feat(furniture-bff): wire rest runtime and grpc client adapter

src/Furniture.Bff.Application/Adapters/FurnitureAvailabilityEdgeContractAdapter.cs

@@ -0,0 +1,37 @@
+using Furniture.Bff.Contracts.Api;
+using Furniture.Service.Contracts.UseCases;
+
+namespace Furniture.Bff.Application.Adapters;
+
+/// <summary>
+/// Default adapter implementation between furniture BFF edge and furniture service contracts.
+/// </summary>
+public sealed class FurnitureAvailabilityEdgeContractAdapter : IFurnitureAvailabilityEdgeContractAdapter
+{
+    /// <inheritdoc />
+    public GetFurnitureAvailabilityRequest ToServiceRequest(GetFurnitureAvailabilityApiRequest request)
+    {
+        return new GetFurnitureAvailabilityRequest(
+            request.FurnitureId,
+            ResolveCorrelationId(request.CorrelationId));
+    }
+
+    /// <inheritdoc />
+    public GetFurnitureAvailabilityApiResponse ToApiResponse(GetFurnitureAvailabilityResponse response)
+    {
+        return new GetFurnitureAvailabilityApiResponse(
+            response.FurnitureId,
+            response.DisplayName,
+            response.QuantityAvailable);
+    }
+
+    private static string ResolveCorrelationId(string correlationId)
+    {
+        if (!string.IsNullOrWhiteSpace(correlationId))
+        {
+            return correlationId;
+        }
+
+        return $"corr-{Guid.NewGuid():N}";
+    }
+}

src/Furniture.Bff.Application/Adapters/FurnitureAvailabilityEdgeGrpcContractAdapter.cs

@@ -0,0 +1,36 @@
+using Furniture.Bff.Application.Grpc;
+using Furniture.Bff.Contracts.Api;
+
+namespace Furniture.Bff.Application.Adapters;
+
+/// <summary>
+/// Default adapter implementation for furniture edge gRPC contract translation.
+/// </summary>
+public sealed class FurnitureAvailabilityEdgeGrpcContractAdapter : IFurnitureAvailabilityEdgeGrpcContractAdapter
+{
+    /// <inheritdoc />
+    public GetFurnitureAvailabilityEdgeGrpcContract ToGrpc(GetFurnitureAvailabilityApiRequest request)
+    {
+        return new GetFurnitureAvailabilityEdgeGrpcContract(
+            request.FurnitureId,
+            ResolveCorrelationId(request.CorrelationId));
+    }
+
+    /// <inheritdoc />
+    public GetFurnitureAvailabilityApiRequest FromGrpc(GetFurnitureAvailabilityEdgeGrpcContract contract)
+    {
+        return new GetFurnitureAvailabilityApiRequest(
+            contract.FurnitureId,
+            ResolveCorrelationId(contract.CorrelationId));
+    }
+
+    private static string ResolveCorrelationId(string correlationId)
+    {
+        if (!string.IsNullOrWhiteSpace(correlationId))
+        {
+            return correlationId;
+        }
+
+        return $"corr-{Guid.NewGuid():N}";
+    }
+}

src/Furniture.Bff.Application/DependencyInjection/FurnitureBffApplicationServiceCollectionExtensions.cs

@@ -0,0 +1,26 @@
+using Furniture.Bff.Application.Adapters;
+using Furniture.Bff.Application.Handlers;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.DependencyInjection.Extensions;
+
+namespace Furniture.Bff.Application.DependencyInjection;
+
+/// <summary>
+/// Registers application-layer runtime wiring for furniture-bff.
+/// </summary>
+public static class FurnitureBffApplicationServiceCollectionExtensions
+{
+    /// <summary>
+    /// Adds furniture-bff application handlers and adapter implementations.
+    /// </summary>
+    /// <param name="services">Service collection.</param>
+    /// <returns>Service collection for fluent chaining.</returns>
+    public static IServiceCollection AddFurnitureBffApplicationRuntime(this IServiceCollection services)
+    {
+        services.TryAddSingleton<IFurnitureAvailabilityEdgeContractAdapter, FurnitureAvailabilityEdgeContractAdapter>();
+        services.TryAddSingleton<IFurnitureAvailabilityEdgeGrpcContractAdapter, FurnitureAvailabilityEdgeGrpcContractAdapter>();
+        services.TryAddScoped<IGetFurnitureAvailabilityHandler, GetFurnitureAvailabilityHandler>();
+
+        return services;
+    }
+}

