Merge pull request #170 from RocketChat/alternative_websocket_connection_management

introduce alternative WebSocket connectivity management

android-ddp/src/main/java/chat/rocket/android_ddp/DDPClient.java

@@ -61,10 +61,6 @@ public class DDPClient {
     return impl.getOnCloseCallback();
   }
 
-  public boolean isConnected() {
-    return impl.isConnected();
-  }
-
   public void close() {
     impl.close(1000, "closed by DDPClient#close()");
   }

android-ddp/src/main/java/chat/rocket/android_ddp/DDPClientImpl.java

@@ -96,10 +96,6 @@ public class DDPClientImpl {
     }
   }
 
-  public boolean isConnected() {
-    return websocket != null && websocket.isConnected();
-  }
-
   public void ping(final TaskCompletionSource<DDPClientCallback.Ping> task,
                    @Nullable final String id) {
 

android-ddp/src/main/java/chat/rocket/android_ddp/rx/RxWebSocket.java

@@ -15,11 +15,9 @@ import rx.observables.ConnectableObservable;
 public class RxWebSocket {
   private OkHttpClient httpClient;
   private WebSocket webSocket;
-  private boolean isConnected;
 
   public RxWebSocket(OkHttpClient client) {
     httpClient = client;
-    isConnected = false;
   }
 
   public ConnectableObservable<RxWebSocketCallback.Base> connect(String url) {
@@ -31,7 +29,6 @@ public class RxWebSocket {
         httpClient.newWebSocket(request, new WebSocketListener() {
           @Override
           public void onOpen(WebSocket webSocket, Response response) {
-            isConnected = true;
             RxWebSocket.this.webSocket = webSocket;
             subscriber.onNext(new RxWebSocketCallback.Open(RxWebSocket.this.webSocket, response));
           }
@@ -39,7 +36,6 @@ public class RxWebSocket {
           @Override
           public void onFailure(WebSocket webSocket, Throwable err, Response response) {
             try {
-              isConnected = false;
               subscriber.onError(new RxWebSocketCallback.Failure(webSocket, err, response));
             } catch (OnErrorNotImplementedException ex) {
               RCLog.w(ex, "OnErrorNotImplementedException ignored");
@@ -48,13 +44,11 @@ public class RxWebSocket {
 
           @Override
           public void onMessage(WebSocket webSocket, String text) {
-            isConnected = true;
             subscriber.onNext(new RxWebSocketCallback.Message(webSocket, text));
           }
 
           @Override
           public void onClosed(WebSocket webSocket, int code, String reason) {
-            isConnected = false;
             subscriber.onNext(new RxWebSocketCallback.Close(webSocket, code, reason));
             subscriber.onCompleted();
           }
@@ -67,10 +61,6 @@ public class RxWebSocket {
     return webSocket.send(message);
   }
 
-  public boolean isConnected() {
-    return isConnected;
-  }
-
   public boolean close(int code, String reason) throws IOException {
     return webSocket.close(code, reason);
   }

app/build.gradle

@@ -114,8 +114,8 @@ dependencies {
     compile 'com.facebook.stetho:stetho-okhttp3:1.4.1'
     compile 'com.uphyca:stetho_realm:2.0.1'
 
-    compile 'com.jakewharton.rxbinding:rxbinding:0.4.0'
-    compile 'com.jakewharton.rxbinding:rxbinding-support-v4:0.4.0'
+    compile 'com.jakewharton.rxbinding:rxbinding:1.0.0'
+    compile 'com.jakewharton.rxbinding:rxbinding-support-v4:1.0.0'
 
     compile 'com.trello:rxlifecycle:1.0'
     compile 'com.trello:rxlifecycle-android:1.0'

app/src/main/java/chat/rocket/android/LaunchUtil.java

@@ -5,12 +5,22 @@ import android.content.Intent;
 
 import chat.rocket.android.activity.AddServerActivity;
 import chat.rocket.android.activity.LoginActivity;
+import chat.rocket.android.activity.MainActivity;
 
 /**
  * utility class for launching Activity.
  */
 public class LaunchUtil {
 
+  /**
+   * launch MainActivity with proper flags.
+   */
+  public static void showMainActivity(Context context) {
+    Intent intent = new Intent(context, MainActivity.class);
+    intent.setFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT | Intent.FLAG_ACTIVITY_CLEAR_TOP);
+    context.startActivity(intent);
+  }
+
   /**
    * launch AddServerActivity with proper flags.
    */
@@ -23,10 +33,10 @@ public class LaunchUtil {
   /**
    * launch ServerConfigActivity with proper flags.
    */
-  public static void showLoginActivity(Context context, String serverCondigId) {
+  public static void showLoginActivity(Context context, String hostname) {
     Intent intent = new Intent(context, LoginActivity.class);
     intent.setFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT | Intent.FLAG_ACTIVITY_CLEAR_TOP);
-    intent.putExtra("serverConfigId", serverCondigId);
+    intent.putExtra(LoginActivity.KEY_HOSTNAME, hostname);
     context.startActivity(intent);
   }
 }

app/src/main/java/chat/rocket/android/RocketChatApplication.java

@@ -7,8 +7,9 @@ import io.realm.Realm;
 import io.realm.RealmConfiguration;
 
 import java.util.List;
-import chat.rocket.android.model.ServerConfig;
 import chat.rocket.android.realm_helper.RealmStore;
+import chat.rocket.android.service.ConnectivityManager;
+import chat.rocket.android.service.ServerInfo;
 import chat.rocket.android.wrappers.InstabugWrapper;
 
 /**
@@ -23,10 +24,9 @@ public class RocketChatApplication extends MultiDexApplication {
     Realm.setDefaultConfiguration(
         new RealmConfiguration.Builder().deleteRealmIfMigrationNeeded().build());
 
-    List<ServerConfig> configs = RealmStore.getDefault().executeTransactionForReadResults(realm ->
-        realm.where(ServerConfig.class).isNotNull(ServerConfig.SESSION).findAll());
-    for (ServerConfig config : configs) {
-      RealmStore.put(config.getServerConfigId());
+    List<ServerInfo> serverInfoList = ConnectivityManager.getInstance(this).getServerList();
+    for (ServerInfo serverInfo : serverInfoList) {
+      RealmStore.put(serverInfo.hostname);
     }
 
     Stetho.initialize(Stetho.newInitializerBuilder(this)

app/src/main/java/chat/rocket/android/RocketChatCache.java

@@ -9,7 +9,7 @@ import java.util.UUID;
  * sharedpreference-based cache.
  */
 public class RocketChatCache {
-  public static final String KEY_SELECTED_SERVER_CONFIG_ID = "selectedServerConfigId";
+  public static final String KEY_SELECTED_SERVER_HOSTNAME = "selectedServerHostname";
   public static final String KEY_SELECTED_ROOM_ID = "selectedRoomId";
 
   private static final String KEY_PUSH_ID = "pushId";

app/src/main/java/chat/rocket/android/activity/AbstractAuthedActivity.java

@@ -5,61 +5,50 @@ import android.content.SharedPreferences;
 import android.os.Bundle;
 import android.support.annotation.Nullable;
 
-import chat.rocket.android.LaunchUtil;
 import chat.rocket.android.RocketChatCache;
-import chat.rocket.android.model.ServerConfig;
 import chat.rocket.android.model.ddp.RoomSubscription;
 import chat.rocket.android.push.PushConstants;
 import chat.rocket.android.push.PushNotificationHandler;
 import chat.rocket.android.realm_helper.RealmListObserver;
 import chat.rocket.android.realm_helper.RealmStore;
-import chat.rocket.android.service.RocketChatService;
+import chat.rocket.android.service.ConnectivityManager;
 import icepick.State;
 
 abstract class AbstractAuthedActivity extends AbstractFragmentActivity {
-  @State protected String serverConfigId;
+  @State protected String hostname;
   @State protected String roomId;
   SharedPreferences.OnSharedPreferenceChangeListener preferenceChangeListener =
       (sharedPreferences, key) -> {
-        if (RocketChatCache.KEY_SELECTED_SERVER_CONFIG_ID.equals(key)) {
-          updateServerConfigIdIfNeeded(sharedPreferences);
+        if (RocketChatCache.KEY_SELECTED_SERVER_HOSTNAME.equals(key)) {
+          updateHostnameIfNeeded(sharedPreferences);
         } else if (RocketChatCache.KEY_SELECTED_ROOM_ID.equals(key)) {
           updateRoomIdIfNeeded(sharedPreferences);
         }
       };
-  private RealmListObserver<ServerConfig> unconfiguredServersObserver =
-      RealmStore.getDefault()
-          .createListObserver(realm ->
-              realm.where(ServerConfig.class).isNotNull(ServerConfig.SESSION).findAll())
-          .setOnUpdateListener(results -> {
-            if (results.isEmpty()) {
-              LaunchUtil.showAddServerActivity(this);
-            }
-          });
 
   @Override
   protected void onCreate(@Nullable Bundle savedInstanceState) {
     super.onCreate(savedInstanceState);
     if (savedInstanceState == null) {
-      onIntent(getIntent());
+      handleIntent(getIntent());
     }
   }
 
   @Override
   protected void onNewIntent(Intent intent) {
     super.onNewIntent(intent);
-    onIntent(intent);
+    handleIntent(intent);
   }
 
-  private void onIntent(Intent intent) {
+  private void handleIntent(Intent intent) {
     if (intent == null) {
       return;
     }
 
-    if (intent.hasExtra(PushConstants.SERVER_CONFIG_ID)) {
+    if (intent.hasExtra(PushConstants.HOSTNAME)) {
       SharedPreferences.Editor editor = RocketChatCache.get(this).edit();
-      editor.putString(RocketChatCache.KEY_SELECTED_SERVER_CONFIG_ID,
-          intent.getStringExtra(PushConstants.SERVER_CONFIG_ID));
+      editor.putString(RocketChatCache.KEY_SELECTED_SERVER_HOSTNAME,
+          intent.getStringExtra(PushConstants.HOSTNAME));
 
       if (intent.hasExtra(PushConstants.ROOM_ID)) {
         editor.putString(RocketChatCache.KEY_SELECTED_ROOM_ID,
@@ -74,24 +63,23 @@ abstract class AbstractAuthedActivity extends AbstractFragmentActivity {
     }
   }
 
-  private void updateServerConfigIdIfNeeded(SharedPreferences prefs) {
-    String newServerConfigId = prefs.getString(RocketChatCache.KEY_SELECTED_SERVER_CONFIG_ID, null);
-    if (serverConfigId == null) {
-      if (newServerConfigId != null && assertServerConfigExists(newServerConfigId, prefs)) {
-        updateServerConfigId(newServerConfigId);
+  private void updateHostnameIfNeeded(SharedPreferences prefs) {
+    String newHostname = prefs.getString(RocketChatCache.KEY_SELECTED_SERVER_HOSTNAME, null);
+    if (hostname == null) {
+      if (newHostname != null && assertServerRealmStoreExists(newHostname, prefs)) {
+        updateHostname(newHostname);
       }
     } else {
-      if (!serverConfigId.equals(newServerConfigId)
-          && assertServerConfigExists(newServerConfigId, prefs)) {
-        updateServerConfigId(newServerConfigId);
+      if (!hostname.equals(newHostname) && assertServerRealmStoreExists(newHostname, prefs)) {
+        updateHostname(newHostname);
       }
     }
   }
 
-  private boolean assertServerConfigExists(String serverConfigId, SharedPreferences prefs) {
-    if (RealmStore.get(serverConfigId) == null) {
+  private boolean assertServerRealmStoreExists(String hostname, SharedPreferences prefs) {
+    if (RealmStore.get(hostname) == null) {
       prefs.edit()
-          .remove(RocketChatCache.KEY_SELECTED_SERVER_CONFIG_ID)
+          .remove(RocketChatCache.KEY_SELECTED_SERVER_HOSTNAME)
           .remove(RocketChatCache.KEY_SELECTED_ROOM_ID)
           .apply();
       return false;
@@ -99,9 +87,9 @@ abstract class AbstractAuthedActivity extends AbstractFragmentActivity {
     return true;
   }
 
