"""
Tests for config loading: shared.json inheritance and extends merging.
"""
import json
import tempfile
import unittest
from pathlib import Path

from src.utils.config import load_config


class ConfigMergeTests(unittest.TestCase):
    def test_shared_and_extends_merge(self):
        with tempfile.TemporaryDirectory() as td:
            root = Path(td)
            cfg_dir = root / "configs" / "phaseX"
            cfg_dir.mkdir(parents=True)

            (root / "configs" / "shared.json").write_text(json.dumps({
                "batch_size": 32,
                "lr": 1e-4,
                "augment": {"hflip_p": 0.5, "blur_p": 0.2},
            }))
            (cfg_dir / "base.json").write_text(json.dumps({
                "epochs": 10,
                "augment": {"hflip_p": 0.1},
            }))
            (cfg_dir / "exp.json").write_text(json.dumps({
                "extends": "base.json",
                "epochs": 15,
                "augment": {"blur_p": 0.0},
            }))

            cfg = load_config(cfg_dir / "exp.json")
            self.assertEqual(cfg["batch_size"], 32)
            self.assertEqual(cfg["epochs"], 15)
            self.assertEqual(cfg["augment"]["hflip_p"], 0.1)
            self.assertEqual(cfg["augment"]["blur_p"], 0.0)


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