How to change the querystring when changing language?

[Eventect]

I have implemented a CountrySelector component as described here and here. However, if in the product page a product variant is selected in a certain language/country, when selecting a country with a different language the variant querystring does not get modified with the proper translation. This makes impossible to select any variant in the new language, as the previously selected language and the current selected language get mixed up in the querystring.
Is there any comprehensive example on how to implement a CountrySelector with querystring translation?