gohr <andi@splitbrain.org>
 */
function rss_buildItems(&$rss, &$data, $opt)
{
    global $conf;
    global $lang;
    /* @var AuthPlugin $auth */
    global $auth;

    $eventData = [
        'rss'  => &$rss,
        'data' => &$data,
        'opt'  => &$opt,
    ];
    $event     = new Event('FEED_DATA_PROCESS', $eventData);
    if ($event->advise_before(false)) {
        foreach ($data as $ditem) {
            if (!is_array($ditem)) {
                // not an array? then only a list of IDs was given
                $ditem = ['id' => $ditem];
            }

            $item = new FeedItem();
            $id   = $ditem['id'];
            if (empty($ditem['media'])) {
                $meta = p_get_metadata($id);
            } else {
                $meta = [];
            }

            // add date
            if (isset($ditem['date'])) {
                $date = $ditem['date'];
            } elseif ($ditem['media']) {
                $date = @filemtime(mediaFN($id));
            } elseif (file_exists(wikiFN($id))) {
                $date = @filemtime(wikiFN($id));
            } elseif ($meta['date']['modified']) {
                $date = $meta['date']['modified'];
            } else {
                $date = 0;
            }
            if ($date) $item->date = date('r', $date);

            // add title
            if ($conf['useheading'] && $meta['title'] ?? '') {
                $item->title = $meta['title'];
            } else {
                $item->title = $ditem['id'];
            }
            if ($conf['rss_show_summary'] && !empty($ditem['sum'])) {
                $item->title .= ' - ' . strip_tags($ditem['sum']);
            }

            // add item link
            switch ($opt['link_to']) {
                case 'page':
                    if (isset($ditem['media'])) {
                        $item->link = media_managerURL(
                            [
                                'image' => $id,
                                'ns'    => getNS($id),
                                'rev'   => $date
                            ],
                            '&',
                            true
                        );
                    } else {
                        $item->link = wl($id, 'rev=' . $date, true, '&');
                    }
                    break;
                case 'rev':
                    if ($ditem['media']) {
                        $item->link = media_managerURL(
                            [
                                'image'       => $id,
                                'ns'          => getNS($id),
                                'rev'         => $date,
                                'tab_details' => 'history'
                            ],
                            '&',
                            true
                        );
                    } else {
                        $item->link = wl($id, 'do=revisions&rev=' . $date, true, '&');
                    }
                    break;
                case 'current':
                    if ($ditem['media']) {
                        $item->link = media_managerURL(
                            [
                                'image' => $id,
                                'ns'    => getNS($id)
                            ],
                            '&',
                            true
                        );
                    } else {
                        $item->link = wl($id, '', true, '&');
                    }
                    break;
                case 'diff':
                default:
                    if ($ditem['media']) {
                        $item->link = media_managerURL(
                            [
                                'image'       => $id,
                                'ns'          => getNS($id),
                                'rev'         => $date,
                                'tab_details' => 'history',
                                'mediado'     => 'diff'
                            ],
                            '&',
                            true
                        );
                    } else {
                        $item->link = wl($id, 'rev=' . $date . '&do=diff', true, '&');
                    }
            }

            // add item content
            switch ($opt['item_content']) {
                case 'diff':
                case 'htmldiff':
                    if ($ditem['media']) {
                        $medialog = new MediaChangeLog($id);
                        $revs     = $medialog->getRevisions(0, 1);
                        $rev      = $revs[0];
                        $src_r    = '';
                        $src_l    = '';

                        if ($size = media_image_preview_size($id, '', new JpegMeta(mediaFN($id)), 300)) {
                            $more  = 'w=' . $size[0] . '&h=' . $size[1] . '&t=' . @filemtime(mediaFN($id));
                            $src_r = ml($id, $more, true, '&amp;', true);
                        }
                        if ($rev && $size = media_image_preview_size($id, $rev, new JpegMeta(mediaFN($id, $rev)),
                                300)) {
                            $more = 'rev=' . $rev . '&w=' . $size[0] . '&h=' . $size[1];
                            $src_l = ml($id, $more, true, '&amp;', true);
                        }
                        $content = '';
                        if ($src_r) {
                            $content = '<table>';
                            $content .= '<tr><th width="50%">' . $rev . '</th>';
                            $content .= '<th width="50%">' . $lang['current'] . '</th></tr>';
                            $content .= '<tr align="center"><td><img src="' . $src_l . '" alt="" /></td><td>';
                            $content .= '<img src="' . $src_r . '" alt="' . $id . '" /></td></tr>';
                            $content .= '</table>';
                        }
                    } else {
                        require_once(DOKU_INC . 'inc/DifferenceEngine.php');
                        $pagelog = new PageChangeLog($id);
                        $revs    = $pagelog->getRevisions(0, 1);
                        $rev     = $revs[0];

                        if ($rev) {
                            $df = new Diff(
                                explode("\n", rawWiki($id, $rev)),
                                explode("\n", rawWiki($id, ''))
                            );
                        } else {
                            $df = new Diff(
                                [''],
                                explode("\n", rawWiki($id, ''))
                            );
                        }

