// Dart side of the cross-language parity harness (T07).
// Must stay fixture-for-fixture identical to tool/parity/main.kt.
import 'dart:math' as math;

import 'package:rippr/src/domain/models.dart';
import 'package:rippr/src/geo/geo.dart';
import 'package:rippr/src/stats/ride_statistics.dart';

/// Same LCG as the Kotlin oracle. Dart ints are 64-bit two's complement on the VM and
/// multiplication wraps, matching Kotlin's Long.
class Lcg {
  Lcg(this._s);
  int _s;
  double nextDouble() {
    _s = _s * 6364136223846793005 + 1442695040888963407;
    final bits = (_s >>> 11) & ((1 << 53) - 1);
    return bits / (1 << 53);
  }
}

TrackPoint p(int seg, int ts, double lat, double lon, double sp, double alt, int id) =>
    TrackPoint(id: id, tripId: 1, segmentId: seg, timestamp: ts,
        latitude: lat, longitude: lon, speedKmh: sp, altitudeM: alt);

void main() {
  void out(String k, Object v) => print('$k=$v');

  out('haversine_calgary_edmonton', haversineMeters(51.0447, -114.0719, 53.5461, -113.4938));
  out('haversine_short_hop', haversineMeters(51.0447, -114.0719, 51.04480, -114.0719));
  out('perp_beyond_end', perpendicularDistanceMeters(
      const LatLon(51.003, -114.0), const LatLon(51.000, -114.0), const LatLon(51.002, -114.0)));

  final ride = List.generate(21600,
      (i) => LatLon(51.0 + i * 0.00001, -114.0 + math.sin(i / 100.0) * 0.001));
  final simplified = simplify(ride, 5.0);
  out('simplify_count', simplified.length);
  out('simplify_last_lat', simplified.last.lat);
  out('path_length_ride', pathLengthMeters(ride));

  final rng = Lcg(42);
  final noisy = List.generate(600,
      (i) => p(1, i * 1000, 51.0, -114.0, 0.0, 1000.0 + (rng.nextDouble() * 16.0 - 8.0), i + 1));
  out('noisy_gain', computeSummary(noisy).elevationGainM);
  out('noisy_loss', computeSummary(noisy).elevationLossM);

  final climb = List.generate(101,
      (i) => p(1, i * 1000, 51.0 + i * 0.0001, -114.0, 50.0, 1000.0 + i, i + 1));
  out('climb_gain', computeSummary(climb).elevationGainM);

  final run = List.generate(100,
      (i) => p(1, i * 1000, 51.0 + i * 0.0001, -114.0, 40.0, 1000.0, i + 1));
  final s = computeSummary(run);
  out('run_distance', s.distanceM);
  out('run_moving_millis', s.movingMillis);
  out('run_avg_speed', s.avgMovingSpeedKmh);

  final prof = elevationProfile(run, maxSamples: 200);
  out('profile_size', prof.length);
  out('profile_last_distance', prof.last.distanceM);

  final hist = speedHistogram(run, bucketKmh: 10);
  out('hist_buckets', hist.length);
  out('hist_first_millis', hist.first.millis);
}