from django.shortcuts import redirect
from django.contrib import auth, messages
from django.views.decorators.cache import never_cache
from django.conf import settings

from test_oauth.session import TESTOAuth2Session


@never_cache
def login(request, next=None):
    authorization_url, request.session['oauth_state'] = TESTOAuth2Session(
        scope=getattr(settings, 'TEST_OAUTH_SCOPES', ['read_profile']),
    ).authorization_url()

    return redirect(authorization_url)


@never_cache
def logout(request):
    if request.user.is_authenticated():
        auth.logout(request)
    return redirect(getattr(settings, 'TEST_OAUTH_REDIRECT', '/'))


@never_cache
def callback(request):
    token = (
        TESTOAuth2Session(state=request.session['oauth_state'])
        .fetch_token(code=request.GET.get('code'))
    )

    user = auth.authenticate(token=token)

    if user is not None:
        auth.login(request, user)
    else:
        messages.error(request, 'Login failed.')

    return redirect(getattr(settings, 'TEST_OAUTH_REDIRECT', '/'))