from django.views.generic import View
from django.http import HttpResponseBadRequest, HttpResponseRedirect
from django.conf import settings

from .auth_core import SSOAuthCore
from .exceptions import AuthError
from pingcap_sso.utils.mixins import LoginRequiredMixin


class SSOProviderEndpoint(LoginRequiredMixin, View):

    sso_core = SSOAuthCore()
    sso_secret = settings.DISCOURSE_SSO_TOKEN
    sso_callback_uri = settings.DISCOURSE_SSO_CALLBACK_URI

    def get(self, request, *args, **kwargs):
        sso = request.GET.get('sso')
        sig = request.GET.get('sig')

        try:
            nonce = self.sso_core.validate_authentication_request(sso, sig, self.sso_secret)
        except AuthError as e:
            return self.error_response(e.description)

        user = request.user
        # Discoure requires a validated email, so we will fake a email if user has not provided.
        # A fake email will like: 1057e02e-0c23-11ea-9fbb-f2189839837a@fake.email
        response_url = self.sso_core.create_response_payload(
            nonce,
            user.email or user.fake_email,
            False,
            user.openid,
            user.username,
            user.name,
            self.sso_secret)

        return HttpResponseRedirect(
            '{}?{}'.format(self.sso_callback_uri, response_url))

    def error_response(self, error):
        return HttpResponseBadRequest(
            'sso client error: {} , please try again or contact support@pincap.com'.format(error))