-  private void updateServerConfigId(String serverConfigId) {
-    this.serverConfigId = serverConfigId;
-    onServerConfigIdUpdated();
+  private void updateHostname(String hostname) {
+    this.hostname = hostname;
+    onHostnameUpdated();
   }
 
   private void updateRoomIdIfNeeded(SharedPreferences prefs) {
@@ -118,11 +106,11 @@ abstract class AbstractAuthedActivity extends AbstractFragmentActivity {
   }
 
   private boolean assertRoomSubscriptionExists(String roomId, SharedPreferences prefs) {
-    if (!assertServerConfigExists(serverConfigId, prefs)) {
+    if (!assertServerRealmStoreExists(hostname, prefs)) {
       return false;
     }
 
-    RoomSubscription room = RealmStore.get(serverConfigId).executeTransactionForRead(realm ->
+    RoomSubscription room = RealmStore.get(hostname).executeTransactionForRead(realm ->
         realm.where(RoomSubscription.class).equalTo(RoomSubscription.ROOM_ID, roomId).findFirst());
     if (room == null) {
       prefs.edit()
@@ -138,7 +126,7 @@ abstract class AbstractAuthedActivity extends AbstractFragmentActivity {
     onRoomIdUpdated();
   }
 
-  protected void onServerConfigIdUpdated() {
+  protected void onHostnameUpdated() {
   }
 
   protected void onRoomIdUpdated() {
@@ -147,11 +135,10 @@ abstract class AbstractAuthedActivity extends AbstractFragmentActivity {
   @Override
   protected void onResume() {
     super.onResume();
-    RocketChatService.keepAlive(this);
-    unconfiguredServersObserver.sub();
+    ConnectivityManager.getInstance(getApplicationContext()).keepAliveServer();
 
     SharedPreferences prefs = RocketChatCache.get(this);
-    updateServerConfigIdIfNeeded(prefs);
+    updateHostnameIfNeeded(prefs);
     updateRoomIdIfNeeded(prefs);
     prefs.registerOnSharedPreferenceChangeListener(preferenceChangeListener);
   }
@@ -161,7 +148,6 @@ abstract class AbstractAuthedActivity extends AbstractFragmentActivity {
     SharedPreferences prefs = RocketChatCache.get(this);
     prefs.unregisterOnSharedPreferenceChangeListener(preferenceChangeListener);
 
-    unconfiguredServersObserver.unsub();
     super.onPause();
   }
 

app/src/main/java/chat/rocket/android/activity/AddServerActivity.java

@@ -2,72 +2,18 @@ package chat.rocket.android.activity;
 
 import android.os.Bundle;
 import android.support.annotation.Nullable;
-import android.support.v4.app.Fragment;
 
-import java.util.UUID;
 import chat.rocket.android.R;
-import chat.rocket.android.RocketChatCache;
-import chat.rocket.android.fragment.server_config.InputHostnameFragment;
-import chat.rocket.android.fragment.server_config.WaitingFragment;
-import chat.rocket.android.model.ServerConfig;
-import chat.rocket.android.realm_helper.RealmListObserver;
-import chat.rocket.android.realm_helper.RealmObjectObserver;
-import chat.rocket.android.realm_helper.RealmStore;
+import chat.rocket.android.fragment.add_server.InputHostnameFragment;
 
 public class AddServerActivity extends AbstractFragmentActivity {
 
-  private String serverConfigId;
-
-  private RealmListObserver<ServerConfig> configuredServersObserver = RealmStore.getDefault()
-      .createListObserver(
-          realm -> realm.where(ServerConfig.class).isNotNull(ServerConfig.SESSION).findAll())
-      .setOnUpdateListener(results -> {
-        if (!results.isEmpty()) {
-          RocketChatCache.get(this).edit()
-              .putString(RocketChatCache.KEY_SELECTED_SERVER_CONFIG_ID, serverConfigId)
-              .apply();
-          finish();
-          overridePendingTransition(android.R.anim.fade_in, android.R.anim.fade_out);
-        }
-      });
-
-  private RealmObjectObserver<ServerConfig> targetServerConfigObserver = RealmStore.getDefault()
-      .createObjectObserver(realm ->
-          realm.where(ServerConfig.class).equalTo(ServerConfig.ID, serverConfigId))
-      .setOnUpdateListener(config -> {
-        if (config == null || config.getState() == ServerConfig.STATE_CONNECTION_ERROR) {
-          showFragment(new InputHostnameFragment());
-        } else {
-          showFragment(
-              WaitingFragment.create(getString(R.string.add_server_activity_waiting_server)));
-        }
-      });
-
   @Override
   protected void onCreate(@Nullable Bundle savedInstanceState) {
     super.onCreate(savedInstanceState);
 
     setContentView(R.layout.simple_screen);
-    setupServerConfigId();
-  }
-
-  private void setupServerConfigId() {
-    ServerConfig config = RealmStore.getDefault().executeTransactionForRead(realm ->
-        realm.where(ServerConfig.class).isNull(ServerConfig.HOSTNAME).findFirst());
-    if (config != null) {
-      serverConfigId = config.getServerConfigId();
-      return;
-    }
-
-    config = RealmStore.getDefault().executeTransactionForRead(realm ->
-        realm.where(ServerConfig.class)
-            .equalTo(ServerConfig.STATE, ServerConfig.STATE_CONNECTION_ERROR).findFirst());
-    if (config != null) {
-      serverConfigId = config.getServerConfigId();
-      return;
-    }
-
-    serverConfigId = UUID.randomUUID().toString();
+    showFragment(new InputHostnameFragment());
   }
 
   @Override
@@ -75,41 +21,6 @@ public class AddServerActivity extends AbstractFragmentActivity {
     return R.id.content;
   }
 
-  @Override
-  protected void onResume() {
-    super.onResume();
-    configuredServersObserver.sub();
-    targetServerConfigObserver.sub();
-  }
-
-  @Override
-  protected void onPause() {
-    configuredServersObserver.unsub();
-    targetServerConfigObserver.unsub();
-    super.onPause();
-  }
-
-  @Override
-  protected void showFragment(Fragment fragment) {
-    injectServerConfigIdArgTo(fragment);
-    super.showFragment(fragment);
-  }
-
-  @Override
-  protected void showFragmentWithBackStack(Fragment fragment) {
-    injectServerConfigIdArgTo(fragment);
-    super.showFragmentWithBackStack(fragment);
-  }
-
-  private void injectServerConfigIdArgTo(Fragment fragment) {
-    Bundle args = fragment.getArguments();
-    if (args == null) {
-      args = new Bundle();
-    }
-    args.putString(ServerConfig.ID, serverConfigId);
-    fragment.setArguments(args);
-  }
-
   @Override
   protected void onBackPressedNotHandled() {
     moveTaskToBack(true);

app/src/main/java/chat/rocket/android/activity/LoginActivity.java

@@ -7,23 +7,20 @@ import android.support.v4.app.Fragment;
 
 import chat.rocket.android.R;
 import chat.rocket.android.fragment.server_config.LoginFragment;
-import chat.rocket.android.fragment.server_config.RetryConnectFragment;
 import chat.rocket.android.fragment.server_config.RetryLoginFragment;
-import chat.rocket.android.fragment.server_config.WaitingFragment;
 import chat.rocket.android.helper.TextUtils;
-import chat.rocket.android.model.ServerConfig;
 import chat.rocket.android.model.internal.Session;
 import chat.rocket.android.realm_helper.RealmObjectObserver;
 import chat.rocket.android.realm_helper.RealmStore;
-import chat.rocket.android.service.RocketChatService;
+import chat.rocket.android.service.ConnectivityManager;
 
 /**
  * Activity for Login, Sign-up, and Retry connecting...
  */
 public class LoginActivity extends AbstractFragmentActivity {
+  public static final String KEY_HOSTNAME = "hostname";
 
-  private String serverConfigId;
-  private RealmObjectObserver<ServerConfig> serverConfigErrorObserver;
+  private String hostname;
   private RealmObjectObserver<Session> sessionObserver;
 
   @Override
@@ -41,53 +38,35 @@ public class LoginActivity extends AbstractFragmentActivity {
       return;
     }
 
-    serverConfigId = intent.getStringExtra(ServerConfig.ID);
-    if (TextUtils.isEmpty(serverConfigId)) {
+    hostname = intent.getStringExtra(KEY_HOSTNAME);
+    if (TextUtils.isEmpty(hostname)) {
       finish();
       return;
     }
 
-    serverConfigErrorObserver = RealmStore.getDefault()
-        .createObjectObserver(realm ->
-            realm.where(ServerConfig.class)
-                .equalTo(ServerConfig.ID, serverConfigId)
-                .equalTo(ServerConfig.STATE, ServerConfig.STATE_CONNECTION_ERROR))
-        .setOnUpdateListener(this::onRenderServerConfigError);
-
-    sessionObserver = RealmStore.get(serverConfigId)
+    sessionObserver = RealmStore.get(hostname)
         .createObjectObserver(Session::queryDefaultSession)
         .setOnUpdateListener(this::onRenderServerConfigSession);
 
     setContentView(R.layout.simple_screen);
-    showFragment(new WaitingFragment());
-    serverConfigErrorObserver.sub();
+    showFragment(new LoginFragment());
   }
 
   @Override
   protected void onResume() {
     super.onResume();
-    RocketChatService.keepAlive(this);
+    ConnectivityManager.getInstance(getApplicationContext()).keepAliveServer();
+    sessionObserver.sub();
   }
 
   @Override
   protected void onDestroy() {
     sessionObserver.unsub();
-    serverConfigErrorObserver.unsub();
     super.onDestroy();
   }
 
-  private void onRenderServerConfigError(ServerConfig config) {
-    if (config != null) {
-      sessionObserver.unsub();
-      showFragment(new RetryConnectFragment());
-    } else {
-      sessionObserver.sub();
-    }
-  }
-
   private void onRenderServerConfigSession(Session session) {
     if (session == null) {
-      showFragment(new LoginFragment());
       return;
     }
 
@@ -101,28 +80,26 @@ public class LoginActivity extends AbstractFragmentActivity {
       }
       return;
     }
-
-    showFragment(new LoginFragment());
   }
 
   @Override
   protected void showFragment(Fragment fragment) {
-    injectServerConfigIdArgTo(fragment);
+    injectHostnameArgTo(fragment);
     super.showFragment(fragment);
   }
 
   @Override
   protected void showFragmentWithBackStack(Fragment fragment) {
-    injectServerConfigIdArgTo(fragment);
+    injectHostnameArgTo(fragment);
     super.showFragmentWithBackStack(fragment);
   }
 
-  private void injectServerConfigIdArgTo(Fragment fragment) {
+  private void injectHostnameArgTo(Fragment fragment) {
     Bundle args = fragment.getArguments();
     if (args == null) {
       args = new Bundle();
     }
-    args.putString(ServerConfig.ID, serverConfigId);
+    args.putString(LoginActivity.KEY_HOSTNAME, hostname);
     fragment.setArguments(args);
   }
 

app/src/main/java/chat/rocket/android/activity/MainActivity.java

@@ -17,7 +17,6 @@ import chat.rocket.android.fragment.chatroom.RoomFragment;
 import chat.rocket.android.fragment.sidebar.SidebarMainFragment;
 import chat.rocket.android.helper.LogcatIfError;
 import chat.rocket.android.helper.TextUtils;
-import chat.rocket.android.model.ServerConfig;
 import chat.rocket.android.model.ddp.RoomSubscription;
 import chat.rocket.android.model.ddp.User;
 import chat.rocket.android.model.internal.Session;
@@ -25,6 +24,7 @@ import chat.rocket.android.realm_helper.RealmHelper;
 import chat.rocket.android.realm_helper.RealmListObserver;
 import chat.rocket.android.realm_helper.RealmObjectObserver;
 import chat.rocket.android.realm_helper.RealmStore;
+import chat.rocket.android.service.ConnectivityManager;
 import chat.rocket.android.widget.RoomToolbar;
 import hugo.weaving.DebugLog;
 
@@ -53,6 +53,10 @@ public class MainActivity extends AbstractAuthedActivity {
     if (roomId == null) {
       showFragment(new HomeFragment());
     }
+
+    if (shouldLaunchAddServerActivity()) {
+      LaunchUtil.showAddServerActivity(this);
+    }
   }
 
