feat(furniture-bff): integrate service contract edge adapters

docs/api/external-api-surface.md

@@ -11,5 +11,6 @@
 ## Edge Responsibilities
 
 - Validate and normalize consumer request inputs.
-- Map downstream service responses to consumer-facing shapes.
+- Map edge requests to furniture-service transport-neutral contracts.
+- Map downstream furniture-service responses to consumer-facing shapes.
 - Map downstream errors to consistent API error models.

docs/architecture/protocol-adaptation.puml

@@ -5,9 +5,14 @@ package "furniture-bff" {
   class Program
   interface IGetFurnitureAvailabilityHandler
   class GetFurnitureAvailabilityHandler
+  interface IFurnitureAvailabilityEdgeContractAdapter
+  interface IFurnitureAvailabilityEdgeGrpcContractAdapter
+  class GetFurnitureAvailabilityEdgeGrpcContract
   interface IFurnitureServiceClient
 
   GetFurnitureAvailabilityHandler ..|> IGetFurnitureAvailabilityHandler
+  GetFurnitureAvailabilityHandler --> IFurnitureAvailabilityEdgeContractAdapter
+  IFurnitureAvailabilityEdgeGrpcContractAdapter --> GetFurnitureAvailabilityEdgeGrpcContract
   GetFurnitureAvailabilityHandler --> IFurnitureServiceClient
 }
 
@@ -16,5 +21,5 @@ package "furniture-service" as FurnitureService
 
 Consumers --> Program : REST
 Program --> IGetFurnitureAvailabilityHandler
-IFurnitureServiceClient ..> FurnitureService : gRPC/internal
+IFurnitureServiceClient ..> FurnitureService : service contracts
 @enduml

docs/operations/tracing-and-headers.md

@@ -9,6 +9,7 @@
 
 - Preserve correlation headers to downstream service calls.
 - Add correlation headers if missing at the edge.
+- Populate furniture-service request contracts with correlation identifiers.
 
 ## Observability Baseline
 

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

@@ -0,0 +1,24 @@
+using Furniture.Bff.Contracts.Api;
+using Furniture.Service.Contracts.UseCases;
+
+namespace Furniture.Bff.Application.Adapters;
+
+/// <summary>
+/// Defines adapter boundary between furniture BFF edge contracts and furniture service contracts.
+/// </summary>
+public interface IFurnitureAvailabilityEdgeContractAdapter
+{
+    /// <summary>
+    /// Maps edge API request into furniture service request contract.
+    /// </summary>
+    /// <param name="request">Edge API request.</param>
+    /// <returns>Furniture service request contract.</returns>
+    GetFurnitureAvailabilityRequest ToServiceRequest(GetFurnitureAvailabilityApiRequest request);
+
+    /// <summary>
+    /// Maps furniture service response contract into edge API response.
+    /// </summary>
+    /// <param name="response">Furniture service response contract.</param>
+    /// <returns>Edge API response.</returns>
+    GetFurnitureAvailabilityApiResponse ToApiResponse(GetFurnitureAvailabilityResponse response);
+}

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

@@ -0,0 +1,24 @@
+using Furniture.Bff.Application.Grpc;
+using Furniture.Bff.Contracts.Api;
+
+namespace Furniture.Bff.Application.Adapters;
+
+/// <summary>
+/// Defines adapter boundary for gRPC translation at the furniture edge.
+/// </summary>
+public interface IFurnitureAvailabilityEdgeGrpcContractAdapter
+{
+    /// <summary>
+    /// Maps edge API request into gRPC contract shape.
+    /// </summary>
+    /// <param name="request">Edge API request.</param>
+    /// <returns>gRPC request contract shape.</returns>
+    GetFurnitureAvailabilityEdgeGrpcContract ToGrpc(GetFurnitureAvailabilityApiRequest request);
+
+    /// <summary>
+    /// Maps gRPC request contract shape back into edge API request.
+    /// </summary>
+    /// <param name="contract">gRPC request contract shape.</param>
+    /// <returns>Edge API request.</returns>
+    GetFurnitureAvailabilityApiRequest FromGrpc(GetFurnitureAvailabilityEdgeGrpcContract contract);
+}

