func init() {
	if err := proto.SetExtension(realNumber, pb.E_Name, &realNumberName); err != nil {
		panic(err)
	}
	if err := proto.SetExtension(realNumber, pb.E_Complex_RealExtension, complexNumber); err != nil {
		panic(err)
	}
}

func newTestMessage() *pb.MyMessage {
	msg := &pb.MyMessage{
		Count: proto.Int32(42),
		Name:  proto.String("Dave"),
		Quote: proto.String(`"I didn't want to go."`),
		Pet:   []string{"bunny", "kitty", "horsey"},
		Inner: &pb.InnerMessage{
			Host:      proto.String("footrest.syd"),
			Port:      proto.Int32(7001),
			Connected: proto.Bool(true),
		},
		Others: []*pb.OtherMessage{
			{
				Key:   proto.Int64(0xdeadbeef),
				Value: []byte{1, 65, 7, 12},
			},
			{
				Weight: proto.Float32(6.022),
				Inner: &pb.InnerMessage{
					Host: proto.String("lesha.mtv"),
					Port: proto.Int32(8002),
				},
			},
		},
		Bikeshed: pb.MyMessage_BLUE.Enum(),
		Somegroup: &pb.MyMessage_SomeGroup{
			GroupField: proto.Int32(8),
		},
		// One normally wouldn't do this.
		// This is an undeclared tag 13, as a varint (wire type 0) with value 4.
		XXX_unrecognized: []byte{13<<3 | 0, 4},
	}
	ext := &pb.Ext{
		Data: proto.String("Big gobs for big rats"),
	}
	if err := proto.SetExtension(msg, pb.E_Ext_More, ext); err != nil {
		panic(err)
	}
	greetings := []string{"adg", "easy", "cow"}
	if err := proto.SetExtension(msg, pb.E_Greeting, greetings); err != nil {
		panic(err)
	}

	// Add an unknown extension. We marshal a pb.Ext, and fake the ID.
	b, err := proto.Marshal(&pb.Ext{Data: proto.String("3G skiing")})
	if err != nil {
		panic(err)
	}
	b = append(proto.EncodeVarint(201<<3|proto.WireBytes), b...)
	proto.SetRawExtension(msg, 201, b)

	// Extensions can be plain fields, too, so let's test that.
	b = append(proto.EncodeVarint(202<<3|proto.WireVarint), 19)
	proto.SetRawExtension(msg, 202, b)

	return msg
}

func TestNilExtension(t *testing.T) {
	msg := &pb.MyMessage{
		Count: proto.Int32(1),
	}
	if err := proto.SetExtension(msg, pb.E_Ext_Text, proto.String("hello")); err != nil {
		t.Fatal(err)
	}
	if err := proto.SetExtension(msg, pb.E_Ext_More, (*pb.Ext)(nil)); err == nil {
		t.Error("expected SetExtension to fail due to a nil extension")
	} else if want := "proto: SetExtension called with nil value of type *testdata.Ext"; err.Error() != want {
		t.Errorf("expected error %v, got %v", want, err)
	}
	// Note: if the behavior of Marshal is ever changed to ignore nil extensions, update
	// this test to verify that E_Ext_Text is properly propagated through marshal->unmarshal.
}

func newClientAuthHSChan(conn *ricochetConn) (err error) {
	ch := new(authHSChan)
	ch.conn = conn
	ch.chanID, err = conn.allocateNextChanID()
	if err != nil {
		return
	}

	ch.clientCookie = make([]byte, authHiddenServiceCookieSize)
	if _, err = rand.Read(ch.clientCookie); err != nil {
		return err
	}
	openChan := &packet.OpenChannel{
		ChannelIdentifier: proto.Int32((int32)(ch.chanID)),
		ChannelType:       proto.String(authHiddenServiceChannelType),
	}
	if err = proto.SetExtension(openChan, packet.E_ClientCookie, ch.clientCookie); err != nil {
		return
	}
	ctrlPkt := &packet.ControlPacket{OpenChannel: openChan}
	rawPkt, err := proto.Marshal(ctrlPkt)
	if err != nil {
		return err
	}
	err = conn.sendPacket(controlChanID, rawPkt)

