add client invocation for management sdk

src/Microsoft.Azure.SignalR.Common/Utilities/Rest/BinaryPayloadContentBuilder.cs

@@ -4,7 +4,6 @@
 using System;
 using System.Collections.Generic;
 using System.Net.Http;
-
 using Microsoft.AspNetCore.SignalR.Protocol;
 
 #nullable enable

src/Microsoft.Azure.SignalR.Common/Utilities/Rest/IPayloadContentBuilder.cs

@@ -3,7 +3,6 @@
 
 using System;
 using System.Net.Http;
-
 using Microsoft.AspNetCore.SignalR.Protocol;
 
 #nullable enable

src/Microsoft.Azure.SignalR.Common/Utilities/Rest/JsonPayloadContentBuilder.cs

@@ -24,4 +24,6 @@ public JsonPayloadContentBuilder(ObjectSerializer jsonObjectSerializer)
     {
         return payload == null ? null : new JsonPayloadMessageContent(payload, _jsonObjectSerializer, typeHint);
     }
+
+    public ObjectSerializer? ObjectSerializer => _jsonObjectSerializer;
 }

src/Microsoft.Azure.SignalR.Common/Utilities/Rest/SimpleInvocationBinder.cs

@@ -0,0 +1,35 @@
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+using System;
+using System.Collections.Generic;
+using Microsoft.AspNetCore.SignalR;
+
+internal sealed class SimpleInvocationBinder : IInvocationBinder
+{
+    private readonly Type _returnType;
+
+    public SimpleInvocationBinder(Type returnType)
+    {
+        _returnType = returnType ?? throw new ArgumentNullException(nameof(returnType));
+    }
+
+    public Type GetReturnType(string invocationId)
+    {
+        return _returnType;
+    }
+
+    public IReadOnlyList<Type> GetParameterTypes(string methodName)
+    {
+        // No parameters for responses in this scenario
+        return Array.Empty<Type>();
+    }
+
+#pragma warning disable IDE0060 // Remove unused parameter
+    public Type GetStreamItemType(string streamId)
+#pragma warning restore IDE0060 // Remove unused parameter
+    {
+        // No streaming in this scenario
+        return typeof(object);
+    }
+}

src/Microsoft.Azure.SignalR.Common/Utilities/RestClient.cs

@@ -55,7 +55,7 @@ public Task SendAsync(
         Func<HttpResponseMessage, Task<bool>>? handleExpectedResponseAsync,
         CancellationToken cancellationToken = default)
     {
-        return SendAsyncCore(Constants.HttpClientNames.UserDefault, api, httpMethod, null, null, handleExpectedResponseAsync, cancellationToken);
+        return SendAsyncCore(Constants.HttpClientNames.UserDefault, api, httpMethod, null, null, handleExpectedResponseAsync, null, cancellationToken);
     }
 
     public Task SendWithRetryAsync(
@@ -73,18 +73,38 @@ public Task SendWithRetryAsync(
         Func<HttpResponseMessage, Task<bool>>? handleExpectedResponseAsync = null,
         CancellationToken cancellationToken = default)
     {
-        return SendAsyncCore(Constants.HttpClientNames.Resilient, api, httpMethod, null, null, handleExpectedResponseAsync, cancellationToken);
+        return SendAsyncCore(Constants.HttpClientNames.Resilient, api, httpMethod, null, null, handleExpectedResponseAsync, null, cancellationToken);
     }
 
