feat: add rest client to get gateway url

src/StevesBot.Worker.Tests/Unit/DiscordRestClientTests.cs

@@ -0,0 +1,73 @@
+using System.Net;
+
+using Microsoft.Extensions.Logging;
+
+using Moq;
+
+using RichardSzalay.MockHttp;
+
+namespace StevesBot.Worker.Tests.Unit;
+
+public sealed class DiscordRestClientTests : IDisposable
+{
+  private const string BaseUrl = "https://discord.com/api/v10";
+  private static string GatewayUrl => $"{BaseUrl}/gateway";
+
+  private readonly Mock<ILogger<DiscordRestClient>> _loggerMock = new();
+  private readonly MockHttpMessageHandler _mockHttpMessageHandler;
+  private readonly DiscordRestClient _discordRestClient;
+
+  public DiscordRestClientTests()
+  {
+    _mockHttpMessageHandler = new MockHttpMessageHandler();
+    var httpClient = _mockHttpMessageHandler.ToHttpClient();
+    httpClient.BaseAddress = new Uri("https://discord.com/api/v10/");
+    _discordRestClient = new DiscordRestClient(_loggerMock.Object, httpClient);
+  }
+
+  [Fact]
+  public async Task GetGatewayUrlAsync_WhenRequestFails_ItShouldThrowException()
+  {
+    _mockHttpMessageHandler
+      .When(GatewayUrl)
+      .Respond(HttpStatusCode.InternalServerError);
+
+    var act = async () => await _discordRestClient.GetGatewayUrlAsync(CancellationToken.None);
+
+    await act.Should().ThrowAsync<DiscordRestClientException>();
+  }
+
+  [Fact]
+  public async Task GetGatewayUrlAsync_WhenResponseIsNull_ItShouldThrowException()
+  {
+    _mockHttpMessageHandler
+      .When(GatewayUrl)
+      .Respond(HttpStatusCode.OK, "application/json", "null");
+
+    var act = async () => await _discordRestClient.GetGatewayUrlAsync(CancellationToken.None);
+
+    await act.Should().ThrowAsync<DiscordRestClientException>();
+  }
+
+  [Fact]
+  public async Task GetGatewayUrlAsync_WhenRequestIsSuccessful_ItShouldReturnGatewayUrl()
+  {
+    var expectedUrl = "test";
+    var jsonResponse = $@"{{ 
+      ""url"": ""{expectedUrl}"" 
+    }}";
+
+    _mockHttpMessageHandler
+      .When(GatewayUrl)
+      .Respond(HttpStatusCode.OK, "application/json", jsonResponse);
+
+    var result = await _discordRestClient.GetGatewayUrlAsync(CancellationToken.None);
+
+    result.Should().Be(expectedUrl);
+  }
+
+  public void Dispose()
+  {
+    _mockHttpMessageHandler.Dispose();
+  }
+}

src/StevesBot.Worker/Discord/DiscordGatewayClient.cs

@@ -5,44 +5,73 @@ internal class DiscordGatewayClient : IDiscordGatewayClient
   private readonly DiscordGatewayClientOptions _options;
   private readonly IWebSocketFactory _webSocketFactory;
   private readonly ILogger<DiscordGatewayClient> _logger;
-  private readonly JsonSerializerOptions _jsonSerializerOptions = new()
-  {
-    PropertyNamingPolicy = JsonNamingPolicy.CamelCase,
-    ReferenceHandler = ReferenceHandler.IgnoreCycles,
-    Converters =
-    {
-      new DiscordEventConverter(),
-    },
-  };
+  private readonly IDiscordRestClient _discordRestClient;
+  // private readonly JsonSerializerOptions _jsonSerializerOptions = new()
+  // {
+  //   PropertyNamingPolicy = JsonNamingPolicy.CamelCase,
+  //   ReferenceHandler = ReferenceHandler.IgnoreCycles,
+  //   Converters =
+  //   {
+  //     new DiscordEventConverter(),
+  //   },
+  // };
   private readonly AsyncLock _lock = new();
 
   private string _gatewayUrl = string.Empty;
   private IWebSocket? _webSocket;
   private Task? _receiveTask;
-  private DateTime _timeLastHeartbeatSent = DateTime.MinValue;
-  private DateTime _timeLastHeartbeatAcknowledged = DateTime.MinValue;
-  private CancellationTokenSource? _heartbeatCts;
-  private Task? _heartbeatTask;
-  private string _sessionId = string.Empty;
-  private string _resumeGatewayUrl = string.Empty;
+  // private DateTime _timeLastHeartbeatSent = DateTime.MinValue;
+  // private DateTime _timeLastHeartbeatAcknowledged = DateTime.MinValue;
+  // private CancellationTokenSource? _heartbeatCts;
+  // private Task? _heartbeatTask;
+  // private string _sessionId = string.Empty;
+  // private string _resumeGatewayUrl = string.Empty;
 