	conn.Lock()
	defer conn.Unlock()
	conn.chanMap[ch.chanID] = ch
	conn.getControlChan().authChan = (int)(ch.chanID)

	return
}

func newClientContactReqChan(conn *ricochetConn, reqData *ContactRequest) (err error) {
	ch := new(contactReqChan)
	ch.conn = conn
	ch.chanID, err = conn.allocateNextChanID()
	if err != nil {
		return
	}

	req := &packet.ContactRequest{
		Nickname:    proto.String(reqData.MyNickname),
		MessageText: proto.String(reqData.Message),
	}
	openChan := &packet.OpenChannel{
		ChannelIdentifier: proto.Int32((int32)(ch.chanID)),
		ChannelType:       proto.String(contactReqChannelType),
	}
	if err = proto.SetExtension(openChan, packet.E_ContactRequest, req); err != nil {
		return
	}
	ctrlPkt := &packet.ControlPacket{OpenChannel: openChan}
	rawPkt, err := proto.Marshal(ctrlPkt)
	if err != nil {
		return err
	}
	err = ch.conn.sendPacket(controlChanID, rawPkt)

	conn.Lock()
	defer conn.Unlock()
	conn.chanMap[ch.chanID] = ch
	conn.getControlChan().contactReqChan = (int)(ch.chanID)

	return
}

func TestMarshalRace(t *testing.T) {
	// unregistered extension
	desc := &proto.ExtensionDesc{
		ExtendedType:  (*pb.MyMessage)(nil),
		ExtensionType: (*bool)(nil),
		Field:         101010100,
		Name:          "emptyextension",
		Tag:           "varint,0,opt",
	}

	m := &pb.MyMessage{Count: proto.Int32(4)}
	if err := proto.SetExtension(m, desc, proto.Bool(true)); err != nil {
		t.Errorf("proto.SetExtension(m, desc, true): got error %q, want nil", err)
	}

	var g errgroup.Group
	for n := 3; n > 0; n-- {
		g.Go(func() error {
			_, err := proto.Marshal(m)
			return err
		})
	}
	if err := g.Wait(); err != nil {
		t.Fatal(err)
	}
}

func TestGetExtensionStability(t *testing.T) {
	check := func(m *pb.MyMessage) bool {
		ext1, err := proto.GetExtension(m, pb.E_Ext_More)
		if err != nil {
			t.Fatalf("GetExtension() failed: %s", err)
		}
		ext2, err := proto.GetExtension(m, pb.E_Ext_More)
		if err != nil {
			t.Fatalf("GetExtension() failed: %s", err)
		}
		return ext1 == ext2
	}
	msg := &pb.MyMessage{Count: proto.Int32(4)}
	ext0 := &pb.Ext{}
	if err := proto.SetExtension(msg, pb.E_Ext_More, ext0); err != nil {
		t.Fatalf("Could not set ext1: %s", ext0)
	}
	if !check(msg) {
		t.Errorf("GetExtension() not stable before marshaling")
	}
	bb, err := proto.Marshal(msg)
	if err != nil {
		t.Fatalf("Marshal() failed: %s", err)
	}
	msg1 := &pb.MyMessage{}
	err = proto.Unmarshal(bb, msg1)
	if err != nil {
		t.Fatalf("Unmarshal() failed: %s", err)
	}
	if !check(msg1) {
		t.Errorf("GetExtension() not stable after unmarshaling")
	}
}

func init() {
	ext := &pb.Ext{
		Data: proto.String("extension"),
	}
	if err := proto.SetExtension(cloneTestMessage, pb.E_Ext_More, ext); err != nil {
		panic("SetExtension: " + err.Error())
	}
}

