Location address conversion algorithm in dart

algo.dart

///In this implementation, the algorithm divides the map into a grid of 0.05 degrees in width and height, which provides a ///balance between granularity and uniqueness of the address identifier. The algorithm uses a reverse geocoding API to ///retrieve the administrative area, city, and street names for the given location, and includes these components in the ///address identifier along with the grid coordinates. The format of the address identifier is designed to be human-readable ///and consistent with local addressing conventions.

String getAddressFromLocation(double latitude, double longitude) {
  // Define the size of the grid in degrees
  final double gridWidth = 0.05;
  final double gridHeight = 0.05;

  // Calculate the grid coordinates for the given latitude and longitude
  final int x = ((longitude + 180) / gridWidth).floor();
  final int y = ((latitude + 90) / gridHeight).floor();

  // Retrieve the administrative area, city, and street names for the given location using a reverse geocoding API
  final String adminArea = await reverseGeocode(latitude, longitude, GeocodeLevel.AdminArea);
  final String city = await reverseGeocode(latitude, longitude, GeocodeLevel.Locality);
  final String street = await reverseGeocode(latitude, longitude, GeocodeLevel.Thoroughfare);

  // Create the address identifier using a format that includes the administrative area, city, street, and grid coordinates
  final String address = '${adminArea}_${city}_${street}_${x}_${y}';

  return address;
}

enum GeocodeLevel {
  Country,
  AdminArea,
  Locality,
  Thoroughfare
}

Future<String> reverseGeocode(double latitude, double longitude, GeocodeLevel level) async {
  // Use a reverse geocoding API to retrieve the address components for the given latitude and longitude
  final String url = 'https://maps.googleapis.com/maps/api/geocode/json?latlng=$latitude,$longitude&result_type=$level&key=YOUR_API_KEY';
  final http.Response response = await http.get(Uri.parse(url));
  final Map<String, dynamic> data = jsonDecode(response.body);

  // Parse the address components and return the requested component (e.g. administrative area, city, or street name)
  final List<dynamic> results = data['results'];
  if (results.isNotEmpty) {
    final List<dynamic> addressComponents = results[0]['address_components'];
    final String component = level == GeocodeLevel.Thoroughfare ? 'route' : level.toString().split('.')[1];
    for (final componentData in addressComponents) {
      if (componentData['types'].contains(component)) {
        return componentData['long_name'];
      }
    }
  }

  return '';
}