import json
import os
import re
import unittest

from utils.config_validate import ConfigError, validate_temp_ctrl

FIXTURES_DIR = os.path.join(os.path.dirname(__file__), 'fixtures')

# filename -> None if the fixture should pass validation, otherwise a regex
# matched against the raised ConfigError's message.
CASES = {
    'valid_sim.json': None,
    'valid_real.json': None,
    'valid_normal.json': None,
    'legacy_unknown_keys.json': None,
    'missing_outer_kp.json': r'TempCtrl\.Outer\.kp',
    'missing_inner_hold_branch.json': r'TempCtrl\.Inner\.Hold',
    'missing_pid_type.json': r'TempCtrl\.pid_type',
    'missing_tempctrl_section.json': r'missing required config key: TempCtrl$',
    'wrong_type_kp_string.json': r'TempCtrl\.Inner\.Heat\.kp',
    'wrong_type_tempctrl_not_dict.json': r'TempCtrl must be dict',
}


def _load(name):
    with open(os.path.join(FIXTURES_DIR, name)) as f:
        return json.load(f)


def _test_name(filename):
    return 'test_' + re.sub(r'\W', '_', filename[:-len('.json')])


class TestConfigFixtures(unittest.TestCase):
    def test_every_fixture_file_is_covered(self):
        on_disk = {f for f in os.listdir(FIXTURES_DIR) if f.endswith('.json')}
        self.assertEqual(on_disk, set(CASES), "fixtures/ and CASES have drifted apart")


def _make_fixture_test(name, expected_error):
    def test(self):
        config = _load(name)
        if expected_error is None:
            validate_temp_ctrl(config)  # must not raise
        else:
            with self.assertRaisesRegex(ConfigError, expected_error):
                validate_temp_ctrl(config)
    return test


# One dedicated test method per fixture file - not a single method looping
# over CASES with subTest - so `unittest discover -v` (and any IDE test
# runner) lists and can re-run each fixture individually instead of folding
# them all into one opaque "did any of these fail" result.
for _name, _expected_error in CASES.items():
    setattr(TestConfigFixtures, _test_name(_name), _make_fixture_test(_name, _expected_error))


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