C# for Exporting Data from Rossum API

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>netcoreapp2.1</TargetFramework>
    <RootNamespace>rossum_example</RootNamespace>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="Newtonsoft.Json" Version="9.0.1" />
  </ItemGroup>

</Project>

using System;
using System.Collections.Specialized;
using System.Net;
using System.Web;
using Newtonsoft.Json;

namespace rossum_example
{
    class Credentials {
        public string username { get; set; }
        public string password { get; set; }
    }
    class LoginResponse {
        public string key { get; set; }
    }

    class RossumClient
    {
        static string ApiEndpoint = "https://example.rossum.app/api/v1/";
        static void Main(string[] args)
        {
            var rossumClient = new RossumClient();
            
            string authToken = rossumClient.authorize(new Credentials() {
                username="[email protected]",
                password="secret_password"
            });

            var queueId = "12345";
            var exported = rossumClient.exportToday(queueId, authToken);
            Console.WriteLine(exported);
        }

        public string authorize(Credentials credentials) {
            
            using(WebClient client = new WebClient()) {  
                client.BaseAddress = ApiEndpoint;
                client.Headers[HttpRequestHeader.ContentType] = "application/json"; 
                var response = client.UploadString("auth/login", JsonConvert.SerializeObject(credentials));
                return JsonConvert.DeserializeObject<LoginResponse>(response).key;
            }
        }

        public string export(string queueId, string dateStart, string dateEnd, string authToken) {
            using(WebClient client = new WebClient()) {  
                client.BaseAddress = ApiEndpoint;

                client.Headers["Authorization"] =  $"token {authToken}";
                client.Headers[HttpRequestHeader.ContentType] = "application/json";

                NameValueCollection query = new NameValueCollection();
                query.Add("format", "json");
                query.Add("exported_at_after", dateStart);
                query.Add("exported_at_before", dateEnd);
                client.QueryString = query;

                return client.DownloadString($"queues/{queueId}/export");
            }
        }

        public string exportToday(string queueId, string authToken) {
            DateTime today = DateTime.Today;
            var dateEnd = today.ToString("yyyy-MM-dd");
            DateTime yesterday = today.AddDays(-1);
            var dateStart = yesterday.ToString("yyyy-MM-dd");
            return export(queueId, dateStart, dateEnd, authToken);
        }
    }
}