<?php
use RankMath\Sitemap\Providers\Provider;

class Madara_Sitemap_Provider implements Provider {
    /**
     * Check if provider supports given item type.
     *
     * @param string $type Type string to check for.
     *
     * @return boolean
     */
    public function handles_type( $type ) {
        return true;
    }

    /**
     * Get set of sitemaps index link data.
     *
     * @param int $max_entries Entries per sitemap.
     *
     * @return array
     */
    public function get_index_links( $max_entries ){
        $index = array();

        global $wpdb;

        $sql = "SELECT count(*) as total FROM {$wpdb->prefix}manga_chapters";

        $count = $wpdb->get_var($sql);
        $total_page = floor($count / $max_entries) + 1;

        for($current_page = 1; $current_page <= $total_page; $current_page++){
            if($max_entries * ($current_page - 1) < $count) {
                $offset = $max_entries * ($current_page - 1);
                $sql = "SELECT max(date_gmt) FROM {$wpdb->prefix}manga_chapters ORDER BY date_gmt DESC LIMIT {$max_entries},{$offset}";
                $date = $wpdb->get_var($sql);

                $index[] = array(
                        'loc'     => \RankMath\Sitemap\Router::get_base_url( 'wp-manga-chapters-sitemap'. $current_page .'.xml' ),
                        'lastmod' => $date,
                    );
            }
        }

        return $index;
    }

    /**
     * Get set of sitemap link data.
     *
     * @param string $type         Sitemap type.
     * @param int    $max_entries  Entries per sitemap.
     * @param int    $current_page Current page of the sitemap.
     *
     * @return array
     */
    public function get_sitemap_links( $type, $max_entries, $current_page ){
        $urls = array();

        global $wpdb, $wp_manga_functions;

        $offset = ($current_page - 1) * $max_entries;

        $sql = "SELECT * FROM {$wpdb->prefix}manga_chapters ORDER BY date_gmt DESC LIMIT {$offset}, {$max_entries}";

        $results = $wpdb->get_results($sql);

        global $_wp_manga_wpseo_sitemap;
        $_wp_manga_wpseo_sitemap = true;
        foreach($results as $result){
            $manga_id = $result->post_id;

            // check if $manga is active
            if(get_post_status($manga_id) == 'publish'){
                $chapter_slug = $result->chapter_slug;

                $link = $wp_manga_functions->build_chapter_url( $manga_id, $chapter_slug );

                $urls[] = array(
                        'loc' => esc_url($link),
                        'mod' => $result->date_gmt,
                        'chf' => 'daily', // Deprecated, kept for backwards data compat. R.
                        'pri' => 1, // Deprecated, kept for backwards data compat. R.
                        'images' => array());
            }
        }
        $_wp_manga_wpseo_sitemap = false;

        return $urls;
    }
}

add_filter( 'rank_math/sitemap/providers', function( $providers ) {
	$providers[] = new Madara_Sitemap_Provider();
	return $providers;
} );