import 'package:gpx/gpx.dart';
import 'package:latlong2/latlong.dart';
import 'package:aves/model/activity/activity_track.dart';
import 'gps_smoothing.dart';

class GpxActivityParser {
  static ActivityTrack parse(String xml, {required String fileName}) {
    final gpx = GpxReader().fromString(xml);

    final points = <LatLng>[];
    final elevations = <double?>[];
    final times = <DateTime?>[];

    for (final trk in gpx.trks) {
      for (final seg in trk.trksegs) {
        for (final p in seg.trkpts) {
          points.add(LatLng(p.lat!, p.lon!));
          elevations.add(p.ele);
          times.add(p.time);
        }
      }
    }

    final smoothed = GpsSmoothing.douglasPeucker(points, 5.0);

    return ActivityTrack(
      name: fileName,
      format: 'GPX',
      tracks: {smoothed},
      pointCount: smoothed.length,
      distanceMeters: null,
      elevationGainMeters: null,
      duration: null,
      startTime: times.first,
      sport: null,
    );
  }
}