#!/usr/bin/env python3
"""Export OSM POIs (e.g. fuel stations) from a .osm.pbf to GeoJSON + CSV.

These exports feed FleetNow's toggleable map-overlay layers (see
docs/OSM_POI_EXPORT.md and the fleetnow repo's README "Map overlay layers").

No system tooling needed — run via uv so pyosmium's prebuilt wheel is fetched:

    uv run --no-project --with osmium python scripts/export_osm_pois.py \
        kenya-260605.osm.pbf --amenity fuel --brand Shell \
        --out-geojson shell_stations.geojson --out-csv shell_stations.csv

Notes:
- Gas stations are OSM ``amenity=fuel``. Brand lives in the ``brand`` tag, but
  only ~36% of Kenyan stations carry it, so when ``--brand`` is given and a
  feature has no ``brand`` tag we fall back to matching ``name``/``operator``.
- Omit ``--brand`` to export every feature of that amenity.
- Nodes use their own coordinate; ways/areas use the centroid of their nodes
  (so ``locations=True`` is required on apply_file).
"""
import argparse, json, csv


def main():
    ap = argparse.ArgumentParser(description=__doc__, formatter_class=argparse.RawDescriptionHelpFormatter)
    ap.add_argument("pbf", help="input .osm.pbf")
    ap.add_argument("--amenity", default="fuel", help="OSM amenity value (default: fuel)")
    ap.add_argument("--brand", default=None, help="case-insensitive brand/name match; omit for all")
    ap.add_argument("--out-geojson", default="pois.geojson")
    ap.add_argument("--out-csv", default="pois.csv")
    args = ap.parse_args()

    import osmium

    brand_lc = args.brand.lower() if args.brand else None

    def match(t):
        if t.get("amenity") != args.amenity:
            return False
        if brand_lc is None:
            return True
        b = (t.get("brand") or "").lower()
        if b:
            return brand_lc in b
        return brand_lc in (t.get("name") or "").lower() or brand_lc in (t.get("operator") or "").lower()

    feats = []

    def add(lon, lat, t, kind, oid):
        feats.append({
            "type": "Feature",
            "properties": {
                "name": t.get("name"), "brand": t.get("brand"),
                "operator": t.get("operator"), "osm_type": kind, "osm_id": oid,
            },
            "geometry": {"type": "Point", "coordinates": [round(lon, 6), round(lat, 6)]},
        })

    class H(osmium.SimpleHandler):
        def node(self, o):
            if match(o.tags):
                add(o.location.lon, o.location.lat, o.tags, "node", o.id)
        def way(self, o):
            if match(o.tags):
                xs = []; ys = []
                for n in o.nodes:
                    try:
                        if n.location.valid():
                            xs.append(n.location.lon); ys.append(n.location.lat)
                    except Exception:
                        pass
                if xs:
                    add(sum(xs) / len(xs), sum(ys) / len(ys), o.tags, "way", o.id)

    H().apply_file(args.pbf, locations=True)

    json.dump({"type": "FeatureCollection", "features": feats}, open(args.out_geojson, "w"))
    with open(args.out_csv, "w", newline="") as f:
        w = csv.writer(f); w.writerow(["name", "lat", "lon", "brand", "operator", "osm_type", "osm_id"])
        for ft in feats:
            p = ft["properties"]; lon, lat = ft["geometry"]["coordinates"]
            w.writerow([p["name"], lat, lon, p["brand"], p["operator"], p["osm_type"], p["osm_id"]])

    print(f"exported {len(feats)} features -> {args.out_geojson}, {args.out_csv}")


if __name__ == "__main__":
    main()