import json


def collect_tokens(cfg):
    vlans = cfg.get('vlans', [])
    dv = next((v for v in vlans if v.get('radius_default')), None)
    return {
        'EXISTING_VLAN_IDS_JSON':   json.dumps([v.get('vlan_id') for v in vlans]),
        'EXISTING_VLAN_NAMES_JSON': json.dumps([v.get('name')    for v in vlans]),
        'RADIUS_DEFAULT_VLAN':      f'"{dv["name"]}" (VLAN {dv["vlan_id"]})' if dv else 'none set',
        'BLOCKLIST_NAME_OPTIONS':   json.dumps([
            {'value': bl.get('name', ''), 'label': bl.get('description', bl.get('name', ''))}
            for bl in cfg.get('dns_blocking', {}).get('blocklists', [])
        ]),
    }