from django.utils.translation import gettext as _

from rest_framework import authentication
from rest_framework.exceptions import AuthenticationFailed

from pingcap_sso.models import ApiToken


class APITokenAuthentication(authentication.BasicAuthentication):

    def authenticate_header(self, request):
        return 'xBasic realm="%s"' % self.www_authenticate_realm

    def authenticate(self, request):
        auth = authentication.get_authorization_header(request).split()

        if not auth or auth[0].lower() != b'bearer':
            return None

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

        return self.authenticate_credentials(auth[1])

    def authenticate_credentials(self, token):
        try:
            token = ApiToken.objects.filter(
                token=token.decode('utf-8')).select_related('user').get()
        except Exception:
            raise AuthenticationFailed(_('Invalid token'))

        if not token.user.is_active:
            raise AuthenticationFailed(_('User has not been activated'))

        return (token.user, token)


class SessionAuthentication(authentication.SessionAuthentication):

    def authenticate_header(self, request):
        return 'xBasic realm="cookie"'


class CsrfExemptSessionAuthentication(authentication.SessionAuthentication):

    def authenticate_header(self, request):
        return 'xBasic realm="cookies"'

    def enforce_csrf(self, request):
        return