import 'package:flutter/material.dart';
import 'package:google_maps_flutter/google_maps_flutter.dart';
import 'package:geolocator/geolocator.dart';

class LocationPickerResult {
  final LatLng position;
  final String address;

  LocationPickerResult({
    required this.position,
    required this.address,
  });
}

class LocationPickerScreen extends StatefulWidget {
  final LatLng? initialPosition;

  const LocationPickerScreen({
    super.key,
    this.initialPosition,
  });

  @override
  State<LocationPickerScreen> createState() => _LocationPickerScreenState();
}

class _LocationPickerScreenState extends State<LocationPickerScreen> {
  late GoogleMapController _mapController;
  LatLng _selectedPosition = const LatLng(0, 0);
  Set<Marker> _markers = {};
  bool _isLoading = true;
  final String _selectedAddress = 'Selected Location';

  @override
  void initState() {
    super.initState();
    _initializeMap();
  }

  Future<void> _initializeMap() async {
    try {
      if (widget.initialPosition != null) {
        _selectedPosition = widget.initialPosition!;
      } else {
        final position = await Geolocator.getCurrentPosition(
          desiredAccuracy: LocationAccuracy.high,
        );
        _selectedPosition = LatLng(position.latitude, position.longitude);
      }
      
      _updateMarker();
      setState(() => _isLoading = false);
    } catch (e) {
      setState(() => _isLoading = false);
    }
  }

  void _updateMarker() {
    setState(() {
      _markers = {
        Marker(
          markerId: const MarkerId('selected_location'),
          position: _selectedPosition,
          draggable: true,
          onDragEnd: (LatLng newPosition) {
            setState(() {
              _selectedPosition = newPosition;
              _markers = {
                Marker(
                  markerId: const MarkerId('selected_location'),
                  position: newPosition,
                  draggable: true,
                ),
              };
            });
          },
        ),
      };
    });
  }

  void _onMapCreated(GoogleMapController controller) {
    _mapController = controller;
  }

  Future<void> _getCurrentLocation() async {
    try {
      final position = await Geolocator.getCurrentPosition(
        desiredAccuracy: LocationAccuracy.high,
      );
      
      final newLatLng = LatLng(position.latitude, position.longitude);
      setState(() => _selectedPosition = newLatLng);
      _updateMarker();
      
      _mapController.animateCamera(
        CameraUpdate.newLatLngZoom(newLatLng, 15),
      );
    } catch (e) {
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(content: Text('Error getting location: $e')),
        );
      }
    }
  }

  void _confirmLocation() {
    Navigator.pop(
      context,
      LocationPickerResult(
        position: _selectedPosition,
        address: _selectedAddress,
      ),
    );
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Select Location'),
        actions: [
          IconButton(
            icon: const Icon(Icons.my_location),
            onPressed: _getCurrentLocation,
            tooltip: 'Use current location',
          ),
        ],
      ),
      body: _isLoading
          ? const Center(child: CircularProgressIndicator())
          : Column(
              children: [
                Expanded(
                  child: GoogleMap(
                    onMapCreated: _onMapCreated,
                    initialCameraPosition: CameraPosition(
                      target: _selectedPosition,
                      zoom: 15,
                    ),
                    markers: _markers,
                    onTap: (LatLng position) {
                      setState(() => _selectedPosition = position);
                      _updateMarker();
                    },
                    myLocationEnabled: true,
                    myLocationButtonEnabled: false,
                  ),
                ),
                Container(
                  padding: const EdgeInsets.all(16),
                  decoration: BoxDecoration(
                    color: Theme.of(context).colorScheme.surface,
                    boxShadow: [
                      BoxShadow(
                        color: Colors.black.withValues(alpha: 0.1),
                        blurRadius: 10,
                        offset: const Offset(0, -2),
                      ),
                    ],
                  ),
                  child: SafeArea(
                    child: Column(
                      mainAxisSize: MainAxisSize.min,
                      children: [
                        Row(
                          children: [
                            const Icon(Icons.location_on),
                            const SizedBox(width: 8),
                            Expanded(
                              child: Text(
                                '${_selectedPosition.latitude.toStringAsFixed(6)}, ${_selectedPosition.longitude.toStringAsFixed(6)}',
                                style: Theme.of(context).textTheme.bodyMedium,
                              ),
                            ),
                          ],
                        ),
                        const SizedBox(height: 16),
                        SizedBox(
                          width: double.infinity,
                          child: ElevatedButton(
                            onPressed: _confirmLocation,
                            style: ElevatedButton.styleFrom(
                              padding: const EdgeInsets.symmetric(vertical: 16),
                              shape: RoundedRectangleBorder(
                                borderRadius: BorderRadius.circular(8),
                              ),
                            ),
                            child: const Text('Confirm Location'),
                          ),
                        ),
                      ],
                    ),
                  ),
                ),
              ],
            ),
    );
  }
}