update the language redirection system of our PHP website

when we open [login to view URL] we would like to have always a redirection to [login to view URL] or another language according to the browser language when opening any links on [login to view URL] without the language code, we would like to have always a redirection with same url with the language code according to the browser language You need to edit .htaccess file You need to edit Apache virtual server configuration file You need to the PHP script which handle the urls without language code [login to view URL] is currently using apache rules and some PHP pages to process languages code, we would prefer to rewrite this system for a better code design The new system must be very well explained with lot of comments inside the code