sitemap.php

require_once get_template_directory() . '/inc/seo/sitemap.php';

<?php
/**
 * RX Theme Advanced XML Sitemap System
 *
 * File: inc/seo/sitemap.php
 *
 * Features:
 * - Sitemap index
 * - Post sitemap
 * - Page sitemap
 * - Custom post type sitemap
 * - Category sitemap
 * - Tag sitemap
 * - Custom taxonomy sitemap
 * - Author sitemap
 * - Image sitemap support
 * - News-style recent sitemap support
 * - Automatic rewrite rules
 * - Query vars
 * - XML headers
 * - Excludes noindex content
 * - Yoast/Rank Math/AIOSEO noindex compatibility checks
 * - Cache with transients
 * - Cache clearing on post/category/tag/term changes
 * - robots.txt sitemap line
 * - Admin helper links
 */

if (!defined('ABSPATH')) {
    exit;
}

if (!class_exists('RX_Theme_Advanced_Sitemap')) :

final class RX_Theme_Advanced_Sitemap {

    /**
     * Main sitemap slug.
     *
     * Example:
     * https://example.com/rx-sitemap.xml
     */
    const INDEX_SLUG = 'rx-sitemap.xml';

    /**
     * Query variable.
     */
    const QUERY_VAR = 'rx_sitemap';

    /**
     * Cache key prefix.
     */
    const CACHE_PREFIX = 'rx_theme_sitemap_';

    /**
     * Cache duration.
     *
     * 12 hours.
     */
    const CACHE_TTL = 43200;

    /**
     * Maximum URLs per sitemap.
     *
     * Search engines usually allow up to 50,000 URLs,
     * but smaller chunks are safer.
     */
    const MAX_URLS = 1000;

    /**
     * Start class.
     */
    public static function init() {
        add_action('init', [__CLASS__, 'add_rewrite_rules']);
        add_filter('query_vars', [__CLASS__, 'add_query_vars']);
        add_action('template_redirect', [__CLASS__, 'render_sitemap']);

        add_action('save_post', [__CLASS__, 'clear_cache']);
        add_action('deleted_post', [__CLASS__, 'clear_cache']);
        add_action('trashed_post', [__CLASS__, 'clear_cache']);
        add_action('transition_post_status', [__CLASS__, 'clear_cache']);

        add_action('created_term', [__CLASS__, 'clear_cache']);
        add_action('edited_term', [__CLASS__, 'clear_cache']);
        add_action('delete_term', [__CLASS__, 'clear_cache']);

        add_filter('robots_txt', [__CLASS__, 'add_sitemap_to_robots'], 20, 2);

        add_action('admin_bar_menu', [__CLASS__, 'admin_bar_link'], 100);
        add_action('admin_notices', [__CLASS__, 'admin_notice_after_theme_switch']);

        add_action('after_switch_theme', [__CLASS__, 'activate']);
    }

    /**
     * Run after theme activation.
     */
    public static function activate() {
        self::add_rewrite_rules();
        flush_rewrite_rules();
        self::clear_cache();
    }

    /**
     * Add pretty rewrite rules.
     */
    public static function add_rewrite_rules() {
        add_rewrite_rule(
            '^rx-sitemap\.xml$',
            'index.php?' . self::QUERY_VAR . '=index',
            'top'
        );

        add_rewrite_rule(
            '^rx-sitemap-([a-zA-Z0-9_-]+)-([0-9]+)\.xml$',
            'index.php?' . self::QUERY_VAR . '=$matches[1]&paged=$matches[2]',
            'top'
        );

        add_rewrite_rule(
            '^rx-sitemap-([a-zA-Z0-9_-]+)\.xml$',
            'index.php?' . self::QUERY_VAR . '=$matches[1]',
            'top'
        );
    }

    /**
     * Add custom query variable.
     */
    public static function add_query_vars($vars) {
        $vars[] = self::QUERY_VAR;
        return $vars;
    }

