parking.py

import sys

import osmium
import geojson
import shapely.geometry

from robosat.osm.core import is_polygon


class ParkingHandler(osmium.SimpleHandler):
    """Extracts parking lot polygon features (visible in satellite imagery) from the map.
    """

    # parking=* to discard because these features are not vislible in satellite imagery
    parking_filter = set(["underground", "sheds", "carports", "garage_boxes"])

    def __init__(self):
        super().__init__()
        self.features = []

    def way(self, w):
        if not is_polygon(w):
            return

        if "amenity" not in w.tags or w.tags["amenity"] != "parking":
            return

        if "parking" in w.tags:
            if w.tags["parking"] in self.parking_filter:
                return

        geometry = geojson.Polygon([[(n.lon, n.lat) for n in w.nodes]])
        shape = shapely.geometry.shape(geometry)

        if shape.is_valid:
            feature = geojson.Feature(geometry=geometry)
            self.features.append(feature)
        else:
            print("Warning: invalid feature: https://www.openstreetmap.org/way/{}".format(w.id), file=sys.stderr)

    def save(self, out):
        collection = geojson.FeatureCollection(self.features)

        with open(out, "w") as fp:
            geojson.dump(collection, fp)