   @Override
@@ -82,15 +86,15 @@ public class MainActivity extends AbstractAuthedActivity {
   }
 
   private void setUserOnlineIfServerAvailable() {
-    if (serverConfigId != null) {
-      new MethodCallHelper(this, serverConfigId).setUserPresence(User.STATUS_ONLINE)
+    if (hostname != null) {
+      new MethodCallHelper(this, hostname).setUserPresence(User.STATUS_ONLINE)
           .continueWith(new LogcatIfError());
     }
   }
 
   private void setUserAwayIfServerAvailable() {
-    if (serverConfigId != null) {
-      new MethodCallHelper(this, serverConfigId).setUserPresence(User.STATUS_AWAY)
+    if (hostname != null) {
+      new MethodCallHelper(this, hostname).setUserPresence(User.STATUS_AWAY)
           .continueWith(new LogcatIfError());
     }
   }
@@ -150,10 +154,14 @@ public class MainActivity extends AbstractAuthedActivity {
     return false;
   }
 
+  private boolean shouldLaunchAddServerActivity() {
+    return ConnectivityManager.getInstance(getApplicationContext()).getServerList().isEmpty();
+  }
+
   @DebugLog
   @Override
-  protected void onServerConfigIdUpdated() {
-    super.onServerConfigIdUpdated();
+  protected void onHostnameUpdated() {
+    super.onHostnameUpdated();
     updateSessionObserver();
     updateUnreadRoomSubscriptionObserver();
     updateSidebarMainFragment();
@@ -165,11 +173,11 @@ public class MainActivity extends AbstractAuthedActivity {
       sessionObserver = null;
     }
 
-    if (serverConfigId == null) {
+    if (hostname == null) {
       return;
     }
 
-    RealmHelper realmHelper = RealmStore.get(serverConfigId);
+    RealmHelper realmHelper = RealmStore.get(hostname);
     if (realmHelper == null) {
       return;
     }
@@ -185,7 +193,7 @@ public class MainActivity extends AbstractAuthedActivity {
   private void onSessionChanged(@Nullable Session session) {
     if (session == null) {
       if (isForeground) {
-        LaunchUtil.showLoginActivity(this, serverConfigId);
+        LaunchUtil.showLoginActivity(this, hostname);
       }
       statusTicker.updateStatus(StatusTicker.STATUS_DISMISS, null);
     } else if (!TextUtils.isEmpty(session.getError())) {
@@ -193,17 +201,7 @@ public class MainActivity extends AbstractAuthedActivity {
           Snackbar.make(findViewById(getLayoutContainerForFragment()),
               R.string.fragment_retry_login_error_title, Snackbar.LENGTH_INDEFINITE)
               .setAction(R.string.fragment_retry_login_retry_title, view ->
-                  RealmStore.getDefault()
-                      .executeTransaction(realm -> {
-                        ServerConfig config = realm.where(ServerConfig.class)
-                            .equalTo(ServerConfig.ID, serverConfigId).findFirst();
-
-                        if (config != null
-                            && config.getState() == ServerConfig.STATE_CONNECTION_ERROR) {
-                          config.setState(ServerConfig.STATE_READY);
-                        }
-                        return null;
-                      }).continueWith(new LogcatIfError())));
+                  Session.retryLogin(RealmStore.get(hostname))));
     } else if (!session.isTokenVerified()) {
       statusTicker.updateStatus(StatusTicker.STATUS_TOKEN_LOGIN,
           Snackbar.make(findViewById(getLayoutContainerForFragment()),
@@ -219,11 +217,11 @@ public class MainActivity extends AbstractAuthedActivity {
       unreadRoomSubscriptionObserver = null;
     }
 
-    if (serverConfigId == null) {
+    if (hostname == null) {
       return;
     }
 
-    RealmHelper realmHelper = RealmStore.get(serverConfigId);
+    RealmHelper realmHelper = RealmStore.get(hostname);
     if (realmHelper == null) {
       return;
     }
@@ -253,7 +251,7 @@ public class MainActivity extends AbstractAuthedActivity {
 
   private void updateSidebarMainFragment() {
     getSupportFragmentManager().beginTransaction()
-        .replace(R.id.sidebar_fragment_container, SidebarMainFragment.create(serverConfigId))
+        .replace(R.id.sidebar_fragment_container, SidebarMainFragment.create(hostname))
         .commit();
   }
 
@@ -261,8 +259,8 @@ public class MainActivity extends AbstractAuthedActivity {
   protected void onRoomIdUpdated() {
     super.onRoomIdUpdated();
 
-    if (roomId != null && RoomFragment.canCreate(RealmStore.get(serverConfigId))) {
-      showFragment(RoomFragment.create(serverConfigId, roomId));
+    if (roomId != null && RoomFragment.canCreate(RealmStore.get(hostname))) {
+      showFragment(RoomFragment.create(hostname, roomId));
       closeSidebarIfNeeded();
     } else {
       showFragment(new HomeFragment());

app/src/main/java/chat/rocket/android/api/DDPClientWrapper.java

 package chat.rocket.android.api;
 
 import android.support.annotation.Nullable;
+import org.json.JSONArray;
+import org.json.JSONException;
 
+import java.util.UUID;
 import bolts.Task;
 import chat.rocket.android.helper.OkHttpHelper;
 import chat.rocket.android.helper.TextUtils;
@@ -9,11 +12,6 @@ import chat.rocket.android.log.RCLog;
 import chat.rocket.android_ddp.DDPClient;
 import chat.rocket.android_ddp.DDPClientCallback;
 import chat.rocket.android_ddp.DDPSubscription;
-import java.util.UUID;
-
-import org.json.JSONArray;
-import org.json.JSONException;
-
 import rx.Observable;
 
 /**
@@ -44,13 +42,6 @@ public class DDPClientWrapper {
     return ddpClient.connect(protocol + hostname + "/websocket", session);
   }
 
-  /**
-   * Returns whether DDP client is connected to WebSocket server.
-   */
-  public boolean isConnected() {
-    return ddpClient.isConnected();
-  }
-
   /**
    * close connection.
    */
@@ -82,10 +73,6 @@ public class DDPClientWrapper {
     return ddpClient.getSubscriptionCallback();
   }
 
-  private String generateId(String method) {
-    return method + "-" + UUID.randomUUID().toString().replace("-", "");
-  }
-
   /**
    * Execute raw RPC.
    */
@@ -117,4 +104,22 @@ public class DDPClientWrapper {
       return Task.forError(exception);
     }
   }
+
+  /**
+   * check WebSocket connectivity with ping.
+   */
+  public Task<Void> ping() {
+    final String pingId = UUID.randomUUID().toString();
+    RCLog.d("ping[%s] >", pingId);
+    return ddpClient.ping(pingId)
+        .continueWithTask(task -> {
+          if (task.isFaulted()) {
+            RCLog.d(task.getError(), "ping[%s] xxx failed xxx", pingId);
+            return Task.forError(task.getError());
+          } else {
+            RCLog.d("pong[%s] <", pingId);
+            return Task.forResult(null);
+          }
+        });
+  }
 }

app/src/main/java/chat/rocket/android/api/FileUploadingHelper.java

@@ -7,17 +7,18 @@ import org.json.JSONObject;
 import bolts.Task;
 import chat.rocket.android.helper.TextUtils;
 import chat.rocket.android.realm_helper.RealmHelper;
+import chat.rocket.android.service.DDPClientRef;
 
 /**
  * MethodCall for uploading file.
  */
 public class FileUploadingHelper extends MethodCallHelper {
-  public FileUploadingHelper(Context context, String serverConfigId) {
-    super(context, serverConfigId);
+  public FileUploadingHelper(Context context, String hostname) {
+    super(context, hostname);
   }
 
-  public FileUploadingHelper(RealmHelper realmHelper, DDPClientWrapper ddpClient) {
-    super(realmHelper, ddpClient);
+  public FileUploadingHelper(RealmHelper realmHelper, DDPClientRef ddpClientRef) {
+    super(realmHelper, ddpClientRef);
   }
 
   public Task<JSONObject> uploadRequest(String filename, long filesize, String mimeType,

app/src/main/java/chat/rocket/android/api/MethodCallHelper.java

@@ -19,6 +19,7 @@ import chat.rocket.android.model.internal.MethodCall;
 import chat.rocket.android.model.internal.Session;
 import chat.rocket.android.realm_helper.RealmHelper;
 import chat.rocket.android.realm_helper.RealmStore;
+import chat.rocket.android.service.DDPClientRef;
 import chat.rocket.android_ddp.DDPClientCallback;
 import hugo.weaving.DebugLog;
 
@@ -36,30 +37,30 @@ public class MethodCallHelper {
       task -> Task.forResult(new JSONArray(task.getResult()));
   protected final Context context;
   protected final RealmHelper realmHelper;
-  protected final DDPClientWrapper ddpClient;
+  protected final DDPClientRef ddpClientRef;
 
   /**
-   * initialize with Context and ServerConfigId.
+   * initialize with Context and hostname.
    */
-  public MethodCallHelper(Context context, String serverConfigId) {
+  public MethodCallHelper(Context context, String hostname) {
     this.context = context;
-    this.realmHelper = RealmStore.get(serverConfigId);
-    ddpClient = null;
+    this.realmHelper = RealmStore.get(hostname);
+    ddpClientRef = null;
   }
 
   /**
    * initialize with RealmHelper and DDPClient.
    */
-  public MethodCallHelper(RealmHelper realmHelper, DDPClientWrapper ddpClient) {
+  public MethodCallHelper(RealmHelper realmHelper, DDPClientRef ddpClientRef) {
     this.context = null;
     this.realmHelper = realmHelper;
-    this.ddpClient = ddpClient;
+    this.ddpClientRef = ddpClientRef;
   }
 
   @DebugLog
   private Task<String> executeMethodCall(String methodName, String param, long timeout) {
-    if (ddpClient != null) {
-      return ddpClient.rpc(UUID.randomUUID().toString(), methodName, param, timeout)
+    if (ddpClientRef != null) {
+      return ddpClientRef.get().rpc(UUID.randomUUID().toString(), methodName, param, timeout)
           .onSuccessTask(task -> Task.forResult(task.getResult().result));
     } else {
       return MethodCall.execute(context, realmHelper, methodName, param, timeout);

app/src/main/java/chat/rocket/android/api/RaixPushHelper.java

@@ -8,15 +8,16 @@ import org.json.JSONObject;
 
 import bolts.Task;
 import chat.rocket.android.realm_helper.RealmHelper;
+import chat.rocket.android.service.DDPClientRef;
 
 public class RaixPushHelper extends MethodCallHelper {
-  public RaixPushHelper(Context context, String serverConfigId) {
-    super(context, serverConfigId);
+  public RaixPushHelper(Context context, String hostname) {
+    super(context, hostname);
   }
 
   public RaixPushHelper(RealmHelper realmHelper,
-                        DDPClientWrapper ddpClient) {
-    super(realmHelper, ddpClient);
+                        DDPClientRef ddpClientRef) {
+    super(realmHelper, ddpClientRef);
   }
 
   public Task<Void> pushUpdate(@NonNull String pushId, @NonNull String gcmToken,

app/src/main/java/chat/rocket/android/fragment/server_config/InputHostnameFragment.java → app/src/main/java/chat/rocket/android/fragment/add_server/InputHostnameFragment.java

