mod' => $query->have_posts() ? $query->posts[0]->post_modified_gmt : $last_modified_gmt,
					],
					'term',
					$tax_name,
				);

				if ( ! $item ) {
					continue;
				}

				$index[] = $item;
			}
		}

		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 ) {
		$links    = [];
		$taxonomy = get_taxonomy( $type );
		$terms    = $this->get_terms( $taxonomy, $max_entries, $current_page );
		Sitemap::maybe_redirect( count( $this->get_terms( $taxonomy, 0, $current_page ) ), $max_entries );

		foreach ( $terms as $term ) {
			$url = [];
			if ( ! Sitemap::is_object_indexable( $term, 'term' ) ) {
				continue;
			}

			$link = $this->get_term_link( $term );
			if ( ! $link ) {
				continue;
			}

			$url['loc']    = $link;
			$url['mod']    = $this->get_lastmod( $term );
			$url['images'] = ! is_null( $this->get_image_parser() ) ? $this->get_image_parser()->get_term_images( $term ) : [];

			/** This filter is documented at inc/sitemaps/class-post-type-sitemap-provider.php */
			$url = $this->do_filter( 'sitemap/entry', $url, 'term', $term );

			if ( ! empty( $url ) ) {
				$links[] = $url;
			}
		}

		return $links;
	}

	/**
	 * Get the Image Parser.
	 *
	 * @return Image_Parser
	 */
	protected function get_image_parser() {
		if ( class_exists( 'RankMath\Sitemap\Image_Parser' ) && ! isset( self::$image_parser ) ) {
			self::$image_parser = new Image_Parser();
		}

		return self::$image_parser;
	}

	/**
	 * Get terms for taxonomy.
	 *
	 * @param  object $taxonomy     Taxonomy name.
	 * @param  int    $max_entries  Entries per sitemap.
	 * @param  int    $current_page Current page of the sitemap.
	 * @return false|array
	 */
	private function get_terms( $taxonomy, $max_entries, $current_page ) {
		$offset     = $current_page > 1 ? ( ( $current_page - 1 ) * $max_entries ) : 0;
		$hide_empty = ! Helper::get_settings( 'sitemap.tax_' . $taxonomy->name . '_include_empty' );

		// Getting terms.
		$terms = get_terms(
			[
				'taxonomy'               => $taxonomy->name,
				'orderby'                => 'term_order',
				'hide_empty'             => $hide_empty,
				'offset'                 => $offset,
				'number'                 => $max_entries,
				'exclude'                => wp_parse_id_list( Helper::get_settings( 'sitemap.exclude_terms' ) ),

				/*
				 * Limits aren't included in queries when hierarchical is set to true (by default).
				 *
				 * @link: https://github.com/WordPress/WordPress/blob/5.3/wp-includes/class-wp-term-query.php#L558-L567
				 */
				'hierarchical'           => false,
				'update_term_meta_cache' => false,
				'meta_query' => [
					'relation' => 'OR',
					[
						'key'     => 'rank_math_robots',
						'value'   => 'noindex',
						'compare' => 'NOT LIKE',
					],
					[
						'key'     => 'rank_math_robots',
						'compare' => 'NOT EXISTS',
					],
				],
			]
		);

		if ( is_wp_error( $terms ) || empty( $terms ) ) {
			return [];
		}

		return $terms;
	}

	/**
	 * Get term link.
	 *
	 * @param  WP_Term $term Term object.
	 * @return string
	 */
	private function get_term_link( $term ) {
		$url       = get_term_link( $term, $term->taxonomy );
		$canonical = Helper::get_term_meta( 'canonical_url', $term, $term->taxonomy );
		if ( $canonical && $canonical !== $url ) {
			/*
			 * Let's assume that if a canonical is set for this term and it's different from
			 * the URL of this term, that page is either already in the XML sitemap OR is on
			 * an external site, either way, we shouldn't include it here.
			 */
			return false;
		}

		return $url;
	}

	/**
	 * Get last modified date of post by term.
	 *
	 * @param  WP_Term $term Term object.
	 * @return string
	 */
	public function get_lastmod( $term ) {
		global $wpdb;

		return $wpdb->get_var(
			$wpdb->prepare(
				"
			SELECT MAX(p.post_modified_gmt) AS lastmod
			FROM	$wpdb->posts AS p
			INNER JOIN $wpdb->term_relationships AS term_rel
				ON		term_rel.object_id = p.ID
			INNER JOIN $wpdb->term_taxonomy AS term_tax
				ON		term_tax.term_taxonomy_id = term_rel.term_taxonomy_id
				AND		term_tax.taxonomy = %s
				AND		term_tax.term_id = %d
			WHERE	p.post_status IN ('publish', 'inherit')
				AND		p.post_password = ''
		",
				$term->taxonomy,
				$term->term_id
			)
		);
	}
}