MotorSignal-App/lib/services/routes/route_provider.dart

import '../map/map_provider_interface.dart';
import 'route_models.dart';

/// Exceptions domain mapped from standard provider API.
class RouteProviderException implements Exception {
  final String code;
  final String message;

  RouteProviderException(this.code, this.message);

  @override
  String toString() => 'RouteProviderException: $message ($code)';
}

/// Result of a place/location search query.
class PlaceSearchResult {
  final String providerId;
  final String primaryText;
  final String secondaryText;
  final double? latitude;
  final double? longitude;
  final String? formattedAddress;
  final String? attribution;

  const PlaceSearchResult({
    required this.providerId,
    required this.primaryText,
    required this.secondaryText,
    this.latitude,
    this.longitude,
    this.formattedAddress,
    this.attribution,
  });

  bool get hasCoordinates => latitude != null && longitude != null;

  AppLatLng? get latLng =>
      hasCoordinates ? AppLatLng(latitude!, longitude!) : null;

  /// Converts directly into a [ResolvedPlace] when coordinates are already present.
  ResolvedPlace? toResolvedPlace() {
    if (!hasCoordinates) return null;
    return ResolvedPlace(
      providerId: providerId,
      displayName: primaryText,
      formattedAddress: formattedAddress ??
          (secondaryText.isNotEmpty
              ? '$primaryText, $secondaryText'
              : primaryText),
      latitude: latitude!,
      longitude: longitude!,
      attribution: attribution,
    );
  }
}

/// Resolved place with authoritative coordinates.
class ResolvedPlace {
  final String providerId;
  final String displayName;
  final String? formattedAddress;
  final double latitude;
  final double longitude;
  final String? attribution;

  const ResolvedPlace({
    required this.providerId,
    required this.displayName,
    this.formattedAddress,
    required this.latitude,
    required this.longitude,
    this.attribution,
  });

  AppLatLng get latLng => AppLatLng(latitude, longitude);
}

/// Result of calculating a route along ordered stops.
class RouteCalculationResult {
  final double straightLineDistanceMeters;
  final double? estimatedDistanceMeters;
  final int? estimatedDurationSeconds;
  final List<AppLatLng> geometry;
  final bool isStraightLine;
  final String providerName;
  final List<String> warnings;

  const RouteCalculationResult({
    required this.straightLineDistanceMeters,
    this.estimatedDistanceMeters,
    this.estimatedDurationSeconds,
    required this.geometry,
    required this.isStraightLine,
    required this.providerName,
    this.warnings = const [],
  });

  /// Alias for geometry points.
  List<AppLatLng> get points => geometry;

  /// Total straight-line distance in meters.
  double get totalDistanceMeters => straightLineDistanceMeters;

  /// Alias for isStraightLine.
  bool get isHonestStraightLine => isStraightLine;

  /// Total distance in miles.
  double get distanceMiles {
    final meters = estimatedDistanceMeters ?? straightLineDistanceMeters;
    return meters * 0.000621371;
  }

  /// Truthful distance description.
  String get distanceLabel {
    if (estimatedDistanceMeters != null) {
      return '${distanceMiles.toStringAsFixed(1)} mi (Road Est.)';
    }
    return '${distanceMiles.toStringAsFixed(1)} mi (Straight-line)';
  }
}

/// Abstract provider interface for calculating routes and searching places.
abstract class RouteProvider {
  String get name;

  /// Calculates route geometry and metrics between ordered stops.
  Future<RouteCalculationResult> calculateRoute(
    List<RouteStop> stops, {
    bool avoidHighways = false,
    bool avoidTolls = false,
    bool avoidFerries = false,
  });

  /// Searches for places by textual query.
  Future<List<PlaceSearchResult>> searchPlaces(
    String query, {
    AppLatLng? nearLocation,
  });

  /// Resolves a place ID into full coordinates.
  Future<ResolvedPlace> resolvePlace(String placeId);
}

/// Default geodesic straight-line preview implementation.
///
/// Truthfully connects stops with direct segments and calculates geodesic
/// distance without fabricating road paths or speculative turn ETAs.
class StraightLineRouteProvider implements RouteProvider {
  const StraightLineRouteProvider();

  @override
  String get name => 'Straight-line Preview';

  @override
  Future<RouteCalculationResult> calculateRoute(
    List<RouteStop> stops, {
    bool avoidHighways = false,
    bool avoidTolls = false,
    bool avoidFerries = false,
  }) async {
    final ordered = List<RouteStop>.from(stops);
    ordered.sort((a, b) => a.order.compareTo(b.order));

    final distanceMeters =
        MotorSignalRoute.calculateTotalDistanceMeters(ordered);
    final points = ordered.map((s) => s.latLng).toList();

    return RouteCalculationResult(
      straightLineDistanceMeters: distanceMeters,
      estimatedDistanceMeters: null,
      estimatedDurationSeconds: null,
      geometry: points,
      isStraightLine: true,
      providerName: name,
    );
  }

  @override
  Future<List<PlaceSearchResult>> searchPlaces(
    String query, {
    AppLatLng? nearLocation,
  }) async {
    final clean = query.trim();
    if (clean.isEmpty) return const [];

    // Check if query is direct coordinates (lat, lng)
    final parts = clean.split(RegExp(r'[,\s]+'));
    if (parts.length == 2) {
      final lat = double.tryParse(parts[0]);
      final lng = double.tryParse(parts[1]);
      if (lat != null &&
          lng != null &&
          lat >= -90 &&
          lat <= 90 &&
          lng >= -180 &&
          lng <= 180) {
        return [
          PlaceSearchResult(
            providerId: 'coord_${lat.toStringAsFixed(4)}_${lng.toStringAsFixed(4)}',
            primaryText: 'Coordinate Pin',
            secondaryText: '${lat.toStringAsFixed(4)}, ${lng.toStringAsFixed(4)}',
            latitude: lat,
            longitude: lng,
            formattedAddress: '${lat.toStringAsFixed(5)}, ${lng.toStringAsFixed(5)}',
          ),
        ];
      }
    }

    return [
      PlaceSearchResult(
        providerId: 'manual',
        primaryText: clean,
        secondaryText: 'Near Current Map Location',
        latitude: nearLocation?.latitude,
        longitude: nearLocation?.longitude,
      ),
    ];
  }

  @override
  Future<ResolvedPlace> resolvePlace(String placeId) async {
    return ResolvedPlace(
      providerId: placeId,
      displayName: 'Unknown Place',
      latitude: 0,
      longitude: 0,
    );
  }
}