-package chat.rocket.android.fragment.server_config;
+package chat.rocket.android.fragment.add_server;
 
 import android.support.design.widget.Snackbar;
 import android.widget.TextView;
-import org.json.JSONObject;
 
 import chat.rocket.android.BuildConfig;
+import chat.rocket.android.LaunchUtil;
 import chat.rocket.android.R;
 import chat.rocket.android.RocketChatCache;
 import chat.rocket.android.api.rest.DefaultServerPolicyApi;
 import chat.rocket.android.api.rest.ServerPolicyApi;
-import chat.rocket.android.helper.LogcatIfError;
+import chat.rocket.android.fragment.AbstractFragment;
 import chat.rocket.android.helper.OkHttpHelper;
 import chat.rocket.android.helper.ServerPolicyApiValidationHelper;
 import chat.rocket.android.helper.ServerPolicyHelper;
 import chat.rocket.android.helper.TextUtils;
-import chat.rocket.android.model.ServerConfig;
-import chat.rocket.android.realm_helper.RealmObjectObserver;
-import chat.rocket.android.realm_helper.RealmStore;
+import chat.rocket.android.service.ConnectivityManager;
+import chat.rocket.android.service.ConnectivityManagerApi;
 import rx.Subscription;
 import rx.android.schedulers.AndroidSchedulers;
 import rx.schedulers.Schedulers;
@@ -24,12 +23,7 @@ import rx.schedulers.Schedulers;
 /**
  * Input server host.
  */
-public class InputHostnameFragment extends AbstractServerConfigFragment {
-  RealmObjectObserver<ServerConfig> serverConfigObserver = RealmStore.getDefault()
-      .createObjectObserver(realm ->
-          realm.where(ServerConfig.class).equalTo(ServerConfig.ID, serverConfigId))
-      .setOnUpdateListener(this::onRenderServerConfig);
-
+public class InputHostnameFragment extends AbstractFragment {
   Subscription serverPolicySubscription;
 
   public InputHostnameFragment() {
@@ -45,8 +39,6 @@ public class InputHostnameFragment extends AbstractServerConfigFragment {
     setupVersionInfo();
 
     rootView.findViewById(R.id.btn_connect).setOnClickListener(view -> handleConnect());
-
-    serverConfigObserver.sub();
   }
 
   private void setupVersionInfo() {
@@ -67,9 +59,12 @@ public class InputHostnameFragment extends AbstractServerConfigFragment {
       serverPolicySubscription.unsubscribe();
     }
 
+    rootView.findViewById(R.id.btn_connect).setEnabled(false);
+
     serverPolicySubscription = ServerPolicyHelper.isApiVersionValid(validationHelper)
         .subscribeOn(Schedulers.io())
         .observeOn(AndroidSchedulers.mainThread())
+        .doOnTerminate(() -> rootView.findViewById(R.id.btn_connect).setEnabled(true))
         .subscribe(
             serverValidation -> {
               if (serverValidation.isValid()) {
@@ -85,7 +80,6 @@ public class InputHostnameFragment extends AbstractServerConfigFragment {
 
   @Override
   public void onDestroyView() {
-    serverConfigObserver.unsub();
     if (serverPolicySubscription != null) {
       serverPolicySubscription.unsubscribe();
     }
@@ -100,36 +94,19 @@ public class InputHostnameFragment extends AbstractServerConfigFragment {
 
   private void onServerValid(final String hostname, boolean usesSecureConnection) {
     RocketChatCache.get(getContext()).edit()
-        .putString(RocketChatCache.KEY_SELECTED_SERVER_CONFIG_ID, serverConfigId)
+        .putString(RocketChatCache.KEY_SELECTED_SERVER_HOSTNAME, hostname)
         .apply();
 
-    RealmStore.getDefault().executeTransaction(
-        realm -> realm.createOrUpdateObjectFromJson(ServerConfig.class,
-            new JSONObject().put(ServerConfig.ID, serverConfigId)
-                .put(ServerConfig.HOSTNAME, hostname)
-                .put(ServerConfig.ERROR, JSONObject.NULL)
-                .put(ServerConfig.SESSION, JSONObject.NULL)
-                .put(ServerConfig.SECURE_CONNECTION, usesSecureConnection)
-                .put(ServerConfig.STATE, ServerConfig.STATE_READY)))
-        .continueWith(new LogcatIfError());
+    ConnectivityManagerApi connectivityManager =
+        ConnectivityManager.getInstance(getContext().getApplicationContext());
+    connectivityManager.addOrUpdateServer(hostname, hostname, !usesSecureConnection);
+    connectivityManager.keepAliveServer();
+
+    LaunchUtil.showMainActivity(getContext());
+    getActivity().overridePendingTransition(android.R.anim.fade_in, android.R.anim.fade_out);
   }
 
   private void showError(String errString) {
     Snackbar.make(rootView, errString, Snackbar.LENGTH_LONG).show();
   }
-
-  private void onRenderServerConfig(ServerConfig config) {
-    if (config == null) {
-      return;
-    }
-
-    final TextView editor = (TextView) rootView.findViewById(R.id.editor_hostname);
-
-    if (!TextUtils.isEmpty(config.getHostname())) {
-      editor.setText(config.getHostname());
-    }
-    if (!TextUtils.isEmpty(config.getError())) {
-      showError(config.getError());
-    }
-  }
 }

app/src/main/java/chat/rocket/android/fragment/chatroom/RoomFragment.java

@@ -34,9 +34,9 @@ import chat.rocket.android.helper.OnBackPressListener;
 import chat.rocket.android.helper.RecyclerViewAutoScrollManager;
 import chat.rocket.android.helper.RecyclerViewScrolledToBottomListener;
 import chat.rocket.android.helper.TextUtils;
+import chat.rocket.android.layouthelper.chatroom.AbstractNewMessageIndicatorManager;
 import chat.rocket.android.layouthelper.chatroom.MessageFormManager;
 import chat.rocket.android.layouthelper.chatroom.MessageListAdapter;
-import chat.rocket.android.layouthelper.chatroom.AbstractNewMessageIndicatorManager;
 import chat.rocket.android.layouthelper.chatroom.PairedMessage;
 import chat.rocket.android.layouthelper.extra_action.AbstractExtraActionItem;
 import chat.rocket.android.layouthelper.extra_action.MessageExtraActionBehavior;
@@ -45,7 +45,6 @@ import chat.rocket.android.layouthelper.extra_action.upload.AudioUploadActionIte
 import chat.rocket.android.layouthelper.extra_action.upload.ImageUploadActionItem;
 import chat.rocket.android.layouthelper.extra_action.upload.VideoUploadActionItem;
 import chat.rocket.android.log.RCLog;
-import chat.rocket.android.model.ServerConfig;
 import chat.rocket.android.model.SyncState;
 import chat.rocket.android.model.ddp.Message;
 import chat.rocket.android.model.ddp.RoomSubscription;
@@ -56,7 +55,7 @@ import chat.rocket.android.realm_helper.RealmHelper;
 import chat.rocket.android.realm_helper.RealmModelListAdapter;
 import chat.rocket.android.realm_helper.RealmObjectObserver;
 import chat.rocket.android.realm_helper.RealmStore;
-import chat.rocket.android.service.RocketChatService;
+import chat.rocket.android.service.ConnectivityManager;
 import chat.rocket.android.widget.internal.ExtraActionPickerDialogFragment;
 import chat.rocket.android.widget.message.MessageFormLayout;
 import permissions.dispatcher.NeedsPermission;
@@ -72,11 +71,10 @@ public class RoomFragment extends AbstractChatRoomFragment
 
   private static final int DIALOG_ID = 1;
 
-  private String serverConfigId;
+  private String hostname;
   private RealmHelper realmHelper;
   private String roomId;
   private RealmObjectObserver<RoomSubscription> roomObserver;
-  private String hostname;
   private String userId;
   private String token;
   private LoadMoreScrollListener scrollListener;
@@ -103,9 +101,9 @@ public class RoomFragment extends AbstractChatRoomFragment
   /**
    * create fragment with roomId.
    */
-  public static RoomFragment create(String serverConfigId, String roomId) {
+  public static RoomFragment create(String hostname, String roomId) {
     Bundle args = new Bundle();
-    args.putString("serverConfigId", serverConfigId);
+    args.putString("hostname", hostname);
     args.putString("roomId", roomId);
     RoomFragment fragment = new RoomFragment();
     fragment.setArguments(args);
@@ -117,14 +115,9 @@ public class RoomFragment extends AbstractChatRoomFragment
     super.onCreate(savedInstanceState);
 
     Bundle args = getArguments();
-    serverConfigId = args.getString("serverConfigId");
-    realmHelper = RealmStore.get(serverConfigId);
+    hostname = args.getString("hostname");
+    realmHelper = RealmStore.get(hostname);
     roomId = args.getString("roomId");
-    hostname = RealmStore.getDefault().executeTransactionForRead(realm ->
-        realm.where(ServerConfig.class)
-            .equalTo(ServerConfig.ID, serverConfigId)
-            .isNotNull(ServerConfig.HOSTNAME)
-            .findFirst()).getHostname();
     userId = realmHelper.executeTransactionForRead(realm ->
         User.queryCurrentUser(realm).findFirst()).getId();
     token = realmHelper.executeTransactionForRead(realm ->
@@ -281,7 +274,7 @@ public class RoomFragment extends AbstractChatRoomFragment
   private void setupSideMenu() {
     View sideMenu = rootView.findViewById(R.id.room_side_menu);
     sideMenu.findViewById(R.id.btn_users).setOnClickListener(view -> {
-      UsersOfRoomDialogFragment.create(serverConfigId, roomId, hostname)
+      UsersOfRoomDialogFragment.create(roomId, hostname)
           .show(getFragmentManager(), UsersOfRoomDialogFragment.class.getSimpleName());
       closeSideMenuIfNeeded();
     });
@@ -347,7 +340,7 @@ public class RoomFragment extends AbstractChatRoomFragment
     String uplId = new FileUploadHelper(getContext(), realmHelper)
         .requestUploading(roomId, data.getData());
     if (!TextUtils.isEmpty(uplId)) {
-      FileUploadProgressDialogFragment.create(serverConfigId, roomId, uplId)
+      FileUploadProgressDialogFragment.create(hostname, roomId, uplId)
           .show(getFragmentManager(), FileUploadProgressDialogFragment.class.getSimpleName());
     } else {
       // show error.
@@ -406,7 +399,8 @@ public class RoomFragment extends AbstractChatRoomFragment
           .put(LoadMessageProcedure.RESET, true));
       return null;
     }).onSuccessTask(task -> {
-      RocketChatService.keepAlive(getContext());
+      ConnectivityManager.getInstance(getContext().getApplicationContext())
+          .keepAliveServer();
       return task;
     }).continueWith(new LogcatIfError());
   }
@@ -427,7 +421,8 @@ public class RoomFragment extends AbstractChatRoomFragment
       }
       return null;
     }).onSuccessTask(task -> {
-      RocketChatService.keepAlive(getContext());
+      ConnectivityManager.getInstance(getContext().getApplicationContext())
+          .keepAliveServer();
       return task;
     }).continueWith(new LogcatIfError());
   }
@@ -436,7 +431,7 @@ public class RoomFragment extends AbstractChatRoomFragment
     RoomSubscription room = realmHelper.executeTransactionForRead(realm ->
         realm.where(RoomSubscription.class).equalTo(RoomSubscription.ROOM_ID, roomId).findFirst());
     if (room != null && room.isAlert()) {
-      new MethodCallHelper(getContext(), serverConfigId).readMessages(roomId)
+      new MethodCallHelper(getContext(), hostname).readMessages(roomId)
           .continueWith(new LogcatIfError());
     }
   }

app/src/main/java/chat/rocket/android/fragment/chatroom/dialog/AbstractChatRoomDialogFragment.java

@@ -31,8 +31,8 @@ abstract class AbstractChatRoomDialogFragment extends BottomSheetDialogFragment
   }
 
   protected void handleArgs(@NonNull Bundle args) {
-    String serverConfigId = args.getString("serverConfigId");
-    realmHelper = RealmStore.get(serverConfigId);
+    String hostname = args.getString("hostname");
+    realmHelper = RealmStore.get(hostname);
     roomId = args.getString("roomId");
   }
 

app/src/main/java/chat/rocket/android/fragment/chatroom/dialog/FileUploadProgressDialogFragment.java

@@ -25,10 +25,10 @@ public class FileUploadProgressDialogFragment extends AbstractChatRoomDialogFrag
   public FileUploadProgressDialogFragment() {
   }
 
-  public static FileUploadProgressDialogFragment create(String serverConfigId,
+  public static FileUploadProgressDialogFragment create(String hostname,
                                                         String roomId, String uplId) {
     Bundle args = new Bundle();
-    args.putString("serverConfigId", serverConfigId);
+    args.putString("hostname", hostname);
     args.putString("roomId", roomId);
     args.putString("uplId", uplId);
 

app/src/main/java/chat/rocket/android/fragment/chatroom/dialog/UsersOfRoomDialogFragment.java

