Add initial Scarlet impl

app/build.gradle

@@ -190,6 +190,11 @@ dependencies {
     implementation 'com.amulyakhare:com.amulyakhare.textdrawable:1.0.1'
     implementation 'com.kevalpatel2106:emoticongifkeyboard:1.1'
 
+    implementation 'com.github.tinder.scarlet:scarlet:0.1.5'
+    implementation 'com.github.tinder.scarlet:scarlet-stream-adapter-rxjava2:0.1.5'
+    implementation 'com.github.tinder.scarlet:scarlet-message-adapter-moshi:0.1.5'
+    implementation 'com.github.tinder.scarlet:scarlet-websocket-okhttp:0.1.5'
+
     testImplementation 'junit:junit:4.12'
     androidTestImplementation ('androidx.test.espresso:espresso-core:3.1.0-alpha4', {
         exclude group: 'com.android.support', module: 'support-annotations'

app/src/main/java/com/nextcloud/talk/api/ExternalSignaling.java

@@ -0,0 +1,37 @@
+/*
+ * Nextcloud Talk application
+ *
+ * @author Mario Danic
+ * Copyright (C) 2017-2018 Mario Danic <mario@lovelyhq.com>
+ *
+ * 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 3 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, see <http://www.gnu.org/licenses/>.
+ */
+
+package com.nextcloud.talk.api;
+
+import com.tinder.scarlet.WebSocket;
+import com.tinder.scarlet.ws.Receive;
+
+import io.reactivex.Flowable;
+
+public interface ExternalSignaling {
+    @Receive
+    Flowable<WebSocket.Event.OnConnectionOpened> observeOnConnectionOpenedEvent();
+
+    @Receive
+    Flowable<WebSocket.Event.OnConnectionFailed> observeOnConnectionFailedEvent();
+
+    @Receive
+    Flowable<WebSocket.Event.OnConnectionClosed> observeOnConnectionClosedEvent();
+}

app/src/main/java/com/nextcloud/talk/webrtc/ScarletHelper.java

@@ -0,0 +1,69 @@
+/*
+ * Nextcloud Talk application
+ *
+ * @author Mario Danic
+ * Copyright (C) 2017-2018 Mario Danic <mario@lovelyhq.com>
+ *
+ * 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 3 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, see <http://www.gnu.org/licenses/>.
+ */
+
+package com.nextcloud.talk.webrtc;
+
+import com.nextcloud.talk.api.ExternalSignaling;
+import com.nextcloud.talk.application.NextcloudTalkApplication;
+import com.tinder.scarlet.Scarlet;
+import com.tinder.scarlet.messageadapter.moshi.MoshiMessageAdapter;
+import com.tinder.scarlet.retry.ExponentialBackoffStrategy;
+import com.tinder.scarlet.retry.LinearBackoffStrategy;
+import com.tinder.scarlet.streamadapter.rxjava2.RxJava2StreamAdapterFactory;
+import com.tinder.scarlet.websocket.okhttp.OkHttpClientUtils;
+import com.tinder.scarlet.websocket.okhttp.OkHttpWebSocket;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import javax.inject.Inject;
+
+import autodagger.AutoInjector;
+import okhttp3.OkHttpClient;
+
+@AutoInjector(NextcloudTalkApplication.class)
+public class ScarletHelper {
+    private Map<String, ExternalSignaling> externalSignalingMap = new HashMap<>();
+
+    @Inject
+    OkHttpClient okHttpClient;
+
+    public ScarletHelper() {
+        NextcloudTalkApplication.getSharedApplication().getComponentApplication().inject(this);
+    }
+
+    public ExternalSignaling getExternalSignalingInstanceForServer(String url) {
+        if (externalSignalingMap.containsKey(url)) {
+            return externalSignalingMap.get(url);
+        } else {
+            Scarlet scarlet = new Scarlet.Builder()
+                    .backoffStrategy(new LinearBackoffStrategy(500))
+                    .webSocketFactory(OkHttpClientUtils.newWebSocketFactory(okHttpClient, url))
+                    .addMessageAdapterFactory(new MoshiMessageAdapter.Factory())
+                    .addStreamAdapterFactory(new RxJava2StreamAdapterFactory())
+                    .build();
+            ExternalSignaling externalSignaling = scarlet.create(ExternalSignaling.class);
+            externalSignalingMap.put(url, externalSignaling);
+            return externalSignaling;
+        }
+    }
+}