import 'package:flutter/material.dart';
import 'package:url_launcher/url_launcher.dart';
import 'route_models.dart';

/// Target navigation application for handoff.
enum NavigationApp {
  googleMaps,
  waze,
  platformDefault;

  String get label {
    switch (this) {
      case NavigationApp.googleMaps:
        return 'Google Maps';
      case NavigationApp.waze:
        return 'Waze';
      case NavigationApp.platformDefault:
        return 'System Map';
    }
  }
}

/// Service handling truthful handoff to external navigation applications.
/// MotorSignal delegates road-following turn-by-turn navigation to trusted
/// navigation apps without claiming internal turn-by-turn guidance.
class NavigationHandoffService {
  const NavigationHandoffService();

  /// Builds a standard Google Maps turn-by-turn navigation URI.
  static Uri buildGoogleMapsUri({
    required double latitude,
    required double longitude,
    String? displayName,
  }) {
    final dest = '${latitude.toStringAsFixed(6)},${longitude.toStringAsFixed(6)}';
    return Uri.parse('https://www.google.com/maps/dir/?api=1&destination=$dest');
  }

  /// Builds a standard Waze navigation URI.
  static Uri buildWazeUri({
    required double latitude,
    required double longitude,
  }) {
    final ll = '${latitude.toStringAsFixed(6)},${longitude.toStringAsFixed(6)}';
    return Uri.parse('https://waze.com/ul?ll=$ll&navigate=yes');
  }

  /// Builds a standard RFC 5870 system geo: navigation URI.
  static Uri buildSystemGeoUri({
    required double latitude,
    required double longitude,
    required String displayName,
  }) {
    final coords = '${latitude.toStringAsFixed(6)},${longitude.toStringAsFixed(6)}';
    return Uri.parse('geo:$coords?q=$coords($displayName)');
  }

  /// Displays an interactive navigation handoff bottom sheet with direct links
  /// to Google Maps, Waze, and native system mapping.
  static void showHandoffSheet({
    required BuildContext context,
    required double latitude,
    required double longitude,
    required String displayName,
  }) {
    showModalBottomSheet(
      context: context,
      backgroundColor: const Color(0xFF1B1E26),
      shape: const RoundedRectangleBorder(
        borderRadius: BorderRadius.vertical(top: Radius.circular(16)),
      ),
      builder: (sheetContext) {
        return SafeArea(
          child: Padding(
            padding: const EdgeInsets.symmetric(vertical: 20, horizontal: 16),
            child: Column(
              mainAxisSize: MainAxisSize.min,
              crossAxisAlignment: CrossAxisAlignment.stretch,
              children: [
                Row(
                  children: [
                    const Icon(Icons.navigation, color: Color(0xFF00E5FF), size: 22),
                    const SizedBox(width: 12),
                    Expanded(
                      child: Column(
                        crossAxisAlignment: CrossAxisAlignment.start,
                        children: [
                          const Text(
                            'NAVIGATION HANDOFF',
                            style: TextStyle(
                              fontSize: 11,
                              letterSpacing: 1.2,
                              fontWeight: FontWeight.w700,
                              color: Color(0xFF00E5FF),
                            ),
                          ),
                          const SizedBox(height: 2),
                          Text(
                            displayName,
                            style: const TextStyle(
                              fontSize: 16,
                              fontWeight: FontWeight.bold,
                              color: Colors.white,
                            ),
                            maxLines: 1,
                            overflow: TextOverflow.ellipsis,
                          ),
                        ],
                      ),
                    ),
                  ],
                ),
                const SizedBox(height: 20),
                ListTile(
                  leading: Container(
                    padding: const EdgeInsets.all(8),
                    decoration: BoxDecoration(
                      color: Colors.white10,
                      borderRadius: BorderRadius.circular(8),
                    ),
                    child: const Icon(Icons.map, color: Colors.white),
                  ),
                  title: const Text('Google Maps', style: TextStyle(color: Colors.white, fontWeight: FontWeight.w600)),
                  subtitle: const Text('Open turn-by-turn in Google Maps', style: TextStyle(color: Colors.white54, fontSize: 12)),
                  trailing: const Icon(Icons.open_in_new, color: Colors.white38, size: 18),
                  onTap: () async {
                    Navigator.pop(sheetContext);
                    final uri = buildGoogleMapsUri(
                      latitude: latitude,
                      longitude: longitude,
                      displayName: displayName,
                    );
                    if (await canLaunchUrl(uri)) {
                      await launchUrl(uri, mode: LaunchMode.externalApplication);
                    }
                  },
                ),
                const Divider(color: Colors.white12, height: 1),
                ListTile(
                  leading: Container(
                    padding: const EdgeInsets.all(8),
                    decoration: BoxDecoration(
                      color: Colors.white10,
                      borderRadius: BorderRadius.circular(8),
                    ),
                    child: const Icon(Icons.directions_car, color: Color(0xFF00E5FF)),
                  ),
                  title: const Text('Waze', style: TextStyle(color: Colors.white, fontWeight: FontWeight.w600)),
                  subtitle: const Text('Open road directions in Waze', style: TextStyle(color: Colors.white54, fontSize: 12)),
                  trailing: const Icon(Icons.open_in_new, color: Colors.white38, size: 18),
                  onTap: () async {
                    Navigator.pop(sheetContext);
                    final uri = buildWazeUri(
                      latitude: latitude,
                      longitude: longitude,
                    );
                    if (await canLaunchUrl(uri)) {
                      await launchUrl(uri, mode: LaunchMode.externalApplication);
                    }
                  },
                ),
                const Divider(color: Colors.white12, height: 1),
                ListTile(
                  leading: Container(
                    padding: const EdgeInsets.all(8),
                    decoration: BoxDecoration(
                      color: Colors.white10,
                      borderRadius: BorderRadius.circular(8),
                    ),
                    child: const Icon(Icons.place, color: Colors.white70),
                  ),
                  title: const Text('System Map', style: TextStyle(color: Colors.white, fontWeight: FontWeight.w600)),
                  subtitle: const Text('Open in default platform mapping app', style: TextStyle(color: Colors.white54, fontSize: 12)),
                  trailing: const Icon(Icons.open_in_new, color: Colors.white38, size: 18),
                  onTap: () async {
                    Navigator.pop(sheetContext);
                    final uri = buildSystemGeoUri(
                      latitude: latitude,
                      longitude: longitude,
                      displayName: displayName,
                    );
                    if (await canLaunchUrl(uri)) {
                      await launchUrl(uri, mode: LaunchMode.externalApplication);
                    }
                  },
                ),
                const SizedBox(height: 8),
              ],
            ),
          ),
        );
      },
    );
  }

