#!/usr/bin/env python3
import json
import sys
from datetime import datetime, timezone
from xml.sax.saxutils import escape

OSMAND_NS = "https://osmand.net"

def epoch_to_iso_z(value):
    if value is None:
        return None
    try:
        ts = int(value)
        return datetime.fromtimestamp(ts, tz=timezone.utc).replace(microsecond=0).isoformat().replace("+00:00", "Z")
    except Exception:
        return None

def norm(s):
    if s is None:
        return None
    s = str(s).strip()
    return s if s else None

def main():
    if len(sys.argv) not in (3, 4):
        print(
            "Usage: nextcloud_favorites_to_osmand_prefixed_groups.py .favorites.json out.gpx [prefix]\n"
            "Example: nextcloud_favorites_to_osmand_prefixed_groups.py .favorites.json favourites.gpx Norwegen",
            file=sys.stderr
        )
        sys.exit(2)

    in_path = sys.argv[1]
    out_path = sys.argv[2]
    prefix = sys.argv[3] if len(sys.argv) == 4 else "Norwegen"

    with open(in_path, "r", encoding="utf-8") as f:
        data = json.load(f)

    if not isinstance(data, dict) or data.get("type") != "FeatureCollection":
        raise SystemExit("Input is not a GeoJSON FeatureCollection")

    features = data.get("features", [])
    if not isinstance(features, list):
        raise SystemExit("GeoJSON 'features' is not a list")

    wpts = []
    for idx, feat in enumerate(features):
        if not isinstance(feat, dict) or feat.get("type") != "Feature":
            continue

        geom = feat.get("geometry") or {}
        if geom.get("type") != "Point":
            continue

        coords = geom.get("coordinates")
        if not (isinstance(coords, list) and len(coords) >= 2):
            continue

        # GeoJSON order: [lon, lat]
        try:
            lon = float(coords[0])
            lat = float(coords[1])
        except Exception:
            continue

        props = feat.get("properties") or {}
        title = norm(props.get("Title")) or f"Favorite {idx+1}"
        comment = norm(props.get("Comment"))
        category = norm(props.get("Category")) or "Uncategorized"

        group = f"{prefix}/{category}"

        # Prefer Updated, else Published (epoch seconds)
        time_iso = epoch_to_iso_z(props.get("Updated", props.get("Published")))

        wpts.append({
            "lat": lat,
            "lon": lon,
            "name": title,
            "desc": comment,
            "time": time_iso,
            "group": group,
            "category": category
        })

    if not wpts:
        raise SystemExit("No Point features found to convert")

    with open(out_path, "w", encoding="utf-8") as f:
        f.write('<?xml version="1.0" encoding="UTF-8"?>\n')
        f.write('<gpx version="1.1" creator="nextcloud_favorites_to_osmand_prefixed_groups.py"\n')
        f.write('     xmlns="http://www.topografix.com/GPX/1/1"\n')
        f.write('     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"\n')
        f.write(f'     xmlns:osmand="{OSMAND_NS}"\n')
        f.write('     xsi:schemaLocation="http://www.topografix.com/GPX/1/1 http://www.topografix.com/GPX/1/1/gpx.xsd">\n')

        f.write('  <metadata>\n')
        f.write(f'    <time>{datetime.now(timezone.utc).replace(microsecond=0).isoformat().replace("+00:00","Z")}</time>\n')
        f.write('  </metadata>\n')

        for w in wpts:
            f.write(f'  <wpt lat="{w["lat"]:.8f}" lon="{w["lon"]:.8f}">\n')
            f.write(f'    <name>{escape(w["name"])}</name>\n')

            # OsmAnd favorites group name (most important)
            f.write(f'    <type>{escape(w["group"])}</type>\n')

            if w["desc"] is not None:
                f.write(f'    <desc>{escape(w["desc"])}</desc>\n')
            if w["time"] is not None:
                f.write(f'    <time>{escape(w["time"])}</time>\n')

            # Extra hints (safe if ignored)
            f.write('    <extensions>\n')
            f.write(f'      <osmand:category>{escape(w["group"])}</osmand:category>\n')
            f.write(f'      <osmand:tag k="nextcloud_category" v="{escape(w["category"])}"/>\n')
            f.write('    </extensions>\n')

            f.write('  </wpt>\n')

        f.write('</gpx>\n')

    print(f"Wrote {len(wpts)} favorites to {out_path} with groups like '{prefix}/<Category>'")

if __name__ == "__main__":
    main()