   public DiscordGatewayClient(
     DiscordGatewayClientOptions options,
     IWebSocketFactory webSocketFactory,
-    ILogger<DiscordGatewayClient> logger
+    ILogger<DiscordGatewayClient> logger,
+    IDiscordRestClient discordRestClient
   )
   {
     _options = options ?? throw new ArgumentNullException(nameof(options));
     _webSocketFactory = webSocketFactory ?? throw new ArgumentNullException(nameof(webSocketFactory));
     _logger = logger ?? throw new ArgumentNullException(nameof(logger));
+    _discordRestClient = discordRestClient ?? throw new ArgumentNullException(nameof(discordRestClient));
+  }
+
+  public async Task ConnectAsync(CancellationToken cancellationToken)
+  {
+    using (await _lock.LockAsync(cancellationToken))
+    {
+      if (string.IsNullOrEmpty(_gatewayUrl))
+      {
+        _gatewayUrl = await _discordRestClient.GetGatewayUrlAsync(cancellationToken);
+      }
+
+      _webSocket = _webSocketFactory.Create();
+
+      var uri = new Uri(_gatewayUrl);
+      await _webSocket.ConnectAsync(uri, cancellationToken);
+
+      _logger.LogInformation("Connected to Discord Gateway at {GatewayUrl}", _gatewayUrl);
+
+      _receiveTask = ReceiveMessagesAsync(cancellationToken);
+    }
+  }
+
+  private static Task ReceiveMessagesAsync(CancellationToken cancellationToken)
+  {
+    return Task.CompletedTask;
   }
 
   public void Dispose()
   {
-    _heartbeatCts?.Cancel();
-    _heartbeatCts?.Dispose();
-    _heartbeatTask?.Dispose();
+    // _heartbeatCts?.Cancel();
+    // _heartbeatCts?.Dispose();
+    // _heartbeatTask?.Dispose();
     _receiveTask?.Dispose();
     _webSocket?.Dispose();
+    _lock.Dispose();
   }
 }

src/StevesBot.Worker/Discord/DiscordRestClient.cs

@@ -0,0 +1,43 @@
+namespace StevesBot.Worker.Discord;
+
+internal class DiscordRestClient : IDiscordRestClient
+{
+  private readonly ILogger<DiscordRestClient> _logger;
+  private readonly HttpClient _httpClient;
+
+  public DiscordRestClient(
+    ILogger<DiscordRestClient> logger,
+    HttpClient httpClient
+  )
+  {
+    _logger = logger ?? throw new ArgumentNullException(nameof(logger));
+    _httpClient = httpClient ?? throw new ArgumentNullException(nameof(httpClient));
+  }
+
+
+  public async Task<string> GetGatewayUrlAsync(CancellationToken cancellationToken)
+  {
+    var uri = new Uri("gateway", UriKind.Relative);
+    var response = await _httpClient.GetAsync(uri, cancellationToken);
+
+    if (!response.IsSuccessStatusCode)
+    {
+      _logger.LogError("Failed to get gateway URL: {StatusCode}", response.StatusCode);
+      throw new DiscordRestClientException("Failed to get gateway URL.");
+    }
+
+    var gatewayResponse = await response.Content.ReadFromJsonAsync<GatewayResponse>(cancellationToken);
+
+    if (gatewayResponse is null)
+    {
+      _logger.LogError("Failed to deserialize gateway response.");
+      throw new DiscordRestClientException("Failed to deserialize gateway response.");
+    }
+
+    return gatewayResponse.Url;
+  }
+}
+
+internal record GatewayResponse(
+  [property: JsonPropertyName("url")] string Url
+);

src/StevesBot.Worker/Discord/DiscordRestClientException.cs

@@ -0,0 +1,16 @@
+namespace StevesBot.Worker.Discord;
+
+internal class DiscordRestClientException : Exception
+{
+  public DiscordRestClientException()
+  {
+  }
+
+  public DiscordRestClientException(string message) : base(message)
+  {
+  }
+
+  public DiscordRestClientException(string message, Exception innerException) : base(message, innerException)
+  {
+  }
+}

src/StevesBot.Worker/Discord/IDiscordGatewayClient.cs

@@ -2,4 +2,5 @@ namespace StevesBot.Worker.Discord;
 
 internal interface IDiscordGatewayClient : IDisposable
 {
+  Task ConnectAsync(CancellationToken cancellationToken);
 }

src/StevesBot.Worker/Discord/IDiscordRestClient.cs

@@ -0,0 +1,6 @@
+namespace StevesBot.Worker.Discord;
+
+internal interface IDiscordRestClient
+{
+  Task<string> GetGatewayUrlAsync(CancellationToken cancellationToken);
+}

src/StevesBot.Worker/Usings.cs

@@ -1,8 +1,8 @@
+global using System.Net.Http.Json;
 global using System.Net.WebSockets;
 global using System.Text.Json;
 global using System.Text.Json.Serialization;
 
-
 global using StevesBot.Worker.Discord.Events;
 global using StevesBot.Worker.Threading;
 global using StevesBot.Worker.WebSockets;