    /**
     * Render sitemap based on query var.
     */
    public static function render_sitemap() {
        $type = get_query_var(self::QUERY_VAR);

        if (empty($type)) {
            return;
        }

        nocache_headers();

        header('Content-Type: application/xml; charset=UTF-8');
        header('X-Robots-Tag: noindex, follow', true);

        $paged = absint(get_query_var('paged'));
        if ($paged < 1) {
            $paged = 1;
        }

        if ($type === 'index') {
            echo self::get_cached_xml('index', function () {
                return self::build_sitemap_index();
            });
            exit;
        }

        echo self::get_cached_xml($type . '_' . $paged, function () use ($type, $paged) {
            return self::build_sitemap_by_type($type, $paged);
        });

        exit;
    }

    /**
     * Cache wrapper.
     */
    private static function get_cached_xml($key, $callback) {
        $cache_key = self::CACHE_PREFIX . sanitize_key($key);

        $cached = get_transient($cache_key);

        if ($cached !== false && !is_user_logged_in()) {
            return $cached;
        }

        $xml = call_user_func($callback);

        set_transient($cache_key, $xml, self::CACHE_TTL);

        return $xml;
    }

    /**
     * Build sitemap index.
     */
    private static function build_sitemap_index() {
        $items = [];

        $items[] = [
            'loc'     => self::sitemap_url('post'),
            'lastmod' => self::get_latest_post_modified('post'),
        ];

        $items[] = [
            'loc'     => self::sitemap_url('page'),
            'lastmod' => self::get_latest_post_modified('page'),
        ];

        foreach (self::get_public_post_types() as $post_type) {
            if (in_array($post_type, ['post', 'page'], true)) {
                continue;
            }

            $count = self::count_posts_for_sitemap($post_type);

            if ($count > 0) {
                $pages = ceil($count / self::MAX_URLS);

                for ($i = 1; $i <= $pages; $i++) {
                    $items[] = [
                        'loc'     => self::sitemap_url($post_type, $i),
                        'lastmod' => self::get_latest_post_modified($post_type),
                    ];
                }
            }
        }

        if (self::has_public_terms('category')) {
            $items[] = [
                'loc'     => self::sitemap_url('category'),
                'lastmod' => current_time('c'),
            ];
        }

        if (self::has_public_terms('post_tag')) {
            $items[] = [
                'loc'     => self::sitemap_url('post_tag'),
                'lastmod' => current_time('c'),
            ];
        }

        foreach (self::get_public_taxonomies() as $taxonomy) {
            if (in_array($taxonomy, ['category', 'post_tag'], true)) {
                continue;
            }

            if (self::has_public_terms($taxonomy)) {
                $items[] = [
                    'loc'     => self::sitemap_url($taxonomy),
                    'lastmod' => current_time('c'),
                ];
            }
        }

        if (self::has_authors()) {
            $items[] = [
                'loc'     => self::sitemap_url('author'),
                'lastmod' => current_time('c'),
            ];
        }

        $items[] = [
            'loc'     => self::sitemap_url('image'),
            'lastmod' => self::get_latest_post_modified('post'),
        ];

        $items[] = [
            'loc'     => self::sitemap_url('news'),
            'lastmod' => current_time('c'),
        ];

        $xml  = self::xml_header();
        $xml .= '<sitemapindex xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">' . "\n";

        foreach ($items as $item) {
            if (empty($item['loc'])) {
                continue;
            }

            $xml .= "\t<sitemap>\n";
            $xml .= "\t\t<loc>" . esc_url($item['loc']) . "</loc>\n";

            if (!empty($item['lastmod'])) {
                $xml .= "\t\t<lastmod>" . esc_html(self::format_lastmod($item['lastmod'])) . "</lastmod>\n";
            }