  /// Launches external navigation to a single target [stop].
  Future<bool> launchNavigationToStop({
    required RouteStop stop,
    NavigationApp app = NavigationApp.googleMaps,
  }) async {
    Uri uri;
    switch (app) {
      case NavigationApp.googleMaps:
        uri = buildGoogleMapsUri(
          latitude: stop.latitude,
          longitude: stop.longitude,
          displayName: stop.displayName,
        );
        break;

      case NavigationApp.waze:
        uri = buildWazeUri(
          latitude: stop.latitude,
          longitude: stop.longitude,
        );
        break;

      case NavigationApp.platformDefault:
        uri = buildSystemGeoUri(
          latitude: stop.latitude,
          longitude: stop.longitude,
          displayName: stop.displayName,
        );
        break;
    }

    try {
      if (await canLaunchUrl(uri)) {
        return await launchUrl(uri, mode: LaunchMode.externalApplication);
      }
      final fallbackUri = Uri.parse(
        'https://www.google.com/maps/search/?api=1&query=${stop.latitude},${stop.longitude}',
      );
      if (await canLaunchUrl(fallbackUri)) {
        return await launchUrl(fallbackUri, mode: LaunchMode.externalApplication);
      }
      return false;
    } catch (e) {
      debugPrint('[NavigationHandoffService] Failed to launch navigation: $e');
      return false;
    }
  }

  /// Launches multi-stop road route navigation in external maps (up to provider limit).
  Future<bool> launchFullRouteNavigation({
    required MotorSignalRoute route,
    NavigationApp app = NavigationApp.googleMaps,
  }) async {
    final stops = route.orderedStops;
    if (stops.isEmpty) return false;
    if (stops.length == 1) {
      return launchNavigationToStop(stop: stops.first, app: app);
    }

    final origin = '${stops.first.latitude},${stops.first.longitude}';
    final dest = '${stops.last.latitude},${stops.last.longitude}';

    if (app == NavigationApp.googleMaps) {
      final intermediateStops = stops.sublist(1, stops.length - 1);
      final cappedIntermediates = intermediateStops.take(9);
      final waypointsStr = cappedIntermediates
          .map((s) => '${s.latitude},${s.longitude}')
          .join('|');

      final waypointsParam =
          waypointsStr.isNotEmpty ? '&waypoints=$waypointsStr' : '';
      final uri = Uri.parse(
        'https://www.google.com/maps/dir/?api=1&origin=$origin&destination=$dest$waypointsParam',
      );

      try {
        if (await canLaunchUrl(uri)) {
          return await launchUrl(uri, mode: LaunchMode.externalApplication);
        }
      } catch (e) {
        debugPrint('[NavigationHandoffService] Failed to launch multi-stop route: $e');
      }
    }

    return launchNavigationToStop(stop: stops.last, app: app);
  }
}