GODT-1932: frontend is instantiated before bridge.

WIP: introduced frontend.Type.
WIP: frontend is create before bridge is instantiated.
WIP: filtering of internet stastus event in gRPC event queue.

internal/frontend/grpc/event_utils.go

@@ -0,0 +1,32 @@
+// Copyright (c) 2022 Proton AG
+//
+// This file is part of Proton Mail Bridge.
+//
+// Proton Mail Bridge is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Proton Mail Bridge is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Proton Mail Bridge. If not, see <https://www.gnu.org/licenses/>.
+
+package grpc
+
+import "github.com/bradenaw/juniper/xslices"
+
+// isInternetStatus returns true iff the event is InternetStatus.
+func (x *StreamEvent) isInternetStatus() bool {
+	appEvent := x.GetApp()
+
+	return (appEvent != nil) && (appEvent.GetInternetStatus() != nil)
+}
+
+// filterOutInternetStatusEvents return a copy of the events list where all internet connection events have been removed.
+func filterOutInternetStatusEvents(events []*StreamEvent) []*StreamEvent {
+	return xslices.Filter(events, func(event *StreamEvent) bool { return !event.isInternetStatus() })
+}

internal/frontend/grpc/grpc_test.go

@@ -53,3 +53,25 @@ func TestConfig(t *testing.T) {
 	// failure to save
 	require.Error(t, conf2.save(filepath.Join(tempDir, "non/existing/folder", tempFileName)))
 }
+
+func TestIsInternetStatus(t *testing.T) {
+	require.True(t, NewInternetStatusEvent(true).isInternetStatus())
+	require.True(t, NewInternetStatusEvent(false).isInternetStatus())
+	require.False(t, NewKeychainHasNoKeychainEvent().isInternetStatus())
+	require.False(t, NewLoginAlreadyLoggedInEvent("").isInternetStatus())
+}
+
+func TestFilterOutInternetStatusEvents(t *testing.T) {
+	require.Zero(t, len(filterOutInternetStatusEvents([]*StreamEvent{})))
+
+	off := NewInternetStatusEvent(false)
+	on := NewInternetStatusEvent(true)
+	show := NewShowMainWindowEvent()
+	finished := NewLoginFinishedEvent("id")
+
+	require.Zero(t, len(filterOutInternetStatusEvents([]*StreamEvent{})))
+	require.Zero(t, len(filterOutInternetStatusEvents([]*StreamEvent{off, on, off})))
+	require.Equal(t, filterOutInternetStatusEvents([]*StreamEvent{off, show, on}), []*StreamEvent{show})
+	require.Equal(t, filterOutInternetStatusEvents([]*StreamEvent{finished, off, show, on}), []*StreamEvent{finished, show})
+	require.Equal(t, filterOutInternetStatusEvents([]*StreamEvent{finished, show}), []*StreamEvent{finished, show})
+}

internal/frontend/grpc/service.go

@@ -90,7 +90,6 @@ func NewService(
 	panicHandler types.PanicHandler,
 	eventListener listener.Listener,
 	updater types.Updater,
-	bridge types.Bridger,
 	restarter types.Restarter,
 	locations *locations.Locations,
 ) *Service {
@@ -99,7 +98,6 @@ func NewService(
 		panicHandler:              panicHandler,
 		eventListener:             eventListener,
 		updater:                   updater,
-		bridge:                    bridge,
 		restarter:                 restarter,
 		showOnStartup:             showOnStartup,
 
@@ -115,6 +113,15 @@ func NewService(
 	// set to 1
 	s.initializing.Add(1)
 
+	go func() {
+		defer s.panicHandler.HandlePanic()
+		s.watchEvents()
+	}()
+
+	return &s
+}
+
+func (s *Service) startGRPCServer() {
 	tlsConfig, pemCert, err := s.generateTLSConfig()
 	if err != nil {
 		s.log.WithError(err).Panic("could not generate gRPC TLS config")
@@ -122,10 +129,9 @@ func NewService(
 
 	s.pemCert = string(pemCert)
 
