Merge pull request #12672 from nextcloud/fix/handle-new-notification

Workaround (or fix maybe) for NEW_NOTIFICATION messages

app/src/gplay/java/com/owncloud/android/services/firebase/NCFirebaseMessagingService.java

@@ -7,15 +7,18 @@
  */
 package com.owncloud.android.services.firebase;
 
+import android.content.Intent;
 import android.text.TextUtils;
 
+import com.google.firebase.messaging.Constants.MessageNotificationKeys;
 import com.google.firebase.messaging.FirebaseMessagingService;
 import com.google.firebase.messaging.RemoteMessage;
 import com.nextcloud.client.account.UserAccountManager;
 import com.nextcloud.client.jobs.BackgroundJobManager;
 import com.nextcloud.client.jobs.NotificationWork;
 import com.nextcloud.client.preferences.AppPreferences;
 import com.owncloud.android.R;
+import com.owncloud.android.lib.common.utils.Log_OC;
 import com.owncloud.android.utils.PushUtils;
 
 import java.util.Map;
@@ -30,14 +33,55 @@ public class NCFirebaseMessagingService extends FirebaseMessagingService {
     @Inject UserAccountManager accountManager;
     @Inject BackgroundJobManager backgroundJobManager;
 
+    static final String TAG = "NCFirebaseMessagingService";
+
+    // Firebase Messaging may apparently use two intent extras to specify a notification message.
+    //
+    // See the following fragments in https://github.com/firebase/firebase-android-sdk/blob/releases/m144_1.release/
+    //  firebase-messaging/src/main/java/com/google/firebase/messaging/FirebaseMessagingService.java#L223
+    //  firebase-messaging/src/main/java/com/google/firebase/messaging/NotificationParams.java#L419
+    //  firebase-messaging/src/main/java/com/google/firebase/messaging/Constants.java#L158
+    //
+    // The "old" key is not exposed in com.google.firebase.messaging.Constants.MessageNotificationKeys,
+    // so we need to define it ourselves.
+    static final String ENABLE_NOTIFICATION_OLD = MessageNotificationKeys.NOTIFICATION_PREFIX_OLD + "e";
+    static final String ENABLE_NOTIFICATION_NEW = MessageNotificationKeys.ENABLE_NOTIFICATION;
+
     @Override
     public void onCreate() {
         super.onCreate();
         AndroidInjection.inject(this);
     }
 
+    @Override
+    public void handleIntent(Intent intent) {
+        Log_OC.d(TAG, "handleIntent - extras: " +
+            ENABLE_NOTIFICATION_NEW + ": " + intent.getExtras().getString(ENABLE_NOTIFICATION_NEW) + ", " +
+            ENABLE_NOTIFICATION_OLD + ": " + intent.getExtras().getString(ENABLE_NOTIFICATION_OLD));
+
+        // When the app is in background and one of the ENABLE_NOTIFICATION or ENABLE_NOTIFICATION_OLD extras is set
+        // to "1" in the intent sent from the FCM system code to the FirebaseMessagingService in the application,
+        // the FCM library code that handles the intent DOES NOT invoke the onMessageReceived method.
+        // It just displays the notification by itself.
+        //
+        // In our case the original FCM message contains dummy values "NEW_NOTIFICATION" and we need to get the
+        // message in onMessageReceived to decrypt it.
+        //
+        // So we cheat here a little, by telling the FCM library that the notification flag is not set.
+        //
+        // Code below depends on implementation details of the firebase-messaging library (Firebase Android SDK).
+        // https://github.com/firebase/firebase-android-sdk/tree/master/firebase-messaging
+
+        intent.removeExtra(ENABLE_NOTIFICATION_OLD);
+        intent.removeExtra(ENABLE_NOTIFICATION_NEW);
+        intent.putExtra(ENABLE_NOTIFICATION_NEW, "0");
+
+        super.handleIntent(intent);
+    }
+
     @Override
     public void onMessageReceived(@NonNull RemoteMessage remoteMessage) {
+        Log_OC.d(TAG, "onMessageReceived");
         final Map<String, String> data = remoteMessage.getData();
         final String subject = data.get(NotificationWork.KEY_NOTIFICATION_SUBJECT);
         final String signature = data.get(NotificationWork.KEY_NOTIFICATION_SIGNATURE);
@@ -48,6 +92,7 @@ public void onMessageReceived(@NonNull RemoteMessage remoteMessage) {
 
     @Override
     public void onNewToken(@NonNull String newToken) {
+        Log_OC.d(TAG, "onNewToken");
         super.onNewToken(newToken);
 
         if (!TextUtils.isEmpty(getResources().getString(R.string.push_server_url))) {