added federationinfo service

src/BirdsiteLive.Domain/TheFedInfoService.cs

@@ -0,0 +1,153 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Net.Http;
+using System.Net.Http.Headers;
+using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
+using Newtonsoft.Json;
+
+namespace BirdsiteLive.Domain
+{
+    public interface ITheFedInfoService
+    {
+        Task<List<BslInstanceInfo>> GetBslInstanceListAsync();
+    }
+
+    public class TheFedInfoService : ITheFedInfoService
+    {
+        private readonly IHttpClientFactory _httpClientFactory;
+        
+        #region Ctor
+        public TheFedInfoService(IHttpClientFactory httpClientFactory)
+        {
+            _httpClientFactory = httpClientFactory;
+        }
+        #endregion
+
+        public async Task<List<BslInstanceInfo>> GetBslInstanceListAsync()
+        {
+            var cancellationToken = CancellationToken.None;
+
+            var result = await CallGraphQlAsync<MyResponseData>(
+                new Uri("https://the-federation.info/graphql"),
+                HttpMethod.Get,
+                "query ($platform: String!) { nodes(platform: $platform) { host, version } }",
+                new
+                {
+                    platform = "birdsitelive",
+                },
+                cancellationToken);
+
+            var convertedResults = ConvertResults(result);
+            return convertedResults;
+        }
+
+        private List<BslInstanceInfo> ConvertResults(GraphQLResponse<MyResponseData> qlData)
+        {
+            var results = new List<BslInstanceInfo>();
+
+            foreach (var instanceInfo in qlData.Data.Nodes)
+            {
+                var rawVersion = instanceInfo.Version.Split('+').FirstOrDefault();
+                var version = Version.Parse(rawVersion);
+
+                var instance = new BslInstanceInfo
+                {
+                    Host = instanceInfo.Host,
+                    Version = version
+                };
+                results.Add(instance);
+            }
+
+            return results;
+        }
+
+        private async Task<GraphQLResponse<TResponse>> CallGraphQlAsync<TResponse>(Uri endpoint, HttpMethod method, string query, object variables, CancellationToken cancellationToken)
+        {
+            var content = new StringContent(SerializeGraphQlCall(query, variables), Encoding.UTF8, "application/json");
+            var httpRequestMessage = new HttpRequestMessage
+            {
+                Method = method,
+                Content = content,
+                RequestUri = endpoint,
+            };
+            //add authorization headers if necessary here
+            httpRequestMessage.Headers.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
+            var httpClient = _httpClientFactory.CreateClient();
+            using (var response = await httpClient.SendAsync(httpRequestMessage, cancellationToken))
+            {
+                //if (response.IsSuccessStatusCode)
+                if (response?.Content.Headers.ContentType?.MediaType == "application/json")
+                {
+                    var responseString = await response.Content.ReadAsStringAsync(); //cancellationToken supported for .NET 5/6
+                    return DeserializeGraphQlCall<TResponse>(responseString);
+                }
+                else
+                {
+                    throw new ApplicationException($"Unable to contact '{endpoint}': {response.StatusCode} - {response.ReasonPhrase}");
+                }
+            }
+        }
+
+        private string SerializeGraphQlCall(string query, object variables)
+        {
+            var sb = new StringBuilder();
+            var textWriter = new StringWriter(sb);
+            var serializer = new JsonSerializer();
+            serializer.Serialize(textWriter, new
+            {
+                query = query,
+                variables = variables,
+            });
+            return sb.ToString();
+        }
+
+        private GraphQLResponse<TResponse> DeserializeGraphQlCall<TResponse>(string response)
+        {
+            var serializer = new JsonSerializer();
+            var stringReader = new StringReader(response);
+            var jsonReader = new JsonTextReader(stringReader);
+            var result = serializer.Deserialize<GraphQLResponse<TResponse>>(jsonReader);
+            return result;
+        }
+        
+        private class GraphQLResponse<TResponse>
+        {
+            public List<GraphQLError> Errors { get; set; }
+            public TResponse Data { get; set; }
+        }
+
+        private class GraphQLError
+        {
+            public string Message { get; set; }
+            public List<GraphQLErrorLocation> Locations { get; set; }
+            public List<object> Path { get; set; } //either int or string
+        }
+
+        private class GraphQLErrorLocation
+        {
+            public int Line { get; set; }
+            public int Column { get; set; }
+        }
+        
+        private class MyResponseData
+        {
+            public Node[] Nodes { get; set; }
+        }
+
+        private class Node
+        {
+            public string Host { get; set; }
+            public string Version { get; set; }
+        }
+    }
+
+    public class BslInstanceInfo
+    {
+        public string Host { get; set; }
+        public Version Version { get; set; }
+    }
+}

src/Tests/BirdsiteLive.Domain.Tests/TheFedInfoServiceTests.cs

@@ -0,0 +1,34 @@
+using System;
+using System.Linq;
+using System.Net.Http;
+using System.Threading.Tasks;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using Moq;
+
+namespace BirdsiteLive.Domain.Tests
+{
+    [TestClass]
+    public class TheFedInfoServiceTests
+    {
+        [TestMethod]
+        public async Task GetBslInstanceListAsyncTest()
+        {
+            var httpClientFactoryMock = new Mock<IHttpClientFactory>();
+            httpClientFactoryMock
+                .Setup(x => x.CreateClient(It.IsAny<string>()))
+                .Returns(new HttpClient());
+
+            var service = new TheFedInfoService(httpClientFactoryMock.Object);
+
+            var bslInstanceList = await service.GetBslInstanceListAsync();
+
+            Assert.IsTrue(bslInstanceList.Count > 0);
+
+            foreach (var instanceInfo in bslInstanceList)
+            {
+                Assert.IsFalse(string.IsNullOrWhiteSpace(instanceInfo.Host));
+                Assert.IsTrue(instanceInfo.Version > new Version(0, 1, 0));
+            }
+        }
+    }
+}