sessions: store geolocated country in CurrentUser.

app/logical/session_loader.rb

@@ -34,6 +34,7 @@ class SessionLoader
     update_last_logged_in_at
     update_last_ip_addr
     set_time_zone
+    set_country
     set_safe_mode
     initialize_session_cookies
     CurrentUser.user.unban! if CurrentUser.user.ban_expired?
@@ -101,6 +102,12 @@ class SessionLoader
     Time.zone = CurrentUser.user.time_zone
   end
 
+  # Depends on Cloudflare
+  # https://support.cloudflare.com/hc/en-us/articles/200168236-Configuring-Cloudflare-IP-Geolocation
+  def set_country
+    CurrentUser.country = request.headers["CF-IPCountry"]
+  end
+
   def set_safe_mode
     safe_mode = request.host.match?(/safebooru/i) || params[:safe_mode].to_s.truthy? || CurrentUser.user.enable_safe_mode?
     CurrentUser.safe_mode = safe_mode