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

@@ -1,4 +1,4 @@
-using Furniture.Bff.Contracts.Api;
+using Furniture.Service.Contracts.UseCases;
 
 namespace Furniture.Bff.Application.Adapters;
 
@@ -10,7 +10,7 @@ public interface IFurnitureServiceClient
     /// <summary>
     /// Retrieves furniture availability from downstream service.
     /// </summary>
-    /// <param name="furnitureId">Furniture identifier.</param>
+    /// <param name="request">Service-layer availability request contract.</param>
-    /// <returns>Consumer-ready availability contract.</returns>
+    /// <returns>Service-layer availability response contract.</returns>
-    Task<GetFurnitureAvailabilityApiResponse> GetAvailabilityAsync(string furnitureId);
+    Task<GetFurnitureAvailabilityResponse> GetAvailabilityAsync(GetFurnitureAvailabilityRequest request);
 }

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

@@ -6,5 +6,6 @@
   </PropertyGroup>
   <ItemGroup>
     <ProjectReference Include="..\Furniture.Bff.Contracts\Furniture.Bff.Contracts.csproj" />
+    <ProjectReference Include="..\..\..\furniture-service\src\Furniture.Service.Contracts\Furniture.Service.Contracts.csproj" />
   </ItemGroup>
 </Project>

src/Furniture.Bff.Application/Grpc/GetFurnitureAvailabilityEdgeGrpcContract.cs

@@ -0,0 +1,8 @@
+namespace Furniture.Bff.Application.Grpc;
+
+/// <summary>
+/// Defines minimal gRPC contract shape for furniture availability edge translation.
+/// </summary>
+/// <param name="FurnitureId">Furniture identifier provided by consumers.</param>
+/// <param name="CorrelationId">Request correlation identifier.</param>
+public sealed record GetFurnitureAvailabilityEdgeGrpcContract(string FurnitureId, string CorrelationId);

src/Furniture.Bff.Application/Handlers/GetFurnitureAvailabilityHandler.cs

@@ -6,12 +6,16 @@ namespace Furniture.Bff.Application.Handlers;
 /// <summary>
 /// Default edge handler implementation for furniture availability.
 /// </summary>
-public sealed class GetFurnitureAvailabilityHandler(IFurnitureServiceClient serviceClient)
+public sealed class GetFurnitureAvailabilityHandler(
+    IFurnitureServiceClient serviceClient,
+    IFurnitureAvailabilityEdgeContractAdapter contractAdapter)
     : IGetFurnitureAvailabilityHandler
 {
     /// <inheritdoc />
-    public Task<GetFurnitureAvailabilityApiResponse> HandleAsync(GetFurnitureAvailabilityApiRequest request)
+    public async Task<GetFurnitureAvailabilityApiResponse> HandleAsync(GetFurnitureAvailabilityApiRequest request)
     {
-        return serviceClient.GetAvailabilityAsync(request.FurnitureId);
+        var serviceRequest = contractAdapter.ToServiceRequest(request);
+        var serviceResponse = await serviceClient.GetAvailabilityAsync(serviceRequest);
+        return contractAdapter.ToApiResponse(serviceResponse);
     }
 }

src/Furniture.Bff.Contracts/Api/GetFurnitureAvailabilityApiRequest.cs

@@ -4,4 +4,5 @@ namespace Furniture.Bff.Contracts.Api;
 /// External REST request contract for furniture availability.
 /// </summary>
 /// <param name="FurnitureId">Furniture identifier provided by consumers.</param>
-public sealed record GetFurnitureAvailabilityApiRequest(string FurnitureId);
+/// <param name="CorrelationId">Cross-service correlation identifier.</param>
+public sealed record GetFurnitureAvailabilityApiRequest(string FurnitureId, string CorrelationId = "");

src/Furniture.Bff.Contracts/Api/GetFurnitureAvailabilityApiResponse.cs

@@ -4,5 +4,6 @@ namespace Furniture.Bff.Contracts.Api;
 /// External REST response contract for furniture availability.
 /// </summary>
 /// <param name="FurnitureId">Requested furniture identifier.</param>
+/// <param name="DisplayName">Display name to present to consumer clients.</param>
 /// <param name="QuantityAvailable">Availability value for client display.</param>
-public sealed record GetFurnitureAvailabilityApiResponse(string FurnitureId, int QuantityAvailable);
+public sealed record GetFurnitureAvailabilityApiResponse(string FurnitureId, string DisplayName, int QuantityAvailable);

