""" Mini-Challenge"""

from os.path import join
from xml.dom import minidom
from twisted.internet import defer


class Adapter:
    """Adapter class

    Aufgabe: Asynchron XML-Daten lesen, konvertieren und zurückliefern.
    """

    def __init__(self, path):
        self.path = path

    def retrieve_token(self, name):
        """
        Retrieve the content from file name.xml in adapters path directory
        in a synchronous way, extract the DataReceived/Token and return it
        as a JSON-Object (stringified) '{"token": value}'.
        """
        try:
            with open(join(self.path, name + ".xml")) as f:
                xml_data = f.read()
                dom = minidom.parseString(xml_data)
                token = dom.getElementsByTagName("Token")[0].firstChild.data

                return '{"token": %s}' % token

        except Exception as e:
            raise ValueError("Could not retrieve token: %s" % e)

    def retrieve_token_async(self, name):
        """
        Retrieve the content from file name.xml in adapters path directory
        in an asynchronous way, extract the DataReceived/Token and return it
        as a Deferred which ends up in a JSON-Object (as above).

        see: https://twistedmatrix.com/documents/8.0.0/api/twisted.internet.defer.Deferred.html

        Hint: The simple way is to use defer.succeed(), bonus points for doing
              it with a callback chain read->parse->convert.
        """
        d = defer.Deferred()

        def read_file():
            try:
                with open(join(self.path, name + ".xml")) as f:
                    xml_data = f.read()
                    return xml_data
            except Exception as e:
                d.errback(e)

        def parse_xml(xml_data):
            try:
                dom = minidom.parseString(xml_data)
                token = dom.getElementsByTagName("Token")[0].firstChild.data

                return token

            except Exception as e:
                d.errback(e)

        def convert_to_json(token):
            try:
                json_string = '{"token": %s}' % token
                d.callback(json_string)
            except Exception as e:
                d.errback(e)

        defer.execute(read_file).addCallback(parse_xml).addCallback(
            convert_to_json
        ).addErrback(d.errback)

        return d