import json
import dns.resolver

misperrors = {'error': 'Error'}
mispattributes = {'input': ['hostname', 'domain', 'domain|ip'], 'output': ['ip-src',
                                                                           'ip-dst']}
moduleinfo = {
    'version': '0.3',
    'author': 'Alexandre Dulaunoy',
    'description': 'Simple DNS expansion service to resolve IP address from MISP attributes',
    'module-type': ['expansion', 'hover'],
    'name': 'DNS Resolver',
    'logo': '',
    'requirements': ['dnspython3: DNS python3 library'],
    'features': 'The module takes a domain of hostname attribute as input, and tries to resolve it. If no error is encountered, the IP address that resolves the domain is returned, otherwise the origin of the error is displayed.\n\nThe address of the DNS resolver to use is also configurable, but if no configuration is set, we use the Google public DNS address (8.8.8.8).\n\nPlease note that composite MISP attributes containing domain or hostname are supported as well.',
    'references': [],
    'input': 'Domain or hostname attribute.',
    'output': 'IP address resolving the input.',
}

moduleconfig = ['nameserver']


def handler(q=False):
    if q is False:
        return False
    request = json.loads(q)
    if request.get('hostname'):
        toquery = request['hostname']
    elif request.get('domain'):
        toquery = request['domain']
    elif request.get('domain|ip'):
        toquery = request['domain|ip'].split('|')[0]
    else:
        return False
    r = dns.resolver.Resolver()
    r.timeout = 2
    r.lifetime = 2

    if request.get('config'):
        if request['config'].get('nameserver'):
            nameservers = []
            nameservers.append(request['config'].get('nameserver'))
            r.nameservers = nameservers
    else:
        r.nameservers = ['8.8.8.8']

    try:
        answer = r.resolve(toquery, 'A')
    except dns.resolver.NXDOMAIN:
        misperrors['error'] = "NXDOMAIN"
        return misperrors
    except dns.exception.Timeout:
        misperrors['error'] = "Timeout"
        return misperrors
    except Exception as e:
        misperrors['error'] = f'DNS resolving error {e}'
        return misperrors

    r = {'results': [{'types': mispattributes['output'],
                      'values':[str(answer[0])]}]}
    return r


def introspection():
    return mispattributes


def version():
    moduleinfo['config'] = moduleconfig
    return moduleinfo