            $xml .= "\t</sitemap>\n";
        }

        $xml .= '</sitemapindex>';

        return $xml;
    }

    /**
     * Build sitemap by type.
     */
    private static function build_sitemap_by_type($type, $paged = 1) {
        if ($type === 'category') {
            return self::build_taxonomy_sitemap('category');
        }

        if ($type === 'post_tag') {
            return self::build_taxonomy_sitemap('post_tag');
        }

        if ($type === 'author') {
            return self::build_author_sitemap();
        }

        if ($type === 'image') {
            return self::build_image_sitemap($paged);
        }

        if ($type === 'news') {
            return self::build_news_sitemap();
        }

        $public_post_types = self::get_public_post_types();

        if (in_array($type, $public_post_types, true)) {
            return self::build_post_type_sitemap($type, $paged);
        }

        $public_taxonomies = self::get_public_taxonomies();

        if (in_array($type, $public_taxonomies, true)) {
            return self::build_taxonomy_sitemap($type);
        }

        status_header(404);

        return self::xml_header() . '<error>Sitemap not found</error>';
    }

    /**
     * Build post type sitemap.
     */
    private static function build_post_type_sitemap($post_type = 'post', $paged = 1) {
        $query = new WP_Query([
            'post_type'              => $post_type,
            'post_status'            => 'publish',
            'posts_per_page'         => self::MAX_URLS,
            'paged'                  => $paged,
            'orderby'                => 'modified',
            'order'                  => 'DESC',
            'no_found_rows'          => true,
            'ignore_sticky_posts'    => true,
            'update_post_meta_cache' => true,
            'update_post_term_cache' => false,
        ]);

        $urls = [];

        if ($query->have_posts()) {
            foreach ($query->posts as $post) {
                if (!self::is_post_indexable($post->ID)) {
                    continue;
                }

                $urls[] = [
                    'loc'        => get_permalink($post),
                    'lastmod'    => get_post_modified_time('c', true, $post),
                    'changefreq' => self::get_changefreq_for_post($post),
                    'priority'   => self::get_priority_for_post($post),
                    'images'     => self::get_post_images($post->ID),
                ];
            }
        }

        wp_reset_postdata();

        return self::build_urlset($urls, true);
    }

    /**
     * Build taxonomy sitemap.
     */
    private static function build_taxonomy_sitemap($taxonomy) {
        $terms = get_terms([
            'taxonomy'   => $taxonomy,
            'hide_empty' => true,
            'number'     => self::MAX_URLS,
        ]);

        $urls = [];

        if (!is_wp_error($terms) && !empty($terms)) {
            foreach ($terms as $term) {
                if (!self::is_term_indexable($term)) {
                    continue;
                }

                $term_link = get_term_link($term);

                if (is_wp_error($term_link)) {
                    continue;
                }

                $urls[] = [
                    'loc'        => $term_link,
                    'lastmod'    => current_time('c'),
                    'changefreq' => 'weekly',
                    'priority'   => '0.60',
                ];
            }
        }

        return self::build_urlset($urls, false);
    }

    /**
     * Build author sitemap.
     */
    private static function build_author_sitemap() {
        $users = get_users([
            'has_published_posts' => true,
            'number'              => self::MAX_URLS,
            'fields'              => ['ID', 'display_name'],
        ]);

        $urls = [];

        if (!empty($users)) {
            foreach ($users as $user) {
                if (!self::is_author_indexable($user->ID)) {
                    continue;
                }

                $urls[] = [
                    'loc'        => get_author_posts_url($user->ID),
                    'lastmod'    => current_time('c'),
                    'changefreq' => 'monthly',
                    'priority'   => '0.40',
                ];
            }
        }

        return self::build_urlset($urls, false);
    }

    /**
     * Build image sitemap.
     */
    private static function build_image_sitemap($paged = 1) {
        $query = new WP_Query([
            'post_type'              => self::get_public_post_types(),
            'post_status'            => 'publish',
            'posts_per_page'         => self::MAX_URLS,
            'paged'                  => $paged,
            'orderby'                => 'modified',
            'order'                  => 'DESC',
            'no_found_rows'          => true,
            'ignore_sticky_posts'    => true,
            'update_post_meta_cache' => true,
            'update_post_term_cache' => false,
        ]);

