"""
Google App Engine support using User API
"""

from google.appengine.api import users

from ..exceptions import AuthException
from .base import BaseAuth


class GoogleAppEngineAuth(BaseAuth):
    """GoogleAppengine authentication backend"""

    name = "google-appengine"

    def get_user_id(self, details, response):
        """Return current user id."""
        user = users.get_current_user()
        if user:
            return user.user_id()
        return None

    def get_user_details(self, response):
        """Return user basic information (id and email only)."""
        user = users.get_current_user()
        return {
            "username": user.user_id(),
            "email": user.email(),
            "fullname": "",
            "first_name": "",
            "last_name": "",
        }

    def auth_url(self):
        """Build and return complete URL."""
        return users.create_login_url(self.redirect_uri)

    def auth_complete(self, *args, **kwargs):
        """Completes login process, must return user instance."""
        if not users.get_current_user():
            raise AuthException(self, "Authentication error")
        kwargs.update({"response": "", "backend": self})
        return self.strategy.authenticate(*args, **kwargs)