import datetime
from decimal import Decimal as D

import pytest
from django.core import exceptions
from django.test import TestCase

from datetime import timezone

from oscar.apps.voucher.models import Voucher
from oscar.core.compat import get_user_model
from oscar.core.loading import get_model
from oscar.test.factories import (
    ConditionFactory,
    OrderFactory,
    RangeFactory,
    UserFactory,
    VoucherFactory,
    VoucherSetFactory,
    create_basket,
    create_offer,
    create_product,
)

START_DATETIME = datetime.datetime(2011, 1, 1).replace(tzinfo=timezone.utc)
END_DATETIME = datetime.datetime(2012, 1, 1).replace(tzinfo=timezone.utc)
User = get_user_model()
ConditionalOffer = get_model("offer", "ConditionalOffer")


class TestSavingAVoucher(TestCase):
    def test_saves_code_as_uppercase(self):
        voucher = VoucherFactory(
            code="lower", start_datetime=START_DATETIME, end_datetime=END_DATETIME
        )
        self.assertEqual("LOWER", voucher.code)

    def test_verifies_dates_are_sensible(self):
        with self.assertRaises(exceptions.ValidationError):
            voucher = Voucher.objects.create(
                code="lower", start_datetime=END_DATETIME, end_datetime=START_DATETIME
            )
            voucher.clean()


class TestAVoucher(TestCase):
    def setUp(self):
        self.voucher = VoucherFactory(
            start_datetime=START_DATETIME, end_datetime=END_DATETIME
        )

    def test_is_active_between_start_and_end_dates(self):
        test = datetime.datetime(2011, 6, 10).replace(tzinfo=timezone.utc)
        self.assertTrue(self.voucher.is_active(test))

    def test_is_active_on_end_date(self):
        self.assertTrue(self.voucher.is_active(END_DATETIME))

    def test_is_active_on_start_date(self):
        self.assertTrue(self.voucher.is_active(START_DATETIME))

    def test_is_inactive_outside_of_start_and_end_dates(self):
        test = datetime.datetime(2012, 3, 10).replace(tzinfo=timezone.utc)
        self.assertFalse(self.voucher.is_active(test))

    def test_increments_total_discount_when_recording_usage(self):
        self.voucher.record_discount({"discount": D("10.00")})
        self.assertEqual(self.voucher.total_discount, D("10.00"))
        self.voucher.record_discount({"discount": D("10.00")})
        self.assertEqual(self.voucher.total_discount, D("20.00"))


class TestMultiuseVoucher(TestCase):
    def setUp(self):
        self.voucher = VoucherFactory(usage=Voucher.MULTI_USE)

    def test_is_available_to_same_user_multiple_times(self):
        user, order = UserFactory(), OrderFactory()
        for _ in range(10):
            self.voucher.record_usage(order, user)
            is_voucher_available_to_user, __ = self.voucher.is_available_to_user(
                user=user
            )
            self.assertTrue(is_voucher_available_to_user)


class TestOncePerCustomerVoucher(TestCase):
    def setUp(self):
        self.voucher = VoucherFactory(usage=Voucher.ONCE_PER_CUSTOMER)

    def test_is_available_to_a_user_once(self):
        user, order = UserFactory(), OrderFactory()
        is_voucher_available_to_user, __ = self.voucher.is_available_to_user(user=user)
        self.assertTrue(is_voucher_available_to_user)

        self.voucher.record_usage(order, user)
        is_voucher_available_to_user, __ = self.voucher.is_available_to_user(user=user)
        self.assertFalse(is_voucher_available_to_user)

    def test_is_available_to_different_users(self):
        users, order = [UserFactory(), UserFactory()], OrderFactory()
        for user in users:
            is_voucher_available_to_user, __ = self.voucher.is_available_to_user(
                user=user
            )
            self.assertTrue(is_voucher_available_to_user)

            self.voucher.record_usage(order, user)
            is_voucher_available_to_user, __ = self.voucher.is_available_to_user(
                user=user
            )
            self.assertFalse(is_voucher_available_to_user)


class TestVoucherDelete(TestCase):
    def setUp(self):
        product = create_product(price=100)
        self.offer_range = RangeFactory(products=[product])
        self.offer_condition = ConditionFactory(range=self.offer_range, value=2)


class TestAvailableForBasket(TestCase):
    def setUp(self):
        self.basket = create_basket(empty=True)
        self.product = create_product(price=100)
        product_range = RangeFactory(products=[self.product])
        condition = ConditionFactory(range=product_range, value=2)
        self.voucher = VoucherFactory()
        self.voucher.offers.add(
            create_offer(
                offer_type="Voucher", product_range=product_range, condition=condition
            )
        )

    def test_is_available_for_basket(self):
        self.basket.add_product(product=self.product)
        is_voucher_available_for_basket, __ = self.voucher.is_available_for_basket(
            self.basket
        )
        self.assertFalse(is_voucher_available_for_basket)

        self.basket.add_product(product=self.product)
        is_voucher_available_for_basket, __ = self.voucher.is_available_for_basket(
            self.basket
        )
        self.assertTrue(is_voucher_available_for_basket)


@pytest.mark.django_db
class TestVoucherSet(object):
    def test_factory(self):
        voucherset = VoucherSetFactory()
        assert voucherset.count == voucherset.vouchers.count()
        assert str(voucherset) == voucherset.name
        offers = voucherset.vouchers.first().offers.all()
        for voucher in voucherset.vouchers.all():
            assert len(voucher.code) == 14
            assert voucher.code.count("-") == 2
            assert list(voucher.offers.all()) == list(offers)
            assert voucher.offers.count() == 1
            assert (
                voucher.offers.filter(offer_type=ConditionalOffer.VOUCHER).count() == 1
            )

    def test_update_count(self):
        voucherset = VoucherSetFactory(count=20)
        assert voucherset.count == 20
        voucherset.count = 10
        voucherset.save()
        voucherset.update_count()
        voucherset.refresh_from_db()
        assert voucherset.count == 20

    def test_num_basket_additions(self):
        voucherset = VoucherSetFactory()
        num_additions = voucherset.num_basket_additions
        assert num_additions == 0

    def test_num_orders(self):
        voucherset = VoucherSetFactory()
        assert voucherset.num_orders == 0

        user, order = UserFactory(), OrderFactory()
        voucher = voucherset.vouchers.first()
        voucher.record_usage(order, user)
        assert voucherset.num_orders == 1