        $urls = [];

        if ($query->have_posts()) {
            foreach ($query->posts as $post) {
                if (!self::is_post_indexable($post->ID)) {
                    continue;
                }

                $images = self::get_post_images($post->ID);

                if (empty($images)) {
                    continue;
                }

                $urls[] = [
                    'loc'        => get_permalink($post),
                    'lastmod'    => get_post_modified_time('c', true, $post),
                    'changefreq' => self::get_changefreq_for_post($post),
                    'priority'   => self::get_priority_for_post($post),
                    'images'     => $images,
                ];
            }
        }

        wp_reset_postdata();

        return self::build_urlset($urls, true);
    }

    /**
     * Build simple news sitemap.
     *
     * Important:
     * Real Google News sitemap requires your site to be accepted in Google Publisher Center.
     * This creates a recent-post XML sitemap structure only.
     */
    private static function build_news_sitemap() {
        $query = new WP_Query([
            'post_type'              => 'post',
            'post_status'            => 'publish',
            'posts_per_page'         => 100,
            'date_query'             => [
                [
                    'after' => '2 days ago',
                ],
            ],
            'orderby'                => 'date',
            'order'                  => 'DESC',
            'no_found_rows'          => true,
            'ignore_sticky_posts'    => true,
            'update_post_meta_cache' => false,
            'update_post_term_cache' => false,
        ]);

        $xml  = self::xml_header();
        $xml .= '<urlset ';
        $xml .= 'xmlns="http://www.sitemaps.org/schemas/sitemap/0.9" ';
        $xml .= 'xmlns:news="http://www.google.com/schemas/sitemap-news/0.9">';
        $xml .= "\n";

        if ($query->have_posts()) {
            foreach ($query->posts as $post) {
                if (!self::is_post_indexable($post->ID)) {
                    continue;
                }

                $title = get_the_title($post);
                $title = wp_strip_all_tags($title);

                $xml .= "\t<url>\n";
                $xml .= "\t\t<loc>" . esc_url(get_permalink($post)) . "</loc>\n";
                $xml .= "\t\t<news:news>\n";
                $xml .= "\t\t\t<news:publication>\n";
                $xml .= "\t\t\t\t<news:name>" . esc_html(get_bloginfo('name')) . "</news:name>\n";
                $xml .= "\t\t\t\t<news:language>" . esc_html(substr(get_bloginfo('language'), 0, 2)) . "</news:language>\n";
                $xml .= "\t\t\t</news:publication>\n";
                $xml .= "\t\t\t<news:publication_date>" . esc_html(get_the_date('c', $post)) . "</news:publication_date>\n";
                $xml .= "\t\t\t<news:title>" . esc_html($title) . "</news:title>\n";
                $xml .= "\t\t</news:news>\n";
                $xml .= "\t</url>\n";
            }
        }

        wp_reset_postdata();

        $xml .= '</urlset>';

        return $xml;
    }

    /**
     * Build URL set.
     */
    private static function build_urlset($urls, $include_images = false) {
        $xml  = self::xml_header();

        $xml .= '<urlset ';
        $xml .= 'xmlns="http://www.sitemaps.org/schemas/sitemap/0.9"';

        if ($include_images) {
            $xml .= ' xmlns:image="http://www.google.com/schemas/sitemap-image/1.1"';
        }

        $xml .= '>' . "\n";

        foreach ($urls as $url) {
            if (empty($url['loc'])) {
                continue;
            }