@@ -20,7 +20,7 @@ import chat.rocket.android.log.RCLog;
 import chat.rocket.android.model.SyncState;
 import chat.rocket.android.model.internal.GetUsersOfRoomsProcedure;
 import chat.rocket.android.realm_helper.RealmObjectObserver;
-import chat.rocket.android.service.RocketChatService;
+import chat.rocket.android.service.ConnectivityManager;
 
 /**
  * Dialog to show members in a room.
@@ -37,12 +37,10 @@ public class UsersOfRoomDialogFragment extends AbstractChatRoomDialogFragment {
   /**
    * create UsersOfRoomDialogFragment with required parameters.
    */
-  public static UsersOfRoomDialogFragment create(String serverConfigId,
-                                                 String roomId, String hostname) {
+  public static UsersOfRoomDialogFragment create(String roomId, String hostname) {
     Bundle args = new Bundle();
-    args.putString("serverConfigId", serverConfigId);
-    args.putString("roomId", roomId);
     args.putString("hostname", hostname);
+    args.putString("roomId", roomId);
 
     UsersOfRoomDialogFragment fragment = new UsersOfRoomDialogFragment();
     fragment.setArguments(args);
@@ -91,7 +89,8 @@ public class UsersOfRoomDialogFragment extends AbstractChatRoomDialogFragment {
           .put("showAll", true));
       return null;
     }).onSuccessTask(task -> {
-      RocketChatService.keepAlive(getContext());
+      ConnectivityManager.getInstance(getContext().getApplicationContext())
+          .keepAliveServer();
       return task;
     }).continueWith(new LogcatIfError());
   }

app/src/main/java/chat/rocket/android/fragment/oauth/AbstractOAuthFragment.java

@@ -14,13 +14,11 @@ import chat.rocket.android.api.MethodCallHelper;
 import chat.rocket.android.fragment.AbstractWebViewFragment;
 import chat.rocket.android.helper.LogcatIfError;
 import chat.rocket.android.log.RCLog;
-import chat.rocket.android.model.ServerConfig;
 import chat.rocket.android.model.ddp.MeteorLoginServiceConfiguration;
 import chat.rocket.android.realm_helper.RealmStore;
 
 public abstract class AbstractOAuthFragment extends AbstractWebViewFragment {
 
-  protected String serverConfigId;
   protected String hostname;
   private String url;
   private boolean resultOK;
@@ -31,7 +29,7 @@ public abstract class AbstractOAuthFragment extends AbstractWebViewFragment {
 
   private boolean hasValidArgs(Bundle args) {
     return args != null
-        && args.containsKey("serverConfigId");
+        && args.containsKey("hostname");
   }
 
   protected final String getStateString() {
@@ -52,22 +50,19 @@ public abstract class AbstractOAuthFragment extends AbstractWebViewFragment {
     Bundle args = getArguments();
     if (!hasValidArgs(args)) {
       throw new IllegalArgumentException(
-          "serverConfigId required");
+          "hostname required");
     }
 
-    serverConfigId = args.getString("serverConfigId");
-    ServerConfig serverConfig = RealmStore.getDefault().executeTransactionForRead(realm ->
-        realm.where(ServerConfig.class).equalTo(ServerConfig.ID, serverConfigId).findFirst());
+    hostname = args.getString("hostname");
     MeteorLoginServiceConfiguration oauthConfig =
-        RealmStore.get(serverConfigId).executeTransactionForRead(realm ->
+        RealmStore.get(hostname).executeTransactionForRead(realm ->
             realm.where(MeteorLoginServiceConfiguration.class)
                 .equalTo(MeteorLoginServiceConfiguration.SERVICE, getOAuthServiceName())
                 .findFirst());
-    if (serverConfig == null || oauthConfig == null) {
+    if (oauthConfig == null) {
       throw new IllegalArgumentException(
-          "Invalid serverConfigId given,");
+          "Invalid hostname given,");
     }
-    hostname = serverConfig.getHostname();
     url = generateURL(oauthConfig);
   }
 
@@ -114,7 +109,7 @@ public abstract class AbstractOAuthFragment extends AbstractWebViewFragment {
   }
 
   private void handleOAuthCallback(final String credentialToken, final String credentialSecret) {
-    new MethodCallHelper(getContext(), serverConfigId)
+    new MethodCallHelper(getContext(), hostname)
         .loginWithOAuth(credentialToken, credentialSecret)
         .continueWith(new LogcatIfError());
   }

app/src/main/java/chat/rocket/android/fragment/server_config/AbstractServerConfigFragment.java

@@ -5,11 +5,12 @@ import android.support.annotation.Nullable;
 import android.support.v4.app.Fragment;
 
 import chat.rocket.android.R;
+import chat.rocket.android.activity.LoginActivity;
 import chat.rocket.android.fragment.AbstractFragment;
 import chat.rocket.android.helper.TextUtils;
 
 abstract class AbstractServerConfigFragment extends AbstractFragment {
-  protected String serverConfigId;
+  protected String hostname;
 
   @Override
   public void onCreate(@Nullable Bundle savedInstanceState) {
@@ -21,8 +22,8 @@ abstract class AbstractServerConfigFragment extends AbstractFragment {
       return;
     }
 
-    serverConfigId = args.getString("serverConfigId");
-    if (TextUtils.isEmpty(serverConfigId)) {
+    hostname = args.getString(LoginActivity.KEY_HOSTNAME);
+    if (TextUtils.isEmpty(hostname)) {
       finish();
       return;
     }

app/src/main/java/chat/rocket/android/fragment/server_config/LoginFragment.java

@@ -32,7 +32,7 @@ public class LoginFragment extends AbstractServerConfigFragment {
   @Override
   public void onCreate(@Nullable Bundle savedInstanceState) {
     super.onCreate(savedInstanceState);
-    authProvidersObserver = RealmStore.get(serverConfigId)
+    authProvidersObserver = RealmStore.get(hostname)
         .createListObserver(realm -> realm.where(MeteorLoginServiceConfiguration.class).findAll())
         .setOnUpdateListener(this::onRenderAuthProviders);
   }
@@ -52,7 +52,7 @@ public class LoginFragment extends AbstractServerConfigFragment {
       view.setEnabled(false);
       waitingView.setVisibility(View.VISIBLE);
 
-      new MethodCallHelper(getContext(), serverConfigId)
+      new MethodCallHelper(getContext(), hostname)
           .loginWithEmail(username.toString(), passwd.toString())
           .continueWith(task -> {
             if (task.isFaulted()) {
@@ -65,7 +65,7 @@ public class LoginFragment extends AbstractServerConfigFragment {
     });
 
     final View btnUserRegistration = rootView.findViewById(R.id.btn_user_registration);
-    btnUserRegistration.setOnClickListener(view -> UserRegistrationDialogFragment.create(serverConfigId,
+    btnUserRegistration.setOnClickListener(view -> UserRegistrationDialogFragment.create(hostname,
         txtUsername.getText().toString(), txtPasswd.getText().toString())
         .show(getFragmentManager(), UserRegistrationDialogFragment.class.getSimpleName()));
   }
@@ -96,7 +96,7 @@ public class LoginFragment extends AbstractServerConfigFragment {
             }
             if (fragment != null) {
               Bundle args = new Bundle();
-              args.putString("serverConfigId", serverConfigId);
+              args.putString("hostname", hostname);
               fragment.setArguments(args);
               showFragmentWithBackStack(fragment);
             }

app/src/main/java/chat/rocket/android/fragment/server_config/RetryConnectFragment.java

-package chat.rocket.android.fragment.server_config;
-
-import android.os.Bundle;
-import android.support.annotation.Nullable;
-import android.view.View;
-import android.widget.TextView;
-
-import chat.rocket.android.R;
-import chat.rocket.android.helper.LogcatIfError;
-import chat.rocket.android.helper.TextUtils;
-import chat.rocket.android.model.ServerConfig;
-import chat.rocket.android.realm_helper.RealmObjectObserver;
-import chat.rocket.android.realm_helper.RealmStore;
-
-/**
- * Login screen.
- */
-public class RetryConnectFragment extends AbstractServerConfigFragment {
-  private RealmObjectObserver<ServerConfig> serverConfigObserver;
-
-  @Override
-  protected int getLayout() {
-    return R.layout.fragment_retry_login;
-  }
-
-  @Override
-  public void onCreate(@Nullable Bundle savedInstanceState) {
-    super.onCreate(savedInstanceState);
-    serverConfigObserver = RealmStore.getDefault()
-        .createObjectObserver(realm ->
-            realm.where(ServerConfig.class).equalTo(ServerConfig.ID, serverConfigId))
-        .setOnUpdateListener(this::onRenderServerConfig);
-  }
-
-  @Override
-  protected void onSetupView() {
-    rootView.findViewById(R.id.waiting).setVisibility(View.GONE);
-
-    final View btnRetry = rootView.findViewById(R.id.btn_retry_login);
-    btnRetry.setOnClickListener(view -> {
-      RealmStore.getDefault()
-          .executeTransaction(realm -> {
-            ServerConfig config = realm.where(ServerConfig.class)
-                .equalTo(ServerConfig.ID, serverConfigId).findFirst();
-            if (config != null && config.getState() == ServerConfig.STATE_CONNECTION_ERROR) {
-              config.setState(ServerConfig.STATE_READY);
-            }
-            return null;
-          }).continueWith(new LogcatIfError());
-    });
-  }
-
-  private void onRenderServerConfig(ServerConfig config) {
-    if (config == null) {
-      return;
-    }
-
-    final String error = config.getError();
-    final TextView txtError = (TextView) rootView.findViewById(R.id.txt_error_description);
-    if (!TextUtils.isEmpty(error)) {
-      txtError.setText(error);
-    }
-
-    final int state = config.getState();
-    if (state == ServerConfig.STATE_CONNECTED) {
-      finish();
-    }
-    rootView.findViewById(R.id.btn_retry_login)
-        .setEnabled(state == ServerConfig.STATE_CONNECTION_ERROR);
-  }
-
-  @Override
-  public void onResume() {
-    super.onResume();
-    serverConfigObserver.sub();
-  }
-
-  @Override
-  public void onPause() {
-    serverConfigObserver.unsub();
-    super.onPause();
-  }
-}

app/src/main/java/chat/rocket/android/fragment/server_config/RetryLoginFragment.java

@@ -26,7 +26,7 @@ public class RetryLoginFragment extends AbstractServerConfigFragment {
   @Override
   public void onCreate(@Nullable Bundle savedInstanceState) {
     super.onCreate(savedInstanceState);
-    sessionObserver = RealmStore.get(serverConfigId)
+    sessionObserver = RealmStore.get(hostname)
         .createObjectObserver(Session::queryDefaultSession)
         .setOnUpdateListener(this::onRenderServerConfigSession);
   }
@@ -49,7 +49,7 @@ public class RetryLoginFragment extends AbstractServerConfigFragment {
         view.setEnabled(false);
         waitingView.setVisibility(View.VISIBLE);
 
-        new MethodCallHelper(getContext(), serverConfigId).loginWithToken(token)
+        new MethodCallHelper(getContext(), hostname).loginWithToken(token)
             .continueWith(task -> {
               if (task.isFaulted()) {
                 view.setEnabled(true);

app/src/main/java/chat/rocket/android/fragment/server_config/UserRegistrationDialogFragment.java

@@ -20,7 +20,7 @@ import chat.rocket.android.helper.TextUtils;
  * Dialog for user registration.
  */
 public class UserRegistrationDialogFragment extends DialogFragment {
-  private String serverConfigId;
+  private String hostname;
   private String username;
   private String email;
   private String password;
@@ -32,23 +32,23 @@ public class UserRegistrationDialogFragment extends DialogFragment {
   /**
    * create UserRegistrationDialogFragment with auto-detect email/username.
    */
-  public static UserRegistrationDialogFragment create(String serverConfigId,
+  public static UserRegistrationDialogFragment create(String hostname,
                                                       String usernameOrEmail, String password) {
     if (Patterns.EMAIL_ADDRESS.matcher(usernameOrEmail).matches()) {
-      return create(serverConfigId, null, usernameOrEmail, password);
+      return create(hostname, null, usernameOrEmail, password);
     } else {
-      return create(serverConfigId, usernameOrEmail, null, password);
+      return create(hostname, usernameOrEmail, null, password);
     }
   }
 
