Gazelle/classes/wiki.class.php

<?php
declare(strict_types = 1);

class Wiki
{
    /**
     * Normalize an alias
     * @param string $str
     * @return string
     */
    public static function normalize_alias($str)
    {
        return trim(substr(preg_replace('/[^a-z0-9]/', '', strtolower(htmlentities($str))), 0, 50));
    }

    /**
     * Get all aliases in an associative array of Alias => ArticleID
     * @return array
     */
    public static function get_aliases()
    {
        $Aliases = G::$Cache->get_value('wiki_aliases');
        if (!$Aliases) {
            $QueryID = G::$DB->get_query_id();
            G::$DB->query("
            SELECT Alias, ArticleID
            FROM wiki_aliases");
            $Aliases = G::$DB->to_pair('Alias', 'ArticleID');
            G::$DB->set_query_id($QueryID);
            G::$Cache->cache_value('wiki_aliases', $Aliases, 3600 * 24 * 14); // 2 weeks
        }
        return $Aliases;
    }

    /**
     * Flush the alias cache. Call this whenever you touch the wiki_aliases table.
     */
    public static function flush_aliases()
    {
        G::$Cache->delete_value('wiki_aliases');
    }

    /**
     * Get the ArticleID corresponding to an alias
     * @param string $Alias
     * @return int
     */
    public static function alias_to_id($Alias)
    {
        $Aliases = self::get_aliases();
        $Alias = self::normalize_alias($Alias);
        if (!isset($Aliases[$Alias])) {
            return false;
        } else {
            return (int)$Aliases[$Alias];
        }
    }

    /**
     * Get an article; returns false on error if $Error = false
     * @param int $ArticleID
     * @param bool $Error
     * @return array|bool
     */
    public static function get_article($ArticleID, $Error = true)
    {
        $Contents = G::$Cache->get_value('wiki_article_'.$ArticleID);
        if (!$Contents) {
            $QueryID = G::$DB->get_query_id();
            G::$DB->query("
            SELECT
              w.Revision,
              w.Title,
              w.Body,
              w.MinClassRead,
              w.MinClassEdit,
              w.Date,
              w.Author,
              u.Username,
            GROUP_CONCAT(a.Alias),
            GROUP_CONCAT(a.UserID)
            FROM wiki_articles AS w
              LEFT JOIN wiki_aliases AS a ON w.ID=a.ArticleID
              LEFT JOIN users_main AS u ON u.ID=w.Author
              WHERE w.ID='$ArticleID'
              GROUP BY w.ID");

            if (!G::$DB->has_results()) {
                if ($Error) {
                    error(404);
                } else {
                    return false;
                }
            }
            
            $Contents = G::$DB->to_array();
            G::$DB->set_query_id($QueryID);
            G::$Cache->cache_value('wiki_article_'.$ArticleID, $Contents, 3600 * 24 * 14); // 2 weeks
        }
        return $Contents;
    }

    /**
     * Flush an article's cache. Call this whenever you edited a wiki article or its aliases.
     * @param int $ArticleID
     */
    public static function flush_article($ArticleID)
    {
        G::$Cache->delete_value('wiki_article_'.$ArticleID);
    }
}