import logging
from urllib.parse import parse_qs, urlsplit

import nose.tools as nt
from behave import step
from flask.sessions import SecureCookieSessionInterface
from itsdangerous import URLSafeTimedSerializer as Serializer

logger = logging.getLogger(__name__)


def deserialize_session(session, session_secret):
    s = Serializer(
        session_secret,
        salt=SecureCookieSessionInterface.salt,
        serializer=SecureCookieSessionInterface.serializer,
        signer_kwargs={
            "key_derivation": SecureCookieSessionInterface.key_derivation,
            "digest_method": SecureCookieSessionInterface.digest_method,
        },
    )
    return s.loads(session)


@step("I should be assigned a session state matching the state param")
def step_should_be_assigned_session_state_matching_state_param(context):
    qs = parse_qs(urlsplit(context.response.headers["Location"]).query)
    session = context.atlas_um_client.cookies["session"]
    session_secret = context.atlas_um_app.config["SECRET_KEY"]
    deserialized_session = deserialize_session(session, session_secret)
    nt.assert_equal(
        qs["state"], [deserialized_session["usm_authentication_state"]]
    )


@step("I should be assigned a session nonce matching the nonce param")
def step_should_be_assigned_session_nonce_matching_nonce_param(context):
    qs = parse_qs(urlsplit(context.response.headers["Location"]).query)
    session = context.atlas_um_client.cookies["session"]
    session_secret = context.atlas_um_app.config["SECRET_KEY"]
    deserialized_session = deserialize_session(session, session_secret)
    nt.assert_equal(
        qs["nonce"], [deserialized_session["usm_authentication_nonce"]]
    )