(function () {
    window.webapi = {
        safeAjax: function (ajaxOptions) {
            var deferredAjax = $.Deferred();

            if (!window.shell || !shell.getTokenDeferred) {
                deferredAjax.reject('Shell não disponível');
                return deferredAjax.promise();
            }

            shell.getTokenDeferred()
                .done(function (token) {

                    ajaxOptions.headers = ajaxOptions.headers || {};
                    ajaxOptions.headers["__RequestVerificationToken"] = token;

                    $.ajax(ajaxOptions)
                        .done(function (data, textStatus, jqXHR) {
                            deferredAjax.resolve(data);
                        })
                        .fail(deferredAjax.reject);
                })
                .fail(deferredAjax.reject);

            return deferredAjax.promise();
        }
    };
})();