     public Task SendMessageWithRetryAsync(
         RestApiEndpoint api,
         HttpMethod httpMethod,
         string methodName,
         object?[] args,
-        Func<HttpResponseMessage, bool>? handleExpectedResponse = null,
+        Func<HttpResponseMessage, Task<bool>>? handleExpectedResponse = null,
+        CancellationToken cancellationToken = default)
+    {
+        return SendAsyncCore(Constants.HttpClientNames.MessageResilient, api, httpMethod, new InvocationMessage(methodName, args), null, handleExpectedResponse, null, cancellationToken);
+    }
+
+    public Task SendMessageWithRetryAsync(
+        RestApiEndpoint api,
+        HttpMethod httpMethod,
+        string methodName,
+        object?[] args,
+        Func<HttpResponseMessage, Task<bool>>? handleExpectedResponse = null,
+        Action<HttpRequestMessage>? preProcessRequest = null,
         CancellationToken cancellationToken = default)
     {
-        return SendAsyncCore(Constants.HttpClientNames.MessageResilient, api, httpMethod, new InvocationMessage(methodName, args), null, AsAsync(handleExpectedResponse), cancellationToken);
+
+        return SendAsyncCore(Constants.HttpClientNames.MessageResilient,
+            api,
+            httpMethod,
+            new InvocationMessage(methodName, args),
+            null,
+            handleExpectedResponse,
+            preProcessRequest,
+            cancellationToken);
     }
 
     public Task SendStreamMessageWithRetryAsync(
@@ -96,7 +116,7 @@ public Task SendStreamMessageWithRetryAsync(
         Func<HttpResponseMessage, bool>? handleExpectedResponse = null,
         CancellationToken cancellationToken = default)
     {
-        return SendAsyncCore(Constants.HttpClientNames.MessageResilient, api, httpMethod, new StreamItemMessage(streamId, arg), typeHint, AsAsync(handleExpectedResponse), cancellationToken);
+        return SendAsyncCore(Constants.HttpClientNames.MessageResilient, api, httpMethod, new StreamItemMessage(streamId, arg), typeHint, AsAsync(handleExpectedResponse), null, cancellationToken);
     }
 
     private static Uri GetUri(string url, IDictionary<string, StringValues>? query)
@@ -164,11 +184,16 @@ private async Task SendAsyncCore(
         HubMessage? body,
         Type? typeHint,
         Func<HttpResponseMessage, Task<bool>>? handleExpectedResponseAsync = null,
+        Action<HttpRequestMessage>? preProcessRequest = null,
         CancellationToken cancellationToken = default)
     {
         using var httpClient = _httpClientFactory.CreateClient(httpClientName);
         using var request = BuildRequest(api, httpMethod, body, typeHint);
 
+        // preprocess the request
+        // used for client invocation to add extra headers today.
+        preProcessRequest?.Invoke(request);
+
         try
         {
             using var response = await httpClient.SendAsync(request, HttpCompletionOption.ResponseHeadersRead, cancellationToken);

src/Microsoft.Azure.SignalR.Management/ClientInvocation/InvocationResponse.cs

@@ -0,0 +1,15 @@
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+using System.Text.Json.Serialization;
+
+namespace Microsoft.Azure.SignalR.Management.ClientInvocation;
+
+sealed class InvocationResponse
+{
+    [JsonPropertyName("result")]
+    public string Result { get; set; }
+
+    [JsonPropertyName("protocol")]
+    public string protocol { get; set; }
+}

src/Microsoft.Azure.SignalR.Management/HubInstanceFactories/ServiceHubLifetimeManagerFactory.cs

@@ -40,7 +40,8 @@ public IServiceHubLifetimeManager<THub> Create<THub>(string hubName) where THub
                         var httpClientFactory = _serviceProvider.GetRequiredService<IHttpClientFactory>();
                         var serviceEndpoint = _serviceProvider.GetRequiredService<IServiceEndpointManager>().Endpoints.First().Key;
                         var restClient = new RestClient(httpClientFactory, payloadBuilderResolver.GetPayloadContentBuilder());
-                        return new RestHubLifetimeManager<THub>(hubName, serviceEndpoint, _options.ApplicationName, restClient);
+                        var protocolResolver = _serviceProvider.GetRequiredService<IHubProtocolResolver>();
+                        return new RestHubLifetimeManager<THub>(hubName, serviceEndpoint, _options.ApplicationName, restClient, protocolResolver);
                     }
                 default: throw new InvalidEnumArgumentException(nameof(ServiceManagerOptions.ServiceTransportType), (int)_options.ServiceTransportType, typeof(ServiceTransportType));
             }

src/Microsoft.Azure.SignalR.Management/Microsoft.Azure.SignalR.Management.csproj

@@ -44,6 +44,7 @@
 
   <ItemGroup Condition=" '$(TargetFrameworkIdentifier)' != '.NETStandard' ">
     <FrameworkReference Include="Microsoft.AspNetCore.App" />
+    <PackageReference Include="Microsoft.AspNetCore.SignalR.Protocols.MessagePack" Version="8.0.11" />
   </ItemGroup>
 