-	s.initAutostart()
 	s.grpcServer = grpc.NewServer(grpc.Creds(credentials.NewTLS(tlsConfig)))
 
-	RegisterBridgeServer(s.grpcServer, &s)
+	RegisterBridgeServer(s.grpcServer, s)
 
 	s.listener, err = net.Listen("tcp", "127.0.0.1:0") // Port 0 means that the port is randomly picked by the system.
 	if err != nil {
@@ -137,8 +143,6 @@ func NewService(
 	}
 
 	s.log.Info("gRPC server listening at ", s.listener.Addr())
-
-	return &s
 }
 
 func (s *Service) initAutostart() {
@@ -158,15 +162,18 @@ func (s *Service) initAutostart() {
 	})
 }
 
-func (s *Service) Loop() error {
+func (s *Service) Loop(b types.Bridger) error {
+	s.bridge = b
+	s.initAutostart()
+	s.startGRPCServer()
+
 	defer func() {
 		s.bridge.SetBool(settings.FirstStartGUIKey, false)
 	}()
 
-	go func() {
-		defer s.panicHandler.HandlePanic()
-		s.watchEvents()
-	}()
+	if s.bridge.HasError(bridge.ErrLocalCacheUnavailable) {
+		_ = s.SendEvent(NewCacheErrorEvent(CacheErrorType_CACHE_UNAVAILABLE_ERROR))
+	}
 
 	err := s.grpcServer.Serve(s.listener)
 	if err != nil {
@@ -203,10 +210,6 @@ func (s *Service) WaitUntilFrontendIsReady() {
 }
 
 func (s *Service) watchEvents() { // nolint:funlen
-	if s.bridge.HasError(bridge.ErrLocalCacheUnavailable) {
-		_ = s.SendEvent(NewCacheErrorEvent(CacheErrorType_CACHE_UNAVAILABLE_ERROR))
-	}
-
 	errorCh := s.eventListener.ProvideChannel(events.ErrorEvent)
 	credentialsErrorCh := s.eventListener.ProvideChannel(events.CredentialsErrorEvent)
 	noActiveKeyForRecipientCh := s.eventListener.ProvideChannel(events.NoActiveKeyForRecipientEvent)
@@ -258,6 +261,10 @@ func (s *Service) watchEvents() { // nolint:funlen
 		case address := <-addressChangedLogoutCh:
 			_ = s.SendEvent(NewMailAddressChangeLogoutEvent(address))
 		case userID := <-logoutCh:
+			if s.bridge == nil {
+				logrus.Error("Received a logout event but bridge is not yet instantiated.")
+				break
+			}
 			user, err := s.bridge.GetUserInfo(userID)
 			if err != nil {
 				return

internal/frontend/grpc/service_stream.go

@@ -95,12 +95,8 @@ func (s *Service) StopEventStream(ctx context.Context, _ *emptypb.Empty) (*empty
 
 // SendEvent sends an event to the via the gRPC event stream.
 func (s *Service) SendEvent(event *StreamEvent) error {
-	s.eventQueueMutex.Lock()
-	defer s.eventQueueMutex.Unlock()
-
-	if s.eventStreamCh == nil {
-		// nobody is connected to the event stream, we queue events
-		s.eventQueue = append(s.eventQueue, event)
+	if s.eventStreamCh == nil { // nobody is connected to the event stream, we queue events
+		s.queueEvent(event)
 		return nil
 	}
 
@@ -175,3 +171,14 @@ func (s *Service) StartEventTest() error { //nolint:funlen
 
 	return nil
 }
+
+func (s *Service) queueEvent(event *StreamEvent) {
+	s.eventQueueMutex.Lock()
+	defer s.eventQueueMutex.Unlock()
+
+	if event.isInternetStatus() {
+		s.eventQueue = append(filterOutInternetStatusEvents(s.eventQueue), event)
+	} else {
+		s.eventQueue = append(s.eventQueue, event)
+	}
+}