from __future__ import annotations

import importlib.util
from pathlib import Path
import unittest


ROOT = Path(__file__).resolve().parents[1]
SPEC = importlib.util.spec_from_file_location("power_study2", ROOT / "scripts" / "power_study2.py")
assert SPEC and SPEC.loader
POWER = importlib.util.module_from_spec(SPEC)
SPEC.loader.exec_module(POWER)


class Study2PowerTests(unittest.TestCase):
    def test_exact_binomial_reference_values(self) -> None:
        self.assertAlmostEqual(POWER.exact_binomial_pvalue(0, 6), 0.03125)
        self.assertAlmostEqual(POWER.exact_binomial_pvalue(3, 6), 1.0)

    def test_preregistered_power(self) -> None:
        value = POWER.exact_mcnemar_power(60, 0.25, 0.05, 0.05)
        self.assertAlmostEqual(value, 0.797, places=3)

    def test_invalid_discordance_is_rejected(self) -> None:
        with self.assertRaises(ValueError):
            POWER.exact_mcnemar_power(60, 0.8, 0.3)


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