            $xml .= "\t<url>\n";
            $xml .= "\t\t<loc>" . esc_url($url['loc']) . "</loc>\n";

            if (!empty($url['lastmod'])) {
                $xml .= "\t\t<lastmod>" . esc_html(self::format_lastmod($url['lastmod'])) . "</lastmod>\n";
            }

            if (!empty($url['changefreq'])) {
                $xml .= "\t\t<changefreq>" . esc_html($url['changefreq']) . "</changefreq>\n";
            }

            if (!empty($url['priority'])) {
                $xml .= "\t\t<priority>" . esc_html($url['priority']) . "</priority>\n";
            }

            if ($include_images && !empty($url['images']) && is_array($url['images'])) {
                foreach ($url['images'] as $image) {
                    if (empty($image['loc'])) {
                        continue;
                    }

                    $xml .= "\t\t<image:image>\n";
                    $xml .= "\t\t\t<image:loc>" . esc_url($image['loc']) . "</image:loc>\n";

                    if (!empty($image['title'])) {
                        $xml .= "\t\t\t<image:title>" . esc_html($image['title']) . "</image:title>\n";
                    }

                    if (!empty($image['caption'])) {
                        $xml .= "\t\t\t<image:caption>" . esc_html($image['caption']) . "</image:caption>\n";
                    }

                    $xml .= "\t\t</image:image>\n";
                }
            }

            $xml .= "\t</url>\n";
        }

        $xml .= '</urlset>';

        return $xml;
    }

    /**
     * XML header.
     */
    private static function xml_header() {
        return '<?xml version="1.0" encoding="UTF-8"?>' . "\n";
    }

    /**
     * Generate sitemap URL.
     */
    private static function sitemap_url($type, $paged = 1) {
        $type = sanitize_key($type);

        if ($type === 'index') {
            return home_url('/rx-sitemap.xml');
        }

        if ($paged > 1) {
            return home_url('/rx-sitemap-' . $type . '-' . absint($paged) . '.xml');
        }

        return home_url('/rx-sitemap-' . $type . '.xml');
    }

    /**
     * Get public post types.
     */
    private static function get_public_post_types() {
        $post_types = get_post_types([
            'public'             => true,
            'publicly_queryable' => true,
        ], 'names');

        unset($post_types['attachment']);

        /**
         * Filter post types included in RX sitemap.
         */
        $post_types = apply_filters('rx_theme_sitemap_post_types', $post_types);

        return array_values(array_unique($post_types));
    }

    /**
     * Get public taxonomies.
     */
    private static function get_public_taxonomies() {
        $taxonomies = get_taxonomies([
            'public' => true,
        ], 'names');

        $taxonomies = apply_filters('rx_theme_sitemap_taxonomies', $taxonomies);

        return array_values(array_unique($taxonomies));
    }

    /**
     * Count posts.
     */
    private static function count_posts_for_sitemap($post_type) {
        $counts = wp_count_posts($post_type);

        if (!isset($counts->publish)) {
            return 0;
        }

        return absint($counts->publish);
    }

    /**
     * Latest modified post date.
     */
    private static function get_latest_post_modified($post_type = 'post') {
        global $wpdb;

        $post_type = sanitize_key($post_type);

        $date = $wpdb->get_var(
            $wpdb->prepare(
                "
                SELECT post_modified_gmt
                FROM {$wpdb->posts}
                WHERE post_type = %s
                AND post_status = 'publish'
                ORDER BY post_modified_gmt DESC
                LIMIT 1
                ",
                $post_type
            )
        );

        if (empty($date)) {
            return current_time('c');
        }

        return mysql2date('c', $date, false);
    }

    /**
     * Format lastmod date.
     */
    private static function format_lastmod($date) {
        $timestamp = strtotime($date);

        if (!$timestamp) {
            return current_time('c');
        }

        return gmdate('c', $timestamp);
    }

    /**
     * Decide post priority.
     */
    private static function get_priority_for_post($post) {
        if (!$post instanceof WP_Post) {
            return '0.60';
        }

        if ($post->post_type === 'page') {
            if ((int) get_option('page_on_front') === (int) $post->ID) {
                return '1.00';
            }

            return '0.80';
        }

        if ($post->post_type === 'post') {
            return '0.70';
        }

        return '0.60';
    }

    /**
     * Decide change frequency.
     */
    private static function get_changefreq_for_post($post) {
        if (!$post instanceof WP_Post) {
            return 'weekly';
        }

