ubuntu - non www to www domain?

I've changed my conf file so that when a user types in the
domain without www it redirects to the domain with
www:

server_name
example.com;
return 301 $scheme://www.example.com$request_uri;
I
also wish for my https for anything under
/user

I get the error of too may redirects,
where am I going wrong?

So I
have:

server
            {

listen 80 default_server;
listen [::]:80 default_server
            ipv6only=on;

root /var/www/example.com/site;
index
            index.html index.htm;

# Make site accessible from
            http://localhost/
server_name example.com;
return 301
            $scheme://www.example.com$request_uri;


location /
            {
 # First attempt to serve request as file, then
 # as directory,
            then fall back to displaying a 404.
 try_files $uri $uri/ =404;
 #
            Uncomment to enable naxsi on this location
 # include
            /etc/nginx/naxsi.rules
}
location /user {
 rewrite ^
            https://$http_host$request_uri?
            permanent;
}

}

For
port 443:

server
            {
listen 443;
server_name example.com;
return 301
            $scheme://www.example.com$request_uri;


root
            /var/www/example.com/site;
index index.html
            index.htm;

ssl on;
ssl_certificate //path
            here
ssl_certificate_key //path here

location /
            {
 rewrite ^ http://$http_host$request_uri?
            permanent;
}

location /user
            {
}
}