from urllib.parse import urlparse

from itsdangerous.timed import TimedSerializer, TimestampSigner
from requests import Response
from requests.sessions import Session

from django.contrib.auth import get_user_model
from django.shortcuts import reverse
from django.test import override_settings, TestCase
from django.utils.timezone import now

from ...conf.test import override_dynamic_settings
from .utils import TEST_SSO_SETTINGS

User = get_user_model()

SSO_USER_ID = 1


def create_verify_response(data):
    signer = TimedSerializer(TEST_SSO_SETTINGS["sso_private_key"])
    return signer.dumps(data)


class ConnectionMock:
    def __init__(self, user_data=None):
        self.session = Session
        self.user_data = user_data

    def __enter__(self):
        self.origin_post = Session.post

        def mocked_post(*args, **kwargs):
            mocked_response = Response()
            requested_url = args[1]
            if "/server/request-token/" == urlparse(requested_url).path:
                # token generated for private key settings.SSO_PRIVATE_KEY = 'priv1'
                mocked_response._content = (
                    b'{"request_token": "XcHtuemqcjnIT6J2WHTFswLQP0W07nI96XfxqGkm6b1zFT'
                    b'oF0YGEoIYu37QOajkc"}.XTd9sA.quRsXFxqMk-ufwSc79q-_YLDNzg'
                )
            elif "/server/verify/" == urlparse(requested_url).path:
                user_data = {
                    "id": SSO_USER_ID,
                    "username": "jkowalski",
                    "email": "jkowalski@example.com",
                    "first_name": "Jan",
                    "last_name": "Kowalski",
                    "is_staff": False,
                    "is_superuser": False,
                    "is_active": True,
                }

                if self.user_data:
                    user_data.update(self.user_data)

                mocked_response._content = create_verify_response(user_data)

            mocked_response.status_code = 200
            return mocked_response

        setattr(self.session, "post", mocked_post)
        return self.session

    def __exit__(self, type, value, traceback):
        setattr(self.session, "post", self.origin_post)


class TimestampSignerMock:
    def __init__(self):
        self.TimestampSigner = TimestampSigner

    def __enter__(self):
        self.origin_unsign = TimestampSigner.unsign

        def mocked_unsign(*args, **kwargs):
            s = args[1]
            if b'"username": "jkowalski"' in s:
                value = s[: s.index(b"}.") + 1]  # {...}
                timestamp_to_datetime = now()
                return value, timestamp_to_datetime
            else:
                return self.origin_unsign(*args, **kwargs)

        setattr(self.TimestampSigner, "unsign", mocked_unsign)
        return self.TimestampSigner

    def __exit__(self, type, value, traceback):
        setattr(self.TimestampSigner, "unsign", self.origin_unsign)


@override_dynamic_settings(enable_sso=False)
def test_sso_login_view_returns_404_if_sso_is_disabled(db, client):
    url_to_external_logging = reverse("simple-sso-login")
    assert url_to_external_logging == "/sso/client/"

    response = client.get(url_to_external_logging)
    assert response.status_code == 404


@override_dynamic_settings(**TEST_SSO_SETTINGS)
def test_sso_login_view_initiates_auth_flow(db, client):
    url_to_external_logging = reverse("simple-sso-login")
    assert url_to_external_logging == "/sso/client/"

    with ConnectionMock():
        response = client.get(url_to_external_logging)

    assert response.status_code == 302

    url_parsed = urlparse(response.url)
    assert url_parsed.path == "/server/authorize/"
    assert url_parsed.query == (
        "token=XcHtuemqcjnIT6J2WHTFswLQP0W07nI96XfxqGkm6b1zFToF0YGEoIYu37QOajkc"
    )


@override_dynamic_settings(enable_sso=False)
def test_sso_auth_view_returns_404_if_sso_is_disabled(db, client):
    url_to_authenticate = reverse("simple-sso-authenticate")
    assert url_to_authenticate == "/sso/client/authenticate/"

    response = client.get(url_to_authenticate)
    assert response.status_code == 404


@override_dynamic_settings(**TEST_SSO_SETTINGS)
def test_sso_auth_view_creates_new_user(db, client):
    url_to_authenticate = reverse("simple-sso-authenticate")
    assert url_to_authenticate == "/sso/client/authenticate/"

    query = (
        "next=%2F&access_token=InBBMjllMlNla2ZWdDdJMnR0c3R3QWIxcjQwRzV6TmphZDRSaEprbjlMbnR0TnF"
        "Ka3Q2d1dNR1lVYkhzVThvZU0i.XTeRVQ.3XiIMg0AFcJKDFCekse6s43uNLI"
    )
    url_to_authenticate += "?" + query

    with ConnectionMock():
        with TimestampSignerMock():
            response = client.get(url_to_authenticate)

    assert response.status_code == 302
    assert response.url == "/"

    user = User.objects.first()
    assert user.username == "jkowalski"


@override_dynamic_settings(**TEST_SSO_SETTINGS)
def test_sso_auth_view_authenticates_existing_user(user, client):
    user.sso_id = SSO_USER_ID
    user.save()

    url_to_authenticate = reverse("simple-sso-authenticate")
    assert url_to_authenticate == "/sso/client/authenticate/"

    query = (
        "next=%2F&access_token=InBBMjllMlNla2ZWdDdJMnR0c3R3QWIxcjQwRzV6TmphZDRSaEprbjlMbnR0TnF"
        "Ka3Q2d1dNR1lVYkhzVThvZU0i.XTeRVQ.3XiIMg0AFcJKDFCekse6s43uNLI"
    )
    url_to_authenticate += "?" + query

    with ConnectionMock():
        with TimestampSignerMock():
            response = client.get(url_to_authenticate)

    assert response.status_code == 302
    assert response.url == "/"

    assert User.objects.count() == 1


@override_dynamic_settings(**TEST_SSO_SETTINGS)
def test_sso_auth_view_updates_existing_user_using_data_from_sso(user, client):
    user.sso_id = SSO_USER_ID
    user.is_active = False
    user.save()

    url_to_authenticate = reverse("simple-sso-authenticate")
    assert url_to_authenticate == "/sso/client/authenticate/"

    query = (
        "next=%2F&access_token=InBBMjllMlNla2ZWdDdJMnR0c3R3QWIxcjQwRzV6TmphZDRSaEprbjlMbnR0TnF"
        "Ka3Q2d1dNR1lVYkhzVThvZU0i.XTeRVQ.3XiIMg0AFcJKDFCekse6s43uNLI"
    )
    url_to_authenticate += "?" + query

    with ConnectionMock():
        with TimestampSignerMock():
            client.get(url_to_authenticate)

    user.refresh_from_db()
    assert user.username == "jkowalski"
    assert user.email == "jkowalski@example.com"
    assert user.is_active is True


@override_dynamic_settings(**TEST_SSO_SETTINGS)
def test_sso_auth_view_returns_bad_request_error_for_invalid_user_data(db, client):

    url_to_authenticate = reverse("simple-sso-authenticate")
    assert url_to_authenticate == "/sso/client/authenticate/"

    query = (
        "next=%2F&access_token=InBBMjllMlNla2ZWdDdJMnR0c3R3QWIxcjQwRzV6TmphZDRSaEprbjlMbnR0TnF"
        "Ka3Q2d1dNR1lVYkhzVThvZU0i.XTeRVQ.3XiIMg0AFcJKDFCekse6s43uNLI"
    )
    url_to_authenticate += "?" + query

    with ConnectionMock({"email": "invalid"}):
        with TimestampSignerMock():
            response = client.get(url_to_authenticate)
            assert response.status_code == 400