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

@@ -0,0 +1,25 @@
+using Furniture.Bff.Contracts.Api;
+
+namespace Furniture.Bff.Application.UnitTests;
+
+public class ContractShapeTests
+{
+    [Fact]
+    public void GetFurnitureAvailabilityApiRequest_WhenCreated_StoresCorrelationId()
+    {
+        var request = new GetFurnitureAvailabilityApiRequest("FUR-001", "corr-123");
+
+        Assert.Equal("FUR-001", request.FurnitureId);
+        Assert.Equal("corr-123", request.CorrelationId);
+    }
+
+    [Fact]
+    public void GetFurnitureAvailabilityApiResponse_WhenCreated_StoresDisplayName()
+    {
+        var response = new GetFurnitureAvailabilityApiResponse("FUR-001", "Chair", 8);
+
+        Assert.Equal("FUR-001", response.FurnitureId);
+        Assert.Equal("Chair", response.DisplayName);
+        Assert.Equal(8, response.QuantityAvailable);
+    }
+}

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

@@ -1,6 +1,7 @@
 using Furniture.Bff.Application.Adapters;
 using Furniture.Bff.Application.Handlers;
 using Furniture.Bff.Contracts.Api;
+using Furniture.Service.Contracts.UseCases;
 
 namespace Furniture.Bff.Application.UnitTests;
 
@@ -9,19 +10,38 @@ public class GetFurnitureAvailabilityHandlerTests
     [Fact]
     public async Task HandleAsync_WhenCalled_DelegatesToServiceClient()
     {
-        var handler = new GetFurnitureAvailabilityHandler(new FakeFurnitureServiceClient());
+        var handler = new GetFurnitureAvailabilityHandler(
+            new FakeFurnitureServiceClient(),
+            new FakeFurnitureAvailabilityEdgeContractAdapter());
 
-        var response = await handler.HandleAsync(new GetFurnitureAvailabilityApiRequest("FUR-001"));
+        var response = await handler.HandleAsync(new GetFurnitureAvailabilityApiRequest("FUR-001", "corr-123"));
 
         Assert.Equal("FUR-001", response.FurnitureId);
+        Assert.Equal("Chair", response.DisplayName);
         Assert.Equal(3, response.QuantityAvailable);
     }
 
     private sealed class FakeFurnitureServiceClient : IFurnitureServiceClient
     {
-        public Task<GetFurnitureAvailabilityApiResponse> GetAvailabilityAsync(string furnitureId)
+        public Task<GetFurnitureAvailabilityResponse> GetAvailabilityAsync(GetFurnitureAvailabilityRequest request)
         {
-            return Task.FromResult(new GetFurnitureAvailabilityApiResponse(furnitureId, 3));
+            return Task.FromResult(new GetFurnitureAvailabilityResponse(request.FurnitureId, "Chair", 3));
+        }
+    }
+
+    private sealed class FakeFurnitureAvailabilityEdgeContractAdapter : IFurnitureAvailabilityEdgeContractAdapter
+    {
+        public GetFurnitureAvailabilityRequest ToServiceRequest(GetFurnitureAvailabilityApiRequest request)
+        {
+            return new GetFurnitureAvailabilityRequest(request.FurnitureId, request.CorrelationId);
+        }
+
+        public GetFurnitureAvailabilityApiResponse ToApiResponse(GetFurnitureAvailabilityResponse response)
+        {
+            return new GetFurnitureAvailabilityApiResponse(
+                response.FurnitureId,
+                response.DisplayName,
+                response.QuantityAvailable);
         }
     }
 }