// Serve accepts incoming connections on the listener lis, creating a new
// ServerTransport and service goroutine for each. The service goroutines
// read gRPC request and then call the registered handlers to reply to them.
// Service returns when lis.Accept fails.
func (s *Server) Serve(lis net.Listener) error {
	s.mu.Lock()
	if s.lis == nil {
		s.mu.Unlock()
		return ErrServerStopped
	}
	s.lis[lis] = true
	s.mu.Unlock()
	defer func() {
		lis.Close()
		s.mu.Lock()
		delete(s.lis, lis)
		s.mu.Unlock()
	}()
	for {
		c, err := lis.Accept()
		if err != nil {
			return err
		}
		if creds, ok := s.opts.creds.(credentials.TransportAuthenticator); ok {
			c, err = creds.ServerHandshake(c)
			if err != nil {
				grpclog.Println("grpc: Server.Serve failed to complete security handshake.")
				continue
			}
		}
		s.mu.Lock()
		if s.conns == nil {
			s.mu.Unlock()
			c.Close()
			return nil
		}
		st, err := transport.NewServerTransport("http2", c, s.opts.maxConcurrentStreams)
		if err != nil {
			s.mu.Unlock()
			c.Close()
			grpclog.Println("grpc: Server.Serve failed to create ServerTransport: ", err)
			continue
		}
		s.conns[st] = true
		s.mu.Unlock()

		go func() {
			st.HandleStreams(func(stream *transport.Stream) {
				s.handleStream(st, stream)
			})
			s.mu.Lock()
			delete(s.conns, st)
			s.mu.Unlock()
		}()
	}
}

// DoPerRPCCreds performs a unary RPC with per RPC OAUTH2 token.
func DoPerRPCCreds(tc testpb.TestServiceClient, serviceAccountKeyFile, oauthScope string) {
	jsonKey := getServiceAccountJSONKey(serviceAccountKeyFile)
	pl := clientNewPayload(testpb.PayloadType_COMPRESSABLE, largeReqSize)
	req := &testpb.SimpleRequest{
		ResponseType:   testpb.PayloadType_COMPRESSABLE.Enum(),
		ResponseSize:   proto.Int32(int32(largeRespSize)),
		Payload:        pl,
		FillUsername:   proto.Bool(true),
		FillOauthScope: proto.Bool(true),
	}
	token := GetToken(serviceAccountKeyFile, oauthScope)
	kv := map[string]string{"authorization": token.TokenType + " " + token.AccessToken}
	ctx := metadata.NewContext(context.Background(), metadata.MD{"authorization": []string{kv["authorization"]}})
	reply, err := tc.UnaryCall(ctx, req)
	if err != nil {
		grpclog.Fatal("/TestService/UnaryCall RPC failed: ", err)
	}
	user := reply.GetUsername()
	scope := reply.GetOauthScope()
	if !strings.Contains(string(jsonKey), user) {
		grpclog.Fatalf("Got user name %q which is NOT a substring of %q.", user, jsonKey)
	}
	if !strings.Contains(oauthScope, scope) {
		grpclog.Fatalf("Got OAuth scope %q which is NOT a substring of %q.", scope, oauthScope)
	}
	grpclog.Println("PerRPCCreds done")
}

// DoCancelAfterFirstResponse cancels the RPC after receiving the first message from the server.
func DoCancelAfterFirstResponse(tc testpb.TestServiceClient) {
	ctx, cancel := context.WithCancel(context.Background())
	stream, err := tc.FullDuplexCall(ctx)
	if err != nil {
		grpclog.Fatalf("%v.FullDuplexCall(_) = _, %v", tc, err)
	}
	respParam := []*testpb.ResponseParameters{
		{
			Size: proto.Int32(31415),
		},
	}
	pl := clientNewPayload(testpb.PayloadType_COMPRESSABLE, 27182)
	req := &testpb.StreamingOutputCallRequest{
		ResponseType:       testpb.PayloadType_COMPRESSABLE.Enum(),
		ResponseParameters: respParam,
		Payload:            pl,
	}
	if err := stream.Send(req); err != nil {
		grpclog.Fatalf("%v.Send(%v) = %v", stream, req, err)
	}
	if _, err := stream.Recv(); err != nil {
		grpclog.Fatalf("%v.Recv() = %v", stream, err)
	}
	cancel()
	if _, err := stream.Recv(); grpc.Code(err) != codes.Canceled {
		grpclog.Fatalf("%v compleled with error code %d, want %d", stream, grpc.Code(err), codes.Canceled)
	}
	grpclog.Println("CancelAfterFirstResponse done")
}