   /**
    * create UserRegistrationDialogFragment.
    */
-  public static UserRegistrationDialogFragment create(String serverConfigId,
+  public static UserRegistrationDialogFragment create(String hostname,
                                                       String username, String email,
                                                       String password) {
     Bundle args = new Bundle();
-    args.putString("serverConfigId", serverConfigId);
+    args.putString("hostname", hostname);
     if (!TextUtils.isEmpty(username)) {
       args.putString("username", username);
     }
@@ -69,7 +69,7 @@ public class UserRegistrationDialogFragment extends DialogFragment {
 
     Bundle args = getArguments();
     if (args != null) {
-      serverConfigId = args.getString("serverConfigId");
+      hostname = args.getString("hostname");
       username = args.getString("username");
       email = args.getString("email");
       password = args.getString("password");
@@ -113,7 +113,7 @@ public class UserRegistrationDialogFragment extends DialogFragment {
       email = txtEmail.getText().toString();
       password = txtPasswd.getText().toString();
 
-      MethodCallHelper methodCallHelper = new MethodCallHelper(getContext(), serverConfigId);
+      MethodCallHelper methodCallHelper = new MethodCallHelper(getContext(), hostname);
       methodCallHelper.registerUser(username, email, password, password)
           .onSuccessTask(task -> methodCallHelper.loginWithEmail(email, password))
           .onSuccessTask(task -> methodCallHelper.setUsername(username)) //TODO: should prompt!

app/src/main/java/chat/rocket/android/fragment/server_config/WaitingFragment.java

-package chat.rocket.android.fragment.server_config;
-
-import android.os.Bundle;
-import android.view.View;
-import android.widget.TextView;
-
-import chat.rocket.android.R;
-import chat.rocket.android.helper.TextUtils;
-
-/**
- * Just showing "connecting..." screen.
- */
-public class WaitingFragment extends AbstractServerConfigFragment {
-
-  private String caption;
-
-  public WaitingFragment() {
-  }
-
-  /**
-   * create new "Waiting..." screen with caption.
-   */
-  public static WaitingFragment create(String caption) {
-    Bundle args = new Bundle();
-    args.putString("caption", caption);
-    WaitingFragment fragment = new WaitingFragment();
-    fragment.setArguments(args);
-    return fragment;
-  }
-
-  @Override
-  protected int getLayout() {
-    return R.layout.fragment_waiting;
-  }
-
-  @Override
-  protected void onSetupView() {
-    Bundle args = getArguments();
-    if (args != null) {
-      caption = args.getString("caption");
-    }
-
-    TextView captionView = (TextView) rootView.findViewById(R.id.txt_caption);
-    if (TextUtils.isEmpty(caption)) {
-      captionView.setVisibility(View.GONE);
-    } else {
-      captionView.setText(caption);
-      captionView.setVisibility(View.VISIBLE);
-    }
-  }
-}

app/src/main/java/chat/rocket/android/fragment/sidebar/SidebarMainFragment.java

@@ -7,6 +7,8 @@ import android.widget.CompoundButton;
 import android.widget.ImageView;
 import android.widget.LinearLayout;
 import android.widget.TextView;
+import com.jakewharton.rxbinding.view.RxView;
+import com.jakewharton.rxbinding.widget.RxCompoundButton;
 
 import chat.rocket.android.BuildConfig;
 import chat.rocket.android.R;
@@ -14,12 +16,11 @@ import chat.rocket.android.RocketChatCache;
 import chat.rocket.android.api.MethodCallHelper;
 import chat.rocket.android.fragment.AbstractFragment;
 import chat.rocket.android.fragment.sidebar.dialog.AbstractAddRoomDialogFragment;
-import chat.rocket.android.fragment.sidebar.dialog.AddDirectMessageDialogFragment;
 import chat.rocket.android.fragment.sidebar.dialog.AddChannelDialogFragment;
+import chat.rocket.android.fragment.sidebar.dialog.AddDirectMessageDialogFragment;
 import chat.rocket.android.helper.LogcatIfError;
 import chat.rocket.android.helper.TextUtils;
 import chat.rocket.android.layouthelper.chatroom.RoomListManager;
-import chat.rocket.android.model.ServerConfig;
 import chat.rocket.android.model.ddp.RoomSubscription;
 import chat.rocket.android.model.ddp.User;
 import chat.rocket.android.realm_helper.RealmHelper;
@@ -28,14 +29,10 @@ import chat.rocket.android.realm_helper.RealmObjectObserver;
 import chat.rocket.android.realm_helper.RealmStore;
 import chat.rocket.android.renderer.UserRenderer;
 
-import com.jakewharton.rxbinding.view.RxView;
-import com.jakewharton.rxbinding.widget.RxCompoundButton;
-
 public class SidebarMainFragment extends AbstractFragment {
 
-  private String serverConfigId;
-  private RoomListManager roomListManager;
   private String hostname;
+  private RoomListManager roomListManager;
   private RealmListObserver<RoomSubscription> roomsObserver;
   private RealmObjectObserver<User> currentUserObserver;
   private MethodCallHelper methodCallHelper;
@@ -44,11 +41,11 @@ public class SidebarMainFragment extends AbstractFragment {
   }
 
   /**
-   * create SidebarMainFragment with serverConfigId.
+   * create SidebarMainFragment with hostname.
    */
-  public static SidebarMainFragment create(String serverConfigId) {
+  public static SidebarMainFragment create(String hostname) {
     Bundle args = new Bundle();
-    args.putString("serverConfigId", serverConfigId);
+    args.putString("hostname", hostname);
 
     SidebarMainFragment fragment = new SidebarMainFragment();
     fragment.setArguments(args);
@@ -60,15 +57,9 @@ public class SidebarMainFragment extends AbstractFragment {
     super.onCreate(savedInstanceState);
 
     Bundle args = getArguments();
-    serverConfigId = args == null ? null : args.getString("serverConfigId");
-    if (!TextUtils.isEmpty(serverConfigId)) {
-      ServerConfig config = RealmStore.getDefault().executeTransactionForRead(realm ->
-          realm.where(ServerConfig.class).equalTo(ServerConfig.ID, serverConfigId).findFirst());
-      if (config != null) {
-        hostname = config.getHostname();
-      }
-
-      RealmHelper realmHelper = RealmStore.get(serverConfigId);
+    hostname = args == null ? null : args.getString("hostname");
+    if (!TextUtils.isEmpty(hostname)) {
+      RealmHelper realmHelper = RealmStore.get(hostname);
       if (realmHelper != null) {
         roomsObserver = realmHelper
             .createListObserver(
@@ -80,14 +71,14 @@ public class SidebarMainFragment extends AbstractFragment {
             .createObjectObserver(User::queryCurrentUser)
             .setOnUpdateListener(this::onCurrentUser);
 
-        methodCallHelper = new MethodCallHelper(getContext(), serverConfigId);
+        methodCallHelper = new MethodCallHelper(getContext(), hostname);
       }
     }
   }
 
   @Override
   protected int getLayout() {
-    if (serverConfigId == null) {
+    if (hostname == null) {
       return R.layout.simple_screen;
     } else {
       return R.layout.fragment_sidebar_main;
@@ -96,7 +87,7 @@ public class SidebarMainFragment extends AbstractFragment {
 
   @Override
   protected void onSetupView() {
-    if (serverConfigId == null) {
+    if (hostname == null) {
       return;
     }
 
@@ -188,11 +179,11 @@ public class SidebarMainFragment extends AbstractFragment {
 
   private void setupAddChannelButton() {
     rootView.findViewById(R.id.btn_add_channel).setOnClickListener(view -> {
-      showAddRoomDialog(new AddChannelDialogFragment());
+      showAddRoomDialog(AddChannelDialogFragment.create(hostname));
     });
 
     rootView.findViewById(R.id.btn_add_direct_message).setOnClickListener(view -> {
-      showAddRoomDialog(new AddDirectMessageDialogFragment());
+      showAddRoomDialog(AddDirectMessageDialogFragment.create(hostname));
     });
   }
 
@@ -202,10 +193,6 @@ public class SidebarMainFragment extends AbstractFragment {
   }
 
   private void showAddRoomDialog(DialogFragment dialog) {
-    Bundle args = new Bundle();
-    args.putString("serverConfigId", serverConfigId);
-    args.putString("hostname", hostname);
-    dialog.setArguments(args);
     dialog.show(getFragmentManager(), AbstractAddRoomDialogFragment.class.getSimpleName());
   }
 

app/src/main/java/chat/rocket/android/fragment/sidebar/dialog/AbstractAddRoomDialogFragment.java

@@ -21,9 +21,7 @@ public abstract class AbstractAddRoomDialogFragment extends RxAppCompatDialogFra
   protected MethodCallHelper methodCall;
   protected String hostname;
 
-  protected
-  @LayoutRes
-  abstract int getLayout();
+  protected @LayoutRes abstract int getLayout();
 
   protected abstract void onSetupDialog();
 
@@ -38,10 +36,9 @@ public abstract class AbstractAddRoomDialogFragment extends RxAppCompatDialogFra
   }
 
   protected void handleArgs(@NonNull Bundle args) {
-    String serverConfigId = args.getString("serverConfigId");
-    realmHelper = RealmStore.get(serverConfigId);
-    methodCall = new MethodCallHelper(getContext(), serverConfigId);
     hostname = args.getString("hostname");
+    realmHelper = RealmStore.get(hostname);
+    methodCall = new MethodCallHelper(getContext(), hostname);
   }
 
   @Override

app/src/main/java/chat/rocket/android/fragment/sidebar/dialog/AddChannelDialogFragment.java

 package chat.rocket.android.fragment.sidebar.dialog;
 
+import android.os.Bundle;
 import android.view.View;
 import android.widget.CompoundButton;
 import android.widget.TextView;
@@ -17,6 +18,15 @@ public class AddChannelDialogFragment extends AbstractAddRoomDialogFragment {
   public AddChannelDialogFragment() {
   }
 
+  public static AddChannelDialogFragment create(String hostname) {
+    Bundle args = new Bundle();
+    args.putString("hostname", hostname);
+
+    AddChannelDialogFragment fragment = new AddChannelDialogFragment();
+    fragment.setArguments(args);
+    return fragment;
+  }
+
   @Override
   protected int getLayout() {
     return R.layout.dialog_add_channel;

app/src/main/java/chat/rocket/android/fragment/sidebar/dialog/AddDirectMessageDialogFragment.java

 package chat.rocket.android.fragment.sidebar.dialog;
 
+import android.os.Bundle;
 import android.view.View;
 import android.widget.AutoCompleteTextView;
 import android.widget.TextView;
@@ -18,7 +19,13 @@ import chat.rocket.android.realm_helper.RealmAutoCompleteAdapter;
  * add Direct Message.
  */
 public class AddDirectMessageDialogFragment extends AbstractAddRoomDialogFragment {
-  public AddDirectMessageDialogFragment() {
+  public static AddDirectMessageDialogFragment create(String hostname) {
+    Bundle args = new Bundle();
+    args.putString("hostname", hostname);
+
+    AddDirectMessageDialogFragment fragment = new AddDirectMessageDialogFragment();
+    fragment.setArguments(args);
+    return fragment;
   }
 
   @Override

app/src/main/java/chat/rocket/android/helper/RxHelper.java

+package chat.rocket.android.helper;
+
+import java.util.concurrent.TimeUnit;
+import rx.Observable;
+import rx.functions.Func1;
+
+/**
+ * Rx operator and so on.
+ */
+public class RxHelper {
+  public static Func1<Observable<? extends Throwable>, Observable<?>> exponentialBackoff(
+      int maxRetryCount, long base, TimeUnit unit) {
+
+    // ref: https://github.com/ReactiveX/RxJava/blob/a8ba158839b67246a742b6f1531995ffd7545c08/src/main/java/io/reactivex/Observable.java#L9601
+    return attempts -> attempts
+        .zipWith(Observable.range(0, maxRetryCount), (error, retryCount) -> retryCount)
+        .flatMap(retryCount -> Observable.timer(base * (long) Math.pow(2, retryCount), unit));
+  }
+}

app/src/main/java/chat/rocket/android/helper/ServerPolicyApiValidationHelper.java

