"""Assert-based tests for station-mapping persistence.

Station CRUD must survive restarts: the scraper loads its mapping from a
runtime-writable JSON file (falling back to bundled defaults) and writes it back
atomically. These tests exercise that load/save behaviour without constructing a
full scraper (which would open network/DB connections).
"""

from src.water_scraper_v3 import EnhancedWaterMonitorScraper as Scraper


def _bare_scraper(config_path):
    """A scraper instance with only the station-config attribute set.

    Bypasses __init__ so no database/HTTP connection is attempted.
    """
    scraper = Scraper.__new__(Scraper)
    scraper.station_config_path = config_path
    return scraper


def test_loads_bundled_defaults_when_runtime_file_absent(tmp_path):
    scraper = _bare_scraper(str(tmp_path / "does_not_exist.json"))
    mapping = scraper._load_station_mapping()

    assert len(mapping) == 16
    assert mapping["8"]["code"] == "P.1"
    assert mapping["8"]["english_name"] == "Nawarat Bridge"


def test_save_then_reload_roundtrips_including_thai(tmp_path):
    path = str(tmp_path / "stations.json")
    scraper = _bare_scraper(path)
    scraper.station_mapping = {
        "1": {
            "code": "P.99",
            "thai_name": "สถานีทดสอบ",
            "english_name": "Test Station",
            "latitude": 1.0,
            "longitude": 2.0,
            "geohash": None,
        }
    }

    assert scraper.save_stations() is True

    reloaded = _bare_scraper(path)._load_station_mapping()
    assert reloaded == scraper.station_mapping
    assert reloaded["1"]["thai_name"] == "สถานีทดสอบ"


def test_runtime_file_takes_precedence_over_defaults(tmp_path):
    path = str(tmp_path / "stations.json")
    writer = _bare_scraper(path)
    writer.station_mapping = {"1": {"code": "ONLY"}}
    assert writer.save_stations() is True

    mapping = _bare_scraper(path)._load_station_mapping()
    assert list(mapping.keys()) == ["1"]
    assert mapping["1"]["code"] == "ONLY"


def test_save_returns_false_without_a_path():
    scraper = _bare_scraper("")
    scraper.station_mapping = {}
    assert scraper.save_stations() is False


def test_save_is_atomic_no_tmp_left_behind(tmp_path):
    path = tmp_path / "stations.json"
    scraper = _bare_scraper(str(path))
    scraper.station_mapping = {"1": {"code": "P.1"}}

    assert scraper.save_stations() is True
    assert path.exists()
    # The temp file used during the atomic write must not remain.
    assert not (tmp_path / "stations.json.tmp").exists()