// DoClientStreaming performs a client streaming RPC.
func DoClientStreaming(tc testpb.TestServiceClient) {
	stream, err := tc.StreamingInputCall(context.Background())
	if err != nil {
		grpclog.Fatalf("%v.StreamingInputCall(_) = _, %v", tc, err)
	}
	var sum int
	for _, s := range reqSizes {
		pl := clientNewPayload(testpb.PayloadType_COMPRESSABLE, s)
		req := &testpb.StreamingInputCallRequest{
			Payload: pl,
		}
		if err := stream.Send(req); err != nil {
			grpclog.Fatalf("%v.Send(%v) = %v", stream, req, err)
		}
		sum += s
		grpclog.Printf("Sent a request of size %d, aggregated size %d", s, sum)

	}
	reply, err := stream.CloseAndRecv()
	if err != nil {
		grpclog.Fatalf("%v.CloseAndRecv() got error %v, want %v", stream, err, nil)
	}
	if reply.GetAggregatedPayloadSize() != int32(sum) {
		grpclog.Fatalf("%v.CloseAndRecv().GetAggregatePayloadSize() = %v; want %v", stream, reply.GetAggregatedPayloadSize(), sum)
	}
	grpclog.Println("ClientStreaming done")
}

// printFeature gets the feature for the given point.
func printFeature(client pb.RouteGuideClient, point *pb.Point) {
	grpclog.Printf("Getting feature for point (%d, %d)", point.Latitude, point.Longitude)
	feature, err := client.GetFeature(context.Background(), point)
	if err != nil {
		grpclog.Fatalf("%v.GetFeatures(_) = _, %v: ", client, err)
	}
	grpclog.Println(feature)
}

func main() {
	flag.Parse()
	go func() {
		lis, err := net.Listen("tcp", ":0")
		if err != nil {
			grpclog.Fatalf("Failed to listen: %v", err)
		}
		grpclog.Println("Server profiling address: ", lis.Addr().String())
		if err := http.Serve(lis, nil); err != nil {
			grpclog.Fatalf("Failed to serve: %v", err)
		}
	}()
	addr, stopper := benchmark.StartServer(":0") // listen on all interfaces
	grpclog.Println("Server Address: ", addr)
	<-time.After(time.Duration(*duration) * time.Second)
	stopper()
}

// DoEmptyUnaryCall performs a unary RPC with empty request and response messages.
func DoEmptyUnaryCall(tc testpb.TestServiceClient) {
	reply, err := tc.EmptyCall(context.Background(), &testpb.Empty{})
	if err != nil {
		grpclog.Fatal("/TestService/EmptyCall RPC failed: ", err)
	}
	if !proto.Equal(&testpb.Empty{}, reply) {
		grpclog.Fatalf("/TestService/EmptyCall receives %v, want %v", reply, testpb.Empty{})
	}
	grpclog.Println("EmptyUnaryCall done")
}

// DoEmptyStream sets up a bi-directional streaming with zero message.
func DoEmptyStream(tc testpb.TestServiceClient) {
	stream, err := tc.FullDuplexCall(context.Background())
	if err != nil {
		grpclog.Fatalf("%v.FullDuplexCall(_) = _, %v", tc, err)
	}
	if err := stream.CloseSend(); err != nil {
		grpclog.Fatalf("%v.CloseSend() got %v, want %v", stream, err, nil)
	}
	if _, err := stream.Recv(); err != io.EOF {
		grpclog.Fatalf("%v failed to complete the empty stream test: %v", stream, err)
	}
	grpclog.Println("Emptystream done")
}

