BeWoPlaner/Service/ServiceUtils/DistanceCalculator/GoogleDistanceMatrixAPI.cs

using BeWo.Data.Entities;
using BS.Shared.DataContracts;
using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.Configuration;
using System.Linq;
using System.Net.Http;
using System.Text;
using System.Threading.Tasks;
using System.Web;

namespace BeWo.Service.ServiceUtils.DistanceCalculator
{
    public class GoogleDistanceMatrixApi : IDistanceAPI
    {
        public class Response
        {
            public string Status { get; set; }

            [JsonProperty(PropertyName = "origin_addresses")]
            public string[] OriginAddresses { get; set; }

            [JsonProperty(PropertyName = "destination_addresses")]
            public string[] DestinationAddresses { get; set; }

            public Row[] Rows { get; set; }

            public class Data
            {
                public int Value { get; set; }
                public string Text { get; set; }
            }

            public class Element
            {
                public string Status { get; set; }
                public Data Duration { get; set; }
                public Data Distance { get; set; }
            }

            public class Row
            {
                public Element[] Elements { get; set; }
            }
        }

        private string Key { get; set; }
        private string Url { get; set; }

        private AddressRouteMatrix Matrix { get; set; }

        private Address[] OriginAddresses { get; set; }
        private Address[] DestinationAddresses { get; set; }
        
        public GoogleDistanceMatrixApi()
        {
            var appSettings = ConfigurationManager.AppSettings;

            if (string.IsNullOrEmpty(appSettings["GoogleDistanceMatrixApiUrl"]))
            {
                throw new Exception("GoogleDistanceMatrixApiUrl is not set in AppSettings.");
            }
            Url = appSettings["GoogleDistanceMatrixApiUrl"];

            if (string.IsNullOrEmpty(appSettings["GoogleDistanceMatrixApiKey"]))
            {
                throw new Exception("GoogleDistanceMatrixApiKey is not set in AppSettings.");
            }
            Key = appSettings["GoogleDistanceMatrixApiKey"];
        }

        public void RequestMissingData(ref AddressRouteMatrix matrix, IEnumerable<Address> origins, IEnumerable<Address> destinations)
        {
            Matrix = matrix;
            OriginAddresses = origins.ToArray();
            DestinationAddresses = destinations.ToArray();

            var task = GetMatrix();

            task.Wait();

            if (task.Exception is object)
            {
                throw task.Exception;
            }
        }

        public async Task<AddressRouteMatrix> GetMatrix()
        {
            using (var client = new HttpClient())
            {
                var uri = new Uri(GetRequestUrl());

                HttpResponseMessage response = await client.GetAsync(uri);
                if (!response.IsSuccessStatusCode)
                {
                    throw new Exception("GoogleDistanceMatrixApi failed with status code: " + response.StatusCode);
                }
                else
                {
                    var content = await response.Content.ReadAsStringAsync();

                    return FillMatrix(JsonConvert.DeserializeObject<Response>(content));
                }
            }
        }

        public AddressRouteMatrix FillMatrix(Response response)
        {
            for (int i = 0; i < response.Rows.Length; i++)
            {
                var row = response.Rows[i];
                var origin = OriginAddresses[i];

                for (int j = 0; j < row.Elements.Length; j++)
                {
                    var element = row.Elements[j];
                    var destination = DestinationAddresses[j];

                    var route = Matrix.GetRoute(origin, destination);

                    route.Distance_in_meter = element.Distance.Value;
                    route.Distance_in_meter_txt = element.Distance.Text;
                    route.Time_in_seconds = element.Duration.Value;
                    route.Time_in_seconds_txt = element.Duration.Text;
                }
            }

            return Matrix;
        }

        public AddressRoute ToAddressRoute(Response.Element element)
        {
            var res = new AddressRoute();
            
            res.Distance_in_meter = element.Distance.Value;
            res.Distance_in_meter_txt = element.Distance.Text;
            res.Time_in_seconds = element.Duration.Value;
            res.Time_in_seconds_txt = element.Duration.Text;

            return res;
        }

        private string GetRequestUrl()
        {
            var originAddresses = OriginAddresses.Select(str => AddressRouteManager.AddressToString(str)).Select(HttpUtility.UrlEncode).ToArray();
            var origins = string.Join("|", originAddresses);
            var destinationAddresses = DestinationAddresses.Select(str => AddressRouteManager.AddressToString(str)).Select(HttpUtility.UrlEncode).ToArray();
            var destinations = string.Join("|", destinationAddresses);
            return $"{Url}?origins={origins}&destinations={destinations}&key={Key}";
        }
    }
}