from django.core.exceptions import ValidationError
from .models import Token, User


class PasswordlessAuthenticationBackend:
    def authenticate(self, request, uid=None):
        if uid is None:
            return None
        try:
            token = Token.objects.get(uid=uid)
        except (Token.DoesNotExist, ValidationError):
            return None
        try:
            return User.objects.get(email=token.email)
        except User.DoesNotExist:
            return User.objects.create(email=token.email)