// DoCancelAfterBegin cancels the RPC after metadata has been sent but before payloads are sent.
func DoCancelAfterBegin(tc testpb.TestServiceClient) {
	ctx, cancel := context.WithCancel(metadata.NewContext(context.Background(), testMetadata))
	stream, err := tc.StreamingInputCall(ctx)
	if err != nil {
		grpclog.Fatalf("%v.StreamingInputCall(_) = _, %v", tc, err)
	}
	cancel()
	_, err = stream.CloseAndRecv()
	if grpc.Code(err) != codes.Canceled {
		grpclog.Fatalf("%v.CloseAndRecv() got error code %d, want %d", stream, grpc.Code(err), codes.Canceled)
	}
	grpclog.Println("CancelAfterBegin done")
}

// DoTimeoutOnSleepingServer performs an RPC on a sleep server which causes RPC timeout.
func DoTimeoutOnSleepingServer(tc testpb.TestServiceClient) {
	ctx, _ := context.WithTimeout(context.Background(), 1*time.Millisecond)
	stream, err := tc.FullDuplexCall(ctx)
	if err != nil {
		if grpc.Code(err) == codes.DeadlineExceeded {
			grpclog.Println("TimeoutOnSleepingServer done")
			return
		}
		grpclog.Fatalf("%v.FullDuplexCall(_) = _, %v", tc, err)
	}
	pl := clientNewPayload(testpb.PayloadType_COMPRESSABLE, 27182)
	req := &testpb.StreamingOutputCallRequest{
		ResponseType: testpb.PayloadType_COMPRESSABLE.Enum(),
		Payload:      pl,
	}
	if err := stream.Send(req); err != nil {
		grpclog.Fatalf("%v.Send(%v) = %v", stream, req, err)
	}
	if _, err := stream.Recv(); grpc.Code(err) != codes.DeadlineExceeded {
		grpclog.Fatalf("%v.Recv() = _, %v, want error code %d", stream, err, codes.DeadlineExceeded)
	}
	grpclog.Println("TimeoutOnSleepingServer done")
}

func main() {
	flag.Parse()
	go func() {
		lis, err := net.Listen("tcp", ":0")
		if err != nil {
			grpclog.Fatalf("Failed to listen: %v", err)
		}
		grpclog.Println("Client profiling address: ", lis.Addr().String())
		if err := http.Serve(lis, nil); err != nil {
			grpclog.Fatalf("Failed to serve: %v", err)
		}
	}()
	closeLoop()
}

func closeLoopStream() {
	s, conn, tc := buildConnection()
	ch := make(chan int, *maxConcurrentRPCs*4)
	var (
		mu sync.Mutex
		wg sync.WaitGroup
	)
	wg.Add(*maxConcurrentRPCs)
	// Distribute RPCs over maxConcurrentCalls workers.
	for i := 0; i < *maxConcurrentRPCs; i++ {
		go func() {
			stream, err := tc.StreamingCall(context.Background())
			if err != nil {
				grpclog.Fatalf("%v.StreamingCall(_) = _, %v", tc, err)
			}
			// Do some warm up.
			for i := 0; i < 100; i++ {
				streamCaller(tc, stream)
			}
			for range ch {
				start := time.Now()
				streamCaller(tc, stream)
				elapse := time.Since(start)
				mu.Lock()
				s.Add(elapse)
				mu.Unlock()
			}
			wg.Done()
		}()
	}
	// Stop the client when time is up.
	done := make(chan struct{})
	go func() {
		<-time.After(time.Duration(*duration) * time.Second)
		close(done)
	}()
	ok := true
	for ok {
		select {
		case ch <- 0:
		case <-done:
			ok = false
		}
	}
	close(ch)
	wg.Wait()
	conn.Close()
	grpclog.Println(s.String())
}

