} elseif (file_exists(ABSPATH.WPINC.'/images/spinner-2x.gif')) {
			$localize['spinnerimg'] = includes_url('images/spinner-2x.gif');
		}

		$localize = apply_filters('simba_tfa_login_enqueue_localize', $localize);

		wp_localize_script('tfa-ajax-request', 'simba_tfasettings', $localize);

	}

	/**
	 * Check whether TFA login scripts should be enqueued or not.
	 *
	 * @return boolean True if the TFA login script should be enqueued, otherwise false.
	 */
	private function should_enqueue_login_scripts() {
		if (defined('TWO_FACTOR_DISABLE') && TWO_FACTOR_DISABLE) {
			return apply_filters('simbatfa_enqueue_login_scripts', false);
		}

		global $wpdb;
		$sql = $wpdb->prepare('SELECT COUNT(user_id) FROM ' . $wpdb->usermeta . ' WHERE meta_key = %s AND meta_value = %d LIMIT 1', 'tfa_enable_tfa', 1);
		$count_user_id = $wpdb->get_var($sql);

		if (is_null($count_user_id)) { // Error in query.
			return apply_filters('simbatfa_enqueue_login_scripts', true);
		} elseif ($count_user_id > 0) { // A user exists with TFA enabled.
			return apply_filters('simbatfa_enqueue_login_scripts', true);
		}

		// No user exists with TFA enabled.
		return apply_filters('simbatfa_enqueue_login_scripts', false);
	}


	/**
	 * Return or output view content
	 *
	 * @param String  $path                   - path to template, usually relative to templates/ within the plugin directory
	 * @param Array	  $extract_these		  - key/value pairs for substitution into the scope of the template
	 * @param Boolean $return_instead_of_echo - what to do with the results
	 *
	 * @return String|Void
	 */
	public function include_template($path, $extract_these = array(), $return_instead_of_echo = false) {

		if ($return_instead_of_echo) ob_start();

		$template_file = apply_filters('simatfa_template_file', $this->templates_dir().'/'.$path, $path, $extract_these, $return_instead_of_echo);

		do_action('simbatfa_before_template', $path, $return_instead_of_echo, $extract_these, $template_file);

		if (!file_exists($template_file)) {
			error_log("TFA: template not found: $template_file (from $path)");
			echo __('Error:', 'all-in-one-wp-security-and-firewall').' '.__('Template path not found:', 'all-in-one-wp-security-and-firewall')." (".htmlspecialchars($path).")";
		} else {
			extract($extract_these);
			// The following are useful variables which can be used in the template.
			// They appear as unused, but may be used in the $template_file.
			$wpdb = $GLOBALS['wpdb'];// phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable -- $wpdb might be used in the included template
			$simba_tfa = $this;// phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable -- $wp_optimize might be used in the included template
			$totp_controller = $this->get_controller('totp');// phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable -- $wp_optimize might be used in the included template
			include $template_file;
		}

		do_action('simbatfa_after_template', $path, $return_instead_of_echo, $extract_these, $template_file);

		if ($return_instead_of_echo) return ob_get_clean();
	}

	/**
	 * Make sure that self::$frontend is the instance of Simba_TFA_Frontend, and return it
	 *
	 * @return Simba_TFA_Frontend
	 */
	public function load_frontend() {
		if (!class_exists('Simba_TFA_Frontend')) require_once($this->includes_dir().'/tfa_frontend.php');
		if (empty($this->frontend)) $this->frontend = new Simba_TFA_Frontend($this);
		return $this->frontend;
	}

	// __return_empty_string() does not exist until WP 3.7
	public function shortcode_when_not_logged_in() {
		return '';
	}

	/**
	 * Set authentication slug.
	 *
	 * @param String $authentication_slug - Authentication slug. Verify that two-factor authentication should not be repeated for the same slug.
	 */
	public function set_authentication_slug($authentication_slug) {
		$this->authentication_slug = $authentication_slug;
	}

	/**
	 * Unserialize data while maintaining compatibility across PHP versions due to different number of arguments required by PHP's "unserialize" function
	 *
	 * @param string        $serialized_data Data to be unserialized, should be one that is already serialized
	 * @param boolean|array $allowed_classes Either an array of class names which should be accepted, false to accept no classes, or true to accept all classes
	 * @param integer       $max_depth       The maximum depth of structures permitted during unserialization, and is intended to prevent stack overflows
	 *
	 * @return mixed Unserialized data can be any of types (integer, float, boolean, string, array or object)
	 */
	private static function unserialize($serialized_data, $allowed_classes = false, $max_depth = 0) {
		if (version_compare(PHP_VERSION, '7.0', '<')) {
			$result = unserialize($serialized_data);
		} else {
			$result = unserialize($serialized_data, array('allowed_classes' => $allowed_classes, 'max_depth' => $max_depth)); // phpcs:ignore PHPCompatibility.FunctionUse.NewFunctionParameters.unserialize_optionsFound -- This is the method used to unserialize data instead of the default unserialize method 
		}
		return $result;
	}
}