From 0635d2c2cab68ca4c0f2dd5883f142edd5bb856a Mon Sep 17 00:00:00 2001
From: Asim Aslam <asim@aslam.me>
Date: Sat, 8 Jun 2019 19:40:44 +0100
Subject: [PATCH] check in this cruft

---
 grpc.go     | 66 ++++++++++++++++++++++++++++++++++++++++++-----------
 response.go | 35 ++++++++++++++++++++++++++++
 2 files changed, 88 insertions(+), 13 deletions(-)
 create mode 100644 response.go

diff --git a/grpc.go b/grpc.go
index 74a2745..bde2e4c 100644
--- a/grpc.go
+++ b/grpc.go
@@ -81,6 +81,14 @@ func newGRPCServer(opts ...server.Option) server.Server {
 	return srv
 }
 
+type grpcRouter struct {
+	h func(context.Context, server.Request, interface{}) error
+}
+
+func (r grpcRouter) ServeRequest(ctx context.Context, req server.Request, rsp server.Response) error {
+	return r.h(ctx, req, rsp)
+}
+
 func (g *grpcServer) configure(opts ...server.Option) {
 	// Don't reprocess where there's no config
 	if len(opts) == 0 && g.srv != nil {
@@ -167,19 +175,6 @@ func (g *grpcServer) handler(srv interface{}, stream grpc.ServerStream) error {
 		return status.New(codes.InvalidArgument, err.Error()).Err()
 	}
 
-	g.rpc.mu.Lock()
-	service := g.rpc.serviceMap[serviceName]
-	g.rpc.mu.Unlock()
-
-	if service == nil {
-		return status.New(codes.Unimplemented, fmt.Sprintf("unknown service %v", service)).Err()
-	}
-
-	mtype := service.method[methodName]
-	if mtype == nil {
-		return status.New(codes.Unimplemented, fmt.Sprintf("unknown service %v", service)).Err()
-	}
-
 	// get grpc metadata
 	gmd, ok := metadata.FromIncomingContext(stream.Context())
 	if !ok {
@@ -214,6 +209,51 @@ func (g *grpcServer) handler(srv interface{}, stream grpc.ServerStream) error {
 		}
 	}
 
+	// process via router
+	if g.opts.Router != nil {
+		// create a client.Request
+		request := &rpcRequest{
+			service:     g.opts.Name,
+			contentType: ct,
+			method:      fmt.Sprintf("%s.%s", serviceName, methodName),
+		}
+
+		response := &rpcResponse{}
+
+		// create a wrapped function
+		handler := func(ctx context.Context, req server.Request, rsp interface{}) error {
+			return g.opts.Router.ServeRequest(ctx, req, rsp.(server.Response))
+		}
+
+		// execute the wrapper for it
+		for i := len(g.opts.HdlrWrappers); i > 0; i-- {
+			handler = g.opts.HdlrWrappers[i-1](handler)
+		}
+
+		r := grpcRouter{handler}
+
+		// serve the actual request using the request router
+		if err := r.ServeRequest(ctx, request, response); err != nil {
+			return status.Errorf(codes.Internal, err.Error())
+		}
+
+		return nil
+	}
+
+	// process the standard request flow
+	g.rpc.mu.Lock()
+	service := g.rpc.serviceMap[serviceName]
+	g.rpc.mu.Unlock()
+
+	if service == nil {
+		return status.New(codes.Unimplemented, fmt.Sprintf("unknown service %v", service)).Err()
+	}
+
+	mtype := service.method[methodName]
+	if mtype == nil {
+		return status.New(codes.Unimplemented, fmt.Sprintf("unknown service %v", service)).Err()
+	}
+
 	// process unary
 	if !mtype.stream {
 		return g.processRequest(stream, service, mtype, ct, ctx)
diff --git a/response.go b/response.go
new file mode 100644
index 0000000..451b1f4
--- /dev/null
+++ b/response.go
@@ -0,0 +1,35 @@
+package grpc
+
+import (
+	"net/http"
+
+	"github.com/micro/go-micro/codec"
+	"github.com/micro/go-micro/transport"
+)
+
+type rpcResponse struct {
+	header map[string]string
+	socket transport.Socket
+	codec  codec.Codec
+}
+
+func (r *rpcResponse) Codec() codec.Writer {
+	return r.codec
+}
+
+func (r *rpcResponse) WriteHeader(hdr map[string]string) {
+	for k, v := range hdr {
+		r.header[k] = v
+	}
+}
+
+func (r *rpcResponse) Write(b []byte) error {
+	if _, ok := r.header["Content-Type"]; !ok {
+		r.header["Content-Type"] = http.DetectContentType(b)
+	}
+
+	return r.socket.Send(&transport.Message{
+		Header: r.header,
+		Body:   b,
+	})
+}