        $modified = strtotime($post->post_modified_gmt);
        $now      = time();
        $days     = ($now - $modified) / DAY_IN_SECONDS;

        if ($days <= 2) {
            return 'daily';
        }

        if ($days <= 30) {
            return 'weekly';
        }

        if ($days <= 180) {
            return 'monthly';
        }

        return 'yearly';
    }

    /**
     * Get images from post.
     */
    private static function get_post_images($post_id) {
        $images = [];

        $thumbnail_id = get_post_thumbnail_id($post_id);

        if ($thumbnail_id) {
            $image = self::get_attachment_image_data($thumbnail_id);

            if (!empty($image)) {
                $images[] = $image;
            }
        }

        $content = get_post_field('post_content', $post_id);

        if (!empty($content)) {
            preg_match_all('/<img[^>]+src=["\']([^"\']+)["\'][^>]*>/i', $content, $matches);

            if (!empty($matches[1])) {
                foreach ($matches[1] as $src) {
                    $src = esc_url_raw($src);

                    if (empty($src)) {
                        continue;
                    }

                    $images[] = [
                        'loc'     => $src,
                        'title'   => '',
                        'caption' => '',
                    ];
                }
            }
        }

        $images = self::unique_images($images);

        /**
         * Filter images included in sitemap.
         */
        return apply_filters('rx_theme_sitemap_post_images', $images, $post_id);
    }

    /**
     * Attachment image data.
     */
    private static function get_attachment_image_data($attachment_id) {
        $src = wp_get_attachment_image_url($attachment_id, 'full');

        if (!$src) {
            return [];
        }

        $title   = get_the_title($attachment_id);
        $caption = wp_get_attachment_caption($attachment_id);

        return [
            'loc'     => esc_url_raw($src),
            'title'   => wp_strip_all_tags($title),
            'caption' => wp_strip_all_tags($caption),
        ];
    }

    /**
     * Remove duplicate images.
     */
    private static function unique_images($images) {
        $unique = [];
        $seen   = [];

        foreach ($images as $image) {
            if (empty($image['loc'])) {
                continue;
            }

            $key = md5($image['loc']);

            if (isset($seen[$key])) {
                continue;
            }

            $seen[$key] = true;
            $unique[]   = $image;
        }

        return $unique;
    }

    /**
     * Check if post should be indexed.
     */
    private static function is_post_indexable($post_id) {
        $post_id = absint($post_id);

        if (!$post_id) {
            return false;
        }

        if (get_post_status($post_id) !== 'publish') {
            return false;
        }

        if (post_password_required($post_id)) {
            return false;
        }

        /**
         * RX custom noindex field.
         *
         * Add custom field:
         * rx_noindex = 1
         */
        if (get_post_meta($post_id, 'rx_noindex', true)) {
            return false;
        }

        /**
         * Yoast SEO noindex support.
         */
        $yoast_noindex = get_post_meta($post_id, '_yoast_wpseo_meta-robots-noindex', true);

        if ($yoast_noindex === '1') {
            return false;
        }

        /**
         * Rank Math noindex support.
         */
        $rank_math_robots = get_post_meta($post_id, 'rank_math_robots', true);

        if (is_array($rank_math_robots) && in_array('noindex', $rank_math_robots, true)) {
            return false;
        }

        /**
         * AIOSEO noindex support.
         */
        $aioseo_robots = get_post_meta($post_id, '_aioseo_robots_default', true);
        $aioseo_noindex = get_post_meta($post_id, '_aioseo_robots_noindex', true);

        if ($aioseo_robots === '0' && $aioseo_noindex === '1') {
            return false;
        }

        return (bool) apply_filters('rx_theme_sitemap_is_post_indexable', true, $post_id);
    }