func TestExtensionsRoundTrip(t *testing.T) {
	msg := &pb.MyMessage{}
	ext1 := &pb.Ext{
		Data: proto.String("hi"),
	}
	ext2 := &pb.Ext{
		Data: proto.String("there"),
	}
	exists := proto.HasExtension(msg, pb.E_Ext_More)
	if exists {
		t.Error("Extension More present unexpectedly")
	}
	if err := proto.SetExtension(msg, pb.E_Ext_More, ext1); err != nil {
		t.Error(err)
	}
	if err := proto.SetExtension(msg, pb.E_Ext_More, ext2); err != nil {
		t.Error(err)
	}
	e, err := proto.GetExtension(msg, pb.E_Ext_More)
	if err != nil {
		t.Error(err)
	}
	x, ok := e.(*pb.Ext)
	if !ok {
		t.Errorf("e has type %T, expected testdata.Ext", e)
	} else if *x.Data != "there" {
		t.Errorf("SetExtension failed to overwrite, got %+v, not 'there'", x)
	}
	proto.ClearExtension(msg, pb.E_Ext_More)
	if _, err = proto.GetExtension(msg, pb.E_Ext_More); err != proto.ErrMissingExtension {
		t.Errorf("got %v, expected ErrMissingExtension", e)
	}
	if _, err := proto.GetExtension(msg, pb.E_X215); err == nil {
		t.Error("expected bad extension error, got nil")
	}
	if err := proto.SetExtension(msg, pb.E_X215, 12); err == nil {
		t.Error("expected extension err")
	}
	if err := proto.SetExtension(msg, pb.E_Ext_More, 12); err == nil {
		t.Error("expected some sort of type mismatch error, got nil")
	}
}

func TestExtensionDescsWithMissingExtensions(t *testing.T) {
	msg := &pb.MyMessage{Count: proto.Int32(0)}
	extdesc1 := pb.E_Ext_More
	if descs, err := proto.ExtensionDescs(msg); len(descs) != 0 || err != nil {
		t.Errorf("proto.ExtensionDescs: got %d descs, error %v; want 0, nil", len(descs), err)
	}

	ext1 := &pb.Ext{}
	if err := proto.SetExtension(msg, extdesc1, ext1); err != nil {
		t.Fatalf("Could not set ext1: %s", err)
	}
	extdesc2 := &proto.ExtensionDesc{
		ExtendedType:  (*pb.MyMessage)(nil),
		ExtensionType: (*bool)(nil),
		Field:         123456789,
		Name:          "a.b",
		Tag:           "varint,123456789,opt",
	}
	ext2 := proto.Bool(false)
	if err := proto.SetExtension(msg, extdesc2, ext2); err != nil {
		t.Fatalf("Could not set ext2: %s", err)
	}

	b, err := proto.Marshal(msg)
	if err != nil {
		t.Fatalf("Could not marshal msg: %v", err)
	}
	if err := proto.Unmarshal(b, msg); err != nil {
		t.Fatalf("Could not unmarshal into msg: %v", err)
	}

	descs, err := proto.ExtensionDescs(msg)
	if err != nil {
		t.Fatalf("proto.ExtensionDescs: got error %v", err)
	}
	sortExtDescs(descs)
	wantDescs := []*proto.ExtensionDesc{extdesc1, &proto.ExtensionDesc{Field: extdesc2.Field}}
	if !reflect.DeepEqual(descs, wantDescs) {
		t.Errorf("proto.ExtensionDescs(msg) sorted extension ids: got %+v, want %+v", descs, wantDescs)
	}
}