 </Project>

src/Microsoft.Azure.SignalR.Management/RestApiProvider.cs

@@ -105,6 +105,11 @@ public RestApiEndpoint GetListConnectionsInGroupEndpoint(string appName, string
         return GenerateRestApiEndpoint(appName, hubName, $"/groups/{Uri.EscapeDataString(groupName)}/connections");
     }
 
+    public RestApiEndpoint GetClientInvocationEndpoint(string appName, string hubName, string connectionId)
+    {
+        return GenerateRestApiEndpoint(appName, hubName, $"/connections/{Uri.EscapeDataString(connectionId)}/:invoke");
+    }
+
     private RestApiEndpoint GenerateRestApiEndpoint(string appName, string hubName, string pathAfterHub, IDictionary<string, StringValues> queries = null)
     {
         var requestPrefixWithHub = $"{_serverEndpoint}api/hubs/{Uri.EscapeDataString(hubName.ToLowerInvariant())}";

src/Microsoft.Azure.SignalR.Management/RestHubLifetimeManager.cs

@@ -14,6 +14,11 @@
 using Azure;
 
 using Microsoft.AspNetCore.SignalR;
+#if NET7_0_OR_GREATER
+using Microsoft.Azure.SignalR.Management.ClientInvocation;
+using Microsoft.AspNetCore.SignalR.Protocol;
+using System.Buffers;
+#endif
 using Microsoft.Extensions.Primitives;
 
 using static Microsoft.Azure.SignalR.Constants;
@@ -31,13 +36,15 @@ internal class RestHubLifetimeManager<THub> : HubLifetimeManager<THub>, IService
     private readonly RestApiProvider _restApiProvider;
     private readonly string _hubName;
     private readonly string _appName;
+    private readonly IHubProtocolResolver _protocolResolver;
 
-    public RestHubLifetimeManager(string hubName, ServiceEndpoint endpoint, string appName, RestClient restClient)
+    public RestHubLifetimeManager(string hubName, ServiceEndpoint endpoint, string appName, RestClient restClient, IHubProtocolResolver protocolResolver)
     {
         _restApiProvider = new RestApiProvider(endpoint);
         _appName = appName;
         _hubName = hubName;
         _restClient = restClient;
+        _protocolResolver = protocolResolver;
     }
 
     public override async Task AddToGroupAsync(string connectionId, string groupName, CancellationToken cancellationToken = default)
@@ -353,6 +360,131 @@ public async Task SendStreamCompletionAsync(string connectionId, string streamId
         await _restClient.SendWithRetryAsync(api, HttpMethod.Post, handleExpectedResponse: null, cancellationToken: cancellationToken);
     }
 
