If google-services.json file is not found, completely disable firebase dependency

app/build.gradle

@@ -122,6 +122,8 @@ android {
 
     sourceSets {
         main {
+            java.excludes = excludeFiles
+
             packagingOptions {
                 excludes = excludePackage
             }
@@ -136,7 +138,9 @@ android {
 }
 
 dependencies {
-    implementation 'com.google.firebase:firebase-messaging:17.3.4'
+    if (firebaseEnabled()) {
+        implementation 'com.google.firebase:firebase-messaging:17.3.4'
+    }
     implementation 'com.android.billingclient:billing:1.2'
     implementation 'org.apache.commons:commons-compress:1.18'
     implementation 'androidx.legacy:legacy-support-v4:1.0.0'
@@ -145,7 +149,6 @@ dependencies {
     implementation 'com.google.android.material:material:1.1.0-alpha02'
     implementation 'com.google.android:flexbox:1.1.0'
     implementation 'com.github.bumptech.glide:glide:4.9.0'
-    annotationProcessor 'com.github.bumptech.glide:compiler:4.9.0'
 
     if (isLocalAarAvailable()) {
         implementation project(":linphone-sdk-android")

app/src/main/java/org/linphone/LinphoneManager.java

@@ -55,11 +55,6 @@ import android.view.View;
 import android.widget.Button;
 import android.widget.CheckBox;
 import android.widget.Toast;
-import androidx.annotation.NonNull;
-import com.google.android.gms.tasks.OnCompleteListener;
-import com.google.android.gms.tasks.Task;
-import com.google.firebase.iid.FirebaseInstanceId;
-import com.google.firebase.iid.InstanceIdResult;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileOutputStream;
@@ -131,6 +126,7 @@ import org.linphone.utils.FileUtils;
 import org.linphone.utils.LinphoneUtils;
 import org.linphone.utils.MediaScanner;
 import org.linphone.utils.MediaScannerListener;
+import org.linphone.utils.PushNotificationUtils;
 
 /**
  * Manager of the low level LibLinphone stuff.<br>
@@ -724,35 +720,7 @@ public class LinphoneManager implements CoreListener, SensorEventListener, Accou
     }
 
     private void initPushNotificationsService() {
-        if (getString(R.string.push_type).equals("firebase")) {
+        PushNotificationUtils.init(mServiceContext);
-            Log.i(
-                    "[Manager][Push Notification] firebase push sender id "
-                            + getString(R.string.gcm_defaultSenderId));
-            try {
-                FirebaseInstanceId.getInstance()
-                        .getInstanceId()
-                        .addOnCompleteListener(
-                                new OnCompleteListener<InstanceIdResult>() {
-                                    @Override
-                                    public void onComplete(@NonNull Task<InstanceIdResult> task) {
-                                        if (!task.isSuccessful()) {
-                                            Log.e(
-                                                    "[Manager][Push Notification] firebase getInstanceId failed: "
-                                                            + task.getException());
-                                            return;
-                                        }
-                                        String token = task.getResult().getToken();
-                                        Log.i(
-                                                "[Manager][Push Notification] firebase token is: "
-                                                        + token);
-                                        LinphonePreferences.instance()
-                                                .setPushNotificationRegistrationID(token);
-                                    }
-                                });
-            } catch (Exception e) {
-                Log.e("[Manager][Push Notification] firebase not available.");
-            }
-        }
     }
 
     private synchronized void initLiblinphone(Core lc) {

app/src/main/java/org/linphone/firebase/FirebasePushHelper.java

@@ -0,0 +1,64 @@
+package org.linphone.firebase;
+
+/*
+FirebasePushHelper.java
+Copyright (C) 2019 Belledonne Communications, Grenoble, France
+
+This program 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 2
+of the License, or (at your option) any later version.
+
+This program 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 this program; if not, write to the Free Software
+Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+*/
+
+import android.content.Context;
+import androidx.annotation.NonNull;
+import com.google.android.gms.tasks.OnCompleteListener;
+import com.google.android.gms.tasks.Task;
+import com.google.firebase.iid.FirebaseInstanceId;
+import com.google.firebase.iid.InstanceIdResult;
+import org.linphone.R;
+import org.linphone.core.tools.Log;
+import org.linphone.settings.LinphonePreferences;
+import org.linphone.utils.PushNotificationUtils;
+
+public class FirebasePushHelper implements PushNotificationUtils.PushHelperInterface {
+    public FirebasePushHelper() {}
+
+    @Override
+    public void init(Context context) {
+        Log.i(
+                "[Push Notification] firebase push sender id "
+                        + context.getString(R.string.gcm_defaultSenderId));
+        try {
+            FirebaseInstanceId.getInstance()
+                    .getInstanceId()
+                    .addOnCompleteListener(
+                            new OnCompleteListener<InstanceIdResult>() {
+                                @Override
+                                public void onComplete(@NonNull Task<InstanceIdResult> task) {
+                                    if (!task.isSuccessful()) {
+                                        Log.e(
+                                                "[Push Notification] firebase getInstanceId failed: "
+                                                        + task.getException());
+                                        return;
+                                    }
+                                    String token = task.getResult().getToken();
+                                    Log.i("[Push Notification] firebase token is: " + token);
+                                    LinphonePreferences.instance()
+                                            .setPushNotificationRegistrationID(token);
+                                }
+                            });
+        } catch (Exception e) {
+            Log.e("[Push Notification] firebase not available.");
+        }
+    }
+}

app/src/main/java/org/linphone/utils/PushNotificationUtils.java

@@ -0,0 +1,55 @@
+package org.linphone.utils;
+
+/*
+PushNotificationUtils.java
+Copyright (C) 2019 Belledonne Communications, Grenoble, France
+
+This program 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 2
+of the License, or (at your option) any later version.
+
+This program 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 this program; if not, write to the Free Software
+Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+*/
+
+import android.content.Context;
+import java.lang.reflect.Constructor;
+import org.linphone.R;
+import org.linphone.core.tools.Log;
+
+public class PushNotificationUtils {
+    public static void init(Context context) {
+        String push_type = context.getString(R.string.push_type);
+        if (push_type.equals("firebase")) {
+            String className = "org.linphone.firebase.FirebasePushHelper";
+            try {
+                Class pushHelper = Class.forName(className);
+                Class[] types = {};
+                Constructor constructor = pushHelper.getConstructor(types);
+                Object[] parameters = {};
+                PushHelperInterface pushHelperImpl =
+                        (PushHelperInterface) constructor.newInstance(parameters);
+                pushHelperImpl.init(context);
+            } catch (NoSuchMethodException e) {
+                Log.w("[Push Utils] Couldn't get push helper constructor");
+            } catch (ClassNotFoundException e) {
+                Log.w("[Push Utils] Couldn't find class " + className);
+            } catch (Exception e) {
+                Log.w("[Push Utils] Couldn't get push helper instance: " + e);
+            }
+        } else {
+            Log.w("[Push Utils] Unknow push type " + push_type);
+        }
+    }
+
+    public interface PushHelperInterface {
+        void init(Context context);
+    }
+}