// OpenAuthenticationChannel constructs a message which will reuqest to open a channel for
// authentication on the given channelID, with the given cookie
func (mb *MessageBuilder) OpenAuthenticationChannel(channelID int32, clientCookie [16]byte) ([]byte, error) {
	oc := &Protocol_Data_Control.OpenChannel{
		ChannelIdentifier: proto.Int32(channelID),
		ChannelType:       proto.String("im.ricochet.auth.hidden-service"),
	}
	err := proto.SetExtension(oc, Protocol_Data_AuthHiddenService.E_ClientCookie, clientCookie[:])
	utils.CheckError(err)

	pc := &Protocol_Data_Control.Packet{
		OpenChannel: oc,
	}
	return proto.Marshal(pc)
}

// ConfirmAuthChannel constructs a message to acknowledge a previous open channel operation.
func (mb *MessageBuilder) ConfirmAuthChannel(channelID int32, serverCookie [16]byte) ([]byte, error) {
	cr := &Protocol_Data_Control.ChannelResult{
		ChannelIdentifier: proto.Int32(channelID),
		Opened:            proto.Bool(true),
	}

	err := proto.SetExtension(cr, Protocol_Data_AuthHiddenService.E_ServerCookie, serverCookie[:])
	utils.CheckError(err)

	pc := &Protocol_Data_Control.Packet{
		ChannelResult: cr,
	}
	return proto.Marshal(pc)
}

func (ch *contactReqChan) onOpenChannel() error {
	log := ch.conn.endpoint.log
	ch.state = chanStateOpen

	// Stop the timer since the peer took sufficient action.
	ch.conn.authTimer.Stop()

	log.Printf("server: ContactRequest from: '%v' (%s)", ch.conn.hostname, ch.reqData)

	// Check to see if we should mark the contact request as accepted,
	// rejected or pending.
	accept, err := ch.conn.endpoint.onContactRequest(ch.conn, ch.reqData)
	if err != nil {
		return err
	}

	resp := &packet.ContactRequestResponse{}
	if accept {
		resp.Status = packet.ContactRequestResponse_Accepted.Enum()
	} else {
		resp.Status = packet.ContactRequestResponse_Pending.Enum()
	}
	chanResult := &packet.ChannelResult{
		ChannelIdentifier: proto.Int32((int32)(ch.chanID)),
		Opened:            proto.Bool(true),
	}
	if err := proto.SetExtension(chanResult, packet.E_Response, resp); err != nil {
		return err
	}
	ctrlPkt := &packet.ControlPacket{ChannelResult: chanResult}
	rawPkt, err := proto.Marshal(ctrlPkt)
	if err != nil {
		return err
	}
	err = ch.conn.sendPacket(controlChanID, rawPkt)
	if !accept {
		return err
	}

	// We immediately accepted the Contact Request.
	ch.conn.endpoint.onConnectionEstablished(ch.conn)
	return ch.conn.sendChanClose(ch.chanID)
}

func TestGetExtensionsWithMissingExtensions(t *testing.T) {
	msg := &pb.MyMessage{}
	ext1 := &pb.Ext{}
	if err := proto.SetExtension(msg, pb.E_Ext_More, ext1); err != nil {
		t.Fatalf("Could not set ext1: %s", ext1)
	}
	exts, err := proto.GetExtensions(msg, []*proto.ExtensionDesc{
		pb.E_Ext_More,
		pb.E_Ext_Text,
	})
	if err != nil {
		t.Fatalf("GetExtensions() failed: %s", err)
	}
	if exts[0] != ext1 {
		t.Errorf("ext1 not in returned extensions: %T %v", exts[0], exts[0])
	}
	if exts[1] != nil {
		t.Errorf("ext2 in returned extensions: %T %v", exts[1], exts[1])
	}
}