+#if NET7_0_OR_GREATER
+    public override async Task<T> InvokeConnectionAsync<T>(string connectionId, string methodName, object?[] args, CancellationToken cancellationToken = default)
+    {
+        if (string.IsNullOrEmpty(methodName))
+        {
+            throw new ArgumentException(NullOrEmptyStringErrorMessage, nameof(methodName));
+        }
+        if (string.IsNullOrEmpty(connectionId))
+        {
+            throw new ArgumentException(NullOrEmptyStringErrorMessage, nameof(connectionId));
+        }
+        if (!_protocolResolver.AllProtocols.All(IsInvocationSupported))
+        {
+            throw new NotSupportedException("Non supported protocol for client invocation.");
+        }
+
+        var api = _restApiProvider.GetClientInvocationEndpoint(_appName, _hubName, connectionId);
+        string? errorContent = null;
+        var isSuccess = false;
+        CompletionMessage? responseMessage = null;
+
+        await _restClient.SendMessageWithRetryAsync(
+            api,
+            HttpMethod.Post,
+            methodName,
+            args,
+            async response =>
+            {
+                isSuccess = response.IsSuccessStatusCode;
+
+                if (isSuccess)
+                {
+                    // 1. Read the outer InvocationResponse (JSON)
+                    await using var contentStream = await response.Content.ReadAsStreamAsync(cancellationToken).ConfigureAwait(false);
+                    var InvocationResponse = await JsonSerializer.DeserializeAsync<InvocationResponse>(contentStream, cancellationToken: cancellationToken).ConfigureAwait(false);
+                    if (InvocationResponse == null || InvocationResponse.protocol == null || InvocationResponse.Result == null)
+                    {
+                        throw new HubException("Response is null or incomplete.");
+                    }
+
+                    // 2. Pick the hub protocol that matches clientResponse.Protocol
+                    var protocol = _protocolResolver.AllProtocols
+                        .FirstOrDefault(p => string.Equals(p.Name, InvocationResponse.protocol, StringComparison.OrdinalIgnoreCase));
+
+                    if (protocol == null)
+                    {
+                        if (string.Equals(InvocationResponse.protocol, "messagepack", StringComparison.OrdinalIgnoreCase) &&
+                            _protocolResolver.AllProtocols.Count == 1 &&
+                            _protocolResolver.AllProtocols[0] is JsonObjectSerializerHubProtocol jsonObjectSerializerHubProtocol)
+                        {
+                            // The hub protocol is the default one. Service will convert it to MessagePack and keep backward compatibility as users may depend on this feature for MessagePack client support.
+                            protocol = new MessagePackHubProtocol();
+                        }
+                        else
+                        {
+                            throw new NotSupportedException($"The protocol '{InvocationResponse.protocol}' is not supported.");
+                        }
+                    }
+
+                    // 3. Use SimpleInvocationBinder with typeof(T)
+                    var binder = new SimpleInvocationBinder(typeof(T));
+
+                    // 4. Parse the payload bytes into CompletionMessage
+                    var messageBytes = Convert.FromBase64String(InvocationResponse.Result);
+                    var sequence = new ReadOnlySequence<byte>(messageBytes);
+                    var local = sequence;
+                    if (!protocol.TryParseMessage(ref local, binder, out var hubMessage))
+                    {
+                        throw new HubException("Failed to parse invocation response.");
+                    }
+
+                    responseMessage = (CompletionMessage)hubMessage!;
+                }
+                else
+                {
+                    errorContent = await response.Content.ReadAsStringAsync(cancellationToken);
+                }
+
+                return isSuccess || response.StatusCode == HttpStatusCode.InternalServerError;
+            },
+            (request) =>
+            {
+                // Add Accept header for SignalR client to recognize the request from management SDK
+                request.Headers.Accept!.Add(new System.Net.Http.Headers.MediaTypeWithQualityHeaderValue("application/octet-stream"));
+            },
+            cancellationToken);
+
+        if (!isSuccess)
+        {
+            throw new HubException(errorContent ?? "Unknown error in response");
+        }
+        if ( responseMessage == null)
+        {
+            throw new HubException("Response message is null.");
+        }
+        if (responseMessage.Error != null)
+        {
+            throw new HubException(responseMessage.Error);
+        }
+
+        return (T)responseMessage!.Result!;
+    }
+
+    public override Task SetConnectionResultAsync(string connectionId, CompletionMessage result)
+    {
+        // This method won't get trigger because in transient we will wait for the returned completion message.
+        // this is to honor the interface
+        throw new NotImplementedException();
+    }
+
+    private static bool IsInvocationSupported(IHubProtocol protocol)
+    {
+        // Use protocol.Name to check for supported protocols
+        switch (protocol.Name)
+        {
+            case "json":
+            case "messagepack":
+                return true;
+            default:
+                return false;
+        }
+    }
+
+#endif
+
     private static bool FilterExpectedResponse(HttpResponseMessage response, string expectedErrorCode) =>
         response.IsSuccessStatusCode
         || (response.StatusCode == HttpStatusCode.NotFound && response.Headers.TryGetValues(Headers.MicrosoftErrorCode, out var errorCodes) && errorCodes.First().Equals(expectedErrorCode, StringComparison.OrdinalIgnoreCase));