// serveNewHTTP2Transport sets up a new http/2 transport (using the
// gRPC http2 server transport in transport/http2_server.go) and
// serves streams on it.
// This is run in its own goroutine (it does network I/O in
// transport.NewServerTransport).
func (s *Server) serveNewHTTP2Transport(c net.Conn, authInfo credentials.AuthInfo) {
	st, err := transport.NewServerTransport("http2", c, s.opts.maxConcurrentStreams, authInfo)
	if err != nil {
		s.mu.Lock()
		s.errorf("NewServerTransport(%q) failed: %v", c.RemoteAddr(), err)
		s.mu.Unlock()
		c.Close()
		grpclog.Println("grpc: Server.Serve failed to create ServerTransport: ", err)
		return
	}
	if !s.addConn(st) {
		st.Close()
		return
	}
	s.serveStreams(st)
}

func closeLoop() {
	s := stats.NewStats(256)
	conn := benchmark.NewClientConn(*server)
	tc := testpb.NewTestServiceClient(conn)
	// Warm up connection.
	for i := 0; i < 100; i++ {
		caller(tc)
	}
	ch := make(chan int, *maxConcurrentRPCs*4)
	var (
		mu sync.Mutex
		wg sync.WaitGroup
	)
	wg.Add(*maxConcurrentRPCs)
	// Distribute RPCs over maxConcurrentCalls workers.
	for i := 0; i < *maxConcurrentRPCs; i++ {
		go func() {
			for _ = range ch {
				start := time.Now()
				caller(tc)
				elapse := time.Since(start)
				mu.Lock()
				s.Add(elapse)
				mu.Unlock()
			}
			wg.Done()
		}()
	}
	// Stop the client when time is up.
	done := make(chan struct{})
	go func() {
		<-time.After(time.Duration(*duration) * time.Second)
		close(done)
	}()
	ok := true
	for ok {
		select {
		case ch <- 0:
		case <-done:
			ok = false
		}
	}
	close(ch)
	wg.Wait()
	conn.Close()
	grpclog.Println(s.String())
}

// printFeatures lists all the features within the given bounding Rectangle.
func printFeatures(client pb.RouteGuideClient, rect *pb.Rectangle) {
	grpclog.Printf("Looking for features within %v", rect)
	stream, err := client.ListFeatures(context.Background(), rect)
	if err != nil {
		grpclog.Fatalf("%v.ListFeatures(_) = _, %v", client, err)
	}
	for {
		feature, err := stream.Recv()
		if err == io.EOF {
			break
		}
		if err != nil {
			grpclog.Fatalf("%v.ListFeatures(_) = _, %v", client, err)
		}
		grpclog.Println(feature)
	}
}

func closeLoopUnary() {
	s, conn, tc := buildConnection()

	for i := 0; i < 100; i++ {
		unaryCaller(tc)
	}
	ch := make(chan int, *maxConcurrentRPCs*4)
	var (
		mu sync.Mutex
		wg sync.WaitGroup
	)
	wg.Add(*maxConcurrentRPCs)

	for i := 0; i < *maxConcurrentRPCs; i++ {
		go func() {
			for _ = range ch {
				start := time.Now()
				unaryCaller(tc)
				elapse := time.Since(start)
				mu.Lock()
				s.Add(elapse)
				mu.Unlock()
			}
			wg.Done()
		}()
	}
	// Stop the client when time is up.
	done := make(chan struct{})
	go func() {
		<-time.After(time.Duration(*duration) * time.Second)
		close(done)
	}()
	ok := true
	for ok {
		select {
		case ch <- 0:
		case <-done:
			ok = false
		}
	}
	close(ch)
	wg.Wait()
	conn.Close()
	grpclog.Println(s.String())

}

// DoLargeUnaryCall performs a unary RPC with large payload in the request and response.
func DoLargeUnaryCall(tc testpb.TestServiceClient) {
	pl := clientNewPayload(testpb.PayloadType_COMPRESSABLE, largeReqSize)
	req := &testpb.SimpleRequest{
		ResponseType: testpb.PayloadType_COMPRESSABLE.Enum(),
		ResponseSize: proto.Int32(int32(largeRespSize)),
		Payload:      pl,
	}
	reply, err := tc.UnaryCall(context.Background(), req)
	if err != nil {
		grpclog.Fatal("/TestService/UnaryCall RPC failed: ", err)
	}
	t := reply.GetPayload().GetType()
	s := len(reply.GetPayload().GetBody())
	if t != testpb.PayloadType_COMPRESSABLE || s != largeRespSize {
		grpclog.Fatalf("Got the reply with type %d len %d; want %d, %d", t, s, testpb.PayloadType_COMPRESSABLE, largeRespSize)
	}
	grpclog.Println("LargeUnaryCall done")
}

