"""Session limits, client address and the signed-in user.

The idle limit is SESSION_COOKIE_AGE with save-every-request; the absolute limit is below.
"""

import time

from django.conf import settings

from . import identity
from .clientip import client_ip, parse_networks
from .session_store import CREATED_AT


class AbsoluteSessionLimitMiddleware:
    def __init__(self, get_response):
        self.get_response = get_response

    def __call__(self, request):
        session = request.session
        created = session.get(CREATED_AT)
        if created is not None and time.time() - created > settings.SESSION_ABSOLUTE_SECONDS:
            # flush() deletes the row; the empty session makes SessionMiddleware clear the cookie.
            session.flush()
        return self.get_response(request)


class ClientIpMiddleware:
    """Set request.client_ip from the peer and, behind a trusted proxy, X-Forwarded-For (AD-7)."""

    def __init__(self, get_response):
        self.get_response = get_response
        self.trusted = parse_networks(settings.TRUSTED_PROXIES)

    def __call__(self, request):
        request.client_ip = client_ip(
            request.META.get("REMOTE_ADDR", ""),
            request.META.get("HTTP_X_FORWARDED_FOR", ""),
            self.trusted,
        )
        return self.get_response(request)


class CurrentUserMiddleware:
    """Set request.portal_user: the signed-in user with roles, or None (AD-5)."""

    def __init__(self, get_response):
        self.get_response = get_response

    def __call__(self, request):
        request.portal_user = identity.current(request)
        return self.get_response(request)