// ReplyToContactRequestOnResponse constructs a message to acknowledge contact request
func (mb *MessageBuilder) ReplyToContactRequestOnResponse(channelID int32, status string) ([]byte, error) {
	cr := &Protocol_Data_Control.ChannelResult{
		ChannelIdentifier: proto.Int32(channelID),
		Opened:            proto.Bool(true),
	}

	statusNum := Protocol_Data_ContactRequest.Response_Status_value[status]
	responseStatus := Protocol_Data_ContactRequest.Response_Status(statusNum)
	contactRequest := &Protocol_Data_ContactRequest.Response{
		Status: &responseStatus,
	}

	err := proto.SetExtension(cr, Protocol_Data_ContactRequest.E_Response, contactRequest)
	utils.CheckError(err)

	pc := &Protocol_Data_Control.Packet{
		ChannelResult: cr,
	}
	return proto.Marshal(pc)
}

// OpenContactRequestChannel contructs a message which will reuqest to open a channel for
// a contact request on the given channelID, with the given nick and message.
func (mb *MessageBuilder) OpenContactRequestChannel(channelID int32, nick string, message string) ([]byte, error) {
	// Construct a Contact Request Channel
	oc := &Protocol_Data_Control.OpenChannel{
		ChannelIdentifier: proto.Int32(channelID),
		ChannelType:       proto.String("im.ricochet.contact.request"),
	}

	contactRequest := &Protocol_Data_ContactRequest.ContactRequest{
		Nickname:    proto.String(nick),
		MessageText: proto.String(message),
	}

	err := proto.SetExtension(oc, Protocol_Data_ContactRequest.E_ContactRequest, contactRequest)
	utils.CheckError(err)

	pc := &Protocol_Data_Control.Packet{
		OpenChannel: oc,
	}
	return proto.Marshal(pc)
}

func (ch *authHSChan) onOpenChannel() error {
	ch.state = chanStateOpen
	ch.serverCookie = make([]byte, authHiddenServiceCookieSize)
	if _, err := rand.Read(ch.serverCookie); err != nil {
		return err
	}

	chanResult := &packet.ChannelResult{
		ChannelIdentifier: proto.Int32((int32)(ch.chanID)),
		Opened:            proto.Bool(true),
	}
	if err := proto.SetExtension(chanResult, packet.E_ServerCookie, ch.serverCookie); err != nil {
		return err
	}
	ctrlPkt := &packet.ControlPacket{ChannelResult: chanResult}
	rawPkt, err := proto.Marshal(ctrlPkt)
	if err != nil {
		return err
	}
	return ch.conn.sendPacket(controlChanID, rawPkt)
}

func TestClearAllExtensions(t *testing.T) {
	// unregistered extension
	desc := &proto.ExtensionDesc{
		ExtendedType:  (*pb.MyMessage)(nil),
		ExtensionType: (*bool)(nil),
		Field:         101010100,
		Name:          "emptyextension",
		Tag:           "varint,0,opt",
	}
	m := &pb.MyMessage{}
	if proto.HasExtension(m, desc) {
		t.Errorf("proto.HasExtension(%s): got true, want false", proto.MarshalTextString(m))
	}
	if err := proto.SetExtension(m, desc, proto.Bool(true)); err != nil {
		t.Errorf("proto.SetExtension(m, desc, true): got error %q, want nil", err)
	}
	if !proto.HasExtension(m, desc) {
		t.Errorf("proto.HasExtension(%s): got false, want true", proto.MarshalTextString(m))
	}
	proto.ClearAllExtensions(m)
	if proto.HasExtension(m, desc) {
		t.Errorf("proto.HasExtension(%s): got true, want false", proto.MarshalTextString(m))
	}
}

