import json
import config_utils


def collect_tokens(cfg):
    tokens = config_utils.collect_layout_tokens(cfg)
    dns = cfg.get('upstream_dns', {})
    servers = dns.get('upstream_servers', [])
    tokens['DNS_STRICT_ORDER'] = 'true' if dns.get('strict_order') else 'false'
    tokens['DNS_CACHE_SIZE'] = str(dns.get('cache_size', '-'))
    tokens['DNS_UPSTREAM_SERVERS_JSON'] = json.dumps(servers)
    return tokens