import unittest
import sys
import os

sys.path.append(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))

from database import calculate_discount, get_discount_description


class TestCalculations(unittest.TestCase):
    """Тестирование алгоритмов расчета скидок"""

    def test_1_discount_thresholds(self):
        """Тест пороговых значений скидок"""
        test_cases = [
            (0, 0),
            (100000, 0),
            (149999, 0),
            (150000, 15),
            (175000, 15),
            (199999, 15),
            (200000, 30),
            (250000, 30),
            (299999, 30),
            (300000, 50),
            (500000, 50),
            (1000000, 50),
        ]

        for amount, expected_discount in test_cases:
            with self.subTest(amount=amount):
                self.assertEqual(calculate_discount(amount), expected_discount)

    def test_2_discount_descriptions(self):
        """Тест описаний скидок"""
        self.assertEqual(get_discount_description(0), '0% (до 150 000 руб.)')
        self.assertEqual(get_discount_description(15), '15% (150 000 - 199 999 руб.)')
        self.assertEqual(get_discount_description(30), '30% (200 000 - 299 999 руб.)')
        self.assertEqual(get_discount_description(50), '50% (300 000+ руб.)')

        self.assertEqual(get_discount_description(99), '0% (до 150 000 руб.)')

    def test_3_edge_cases(self):
        """Тест граничных случаев"""
        self.assertEqual(calculate_discount(150000), 15)
        self.assertEqual(calculate_discount(200000), 30)
        self.assertEqual(calculate_discount(300000), 50)

        self.assertEqual(calculate_discount(149999), 0)
        self.assertEqual(calculate_discount(199999), 15)
        self.assertEqual(calculate_discount(299999), 30)

    def test_4_negative_amounts(self):
        """Тест отрицательных сумм"""
        self.assertEqual(calculate_discount(-1000), 0)
        self.assertEqual(calculate_discount(-150000), 0)


if __name__ == '__main__':
    unittest.main()