func lookupCountry(db *geoip2.Reader, ip net.IP) (string, error) {
if db == nil {
return "", nil
}
record, err := db.Country(ip)
if err != nil {
return "", err
}
if country, exists := record.Country.Names["en"]; exists {
return country, nil
}
if country, exists := record.RegisteredCountry.Names["en"]; exists {
return country, nil
}
return "", fmt.Errorf("could not determine country for IP: %s", ip)
}
