import 'package:flutter_riverpod/flutter_riverpod.dart';
import '../../../core/api/api_client.dart';

/// A single route from the OSRM response.
class RouteData {
  final double distance; // meters
  final double duration; // seconds
  final List<List<double>> geometry; // [[lon, lat], ...]
  final List<RouteLeg> legs;

  RouteData({
    required this.distance,
    required this.duration,
    required this.geometry,
    required this.legs,
  });

  String get distanceFormatted {
    if (distance < 1000) {
      return '${distance.round()} m';
    }
    return '${(distance / 1000).toStringAsFixed(1)} km';
  }

  String get durationFormatted {
    final minutes = (duration / 60).round();
    if (minutes < 60) {
      return '$minutes min';
    }
    final hours = minutes ~/ 60;
    final remainingMin = minutes % 60;
    return '${hours}h ${remainingMin}min';
  }

  factory RouteData.fromJson(Map<String, dynamic> json) {
    final geom = json['geometry'] as Map<String, dynamic>;
    final coords = (geom['coordinates'] as List)
        .map((c) => [(c[0] as num).toDouble(), (c[1] as num).toDouble()])
        .toList();

    final legs = (json['legs'] as List)
        .map((l) => RouteLeg.fromJson(l as Map<String, dynamic>))
        .toList();

    return RouteData(
      distance: (json['distance'] as num).toDouble(),
      duration: (json['duration'] as num).toDouble(),
      geometry: coords,
      legs: legs,
    );
  }
}

class RouteLeg {
  final double distance;
  final double duration;
  final String summary;
  final List<RouteStep> steps;

  RouteLeg({
    required this.distance,
    required this.duration,
    required this.summary,
    required this.steps,
  });

  factory RouteLeg.fromJson(Map<String, dynamic> json) {
    final steps = (json['steps'] as List?)
            ?.map((s) => RouteStep.fromJson(s as Map<String, dynamic>))
            .toList() ??
        [];
    return RouteLeg(
      distance: (json['distance'] as num).toDouble(),
      duration: (json['duration'] as num).toDouble(),
      summary: json['summary'] as String? ?? '',
      steps: steps,
    );
  }
}

class RouteStep {
  final double distance;
  final double duration;
  final String name;
  final Maneuver maneuver;

  RouteStep({
    required this.distance,
    required this.duration,
    required this.name,
    required this.maneuver,
  });

  factory RouteStep.fromJson(Map<String, dynamic> json) {
    return RouteStep(
      distance: (json['distance'] as num).toDouble(),
      duration: (json['duration'] as num).toDouble(),
      name: json['name'] as String? ?? '',
      maneuver:
          Maneuver.fromJson(json['maneuver'] as Map<String, dynamic>),
    );
  }
}

class Maneuver {
  final String type;
  final String? modifier;
  final List<double> location; // [lon, lat]
  final String instruction;

  Maneuver({
    required this.type,
    this.modifier,
    required this.location,
    required this.instruction,
  });

  factory Maneuver.fromJson(Map<String, dynamic> json) {
    final loc = (json['location'] as List)
        .map((e) => (e as num).toDouble())
        .toList();
    return Maneuver(
      type: json['type'] as String,
      modifier: json['modifier'] as String?,
      location: loc,
      instruction: json['instruction'] as String? ?? '',
    );
  }
}

class RoutingRepository {
  final ApiClient _apiClient;

  RoutingRepository(this._apiClient);

  /// Calculate a route via GET /api/route/{profile}/{coordinates}.
  /// [origin] and [destination] are [lat, lon] pairs.
  Future<List<RouteData>> getRoute({
    required String profile,
    required double originLat,
    required double originLon,
    required double destLat,
    required double destLon,
  }) async {
    // OSRM coordinates format: lon,lat;lon,lat
    final coordinates =
        '$originLon,$originLat;$destLon,$destLat';

    final data = await _apiClient.get(
      '/api/route/$profile/$coordinates',
      queryParameters: {
        'alternatives': 2,
        'steps': true,
        'geometries': 'geojson',
      },
    );

    final code = data['code'] as String?;
    if (code != 'Ok') {
      throw Exception('Routing failed: $code');
    }

    final routes = (data['routes'] as List)
        .map((r) => RouteData.fromJson(r as Map<String, dynamic>))
        .toList();

    return routes;
  }
}

final routingRepositoryProvider = Provider<RoutingRepository>((ref) {
  return RoutingRepository(ref.watch(apiClientProvider));
});