from django.contrib.auth.models import User
from rest_framework import authentication, exceptions, serializers

import urllib.request
import pyotp
import json

# For parsing
class TokenSerializer(serializers.Serializer):
    name = serializers.CharField(max_length=128)
    token = serializers.CharField(max_length=128)
    realm = serializers.CharField(max_length=128)

    token_name = 'token'
    name_name = 'name'
    realm_name = 'realm'

    def __init__(self, name, realm, seed, serverurl, *args, **kwargs):
        self.name = name
        self.realm = realm
        self.seed = seed
        self.serverurl = serverurl

        super(serializers.Serializer, self).__init__(*args, **kwargs)

    def save(self):
        to_send = {}

        # Client credentials to be verified
        to_send['verifytoken'] = self.validated_data.get(self.token_name)
        to_send['verifyname']  = self.validated_data.get(self.name_name)
        to_send['verifyrealm'] = self.validated_data.get(self.real_name)

        # Our credentials
        to_send['token'] = pyotp.TOTP(self.seed)
        to_send['name']  = self.name
        to_send['realm'] = self.realm

        data = json.dumps(to_send).encode("utf-8")

        req = urllib.request.Request(url=serverurl,
                                     data=data,
                                     headers={'Content-Type': 'application/json'},
                                     method='POST')

        f = urllib.request.urlopen(req)

        if not f.status == 200:
            raise exceptions.AuthenticationFailed()

        return True


class OTPAuthentication(authentication.BaseAuthentication):
    def authenticate(self, request):
        serializer = TokenSerializer(data=request.data)

        if serializer.is_valid():
            print("trying to save... {}".format(serializer))
            user, token = serializer.save()
        else:
            raise exceptions.AuthenticationFailed()

        return (user, token)