from django.contrib.auth import get_user_model
from django.core.exceptions import FieldError, ValidationError
from rest_framework import exceptions
from rest_framework.authentication import BaseAuthentication

from drf_uuid_auth.settings import api_settings


class UuidAuthentication(BaseAuthentication):
    def authenticate(self, request):
        header = request.META.get(api_settings.AUTH_HEADER.upper(), None)
        if header is None or header == "" or header == "-":
            return None

        payload = header
        user = self.authenticate_credentials(payload)
        return user, payload

    def authenticate_credentials(self, payload):
        User = get_user_model()

        try:
            user = User.objects.get(uid=payload)
        except User.DoesNotExist:
            raise exceptions.AuthenticationFailed("Invalid user id")
        except FieldError:
            raise exceptions.AuthenticationFailed("Incorrect user model")
        except ValidationError:
            raise exceptions.AuthenticationFailed("Incorrect user id")

        if not user.is_active:
            raise exceptions.AuthenticationFailed("User isn't active")

        return user

    def authenticate_header(self, request):
        return ""