from decimal import Decimal, InvalidOperation

from django.test import TestCase
from django.utils import timezone

from core.models import Balance


def _create_and_reload_balance(amount):
    bal = Balance.objects.create(amount=amount, date=timezone.now().date())
    bal.refresh_from_db()
    return bal


class PriceFieldTestCase(TestCase):

    def test_normal_decimal(self):
        bal = _create_and_reload_balance(Decimal("13.37"))
        self.assertEqual(bal.amount, Decimal("13.37"))

    def test_too_big_decimal(self):
        with self.assertRaises(InvalidOperation):
            _create_and_reload_balance(Decimal("13371337.00"))

    def test_rounding_decimal(self):
        bal = _create_and_reload_balance(Decimal("1.337"))
        self.assertEqual(bal.amount, Decimal("1.34"))

    def test_normal_int(self):
        bal = _create_and_reload_balance(1337)
        self.assertEqual(bal.amount, Decimal("1337.00"))

    def test_too_big_int(self):
        with self.assertRaises(InvalidOperation):
            _create_and_reload_balance(13371337)

    def test_normal_float(self):
        bal = _create_and_reload_balance(13.37)
        self.assertEqual(bal.amount, Decimal("13.37"))

    def test_too_big_float(self):
        with self.assertRaises(InvalidOperation):
            _create_and_reload_balance(13371337.00)

    def test_rounding_float(self):
        bal = _create_and_reload_balance(1.337)
        self.assertEqual(bal.amount, Decimal("1.34"))