SWANSEA_FRZ_POLYGONS = [
    {
        "name": "EGR1U003A SWANSEA",
        "coordinates": [
            [51.6385691199, -4.0677777778],
            [51.6383925433, -4.0732789905],
            [51.6378646894, -4.0787217619],
            [51.6369911656, -4.0840482758],
            [51.6357812508, -4.0892019586],
            [51.6342477966, -4.0941280843],
            [51.6324070894, -4.0987743581],
            [51.6302786768, -4.1030914745],
            [51.6278851591, -4.1070336417],
            [51.6252519474, -4.1105590688],
            [51.6224069933, -4.1136304084],
            [51.6193804903, -4.1162151518],
            [51.6162045529, -4.1182859716],
            [51.6129128741, -4.1198210079],
            [51.6095403677, -4.1208040969],
            [51.606122797, -4.1212249367],
            [51.6026963949, -4.1210791924],
            [51.5992974802, -4.120368536],
            [51.595962072, -4.1191006239],
            [51.592725509, -4.1172890099],
            [51.5896220749, -4.1149529973],
            [51.5866846367, -4.1121174298],
            [51.5839442973, -4.1088124245],
            [51.5814300673, -4.1050730509],
            [51.5791685587, -4.1009389566],
            [51.5771837053, -4.0964539477],
            [51.5754965099, -4.0916655245],
            [51.5741248235, -4.0866243798],
            [51.5730831575, -4.0813838645],
            [51.572382531, -4.0759994259],
            [51.5720303553, -4.0705280237],
            [51.5720303553, -4.0650275318],
            [51.572382531, -4.0595561297],
            [51.5730831575, -4.054171691],
            [51.5741248235, -4.0489311758],
            [51.5754965099, -4.0438900311],
            [51.5771837053, -4.0391016078],
            [51.5791685587, -4.0346165989],
            [51.5814300673, -4.0304825047],
            [51.5839442973, -4.026743131],
            [51.5866846367, -4.0234381258],
            [51.5896220749, -4.0206025582],
            [51.592725509, -4.0182665456],
            [51.595962072, -4.0164549317],
            [51.5992974802, -4.0151870195],
            [51.6026963949, -4.0144763632],
            [51.606122797, -4.0143306189],
            [51.6095403677, -4.0147514587],
            [51.6129128741, -4.0157345476],
            [51.6162045529, -4.017269584],
            [51.6193804903, -4.0193404037],
            [51.6224069933, -4.0219251472],
            [51.6252519474, -4.0249964868],
            [51.6278851591, -4.0285219138],
            [51.6302786768, -4.0324640811],
            [51.6324070894, -4.0367811974],
            [51.6342477966, -4.0414274713],
            [51.6357812508, -4.0463535969],
            [51.6369911656, -4.0515072798],
            [51.6378646894, -4.0568337937],
            [51.6383925433, -4.0622765651],
            [51.6385691199, -4.0677777778],
        ],
    },
    {
        "name": "EGR1U003B SWANSEA RWY 04",
        "coordinates": [
            [51.5614305556, -4.1105694444],
            [51.5760447778, -4.0933516667],
            [51.5775992074, -4.0974772875],
            [51.5793789018, -4.1013615228],
            [51.5813693889, -4.1049727778],
            [51.5667527778, -4.1221888889],
            [51.5614305556, -4.1105694444],
        ],
    },
    {
        "name": "EGR1U003C SWANSEA RWY 22",
        "coordinates": [
            [51.6483027778, -4.0259555556],
            [51.6345286389, -4.0422406389],
            [51.632975828, -4.0381074205],
            [51.631197314, -4.0342163026],
            [51.6292076111, -4.030599],
            [51.6429805556, -4.0143111111],
            [51.6483027778, -4.0259555556],
        ],
    },
    {
        "name": "EGR1U003D SWANSEA RWY 10",
        "coordinates": [
            [51.6016305556, -4.1483194444],
            [51.5997253611, -4.1204896111],
            [51.602737017, -4.1210842429],
            [51.605769878, -4.1212361072],
            [51.60879875, -4.1209438611],
            [51.6105638889, -4.1467305556],
            [51.6016305556, -4.1483194444],
        ],
    },
    {
        "name": "EGR1U003E SWANSEA RWY 28",
        "coordinates": [
            [51.5998777778, -3.9918916667],
            [51.6014628333, -4.0146683056],
            [51.5984676719, -4.015448363],
            [51.5955291688, -4.0166629251],
            [51.5926717222, -4.0183018333],
            [51.5909444444, -3.9934777778],
            [51.5998777778, -3.9918916667],
        ],
    },
]


def point_inside_swansea_frz(lat: float, lng: float) -> bool:
    """Return whether a point is inside the Swansea UAS FRZ polygons from the KML source."""
    return any(_point_inside_polygon(lat, lng, polygon["coordinates"]) for polygon in SWANSEA_FRZ_POLYGONS)


def swansea_frz_geojson() -> dict:
    return {
        "type": "FeatureCollection",
        "features": [
            {
                "type": "Feature",
                "properties": {"name": polygon["name"]},
                "geometry": {
                    "type": "Polygon",
                    "coordinates": [[
                        [lng, lat] for lat, lng in polygon["coordinates"]
                    ]],
                },
            }
            for polygon in SWANSEA_FRZ_POLYGONS
        ],
    }


def _point_inside_polygon(lat: float, lng: float, coordinates: list[list[float]]) -> bool:
    inside = False
    j = len(coordinates) - 1
    for i, (point_lat, point_lng) in enumerate(coordinates):
        previous_lat, previous_lng = coordinates[j]
        intersects = (
            (point_lat > lat) != (previous_lat > lat)
            and lng < (previous_lng - point_lng) * (lat - point_lat) / (previous_lat - point_lat) + point_lng
        )
        if intersects:
            inside = not inside
        j = i
    return inside