//The below code is untested - it was modified from working, but non-public code.


// testServer represents an actual running grpc server
type testServer struct {
	address  string
	listener net.Listener
	server   *grpc.Server
}

func newTestServer(t *testing.T) *testServer {
	//go command to generate a cert and key; see https://golang.org/src/crypto/tls/generate_cert.go
	// creates `cert.pem and key.pem`
	goroot := os.Getenv("GOROOT")
	out, err := exec.Command("go", "run", fmt.Sprintf("%s/src/crypto/tls/generate_cert.go", goroot),
		"--rsa-bits", "1024", "--host", "127.0.0.1,::1,localhost", "--ca", "--start-date", `Jan 1 00:00:00 1970`, "--duration=1000000h").CombinedOutput()

	if err != nil {
		fmt.Printf("%s: %s\n", string(out), err.Error())
    t.Fatalf("error creating certs: %s", err)
	}

	creds, err := credentials.NewServerTLSFromFile("cert.pem", "key.pem")
	if err != nil {
		logger.Fatal("Failed to generate credentials", zap.Error(err))
	}

	lis, err := net.Listen("tcp", "localhost:0")
	if err != nil {
		t.Fatalf("failed to create listener: %v", err)
	}
	ts := testServer{}

	ts.address = lis.Addr().String()
	ts.listener = lis
	ts.server = grpc.NewServer(grpc.Creds(creds))

	return &ts
}

func (ts *testServer) startRouteGuideServer(rgs routeguide.RouteGuideServer) error {

	routeguide.RegisterRouteGuideServer(ts.server, rgs)
	return ts.server.Serve(ts.listener)
}

func (ts *testServer) gracefulShutdown() {
	os.Remove("cert.pem")
	os.Remove("key.pem")
	ts.server.GracefulStop()
}

func TestFeature(t *testing.T) {
	mockedRouteGuide := &RouteGuideServerMock{
		GetFeatureFunc: func(in1 context.Context, in2 *routeguide.Point) (*routeguide.Feature, error) {
      return &routeguide.Feature{Name: "ExpectedFeatureName"}, nil
		},
	}

	ts := newTestServer(t)
	go ts.startRouteGuideServer(mockedRouteGuide)
	defer ts.gracefulShutdown()
	fmt.Printf("started route guide server on %s\n", ts.address)
	time.Sleep(time.Second * 1)
  
  transportCreds, err := credentials.NewClientTLSFromFile("cert.pem", ""); 
  if err != nil {
			logger.Fatal("failed load CA Cert file to run TLS in local mode")
  }
  
  opts := []grpc.DialOption {grpc.WithTransportCredentials(transportCreds)}
  
  conn, err := grpc.Dial(ts.address, opts...)
  if err != nil {
    t.Failf("couldn't connect to routeguide server at %s - %s" ts.address, err)
  }
  defer conn.Close()

  client := NewRouteGuideClient(conn)
  
  feature, err := client.GetFeature(context.Background(), &routeguide.Point{Latitude:0 , Longitude:0})
  if err != nil {
    t.Failf("unexpected error calling routeguide")
  }
  
  if feature.Name != "ExpectedFeatureName" {
    t.Failf("expected %s, got %s", "ExpectedFeatureName", feature.Name)
  }
}