src/Furniture.Bff.Application/Furniture.Bff.Application.csproj

@@ -5,6 +5,7 @@
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
+    <PackageReference Include="Microsoft.Extensions.DependencyInjection.Abstractions" Version="10.0.0" />
     <ProjectReference Include="..\Furniture.Bff.Contracts\Furniture.Bff.Contracts.csproj" />
     <ProjectReference Include="..\..\..\furniture-service\src\Furniture.Service.Contracts\Furniture.Service.Contracts.csproj" />
   </ItemGroup>

src/Furniture.Bff.Rest/Adapters/FurnitureServiceGrpcClientAdapter.cs

@@ -0,0 +1,70 @@
+using Furniture.Bff.Application.Adapters;
+using Furniture.Service.Contracts.UseCases;
+using Furniture.Service.Grpc;
+using Grpc.Core;
+using Microsoft.Extensions.Primitives;
+
+namespace Furniture.Bff.Rest.Adapters;
+
+/// <summary>
+/// gRPC-backed adapter for downstream furniture-service calls.
+/// </summary>
+public sealed class FurnitureServiceGrpcClientAdapter(
+    FurnitureRuntime.FurnitureRuntimeClient grpcClient,
+    IHttpContextAccessor httpContextAccessor) : IFurnitureServiceClient
+{
+    private const string CorrelationHeaderName = "x-correlation-id";
+
+    /// <inheritdoc />
+    public async Task<GetFurnitureAvailabilityResponse> GetAvailabilityAsync(GetFurnitureAvailabilityRequest request)
+    {
+        var correlationId = ResolveCorrelationId(request.CorrelationId);
+        var grpcRequest = new GetFurnitureAvailabilityGrpcRequest
+        {
+            FurnitureId = request.FurnitureId,
+            CorrelationId = correlationId
+        };
+
+        var grpcResponse = await grpcClient.GetFurnitureAvailabilityAsync(
+            grpcRequest,
+            headers: CreateHeaders(correlationId),
+            deadline: DateTime.UtcNow.AddSeconds(10));
+
+        return new GetFurnitureAvailabilityResponse(
+            grpcResponse.FurnitureId,
+            grpcResponse.DisplayName,
+            grpcResponse.QuantityAvailable);
+    }
+
+    private string ResolveCorrelationId(string? preferred = null)
+    {
+        if (!string.IsNullOrWhiteSpace(preferred))
+        {
+            return preferred;
+        }
+
+        var context = httpContextAccessor.HttpContext;
+        if (context?.Items.TryGetValue(CorrelationHeaderName, out var itemValue) == true &&
+            itemValue is string itemCorrelationId &&
+            !string.IsNullOrWhiteSpace(itemCorrelationId))
+        {
+            return itemCorrelationId;
+        }
+
+        if (context?.Request.Headers.TryGetValue(CorrelationHeaderName, out var headerValue) == true &&
+            !StringValues.IsNullOrEmpty(headerValue))
+        {
+            return headerValue.ToString();
+        }
+
+        return context?.TraceIdentifier ?? $"corr-{Guid.NewGuid():N}";
+    }
+
+    private static Metadata CreateHeaders(string correlationId)
+    {
+        return
+        [
+            new Metadata.Entry(CorrelationHeaderName, correlationId)
+        ];
+    }
+}

