import jwt
from django.conf import settings
from django.contrib.auth.models import User
from rest_framework import authentication, exceptions


class JWTAuthentication(authentication.BaseAuthentication):
    def authenticate(self, request):

        auth_data = authentication.get_authorization_header(request)

        if not auth_data:
            return None

        prefix, token = auth_data.decode("utf-8").split(" ")

        try:
            payload = jwt.decode(token, settings.JWT_SECRET_KEY, algorithms="HS256")
            user = User.objects.get(username=payload["username"])
            return (user, token)
        except jwt.DecodeError as err:
            raise exceptions.AuthenticationFailed("Your token is invalid, please login")
        except jwt.ExpiredSignatureError as err:
            raise exceptions.AuthenticationFailed("Your token is expired, login")

        return super().authenticate(request)