"""OIDC Permission checking"""
from django.contrib import messages
from django.shortcuts import redirect
from structlog import get_logger

from passbook.core.models import Application
from passbook.policy.engine import PolicyEngine

LOGGER = get_logger()

def check_permissions(request, user, client):
    """Check permissions, used for
    https://django-oidc-provider.readthedocs.io/en/latest/
    sections/settings.html#oidc-after-userlogin-hook"""
    try:
        application = client.openidprovider.application
    except Application.DoesNotExist:
        return redirect('passbook_oauth_provider:oauth2-permission-denied')
    LOGGER.debug("Checking permissions of %s on application %s...", user, application)
    policy_engine = PolicyEngine(application.policies.all())
    policy_engine.for_user(user).with_request(request).build()

    # Check permissions
    passing, policy_messages = policy_engine.result
    if not passing:
        for policy_message in policy_messages:
            messages.error(request, policy_message)
        return redirect('passbook_oauth_provider:oauth2-permission-denied')
    return None