s.wp-rocket.me/article/1065-sitemap-preload-is-slow-or-some-pages-are-not-preloaded-at-all#failed-preload" rel="noopener noreferrer" target=_"blank">', '</a>' );

			set_transient( 'rocket_preload_errors', $errors );
			return false;
		}

		$response_code = wp_remote_retrieve_response_code( $response );

		if ( 200 !== $response_code ) {
			switch ( $response_code ) {
				case 401:
				case 403:
					// Translators: %1$s is an URL, %2$s is the HTTP response code, %3$s = opening link tag, %4$s = closing link tag.
					$errors['errors'][] = sprintf( __( 'Preload encountered an error. %1$s is not accessible to due to the following response code: %2$s. Security measures could be preventing access. %3$sLearn more%4$s.', 'rocket' ), $item['url'], $response_code, '<a href="https://docs.wp-rocket.me/article/1065-sitemap-preload-is-slow-or-some-pages-are-not-preloaded-at-all#failed-preload" rel="noopener noreferrer" target=_"blank">', '</a>' );

					set_transient( 'rocket_preload_errors', $errors );
					break;
				case 404:
					// Translators: %1$s is an URL, %2$s = opening link tag, %3$s = closing link tag.
					$errors['errors'][] = sprintf( __( 'Preload encountered an error. %1$s is not accessible to due to the following response code: 404. Please make sure your homepage is accessible in your browser. %2$sLearn more%3$s.', 'rocket' ), $item['url'], '<a href="https://docs.wp-rocket.me/article/1065-sitemap-preload-is-slow-or-some-pages-are-not-preloaded-at-all#failed-preload" rel="noopener noreferrer" target=_"blank">', '</a>' );

					set_transient( 'rocket_preload_errors', $errors );
					break;
				case 500:
					// Translators: %1$s is an URL, %2$s = opening link tag, %3$s = closing link tag.
					$errors['errors'][] = sprintf( __( 'Preload encountered an error. %1$s is not accessible to due to the following response code: 500. Please check with your web host about server access. %2$sLearn more%3$s.', 'rocket' ), $item['url'], '<a href="https://docs.wp-rocket.me/article/1065-sitemap-preload-is-slow-or-some-pages-are-not-preloaded-at-all#failed-preload" rel="noopener noreferrer" target=_"blank">', '</a>' );

					set_transient( 'rocket_preload_errors', $errors );
					break;
				default:
					// Translators: %1$s is an URL, %2$s is the HTTP response code, %3$s = opening link tag, %4$s = closing link tag.
					$errors['errors'][] = sprintf( __( 'Preload encountered an error. Could not gather links on %1$s because it returned the following response code: %2$s. %3$sLearn more%4$s.', 'rocket' ), $item['url'], $response_code, '<a href="https://docs.wp-rocket.me/article/1065-sitemap-preload-is-slow-or-some-pages-are-not-preloaded-at-all#failed-preload" rel="noopener noreferrer" target=_"blank">', '</a>' );

					set_transient( 'rocket_preload_errors', $errors );
					break;
			}

			return false;
		}

		$content = wp_remote_retrieve_body( $response );

		preg_match_all( '/<a\s+(?:[^>]+?[\s"\']|)href\s*=\s*(["\'])(?<href>[^"\']+)\1/imU', $content, $urls );

		return array_unique( $urls['href'] );
	}

	/**
	 * Checks if the URL should be preloaded.
	 *
	 * @since  3.2.2
	 * @access private
	 * @author Remy Perona
	 *
	 * @param  string $url URL to check.
	 * @param  string $home_url Homepage URL.
	 * @param  string $home_host Homepage host.
	 * @return bool
	 */
	private function should_preload( $url, $home_url, $home_host ) {
		$url = html_entity_decode( $url ); // & symbols in URLs are changed to &#038; when using WP Menu editor

		$url_data = get_rocket_parse_url( $url );

		if ( empty( $url_data ) ) {
			return false;
		}

		if ( ! empty( $url_data['fragment'] ) ) {
			return false;
		}

		if ( empty( $url_data['host'] ) ) {
			$url = home_url( $url );
		}

		$url = \rocket_add_url_protocol( $url );

		if ( untrailingslashit( $url ) === untrailingslashit( $home_url ) ) {
			return false;
		}

		if ( $home_host !== $url_data['host'] ) {
			return false;
		}

		if ( $this->is_file_url( $url ) ) {
			return false;
		}

		if ( ! empty( $url_data['path'] ) && preg_match( '#^(' . \get_rocket_cache_reject_uri() . ')$#', $url_data['path'] ) ) {
			return false;
		}

		$cache_query_strings = implode( '|', \get_rocket_cache_query_string() );

		if ( ! empty( $url_data['query'] ) && ! preg_match( '/(' . $cache_query_strings . ')/iU', $url_data['query'] ) ) {
			return false;
		}

		return true;
	}

	/**
	 * Checks if URL is an URL to a file.
	 *
	 * @since  3.2.2
	 * @access private
	 * @author Remy Perona
	 *
	 * @param  string $url URL to check.
	 * @return bool
	 */
	private function is_file_url( $url ) {
		/**
		 * Filters the list of files types to check when getting URLs on the homepage
		 *
		 * @since 3.2.2
		 * @author Remy Perona
		 *
		 * @param array $file_types Array of file extensions.
		 */
		$file_types = apply_filters(
			'rocket_preload_file_types',
			[
				'jpg',
				'jpeg',
				'jpe',
				'png',
				'gif',
				'webp',
				'bmp',
				'tiff',
				'mp3',
				'ogg',
				'mp4',
				'm4v',
				'avi',
				'mov',
				'flv',
				'swf',
				'webm',
				'pdf',
				'doc',
				'docx',
				'txt',
				'zip',
				'tar',
				'bz2',
				'tgz',
				'rar',
			]
		);

		$file_types = implode( '|', $file_types );

		if ( preg_match( '#\.(?:' . $file_types . ')$#iU', $url ) ) {
			return true;
		}

		return false;
	}
}