import json
import requests
from . import check_input_attribute, standard_error_message
from pymisp import MISPEvent, MISPObject

misperrors = {'error': 'Error'}
mispattributes = {'input': ['cpe'], 'format': 'misp_standard'}
moduleinfo = {
    'version': '2',
    'author': 'Christian Studer',
    'description': 'An expansion module to query the CVE search API with a cpe code to get its related vulnerabilities.',
    'module-type': ['expansion', 'hover'],
    'name': 'CPE Lookup',
    'logo': 'cve.png',
    'requirements': [],
    'features': 'The module takes a cpe attribute as input and queries the CVE search API to get its related vulnerabilities.  \nThe list of vulnerabilities is then parsed and returned as vulnerability objects.\n\nUsers can use their own CVE search API url by defining a value to the custom_API_URL parameter. If no custom API url is given, the default vulnerability.circl.lu api url is used.\n\nIn order to limit the amount of data returned by CVE serach, users can also the limit parameter. With the limit set, the API returns only the requested number of vulnerabilities, sorted from the highest cvss score to the lowest one.',
    'references': ['https://vulnerability.circl.lu/api/'],
    'input': 'CPE attribute.',
    'output': 'The vulnerabilities related to the CPE.',
}
moduleconfig = ["custom_API_URL", "limit"]
cveapi_url = 'https://cvepremium.circl.lu/api/query'
DEFAULT_LIMIT = 10


class VulnerabilitiesParser():
    def __init__(self, attribute):
        self.attribute = attribute
        self.misp_event = MISPEvent()
        self.misp_event.add_attribute(**attribute)
        self.vulnerability_mapping = {
            'id': {
                'type': 'vulnerability',
                'object_relation': 'id'
            },
            'summary': {
                'type': 'text',
                'object_relation': 'summary'
            },
            'vulnerable_configuration': {
                'type': 'cpe',
                'object_relation': 'vulnerable-configuration'
            },
            'vulnerable_configuration_cpe_2_2': {
                'type': 'cpe',
                'object_relation': 'vulnerable-configuration'
            },
            'Modified': {
                'type': 'datetime',
                'object_relation': 'modified'
            },
            'Published': {
                'type': 'datetime',
                'object_relation': 'published'
            },
            'references': {
                'type': 'link',
                'object_relation': 'references'
            },
            'cvss': {
                'type': 'float',
                'object_relation': 'cvss-score'
            }
        }

    def parse_vulnerabilities(self, vulnerabilities):
        for vulnerability in vulnerabilities:
            vulnerability_object = MISPObject('vulnerability')
            for feature in ('id', 'summary', 'Modified', 'Published', 'cvss'):
                if vulnerability.get(feature):
                    attribute = {'value': vulnerability[feature]}
                    attribute.update(self.vulnerability_mapping[feature])
                    vulnerability_object.add_attribute(**attribute)
            if vulnerability.get('Published'):
                vulnerability_object.add_attribute(**{
                    'type': 'text',
                    'object_relation': 'state',
                    'value': 'Published'
                })
            for feature in ('references', 'vulnerable_configuration', 'vulnerable_configuration_cpe_2_2'):
                if vulnerability.get(feature):
                    for value in vulnerability[feature]:
                        if isinstance(value, dict):
                            value = value['title']
                        attribute = {'value': value}
                        attribute.update(self.vulnerability_mapping[feature])
                        vulnerability_object.add_attribute(**attribute)
            vulnerability_object.add_reference(self.attribute['uuid'], 'related-to')
            self.misp_event.add_object(vulnerability_object)

    def get_result(self):
        event = json.loads(self.misp_event.to_json())
        results = {key: event[key] for key in ('Attribute', 'Object')}
        return {'results': results}


def check_url(url):
    return url if url.endswith('/') else f"{url}/"


def handler(q=False):
    if q is False:
        return False
    request = json.loads(q)
    if not request.get('attribute') or not check_input_attribute(request['attribute']):
        return {'error': f'{standard_error_message}, which should contain at least a type, a value and an uuid.'}
    attribute = request['attribute']
    if attribute.get('type') != 'cpe':
        return {'error': 'Wrong input attribute type.'}
    config = request['config']
    url = check_url(config['custom_API_URL']) if config.get('custom_API_URL') else cveapi_url
    limit = int(config['limit']) if config.get('limit') else DEFAULT_LIMIT
    params = {
        "retrieve": "cves",
        "dict_filter": {
            "vulnerable_configuration": attribute['value']
        },
        "limit": limit,
        "sort": "cvss",
        "sort_dir": "DESC"
    }
    response = requests.post(url, json=params)
    if response.status_code == 200:
        vulnerabilities = response.json()['data']
        if not vulnerabilities:
            return {'error': 'No related vulnerability for this CPE.'}
    else:
        return {'error': 'API not accessible.'}
    parser = VulnerabilitiesParser(attribute)
    parser.parse_vulnerabilities(vulnerabilities)
    return parser.get_result()


def introspection():
    return mispattributes


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