import core.elevation as elev


class _FakeResponse:
    def __init__(self, payload):
        self._payload = payload

    def raise_for_status(self):
        return None

    def json(self):
        return self._payload


class _FakeClient:
    def __init__(self, **kwargs):
        self.kwargs = kwargs

    def __enter__(self):
        return self

    def __exit__(self, *args):
        return False

    def get(self, url, params=None):
        return _FakeResponse({"elevation": [152.0]})


def test_probe_elevation_api_ok(monkeypatch):
    monkeypatch.setattr(elev, "_probe_checked_at", 0.0)
    monkeypatch.setattr(elev.httpx, "Client", _FakeClient)

    status = elev.probe_elevation_api(force=True)

    assert status["ok"] is True
    assert status["error"] is None


def test_fetch_skips_when_unreachable(monkeypatch):
    monkeypatch.setattr(
        elev,
        "probe_elevation_api",
        lambda force=False: {"ok": False, "url": elev.ELEVATION_API_URL, "error": "down"},
    )

    vals = elev.fetch_elevations_batch([55.75], [37.62])

    assert vals == [None]


def test_build_profile_reports_unreachable(monkeypatch):
    monkeypatch.setattr(
        elev,
        "probe_elevation_api",
        lambda force=False: {"ok": False, "url": elev.ELEVATION_API_URL, "error": "down"},
    )

    profile = elev.build_elevation_profile(
        [{"lat": 55.75, "lon": 37.62}, {"lat": 55.76, "lon": 37.63}],
        10,
    )

    assert profile["points"] == []
    assert "unreachable" in profile["api_error"]


def test_find_nearest_hill_unreachable(monkeypatch):
    monkeypatch.setattr(
        elev,
        "probe_elevation_api",
        lambda force=False: {"ok": False, "url": elev.ELEVATION_API_URL, "error": "down"},
    )
    result = elev.find_nearest_hill(55.75, 37.62)
    assert result["ok"] is False


def test_find_nearest_hill_picks_nearest_peak(monkeypatch):
    monkeypatch.setattr(elev, "_probe_checked_at", 0.0)
    monkeypatch.setattr(elev, "probe_elevation_api", lambda force=False: {"ok": True, "error": None})

    def fake_batch(lats, lons):
        out = []
        for la, lo in zip(lats, lons):
            if abs(la - 55.75) < 1e-4 and abs(lo - 37.62) < 1e-4:
                out.append(100.0)
            elif la > 55.75:
                out.append(130.0)
            else:
                out.append(95.0)
        return out

    monkeypatch.setattr(elev, "fetch_elevations_batch", fake_batch)
    result = elev.find_nearest_hill(55.75, 37.62, radius_m=2000, step_m=300, min_prominence_m=8)
    assert result["ok"] is True
    assert result["hill"]["elevation_m"] >= 120.0


def test_build_elevation_grid_delta(monkeypatch):
    monkeypatch.setattr(elev, "_probe_checked_at", 0.0)
    monkeypatch.setattr(elev, "probe_elevation_api", lambda force=False: {"ok": True, "error": None})

    def fake_batch(lats, lons):
        return [100.0 + (la - 55.75) * 1000.0 for la, lo in zip(lats, lons)]

    monkeypatch.setattr(elev, "fetch_elevation_m", lambda lat, lon: 100.0)
    monkeypatch.setattr(elev, "fetch_elevations_batch", fake_batch)

    result = elev.build_elevation_grid(55.75, 37.62, radius_m=100, step_m=10)
    assert result["ok"] is True
    assert result["step_m"] == 10
    assert len(result["points"]) > 0
    assert result["min_delta_m"] <= 0 <= result["max_delta_m"]
    assert all("delta_m" in p for p in result["points"])


def test_build_elevation_grid_limits_points(monkeypatch):
    monkeypatch.setattr(elev, "_probe_checked_at", 0.0)
    monkeypatch.setattr(elev, "probe_elevation_api", lambda force=False: {"ok": True, "error": None})
    monkeypatch.setattr(elev, "fetch_elevation_m", lambda lat, lon: 50.0)
    monkeypatch.setattr(
        elev,
        "fetch_elevations_batch",
        lambda lats, lons: [50.0] * len(lats),
    )

    step = elev._resolve_grid_step(55.75, 37.62, 500.0, 5.0)
    cells = elev._sample_circular_grid(55.75, 37.62, 500.0, step)
    assert len(cells) <= elev._MAX_GRID_POINTS