                        if ($opt['item_content'] == 'htmldiff') {
                            // note: no need to escape diff output, TableDiffFormatter provides 'safe' html
                            $tdf     = new TableDiffFormatter();
                            $content = '<table>';
                            $content .= '<tr><th colspan="2" width="50%">' . $rev . '</th>';
                            $content .= '<th colspan="2" width="50%">' . $lang['current'] . '</th></tr>';
                            $content .= $tdf->format($df);
                            $content .= '</table>';
                        } else {
                            // note: diff output must be escaped, UnifiedDiffFormatter provides plain text
                            $udf     = new UnifiedDiffFormatter();
                            $content = "<pre>\n" . hsc($udf->format($df)) . "\n</pre>";
                        }
                    }
                    break;
                case 'html':
                    if ($ditem['media']) {
                        if ($size = media_image_preview_size($id, '', new JpegMeta(mediaFN($id)))) {
                            $more    = 'w=' . $size[0] . '&h=' . $size[1] . '&t=' . @filemtime(mediaFN($id));
                            $src  = ml($id, $more, true, '&amp;', true);
                            $content = '<img src="' . $src . '" alt="' . $id . '" />';
                        } else {
                            $content = '';
                        }
                    } else {
                        if (@filemtime(wikiFN($id)) === $date) {
                            $content = p_wiki_xhtml($id, '', false);
                        } else {
                            $content = p_wiki_xhtml($id, $date, false);
                        }
                        // no TOC in feeds
                        $content = preg_replace('/(<!-- TOC START -->).*(<!-- TOC END -->)/s', '', $content);

                        // add alignment for images
                        $content = preg_replace('/(<img .*?class="medialeft")/s', '\\1 align="left"', $content);
                        $content = preg_replace('/(<img .*?class="mediaright")/s', '\\1 align="right"', $content);

                        // make URLs work when canonical is not set, regexp instead of rerendering!
                        if (!$conf['canonical']) {
                            $base    = preg_quote(DOKU_REL, '/');
                            $content = preg_replace(
                                '/(<a href|<img src)="(' . $base . ')/s', '$1="' . DOKU_URL,
                                $content
                            );
                        }
                    }

                    break;
                case 'abstract':
                default:
                    if (isset($ditem['media'])) {
                        if ($size = media_image_preview_size($id, '', new JpegMeta(mediaFN($id)))) {
                            $more    = 'w=' . $size[0] . '&h=' . $size[1] . '&t=' . @filemtime(mediaFN($id));
                            $src  = ml($id, $more, true, '&amp;', true);
                            $content = '<img src="' . $src . '" alt="' . $id . '" />';
                        } else {
                            $content = '';
                        }
                    } else {
                        $content = $meta['description']['abstract'];
                    }
            }
            $item->description = $content; //FIXME a plugin hook here could be senseful

            // add user
            # FIXME should the user be pulled from metadata as well?
            $user = @$ditem['user']; // the @ spares time repeating lookup
            if (blank($user)) {
                $item->author      = 'Anonymous';
                $item->authorEmail = 'anonymous@undisclosed.example.com';
            } else {
                $item->author      = $user;
                $item->authorEmail = $user . '@undisclosed.example.com';

                // get real user name if configured
                if ($conf['useacl'] && $auth) {
                    $userInfo = $auth->getUserData($user);
                    if ($userInfo) {
                        switch ($conf['showuseras']) {
                            case 'username':
                            case 'username_link':
                                $item->author = $userInfo['name'];
                                break;
                            default:
                                $item->author = $user;
                                break;
                        }
                    } else {
                        $item->author = $user;
                    }
                }
            }

            // add category
            if (isset($meta['subject'])) {
                $item->category = $meta['subject'];
            } else {
                $cat = getNS($id);
                if ($cat) $item->category = $cat;
            }

            // finally add the item to the feed object, after handing it to registered plugins
            $evdata = [
                'item'  => &$item,
                'opt'   => &$opt,
                'ditem' => &$ditem,
                'rss'   => &$rss
            ];
            $evt    = new Event('FEED_ITEM_ADD', $evdata);
            if ($evt->advise_before()) {
                $rss->addItem($item);
            }
            $evt->advise_after(); // for completeness
        }
    }
    $event->advise_after();
}

/**
 * Add recent changed pages to the feed object
 *
 * @author Andreas Gohr <andi@splitbrain.org>
 */
function rssRecentChanges($opt)
{
    global $conf;
    $flags = 0;
    if (!$conf['rss_show_deleted']) $flags += RECENTS_SKIP_DELETED;
    if (!$opt['show_minor']) $flags += RECENTS_SKIP_MINORS;
    if ($opt['only_new']) $flags += RECENTS_ONLY_CREATION;
    if ($opt['content_type'] == 'media' && $conf['mediarevisions']) $flags += RECENTS_MEDIA_CHANGES;
    if ($opt['content_type'] == 'both' && $conf['mediarevisions']) $flags += RECENTS_MEDIA_PAGES_MIXED;

    $recents = getRecents(0, $opt['items'], $opt['namespace'], $flags);
    return $recents;
}

/**
 * Add all pages of a namespace to the feed object
 *
 * @author Andreas Gohr <andi@splitbrain.org>
 */
function rssListNamespace($opt)
{
    require_once(DOKU_INC . 'inc/search.php');
    global $conf;

    $ns = ':' . cleanID($opt['namespace']);
    $ns = utf8_encodeFN(str_replace(':', '/', $ns));

    $data        = [];
    $search_opts = [
        'depth'     => 1,
        'pagesonly' => true,
        'listfiles' => true
    ];
    search($data, $conf['datadir'], 'search_universal', $search_opts, $ns, $lvl = 1, $opt['sort']);

    return $data;
}

/**
 * Add the result of a full text search to the feed object
 *
 * @author Andreas Gohr <andi@splitbrain.org>
 */
function rssSearch($opt)
{
    if (!$opt['search_query'] || !actionOK('search')) return [];

    require_once(DOKU_INC . 'inc/fulltext.php');
    $data = ft_pageSearch($opt['search_query'], $poswords);
    $data = array_keys($data);

    return $data;
}

//Setup VIM: ex: et ts=4 :
