# -*- coding: utf-8 -*-
#

from rest_framework import authentication, exceptions
from django.utils.translation import ugettext as _

from common.utils import unsign
from .models import User


class APPSignAuthentication(authentication.BaseAuthentication):
    keyword = 'Sign'
    model = User

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

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

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

        try:
            sign = auth[1].decode()
        except UnicodeError:
            msg = _('Invalid token header. Sign string should not contain invalid characters.')
            raise exceptions.AuthenticationFailed(msg)

        return self.authenticate_credentials(sign)

    def authenticate_credentials(self, key):
        try:
            token = self.model.objects.select_related('user').get(key=key)
        except self.model.DoesNotExist:
            raise exceptions.AuthenticationFailed(_('Invalid token.'))

        if not token.user.is_active:
            raise exceptions.AuthenticationFailed(_('User inactive or deleted.'))


if __name__ == '__main__':
    pass