import sys
from importlib import import_module, reload
from unittest import mock
from urllib.parse import quote

from django.conf import settings
from django.test.utils import override_settings
from django.urls import clear_url_caches, reverse

from oscar.core.loading import get_class
from oscar.test import factories
from oscar.test.testcases import WebTestCase

from . import (
    CheckoutMixin, IndexViewPreConditionsMixin, PaymentDetailsPreviewViewMixin,
    PaymentDetailsViewMixin, PaymentMethodViewMixin, ShippingAddressViewMixin,
    ShippingMethodViewMixin)

GatewayForm = get_class('checkout.forms', 'GatewayForm')


def reload_url_conf():
    # Reload URLs to pick up the overridden settings
    if settings.ROOT_URLCONF in sys.modules:
        reload(sys.modules[settings.ROOT_URLCONF])
    import_module(settings.ROOT_URLCONF)
    clear_url_caches()


class AnonymousMixin:

    is_anonymous = True

    def setUp(self):
        reload_url_conf()
        super().setUp()

    # Disable skip conditions, so that we do not first get redirected forwards
    @mock.patch('oscar.apps.checkout.session.CheckoutSessionMixin.skip_unless_basket_requires_shipping')
    @mock.patch('oscar.apps.checkout.session.CheckoutSessionMixin.skip_unless_payment_is_required')
    def test_does_not_require_login(
        self,
        mock_skip_unless_payment_is_required,
        mock_skip_unless_basket_requires_shipping,
    ):
        response = self.get(reverse(self.view_name))
        self.assertRedirectsTo(response, 'basket:summary')


@override_settings(OSCAR_ALLOW_ANON_CHECKOUT=True)
class TestIndexView(AnonymousMixin, IndexViewPreConditionsMixin, CheckoutMixin, WebTestCase):

    view_name = 'checkout:index'

    def test_redirects_new_customers_to_registration_page(self):
        self.add_product_to_basket()
        page = self.get(reverse('checkout:index'))

        form = page.form
        form['options'].select(GatewayForm.NEW)
        new_user_email = 'newcustomer@test.com'
        form['username'].value = new_user_email
        response = form.submit()

        expected_url = '{register_url}?next={forward}&email={email}'.format(
            register_url=reverse('customer:register'),
            forward=reverse('checkout:shipping-address'),
            email=quote(new_user_email))
        self.assertRedirects(response, expected_url)

    def test_redirects_existing_customers_to_shipping_address_page(self):
        password = 'password'
        user = factories.UserFactory(password=password)
        self.add_product_to_basket()
        page = self.get(reverse('checkout:index'))
        form = page.form
        form.select('options', GatewayForm.EXISTING)
        form['username'].value = user.email
        form['password'].value = password
        response = form.submit()
        self.assertRedirectsTo(response, 'checkout:shipping-address')

    def test_redirects_guest_customers_to_shipping_address_page(self):
        self.add_product_to_basket()
        page = self.get(reverse('checkout:index'))
        form = page.form
        form.select('options', GatewayForm.GUEST)
        form['username'] = 'guest@example.com'
        response = form.submit()
        self.assertRedirectsTo(response, 'checkout:shipping-address')

    def test_prefill_form_with_email_for_returning_guest(self):
        self.add_product_to_basket()
        email = 'forgetfulguest@test.com'
        self.enter_guest_details(email)
        page = self.get(reverse('checkout:index'))
        self.assertEqual(email, page.form['username'].value)


@override_settings(OSCAR_ALLOW_ANON_CHECKOUT=True)
class TestShippingAddressView(AnonymousMixin, ShippingAddressViewMixin, CheckoutMixin, WebTestCase):

    view_name = 'checkout:shipping-address'
    next_view_name = 'checkout:shipping-method'


@override_settings(OSCAR_ALLOW_ANON_CHECKOUT=True)
class TestShippingMethodView(AnonymousMixin, ShippingMethodViewMixin, CheckoutMixin, WebTestCase):

    view_name = 'checkout:shipping-method'
    next_view_name = 'checkout:payment-method'


@override_settings(OSCAR_ALLOW_ANON_CHECKOUT=True)
class TestPaymentMethodView(AnonymousMixin, PaymentMethodViewMixin, CheckoutMixin, WebTestCase):

    view_name = 'checkout:payment-method'


@override_settings(OSCAR_ALLOW_ANON_CHECKOUT=True)
class TestPaymentDetailsView(AnonymousMixin, PaymentDetailsViewMixin, CheckoutMixin, WebTestCase):

    view_name = 'checkout:payment-details'


@override_settings(OSCAR_ALLOW_ANON_CHECKOUT=True)
class TestPaymentDetailsPreviewView(AnonymousMixin, PaymentDetailsPreviewViewMixin, CheckoutMixin, WebTestCase):

    view_name = 'checkout:preview'

    def test_placing_order_saves_guest_email_with_order(self):
        preview = self.ready_to_place_an_order()
        thank_you = preview.forms['place_order_form'].submit().follow()
        order = thank_you.context['order']
        self.assertEqual('hello@egg.com', order.guest_email)