    /**
     * Check if term should be indexed.
     */
    private static function is_term_indexable($term) {
        if (!$term || empty($term->term_id)) {
            return false;
        }

        /**
         * RX custom term noindex.
         */
        $rx_noindex = get_term_meta($term->term_id, 'rx_noindex', true);

        if ($rx_noindex) {
            return false;
        }

        /**
         * Yoast term noindex support.
         */
        $yoast_noindex = get_term_meta($term->term_id, 'wpseo_noindex', true);

        if ($yoast_noindex === 'noindex') {
            return false;
        }

        /**
         * Rank Math term noindex support.
         */
        $rank_math_robots = get_term_meta($term->term_id, 'rank_math_robots', true);

        if (is_array($rank_math_robots) && in_array('noindex', $rank_math_robots, true)) {
            return false;
        }

        return (bool) apply_filters('rx_theme_sitemap_is_term_indexable', true, $term);
    }

    /**
     * Check if author should be indexed.
     */
    private static function is_author_indexable($user_id) {
        $user_id = absint($user_id);

        if (!$user_id) {
            return false;
        }

        $noindex = get_user_meta($user_id, 'rx_noindex_author', true);

        if ($noindex) {
            return false;
        }

        return (bool) apply_filters('rx_theme_sitemap_is_author_indexable', true, $user_id);
    }

    /**
     * Check if taxonomy has public terms.
     */
    private static function has_public_terms($taxonomy) {
        $terms = get_terms([
            'taxonomy'   => $taxonomy,
            'hide_empty' => true,
            'number'     => 1,
            'fields'     => 'ids',
        ]);

        return !is_wp_error($terms) && !empty($terms);
    }

    /**
     * Check if site has authors.
     */
    private static function has_authors() {
        $users = get_users([
            'has_published_posts' => true,
            'number'              => 1,
            'fields'              => 'ID',
        ]);

        return !empty($users);
    }

    /**
     * Add sitemap to robots.txt.
     */
    public static function add_sitemap_to_robots($output, $public) {
        if ('0' === (string) $public) {
            return $output;
        }

        $output .= "\n";
        $output .= 'Sitemap: ' . esc_url_raw(home_url('/rx-sitemap.xml')) . "\n";

        return $output;
    }

    /**
     * Clear sitemap cache.
     */
    public static function clear_cache() {
        global $wpdb;

        $like = $wpdb->esc_like('_transient_' . self::CACHE_PREFIX) . '%';

        $wpdb->query(
            $wpdb->prepare(
                "DELETE FROM {$wpdb->options} WHERE option_name LIKE %s",
                $like
            )
        );

        $timeout_like = $wpdb->esc_like('_transient_timeout_' . self::CACHE_PREFIX) . '%';

        $wpdb->query(
            $wpdb->prepare(
                "DELETE FROM {$wpdb->options} WHERE option_name LIKE %s",
                $timeout_like
            )
        );
    }

    /**
     * Admin bar sitemap link.
     */
    public static function admin_bar_link($wp_admin_bar) {
        if (!current_user_can('manage_options')) {
            return;
        }

        $wp_admin_bar->add_node([
            'id'    => 'rx-theme-sitemap',
            'title' => 'RX Sitemap',
            'href'  => home_url('/rx-sitemap.xml'),
            'meta'  => [
                'target' => '_blank',
            ],
        ]);
    }

    /**
     * Admin notice after theme switch.
     */
    public static function admin_notice_after_theme_switch() {
        if (!current_user_can('manage_options')) {
            return;
        }

        if (!isset($_GET['activated'])) {
            return;
        }

        echo '<div class="notice notice-info is-dismissible">';
        echo '<p><strong>RX Theme Sitemap:</strong> Please visit <a href="' . esc_url(admin_url('options-permalink.php')) . '">Settings → Permalinks</a> and click <strong>Save Changes</strong> once to activate sitemap URLs.</p>';
        echo '</div>';
    }
}

RX_Theme_Advanced_Sitemap::init();

endif;