func (t *http2Client) handleRSTStream(f *http2.RSTStreamFrame) {
	s, ok := t.getStream(f)
	if !ok {
		return
	}
	s.mu.Lock()
	if s.state == streamDone {
		s.mu.Unlock()
		return
	}
	s.state = streamDone
	s.statusCode, ok = http2RSTErrConvTab[http2.ErrCode(f.ErrCode)]
	if !ok {
		grpclog.Println("transport: http2Client.handleRSTStream found no mapped gRPC status for the received http2 error ", f.ErrCode)
	}
	s.mu.Unlock()
	s.write(recvMsg{err: io.EOF})
}

// processUpdates calls Watcher.Next() once and processes the obtained updates.
func (p *unicastNamingPicker) processUpdates() error {
	updates, err := p.watcher.Next()
	if err != nil {
		return err
	}
	for _, update := range updates {
		switch update.Op {
		case naming.Add:
			p.mu.Lock()
			p.addrs.PushBack(&addrInfo{
				addr: update.Addr,
			})
			p.mu.Unlock()
			// Initial connection setup
			if p.conn == nil {
				conn, err := NewConn(p.cc)
				if err != nil {
					return err
				}
				p.conn = conn
			}
		case naming.Delete:
			p.mu.Lock()
			for e := p.addrs.Front(); e != nil; e = e.Next() {
				if update.Addr == e.Value.(*addrInfo).addr {
					if e == p.pickedAddr {
						// Do not remove the element now if it is the current picked
						// one. We leave the deletion to the next PickAddr() call.
						e.Value.(*addrInfo).deleting = true
						// Notify Conn to close it. All the live RPCs on this connection
						// will be aborted.
						p.conn.NotifyReset()
					} else {
						p.addrs.Remove(e)
					}
				}
			}
			p.mu.Unlock()
		default:
			grpclog.Println("Unknown update.Op ", update.Op)
		}
	}
	return nil
}

// DoPingPong performs ping-pong style bi-directional streaming RPC.
func DoPingPong(tc testpb.TestServiceClient) {
	stream, err := tc.FullDuplexCall(context.Background())
	if err != nil {
		grpclog.Fatalf("%v.FullDuplexCall(_) = _, %v", tc, err)
	}
	var index int
	for index < len(reqSizes) {
		respParam := []*testpb.ResponseParameters{
			{
				Size: proto.Int32(int32(respSizes[index])),
			},
		}
		pl := clientNewPayload(testpb.PayloadType_COMPRESSABLE, reqSizes[index])
		req := &testpb.StreamingOutputCallRequest{
			ResponseType:       testpb.PayloadType_COMPRESSABLE.Enum(),
			ResponseParameters: respParam,
			Payload:            pl,
		}
		if err := stream.Send(req); err != nil {
			grpclog.Fatalf("%v.Send(%v) = %v", stream, req, err)
		}
		reply, err := stream.Recv()
		if err != nil {
			grpclog.Fatalf("%v.Recv() = %v", stream, err)
		}
		t := reply.GetPayload().GetType()
		if t != testpb.PayloadType_COMPRESSABLE {
			grpclog.Fatalf("Got the reply of type %d, want %d", t, testpb.PayloadType_COMPRESSABLE)
		}
		size := len(reply.GetPayload().GetBody())
		if size != int(respSizes[index]) {
			grpclog.Fatalf("Got reply body of length %d, want %d", size, respSizes[index])
		}
		index++
	}
	if err := stream.CloseSend(); err != nil {
		grpclog.Fatalf("%v.CloseSend() got %v, want %v", stream, err, nil)
	}
	if _, err := stream.Recv(); err != io.EOF {
		grpclog.Fatalf("%v failed to complele the ping pong test: %v", stream, err)
	}
	grpclog.Println("Pingpong done")
}