import 'package:equatable/equatable.dart';
import 'package:intaleq_maps/intaleq_maps.dart';

/// خطاب polyline مشفر ومسافة/وقت تقريبيان.
class RouteModel extends Equatable {
  final int distanceMeters;
  final int durationSeconds;
  final String? polyline;

  const RouteModel({
    required this.distanceMeters,
    required this.durationSeconds,
    this.polyline,
  });

  factory RouteModel.fromJson(Map<String, dynamic> j) {
    final dist = j['distanceMeters'] ?? j['distance'];
    final dur = j['durationSeconds'] ?? j['duration'];
    return RouteModel(
      distanceMeters: dist is int ? dist : int.tryParse('$dist') ?? 0,
      durationSeconds: dur is int ? dur : int.tryParse('$dur') ?? 0,
      polyline: j['polyline'] as String?,
    );
  }

  String get distanceText {
    if (distanceMeters < 1000) return '$distanceMeters m';
    return '${(distanceMeters / 1000).toStringAsFixed(1)} km';
  }

  String get durationText {
    final min = durationSeconds ~/ 60;
    if (min < 60) return '$min min';
    final h = min ~/ 60;
    final rem = min % 60;
    return '$h h ${rem > 0 ? '$rem min' : ''}';
  }

  List<LatLng> decodePolyline() {
    if (polyline == null || polyline!.isEmpty) return [];
    return _decodeEncodedPolyline(polyline!);
  }

  /// فك تشفير polyline وفقاً لخوارزمية Google.
  static List<LatLng> _decodeEncodedPolyline(String encoded) {
    final List<LatLng> poly = [];
    int index = 0, lat = 0, lng = 0;

    while (index < encoded.length) {
      int b, shift = 0, result = 0;
      do {
        b = encoded.codeUnitAt(index++) - 63;
        result |= (b & 0x1f) << shift;
        shift += 5;
      } while (b >= 0x20);
      lat += ((result & 1) != 0) ? ~(result >> 1) : (result >> 1);

      shift = 0;
      result = 0;
      do {
        b = encoded.codeUnitAt(index++) - 63;
        result |= (b & 0x1f) << shift;
        shift += 5;
      } while (b >= 0x20);
      lng += ((result & 1) != 0) ? ~(result >> 1) : (result >> 1);

      poly.add(LatLng(lat / 1e5, lng / 1e5));
    }
    return poly;
  }

  @override
  List<Object?> get props => [distanceMeters, durationSeconds, polyline];
}