from fastapi import HTTPException

from app.api.v1 import layers


def test_layer_guard_requires_bbox():
    try:
        layers._parse_layer_bbox("")
    except HTTPException as exc:
        assert exc.status_code == 400
    else:
        raise AssertionError("Expected missing bbox to fail")


def test_layer_guard_filters_bbox_and_clamps_low_zoom_limit():
    geojson = {
        "type": "FeatureCollection",
        "features": [
            {
                "type": "Feature",
                "geometry": {"type": "Point", "coordinates": [121.0, 31.0]},
                "properties": {"id": "inside"},
            },
            {
                "type": "Feature",
                "geometry": {"type": "Point", "coordinates": [10.0, 10.0]},
                "properties": {"id": "outside"},
            },
        ],
    }

    result = layers._guard_geojson_layer(
        geojson,
        bbox=(120.0, 30.0, 122.0, 32.0),
        zoom=2,
        limit=6000,
    )

    assert result["returned_count"] == 1
    assert result["visible_count"] == 1
    assert result["features"][0]["properties"]["id"] == "inside"
    assert result["diagnostics"]["limit"] == layers.LOW_ZOOM_FEATURE_LIMIT
    assert result["diagnostics"]["limit_clamped"] is True
    assert result["diagnostics"]["degraded"] is True