@@ -13,10 +13,10 @@ public class ServerPolicyApiValidationHelper {
     this.serverPolicyApi = serverPolicyApi;
   }
 
-  public Observable<ServerPolicyHelper.ServerInfo> getApiVersion() {
+  public Observable<ServerPolicyHelper.ServerInfoResponse> getApiVersion() {
     return serverPolicyApi.getApiInfoSecurely()
         .onErrorResumeNext(serverPolicyApi.getApiInfoInsecurely())
-        .map(response -> new ServerPolicyHelper.ServerInfo(
+        .map(response -> new ServerPolicyHelper.ServerInfoResponse(
             response.getProtocol().equals(ServerPolicyApi.SECURE_PROTOCOL),
             response.getData()
         ));

app/src/main/java/chat/rocket/android/helper/ServerPolicyHelper.java

@@ -72,11 +72,11 @@ public class ServerPolicyHelper {
     return versionParts.length >= 3 && Integer.parseInt(versionParts[1]) >= 49;
   }
 
-  public static class ServerInfo {
+  public static class ServerInfoResponse {
     private final boolean secureConnection;
     private final JSONObject apiInfo;
 
-    public ServerInfo(boolean secureConnection, JSONObject apiInfo) {
+    public ServerInfoResponse(boolean secureConnection, JSONObject apiInfo) {
       this.secureConnection = secureConnection;
       this.apiInfo = apiInfo;
     }

app/src/main/java/chat/rocket/android/model/ServerConfig.java

-package chat.rocket.android.model;
-
-import io.realm.RealmObject;
-import io.realm.annotations.PrimaryKey;
-import org.json.JSONObject;
-
-import bolts.Task;
-import chat.rocket.android.helper.LogcatIfError;
-import chat.rocket.android.realm_helper.RealmStore;
-import hugo.weaving.DebugLog;
-
-/**
- * Server configuration.
- */
-public class ServerConfig extends RealmObject {
-
-  @SuppressWarnings({"PMD.ShortVariable"})
-  public static final String ID = "serverConfigId";
-  public static final String HOSTNAME = "hostname";
-  public static final String STATE = "state";
-  public static final String SESSION = "session";
-  public static final String SECURE_CONNECTION = "secureConnection";
-  public static final String ERROR = "error";
-
-  public static final int STATE_READY = 0;
-  public static final int STATE_CONNECTING = 1;
-  public static final int STATE_CONNECTED = 2;
-  public static final int STATE_CONNECTION_ERROR = 3;
-
-  @PrimaryKey private String serverConfigId;
-  private String hostname;
-  private int state;
-  private String session;
-  private boolean secureConnection;
-  private String error;
-
-  /**
-   * Log the server connection is lost due to some exception.
-   */
-  @DebugLog
-  public static void logConnectionError(String serverConfigId, Exception exception) {
-    RealmStore.getDefault().executeTransaction(
-        realm -> realm.createOrUpdateObjectFromJson(ServerConfig.class, new JSONObject()
-            .put(ID, serverConfigId)
-            .put(STATE, STATE_CONNECTION_ERROR)
-            .put(ERROR, exception.getMessage())))
-        .continueWith(new LogcatIfError());
-  }
-
-  /**
-   * Update the state of the ServerConfig with serverConfigId.
-   */
-  public static Task<Void> updateState(final String serverConfigId, int state) {
-    return RealmStore.getDefault().executeTransaction(realm -> {
-      ServerConfig config =
-          realm.where(ServerConfig.class).equalTo(ID, serverConfigId).findFirst();
-      if (config == null || config.getState() != state) {
-        realm.createOrUpdateObjectFromJson(ServerConfig.class, new JSONObject()
-            .put(ID, serverConfigId)
-            .put(STATE, state));
-      }
-      return null;
-    });
-  }
-
-  public String getServerConfigId() {
-    return serverConfigId;
-  }
-
-  public void setServerConfigId(String serverConfigId) {
-    this.serverConfigId = serverConfigId;
-  }
-
-  public String getHostname() {
-    return hostname;
-  }
-
-  public void setHostname(String hostname) {
-    this.hostname = hostname;
-  }
-
-  public int getState() {
-    return state;
-  }
-
-  public void setState(int state) {
-    this.state = state;
-  }
-
-  public String getSession() {
-    return session;
-  }
-
-  public void setSession(String session) {
-    this.session = session;
-  }
-
-  public boolean usesSecureConnection() {
-    return secureConnection;
-  }
-
-  public void setSecureConnection(boolean usesSecureConnection) {
-    this.secureConnection = usesSecureConnection;
-  }
-
-  public String getError() {
-    return error;
-  }
-
-  public void setError(String error) {
-    this.error = error;
-  }
-}

app/src/main/java/chat/rocket/android/model/internal/MethodCall.java

@@ -16,7 +16,7 @@ import chat.rocket.android.log.RCLog;
 import chat.rocket.android.model.SyncState;
 import chat.rocket.android.realm_helper.RealmHelper;
 import chat.rocket.android.realm_helper.RealmObjectObserver;
-import chat.rocket.android.service.RocketChatService;
+import chat.rocket.android.service.ConnectivityManager;
 
 public class MethodCall extends RealmObject {
 
@@ -89,7 +89,8 @@ public class MethodCall extends RealmObject {
         REF_MAP.put(newId, observer);
 
         if (context != null) {
-          RocketChatService.keepAlive(context);
+          ConnectivityManager.getInstance(context.getApplicationContext())
+              .keepAliveServer();
         }
       }
       return null;

app/src/main/java/chat/rocket/android/model/internal/Session.java

@@ -55,6 +55,24 @@ public class Session extends RealmObject {
     }
   }
 
+  /**
+   * retry authentication.
+   */
+  @DebugLog
+  public static void retryLogin(RealmHelper realmHelper) {
+    final Session session = realmHelper.executeTransactionForRead(realm ->
+        queryDefaultSession(realm).isNotNull(TOKEN).findFirst());
+
+    if (!session.isTokenVerified() || !TextUtils.isEmpty(session.getError())) {
+      realmHelper.executeTransaction(
+          realm -> realm.createOrUpdateObjectFromJson(Session.class, new JSONObject()
+              .put(ID, Session.DEFAULT_ID)
+              .put(TOKEN_VERIFIED, false)
+              .put(ERROR, JSONObject.NULL)))
+          .continueWith(new LogcatIfError());
+    }
+  }
+
   public int getSessionId() {
     return sessionId;
   }

app/src/main/java/chat/rocket/android/push/PushConstants.java

@@ -70,6 +70,6 @@ public interface PushConstants {
   String FORCE_START = "force-start";
 
   // RC specific constants
-  String SERVER_CONFIG_ID = "serverConfigId";
+  String HOSTNAME = "hostname";
   String ROOM_ID = "roomId";
 }
\ No newline at end of file

app/src/main/java/chat/rocket/android/push/PushNotificationHandler.java

@@ -20,7 +20,6 @@ import android.support.v4.util.SparseArrayCompat;
 import android.text.Html;
 import android.text.Spanned;
 import android.util.Log;
-
 import org.json.JSONArray;
 import org.json.JSONException;
 import org.json.JSONObject;
@@ -32,7 +31,6 @@ import java.net.URL;
 import java.util.ArrayList;
 import java.util.Random;
 import chat.rocket.android.activity.MainActivity;
-import chat.rocket.android.push.interactors.PushInteractor;
 
 public class PushNotificationHandler implements PushConstants {
 
@@ -64,8 +62,7 @@ public class PushNotificationHandler implements PushConstants {
     return messageMap.get(notId);
   }
 
-  public void showNotificationIfPossible(Context context, PushInteractor pushInteractor,
-                                         Bundle extras) {
+  public void showNotificationIfPossible(Context context, Bundle extras) {
 
     // Send a notification if there is a message or title, otherwise just send data
     String message = extras.getString(MESSAGE);
@@ -87,26 +84,21 @@ public class PushNotificationHandler implements PushConstants {
         extras.putString(TITLE, getAppName(context));
       }
 
-      createNotification(context, pushInteractor, extras);
+      createNotification(context, extras);
     }
   }
 
-  public void createNotification(Context context, PushInteractor pushInteractor, Bundle extras) {
+  public void createNotification(Context context, Bundle extras) {
     NotificationManager mNotificationManager =
         (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
     String appName = getAppName(context);
     String packageName = context.getPackageName();
     Resources resources = context.getResources();
 
-    String serverUrl = getServerUrl(extras);
+    String hostname = getHostname(extras);
     String roomId = getRoomId(extras);
 
-    if (serverUrl == null || roomId == null) {
-      return;
-    }
-
-    String serverConfigId = pushInteractor.getServerConfigId(serverUrl);
-    if (serverConfigId == null) {
+    if (hostname == null || roomId == null) {
       return;
     }
 
@@ -114,7 +106,7 @@ public class PushNotificationHandler implements PushConstants {
     Intent notificationIntent = new Intent(context, MainActivity.class);
     notificationIntent.addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP | Intent.FLAG_ACTIVITY_CLEAR_TOP);
     notificationIntent.putExtra(PUSH_BUNDLE, extras);
-    notificationIntent.putExtra(SERVER_CONFIG_ID, serverConfigId);
+    notificationIntent.putExtra(HOSTNAME, hostname);
     notificationIntent.putExtra(ROOM_ID, roomId);
     notificationIntent.putExtra(NOT_ID, notId);
 
@@ -634,7 +626,7 @@ public class PushNotificationHandler implements PushConstants {
     return count;
   }
 
-  private String getServerUrl(Bundle extras) {
+  private String getHostname(Bundle extras) {
     try {
       JSONObject jsonObject = new JSONObject(extras.getString("ejson", "[]"));
       if (!jsonObject.has("host")) {

app/src/main/java/chat/rocket/android/push/gcm/GCMIntentService.java

@@ -15,8 +15,6 @@ import java.util.ArrayList;
 import java.util.Iterator;
 import chat.rocket.android.push.PushConstants;
 import chat.rocket.android.push.PushNotificationHandler;
-import chat.rocket.android.push.interactors.DefaultPushInteractor;
-import chat.rocket.android.push.interactors.PushInteractor;
 
 @SuppressLint("NewApi")
 public class GCMIntentService extends GcmListenerService implements PushConstants {
@@ -33,13 +31,11 @@ public class GCMIntentService extends GcmListenerService implements PushConstant
 
     Context applicationContext = getApplicationContext();
 
-    PushInteractor pushInteractor = new DefaultPushInteractor();
-
     extras = normalizeExtras(applicationContext, extras);
 
     PushNotificationHandler pushNotificationHandler = new PushNotificationHandler();
 
-    pushNotificationHandler.showNotificationIfPossible(applicationContext, pushInteractor, extras);
+    pushNotificationHandler.showNotificationIfPossible(applicationContext, extras);
   }
 
   /*

app/src/main/java/chat/rocket/android/push/gcm/GcmInstanceIDListenerService.java

@@ -4,24 +4,21 @@ import com.google.android.gms.iid.InstanceIDListenerService;
 
 import java.util.List;
 import chat.rocket.android.helper.GcmPushSettingHelper;
-import chat.rocket.android.model.ServerConfig;
 import chat.rocket.android.model.ddp.PublicSetting;
 import chat.rocket.android.model.internal.GcmPushRegistration;
 import chat.rocket.android.realm_helper.RealmHelper;
 import chat.rocket.android.realm_helper.RealmStore;
+import chat.rocket.android.service.ConnectivityManager;
+import chat.rocket.android.service.ServerInfo;
 
 public class GcmInstanceIDListenerService extends InstanceIDListenerService {
 
   @Override
   public void onTokenRefresh() {
-    List<ServerConfig> serverConfigs = RealmStore.getDefault()
-        .executeTransactionForReadResults(realm ->
-            realm.where(ServerConfig.class)
-                .isNotNull(ServerConfig.ID)
-                .isNotNull(ServerConfig.HOSTNAME)
-                .findAll());
-    for (ServerConfig serverConfig : serverConfigs) {
-      RealmHelper realmHelper = RealmStore.get(serverConfig.getServerConfigId());
+    List<ServerInfo> serverInfoList = ConnectivityManager.getInstance(getApplicationContext())
+        .getServerList();
+    for (ServerInfo serverInfo : serverInfoList) {
+      RealmHelper realmHelper = RealmStore.get(serverInfo.hostname);
       if (realmHelper != null) {
         updateGcmToken(realmHelper);
       }

app/src/main/java/chat/rocket/android/push/interactors/DefaultPushInteractor.java

