CaritasPWA/Shared/Services/Fundvelo/OSM/NominatimService.cs

using cwebplusApp.Shared.Models;
using FisSst.BlazorMaps;
using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.Globalization;
using System.Net.Http;
using System.Threading.Tasks;

namespace cwebplusApp.Shared.Services {
    public class NominatimService {

        public static async ValueTask<NominatimReverseAddress> GetAddressForCoordinates(double latitude, double longitude) {
            string lat = latitude.ToString("0.0000000000", CultureInfo.InvariantCulture);
            string lng = longitude.ToString("0.0000000000", CultureInfo.InvariantCulture);

            HttpClient httpClient = new() { BaseAddress = new Uri("https://nominatim.openstreetmap.org/") };
            try {
                HttpResponseMessage httpResult = await httpClient.GetAsync(string.Format("reverse?format=json&accept-language={0}&lat={1}&lon={2}",
                                                                           CultureInfo.CurrentCulture.Name, lat, lng));
                if (httpResult.StatusCode == System.Net.HttpStatusCode.OK) {
                    string contentStr = await httpResult.Content.ReadAsStringAsync();
                    NominatimReverseAddress addressDto = JsonConvert.DeserializeObject<NominatimReverseAddress>(contentStr);
                    return addressDto;
                }
                return null;

            } catch (Exception) {
                return null;
            }
        }


        public static async ValueTask<LatLng> GetCoordinatesForAddress(string addressZipCity) {
            HttpClient httpClient = new() { BaseAddress = new Uri("https://nominatim.openstreetmap.org/") };
            try {
                HttpResponseMessage httpResult = await httpClient.GetAsync(string.Format("search?q={0}&format=json", addressZipCity));
                if (httpResult.StatusCode == System.Net.HttpStatusCode.OK) {
                    string contentStr = await httpResult.Content.ReadAsStringAsync();
                    var settings = new JsonSerializerSettings();
                    settings.NullValueHandling = NullValueHandling.Ignore;
                    List<NominatimCoordinates> coordinatesDtos = JsonConvert.DeserializeObject<List<NominatimCoordinates>>(contentStr, settings);
                    return new LatLng(coordinatesDtos[0].lat, coordinatesDtos[0].lon);
                }
                return null;

            } catch (Exception) {
                return null;
            }
        }


    }
    public class NominatimCoordinates {
        public double lat;
        public double lon;
    }
}