"""Python 3.10+; parse service-day offsets, not timezone instants."""
import re
import unittest


def service_seconds(value):
    if not isinstance(value, str) or not re.fullmatch(r"[0-9]+:[0-5][0-9]:[0-5][0-9]", value):
        raise ValueError("expected nonnegative H:MM:SS")
    hours, minutes, seconds = map(int, value.split(":"))
    return hours * 3600 + minutes * 60 + seconds


class ServiceTimeTests(unittest.TestCase):
    def test_midnight_and_next_day(self):
        self.assertEqual(service_seconds("23:59:59"), 86399)
        self.assertEqual(service_seconds("24:00:00"), 86400)
        self.assertEqual(service_seconds("27:15:00"), 98100)
        self.assertEqual(service_seconds("8:05:00"), 29100)

    def test_order_is_numeric(self):
        self.assertLess(service_seconds("9:00:00"), service_seconds("10:00:00"))
        self.assertGreater(service_seconds("25:00:00"), service_seconds("23:00:00"))

    def test_bad_values(self):
        for bad in ("-1:00:00", "24:60:00", "24:00:60", "1:2:03", " 24:00:00", "", None):
            with self.subTest(value=bad), self.assertRaises(ValueError):
                service_seconds(bad)


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