src/Furniture.Bff.Rest/Furniture.Bff.Rest.csproj

@@ -4,8 +4,22 @@
     <Nullable>enable</Nullable>
     <ImplicitUsings>enable</ImplicitUsings>
   </PropertyGroup>
+  <ItemGroup>
+    <PackageReference Include="Google.Protobuf" Version="3.31.1" />
+    <PackageReference Include="Grpc.Core.Api" Version="2.71.0" />
+    <PackageReference Include="Grpc.Net.Client" Version="2.71.0" />
+    <PackageReference Include="Grpc.Net.ClientFactory" Version="2.71.0" />
+    <PackageReference Include="Grpc.Tools" Version="2.71.0">
+      <PrivateAssets>all</PrivateAssets>
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+    </PackageReference>
+  </ItemGroup>
+  <ItemGroup>
+    <Protobuf Include="..\..\..\furniture-service\src\Furniture.Service.Grpc\Protos\furniture_runtime.proto" GrpcServices="Client" Link="Protos\furniture_runtime.proto" />
+  </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\Furniture.Bff.Application\Furniture.Bff.Application.csproj" />
     <ProjectReference Include="..\Furniture.Bff.Contracts\Furniture.Bff.Contracts.csproj" />
+    <ProjectReference Include="..\..\..\blueprint-platform\src\Core.Blueprint.Common\Core.Blueprint.Common.csproj" />
   </ItemGroup>
 </Project>

src/Furniture.Bff.Rest/Program.cs

@@ -1,13 +1,70 @@
+using Core.Blueprint.Common.DependencyInjection;
+using Furniture.Bff.Application.Adapters;
+using Furniture.Bff.Application.DependencyInjection;
+using Furniture.Bff.Application.Handlers;
 using Furniture.Bff.Contracts.Api;
+using Furniture.Bff.Rest.Adapters;
+using Furniture.Bff.Rest.Endpoints;
+using Furniture.Service.Grpc;
+using Microsoft.Extensions.Primitives;
+
+const string CorrelationHeaderName = "x-correlation-id";
 
 var builder = WebApplication.CreateBuilder(args);
 
-// Stage 3 skeleton: single active external protocol for this deployment is REST.
+builder.Services.AddHttpContextAccessor();
-var app = builder.Build();
+builder.Services.AddHealthChecks();
-
+builder.Services.AddBlueprintRuntimeCore();
-app.MapGet("/api/furniture/{furnitureId}/availability", (string furnitureId) =>
+builder.Services.AddFurnitureBffApplicationRuntime();
+builder.Services.AddScoped<IFurnitureServiceClient, FurnitureServiceGrpcClientAdapter>();
+builder.Services.AddGrpcClient<FurnitureRuntime.FurnitureRuntimeClient>(options =>
 {
-    return Results.Ok(new GetFurnitureAvailabilityApiResponse(furnitureId, string.Empty, 0));
+    var serviceAddress = builder.Configuration["FurnitureService:GrpcAddress"] ?? "http://localhost:5252";
+    options.Address = new Uri(serviceAddress);
 });
 
+var app = builder.Build();
+
+app.Use(async (context, next) =>
+{
+    var correlationId = ResolveCorrelationId(context);
+    context.Items[CorrelationHeaderName] = correlationId;
+    context.Request.Headers[CorrelationHeaderName] = correlationId;
+    context.Response.Headers[CorrelationHeaderName] = correlationId;
+    await next();
+});
+
+app.MapGet($"{EndpointConventions.ApiPrefix}/{{furnitureId}}/availability", async (
+    string furnitureId,
+    HttpContext context,
+    IGetFurnitureAvailabilityHandler handler) =>
+{
+    var request = new GetFurnitureAvailabilityApiRequest(
+        furnitureId,
+        ResolveCorrelationId(context));
+
+    var response = await handler.HandleAsync(request);
+    return Results.Ok(response);
+});
+
+app.MapHealthChecks("/healthz");
+
 app.Run();
+
+string ResolveCorrelationId(HttpContext context)
+{
+    if (context.Items.TryGetValue(CorrelationHeaderName, out var itemValue) &&
+        itemValue is string itemCorrelationId &&
+        !string.IsNullOrWhiteSpace(itemCorrelationId))
+    {
+        return itemCorrelationId;
+    }
+
+    if (context.Request.Headers.TryGetValue(CorrelationHeaderName, out var headerValue) &&
+        !StringValues.IsNullOrEmpty(headerValue))
+    {
+        return headerValue.ToString();
+    }
+
+    return context.TraceIdentifier;
+}

tests/Furniture.Bff.Application.UnitTests/Furniture.Bff.Application.UnitTests.csproj

