Intelligent `\vref`

Question

I want to use the package varioref, but using abbreviations ... (p.1) instead of ... on page 1. Unfortunately, I have also references in parentheses, where this would lead to unaesthetic/forbidden (?) double closing brackets.

I tried using \@ifnextchar to recognize this case, but this seems not to work.

Here, a minimal example:

\documentclass[]{article}
\usepackage{varioref}
\usepackage{cleveref}
\usepackage[english]{babel}

\makeatletter
\addto\extrasenglish{%
     \def\reftextfaraway#1{\@ifnextchar){on p.~\pageref{#1}}{(p.~\pageref{#1})}}%
}
\makeatother

\begin{document}
In \vref{sec:test}, this is explained.
Other text (cf.\ \vref{sec:test}).

\newpage
\null\newpage
\section{Test}
\label{sec:test}
\end{document}

Intended output:

In chapter 1 (p. 3), this is explained. Other text (cf. chapter 1 on p. 3).

Current output:

In chapter 1 (p. 3), this is explained. Other text (cf. chapter 1 (p. 3)).

Answer 1

Here I save the definition of \vref and then redefine it with two arguments. I check if the second argument is a ) and redefine \reftextfaraway accordingly. I then call on the saved version of \vref with the first argument and pass freely the 2nd argument.

\documentclass[]{article}
\usepackage{varioref}
\usepackage{cleveref}
%\usepackage[english]{babel}

\let\svvref\vref
\makeatletter
%\addto\extrasenglish{%
     \renewcommand\vref[2]{%
       \ifx)#2%
         \renewcommand*{\reftextfaraway}[1]{on p.~\pageref{#1}}%
       \else
         \renewcommand*{\reftextfaraway}[1]{(p.~\pageref{#1})}%
       \fi
     \svvref{#1}#2%
     }%
%}
\makeatother

\begin{document}
In \vref{sec:test}, this is explained.
Other text (cf.\ \vref{sec:test}).

\newpage
\null\newpage
\section{Test}
\label{sec:test}
\end{document}