How can I match the following in Nginx - nginx

Question

Dear StackOverflow Population,
I have been trying to get two simple things to work but I can't get but 1 of them to.
So I have nginx server block it looks like the following
server {
listen 443 default;
server_name secure.<domain>.com;
if ($host = $server_name) {
rewrite ^(.*) https://secure.<domain2>.com$request_uri?systpl=<template> permanent;
}
I have also tried since I know that IF is evil I have tried something like
return 301 https://secure.<domain2>.com$request_uri?systpl=<template>;
of course then I disable the if statement above, this works okay so when we goto
https://secure.domain.com => https://secure.domain2.com/?systpl=template
That works fine and when you enter a PHP ending such as
https://secure.domain.com/cart.php => https://secure.domain2.com/cart.php?systpl=template
This works both with IF and simple return, and I figure I need to get the other in a different server block or a statement but here is where the problem lies
Now if you goto
https://secure.domain.com/cart.php?id=7 => https://secure.domain2.com/cart.php?id=7?systpl=template
This of course doesn't work since it would have to be &systpl since it doesn't end with .php, how can I achieve this so it appends &systpl if it does not end with .php and ends with string and if not then append it with ?systpl if it ends with .php
I hope someone knows how this is done because I have crawled the first 6 pages of google results with various search strings.

Answer 1

If you are adding arguments, you should probably avoid using $request_uri and use $uri and $args instead.
The return statement could be rewritten as:
return 301 https://example.com$uri?systpl=template&$args;
The rewrite directive appends arguments by default, so this should work:
rewrite ^ https://example.com$uri?systpl=template permanent;
But as it is identical to the return statement, the return statement is preferred. See this document for details.