@@ -7,6 +7,7 @@
   </PropertyGroup>
   <ItemGroup>
     <PackageReference Include="coverlet.collector" Version="6.0.4" />
+    <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="10.0.0" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.14.1" />
     <PackageReference Include="xunit" Version="2.9.3" />
     <PackageReference Include="xunit.runner.visualstudio" Version="3.1.4" />

tests/Furniture.Bff.Application.UnitTests/RuntimeWiringTests.cs

@@ -0,0 +1,62 @@
+using Furniture.Bff.Application.Adapters;
+using Furniture.Bff.Application.DependencyInjection;
+using Furniture.Bff.Application.Grpc;
+using Furniture.Bff.Application.Handlers;
+using Furniture.Bff.Contracts.Api;
+using Furniture.Service.Contracts.UseCases;
+using Microsoft.Extensions.DependencyInjection;
+
+namespace Furniture.Bff.Application.UnitTests;
+
+public class RuntimeWiringTests
+{
+    [Fact]
+    public async Task AddFurnitureBffApplicationRuntime_WhenResolved_WiresHandler()
+    {
+        var services = new ServiceCollection();
+        services.AddFurnitureBffApplicationRuntime();
+        services.AddSingleton<IFurnitureServiceClient, FakeFurnitureServiceClient>();
+
+        using var provider = services.BuildServiceProvider();
+        var handler = provider.GetRequiredService<IGetFurnitureAvailabilityHandler>();
+
+        var response = await handler.HandleAsync(new GetFurnitureAvailabilityApiRequest("FUR-001", "corr-123"));
+
+        Assert.Equal("FUR-001", response.FurnitureId);
+        Assert.Equal("Chair", response.DisplayName);
+        Assert.Equal(7, response.QuantityAvailable);
+    }
+
+    [Fact]
+    public void FurnitureAvailabilityEdgeGrpcContractAdapter_WhenMapped_PreservesValues()
+    {
+        var adapter = new FurnitureAvailabilityEdgeGrpcContractAdapter();
+        var request = new GetFurnitureAvailabilityApiRequest("FUR-002", "corr-456");
+
+        var grpcContract = adapter.ToGrpc(request);
+        var roundtrip = adapter.FromGrpc(grpcContract);
+
+        Assert.Equal("FUR-002", roundtrip.FurnitureId);
+        Assert.Equal("corr-456", roundtrip.CorrelationId);
+    }
+
+    [Fact]
+    public void FurnitureAvailabilityEdgeGrpcContractAdapter_WhenCorrelationMissing_GeneratesCorrelation()
+    {
+        var adapter = new FurnitureAvailabilityEdgeGrpcContractAdapter();
+        var grpcContract = new GetFurnitureAvailabilityEdgeGrpcContract("FUR-003", string.Empty);
+
+        var mapped = adapter.FromGrpc(grpcContract);
+
+        Assert.Equal("FUR-003", mapped.FurnitureId);
+        Assert.NotEmpty(mapped.CorrelationId);
+    }
+
+    private sealed class FakeFurnitureServiceClient : IFurnitureServiceClient
+    {
+        public Task<GetFurnitureAvailabilityResponse> GetAvailabilityAsync(GetFurnitureAvailabilityRequest request)
+        {
+            return Task.FromResult(new GetFurnitureAvailabilityResponse(request.FurnitureId, "Chair", 7));
+        }
+    }
+}