import logging
from django.conf import settings
from django.contrib.auth.models import AnonymousUser
from django.core.cache import cache
from django.utils.translation import gettext_lazy
from rest_framework import authentication
from rest_framework.authentication import TokenAuthentication, \
    get_authorization_header
from rest_framework import exceptions


logger = logging.getLogger(__name__)


class AnonymousAuthentication(authentication.BaseAuthentication):

    def authenticate(self, request):
        """
        Authenticate the request for anyone!
        """
        return AnonymousUser(), None


class DryccAuthentication(TokenAuthentication):

    def authenticate(self, request):
        if 'Drycc' in request.META.get('HTTP_USER_AGENT', ''):
            auth = get_authorization_header(request).split()

            if not auth or auth[0].lower() != self.keyword.lower().encode():
                return None

            if len(auth) == 1:
                msg = gettext_lazy('Invalid token header. No credentials provided.')
                raise exceptions.AuthenticationFailed(msg)
            elif len(auth) > 2:
                msg = gettext_lazy(
                    'Invalid token header. Token string should not contain spaces.')
                raise exceptions.AuthenticationFailed(msg)

            try:
                token = auth[1].decode()
            except UnicodeError:
                msg = gettext_lazy(
                    'Invalid token header. Token string should not contain invalid characters.')
                raise exceptions.AuthenticationFailed(msg)
            return self.sync_user(token), None
        return super(DryccAuthentication, self).authenticate(request)

    @staticmethod
    def sync_user(token):
        def _sync_user(token):
            from api import serializers
            from api.oauth import OAuthManager
            try:
                user_info = OAuthManager().get_user_by_token(token)
                if not user_info.get('email'):
                    user_info['email'] = OAuthManager().get_email_by_token(token)
                user, _ = serializers.UserSerializer.update_or_create(user_info)
                return user
            except Exception as e:
                logger.info(e)
                raise exceptions.AuthenticationFailed(gettext_lazy('Verify token fail.'))
        return cache.get_or_set(token, lambda: _sync_user(token), settings.OAUTH_CACHE_USER_TIME)