htaccess rewrite giving off .php at the end of a paremeter - php

Question

I have created my own .htaccess file which purpose is to change the username URL of my site (along with remove the .php extension from all urls).
The intent is for the URL to transform from:
www.example.one/profile.php?id=username
to
www.example.one/username
I know this is a common problem with "username" htaccess rewrites, however, none of the answers I have found have helped me solve my problem.
This is my full .htaccess:
Options -Indexes
Options +FollowSymLinks
RewriteEngine On
# only allow rewriting to paths that dont exist
RewriteCond %{SCRIPT_FILENAME} !-d
RewriteCond %{SCRIPT_FILENAME} !-f
# redirect example.one to www.*
RewriteCond %{HTTP_HOST} ^example\.one$ [NC]
RewriteRule ^(.*)$ http://www.example.one [R=301,L]
# no php extension
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^([^\.]+)$ $1.php [NC,L]
# example.one/username
RewriteRule ^/([a-zA-Z_\-0-9]+)*$ ./profile.php?id=$1
Cheers.

Answer 1

You may use these rules in your site root .htaccess:
Options +FollowSymLinks -Indexes
RewriteEngine On
# redirect example.one to www.*
RewriteCond %{HTTP_HOST} !^www\. [NC]
RewriteRule ^ http://www.%{HTTP_HOST}%{REQUEST_URI} [R=301,L]
# external redirect from actual URL to pretty one
RewriteCond %{THE_REQUEST} /profile\.php\?id=([\w-]+) [NC]
RewriteRule ^ /%1? [R=301,L]
# no php extension
RewriteCond %{REQUEST_FILENAME}.php -f
RewriteRule ^(.+?)/?$ $1.php [L]
# example.one/username
# only allow rewriting to paths that dont exist
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^([\w-]+)/?$ profile.php?id=$1 [L,QSA]