func TestMarshalUnmarshalRepeatedExtension(t *testing.T) {
	// Add a repeated extension to the result.
	tests := []struct {
		name string
		ext  []*pb.ComplexExtension
	}{
		{
			"two fields",
			[]*pb.ComplexExtension{
				{First: proto.Int32(7)},
				{Second: proto.Int32(11)},
			},
		},
		{
			"repeated field",
			[]*pb.ComplexExtension{
				{Third: []int32{1000}},
				{Third: []int32{2000}},
			},
		},
		{
			"two fields and repeated field",
			[]*pb.ComplexExtension{
				{Third: []int32{1000}},
				{First: proto.Int32(9)},
				{Second: proto.Int32(21)},
				{Third: []int32{2000}},
			},
		},
	}
	for _, test := range tests {
		// Marshal message with a repeated extension.
		msg1 := new(pb.OtherMessage)
		err := proto.SetExtension(msg1, pb.E_RComplex, test.ext)
		if err != nil {
			t.Fatalf("[%s] Error setting extension: %v", test.name, err)
		}
		b, err := proto.Marshal(msg1)
		if err != nil {
			t.Fatalf("[%s] Error marshaling message: %v", test.name, err)
		}

		// Unmarshal and read the merged proto.
		msg2 := new(pb.OtherMessage)
		err = proto.Unmarshal(b, msg2)
		if err != nil {
			t.Fatalf("[%s] Error unmarshaling message: %v", test.name, err)
		}
		e, err := proto.GetExtension(msg2, pb.E_RComplex)
		if err != nil {
			t.Fatalf("[%s] Error getting extension: %v", test.name, err)
		}
		ext := e.([]*pb.ComplexExtension)
		if ext == nil {
			t.Fatalf("[%s] Invalid extension", test.name)
		}
		if !reflect.DeepEqual(ext, test.ext) {
			t.Errorf("[%s] Wrong value for ComplexExtension: got: %v want: %v\n", test.name, ext, test.ext)
		}
	}
}

func TestUnmarshalRepeatingNonRepeatedExtension(t *testing.T) {
	// We may see multiple instances of the same extension in the wire
	// format. For example, the proto compiler may encode custom options in
	// this way. Here, we verify that we merge the extensions together.
	tests := []struct {
		name string
		ext  []*pb.ComplexExtension
	}{
		{
			"two fields",
			[]*pb.ComplexExtension{
				{First: proto.Int32(7)},
				{Second: proto.Int32(11)},
			},
		},
		{
			"repeated field",
			[]*pb.ComplexExtension{
				{Third: []int32{1000}},
				{Third: []int32{2000}},
			},
		},
		{
			"two fields and repeated field",
			[]*pb.ComplexExtension{
				{Third: []int32{1000}},
				{First: proto.Int32(9)},
				{Second: proto.Int32(21)},
				{Third: []int32{2000}},
			},
		},
	}
	for _, test := range tests {
		var buf bytes.Buffer
		var want pb.ComplexExtension

		// Generate a serialized representation of a repeated extension
		// by catenating bytes together.
		for i, e := range test.ext {
			// Merge to create the wanted proto.
			proto.Merge(&want, e)

			// serialize the message
			msg := new(pb.OtherMessage)
			err := proto.SetExtension(msg, pb.E_Complex, e)
			if err != nil {
				t.Fatalf("[%s] Error setting extension %d: %v", test.name, i, err)
			}
			b, err := proto.Marshal(msg)
			if err != nil {
				t.Fatalf("[%s] Error marshaling message %d: %v", test.name, i, err)
			}
			buf.Write(b)
		}

		// Unmarshal and read the merged proto.
		msg2 := new(pb.OtherMessage)
		err := proto.Unmarshal(buf.Bytes(), msg2)
		if err != nil {
			t.Fatalf("[%s] Error unmarshaling message: %v", test.name, err)
		}
		e, err := proto.GetExtension(msg2, pb.E_Complex)
		if err != nil {
			t.Fatalf("[%s] Error getting extension: %v", test.name, err)
		}
		ext := e.(*pb.ComplexExtension)
		if ext == nil {
			t.Fatalf("[%s] Invalid extension", test.name)
		}
		if !reflect.DeepEqual(*ext, want) {
			t.Errorf("[%s] Wrong value for ComplexExtension: got: %s want: %s\n", test.name, ext, want)
		}
	}
}