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 {
}
}