-package chat.rocket.android.push.interactors;
-
-import chat.rocket.android.helper.ServerPolicyHelper;
-import chat.rocket.android.model.ServerConfig;
-import chat.rocket.android.realm_helper.RealmStore;
-
-public class DefaultPushInteractor implements PushInteractor {
-
-  @Override
-  public String getServerConfigId(String hostname) {
-    final ServerConfig serverConfig = RealmStore.getDefault()
-        .executeTransactionForRead(
-            realm -> realm.where(ServerConfig.class)
-                .equalTo(ServerConfig.HOSTNAME, ServerPolicyHelper.enforceHostname(hostname))
-                .findFirst());
-
-    return serverConfig != null ? serverConfig.getServerConfigId() : "";
-  }
-}

app/src/main/java/chat/rocket/android/push/interactors/PushInteractor.java

-package chat.rocket.android.push.interactors;
-
-public interface PushInteractor {
-  String getServerConfigId(String hostname);
-}

app/src/main/java/chat/rocket/android/service/ConnectivityManager.java

+package chat.rocket.android.service;
+
+import android.content.Context;
+
+/**
+ * Connectivity Manager API Factory.
+ */
+public class ConnectivityManager {
+  private static final RealmBasedConnectivityManager IMPL = new RealmBasedConnectivityManager();
+
+  public static ConnectivityManagerApi getInstance(Context appContext) {
+    return IMPL.setContext(appContext);
+  }
+
+  /*package*/ static ConnectivityManagerInternal getInstanceForInternal(Context appContext) {
+    return IMPL.setContext(appContext);
+  }
+}

app/src/main/java/chat/rocket/android/service/ConnectivityManagerApi.java

+package chat.rocket.android.service;
+
+import android.support.annotation.Nullable;
+
+import java.util.List;
+import rx.Observable;
+import rx.Single;
+
+/**
+ * interfaces used for Activity/Fragment and other UI-related logic.
+ */
+public interface ConnectivityManagerApi {
+  void keepAliveServer();
+
+  void addOrUpdateServer(String hostname, @Nullable String name, boolean insecure);
+
+  void removeServer(String hostname);
+
+  Single<Boolean> connect(String hostname);
+
+  List<ServerInfo> getServerList();
+
+  Observable<ServerConnectivity> getServerConnectivityAsObservable();
+}

app/src/main/java/chat/rocket/android/service/ConnectivityManagerInternal.java

+package chat.rocket.android.service;
+
+import java.util.List;
+
+/**
+ * interfaces used for RocketChatService and RocketChatwebSocketThread.
+ */
+/*package*/ interface ConnectivityManagerInternal {
+  int REASON_CLOSED_BY_USER = 101;
+  int REASON_NETWORK_ERROR = 102;
+  int REASON_SERVER_ERROR = 103;
+  int REASON_UNKNOWN = 104;
+
+  void resetConnectivityStateList();
+
+  void ensureConnections();
+
+  List<ServerInfo> getServerList();
+
+  ServerInfo getServerInfoForHost(String hostname);
+
+  void notifyConnectionEstablished(String hostname, String session);
+
+  void notifyConnectionLost(String hostname, int reason);
+}

app/src/main/java/chat/rocket/android/service/ConnectivityServiceInterface.java

+package chat.rocket.android.service;
+
+import rx.Single;
+
+public interface ConnectivityServiceInterface {
+  Single<Boolean> ensureConnectionToServer(String hostname);
+
+  Single<Boolean> disconnectFromServer(String hostname);
+}

app/src/main/java/chat/rocket/android/service/DDPClientRef.java

+package chat.rocket.android.service;
+
+import chat.rocket.android.api.DDPClientWrapper;
+
+/**
+ * reference to get fresh DDPClient instance.
+ */
+public interface DDPClientRef {
+  DDPClientWrapper get();
+}

app/src/main/java/chat/rocket/android/service/RealmBasedConnectivityManager.java

+package chat.rocket.android.service;
+
+import android.content.ComponentName;
+import android.content.Context;
+import android.content.ServiceConnection;
+import android.os.IBinder;
+import android.support.annotation.Nullable;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.TimeUnit;
+import chat.rocket.android.helper.RxHelper;
+import chat.rocket.android.log.RCLog;
+import hugo.weaving.DebugLog;
+import rx.Observable;
+import rx.Single;
+import rx.subjects.PublishSubject;
+
+/**
+ * Connectivity management implementation.
+ */
+/*package*/ class RealmBasedConnectivityManager
+    implements ConnectivityManagerApi, ConnectivityManagerInternal {
+  private final HashMap<String, Integer> serverConnectivityList = new HashMap<>();
+  private final PublishSubject<ServerConnectivity> connectivitySubject = PublishSubject.create();
+  private Context appContext;
+  private final ServiceConnection serviceConnection = new ServiceConnection() {
+    @Override
+    public void onServiceConnected(ComponentName componentName, IBinder binder) {
+      serviceInterface = ((RocketChatService.LocalBinder) binder).getServiceInterface();
+    }
+
+    @Override
+    public void onServiceDisconnected(ComponentName componentName) {
+      serviceInterface = null;
+    }
+  };
+  private ConnectivityServiceInterface serviceInterface;
+
+
+  /*package*/ RealmBasedConnectivityManager setContext(Context appContext) {
+    this.appContext = appContext;
+    return this;
+  }
+
+  @Override
+  public void resetConnectivityStateList() {
+    serverConnectivityList.clear();
+    for (ServerInfo serverInfo : RealmBasedServerInfo.getServerInfoList()) {
+      serverConnectivityList.put(serverInfo.hostname, ServerConnectivity.STATE_DISCONNECTED);
+    }
+  }
+
+  @Override
+  public void keepAliveServer() {
+    RocketChatService.keepAlive(appContext);
+    if (serviceInterface == null) {
+      RocketChatService.bind(appContext, serviceConnection);
+    }
+  }
+
+  @Override
+  public void ensureConnections() {
+    for (String hostname : serverConnectivityList.keySet()) {
+      connectToServer(hostname) //force connect.
+          //.doOnError(RCLog::e)
+          .retryWhen(RxHelper.exponentialBackoff(3, 500, TimeUnit.MILLISECONDS))
+          .subscribe(_val -> { }, RCLog::e);
+    }
+  }
+
+  @Override
+  public void addOrUpdateServer(String hostname, @Nullable String name, boolean insecure) {
+    RealmBasedServerInfo.addOrUpdate(hostname, name);
+    RealmBasedServerInfo.setInsecure(hostname, insecure);
+    if (!serverConnectivityList.containsKey(hostname)) {
+      serverConnectivityList.put(hostname, ServerConnectivity.STATE_DISCONNECTED);
+    }
+    connectToServerIfNeeded(hostname)
+        .subscribe(_val -> { }, RCLog::e);
+  }
+
+  @Override
+  public void removeServer(String hostname) {
+    RealmBasedServerInfo.remove(hostname);
+    if (serverConnectivityList.containsKey(hostname)) {
+      disconnectFromServerIfNeeded(hostname)
+          .subscribe(_val -> { }, RCLog::e);
+    }
+  }
+
+  @Override
+  public Single<Boolean> connect(String hostname) {
+    return connectToServerIfNeeded(hostname);
+  }
+
+  @Override
+  public List<ServerInfo> getServerList() {
+    return RealmBasedServerInfo.getServerInfoList();
+  }
+
+  @Override
+  public ServerInfo getServerInfoForHost(String hostname) {
+    return RealmBasedServerInfo.getServerInfoForHost(hostname);
+  }
+
+  private List<ServerConnectivity> getCurrentConnectivityList() {
+    ArrayList<ServerConnectivity> list = new ArrayList<>();
+    for (Map.Entry<String, Integer> entry : serverConnectivityList.entrySet()) {
+      list.add(new ServerConnectivity(entry.getKey(), entry.getValue()));
+    }
+    return list;
+  }
+
+  @DebugLog
+  @Override
+  public void notifyConnectionEstablished(String hostname, String session) {
+    RealmBasedServerInfo.updateSession(hostname, session);
+    serverConnectivityList.put(hostname, ServerConnectivity.STATE_CONNECTED);
+    connectivitySubject.onNext(
+        new ServerConnectivity(hostname, ServerConnectivity.STATE_CONNECTED));
+  }
+
+  @DebugLog
+  @Override
+  public void notifyConnectionLost(String hostname, int reason) {
+    serverConnectivityList.put(hostname, ServerConnectivity.STATE_DISCONNECTED);
+    connectivitySubject.onNext(
+        new ServerConnectivity(hostname, ServerConnectivity.STATE_DISCONNECTED));
+  }
+
+  @Override
+  public Observable<ServerConnectivity> getServerConnectivityAsObservable() {
+    return Observable.concat(Observable.from(getCurrentConnectivityList()), connectivitySubject);
+  }
+
+  private Single<Boolean> connectToServerIfNeeded(String hostname) {
+    return Single.defer(() -> {
+      final int connectivity = serverConnectivityList.get(hostname);
+      if (connectivity == ServerConnectivity.STATE_CONNECTED) {
+        return Single.just(true);
+      }
+
+      if (connectivity == ServerConnectivity.STATE_DISCONNECTING) {
+        return waitForDisconnected(hostname)
+            .flatMap(_val -> connectToServerIfNeeded(hostname));
+      }
+
+      if (connectivity == ServerConnectivity.STATE_CONNECTING) {
+        return waitForConnected(hostname);
+      }
+
+      return connectToServer(hostname)
+          //.doOnError(RCLog::e)
+          .retryWhen(RxHelper.exponentialBackoff(3, 500, TimeUnit.MILLISECONDS));
+    });
+  }
+
+  private Single<Boolean> disconnectFromServerIfNeeded(String hostname) {
+    return Single.defer(() -> {
+      final int connectivity = serverConnectivityList.get(hostname);
+      if (connectivity == ServerConnectivity.STATE_DISCONNECTED) {
+        return Single.just(true);
+      }
+
+      if (connectivity == ServerConnectivity.STATE_CONNECTING) {
+        return waitForConnected(hostname)
+            .flatMap(_val -> disconnectFromServerIfNeeded(hostname));
+      }
+
+      if (connectivity == ServerConnectivity.STATE_DISCONNECTING) {
+        return waitForDisconnected(hostname);
+      }
+
+      return disconnectFromServer(hostname)
+          //.doOnError(RCLog::e)
+          .retryWhen(RxHelper.exponentialBackoff(3, 500, TimeUnit.MILLISECONDS));
+    });
+  }
+
+
+  private Single<Boolean> waitForConnected(String hostname) {
+    return connectivitySubject
+        .filter(serverConnectivity -> (hostname.equals(serverConnectivity.hostname)
+            && serverConnectivity.state == ServerConnectivity.STATE_CONNECTED))
+        .first()
+        .map(serverConnectivity -> true)
+        .toSingle();
+  }
+
+  private Single<Boolean> waitForDisconnected(String hostname) {
+    return connectivitySubject
+        .filter(serverConnectivity -> (hostname.equals(serverConnectivity.hostname)
+            && serverConnectivity.state == ServerConnectivity.STATE_DISCONNECTED))
+        .first()
+        .map(serverConnectivity -> true)
+        .toSingle();
+  }
+
+  private Single<Boolean> connectToServer(String hostname) {
+    return Single.defer(() -> {
+      if (!serverConnectivityList.containsKey(hostname)) {
+        return Single.error(new IllegalArgumentException("hostname not found"));
+      }
+      serverConnectivityList.put(hostname, ServerConnectivity.STATE_CONNECTING);
+
+      if (serviceInterface != null) {
+        return serviceInterface.ensureConnectionToServer(hostname);
+      } else {
+        return Single.error(new IllegalStateException("not prepared"));
+      }
+    });
+  }
+
+  private Single<Boolean> disconnectFromServer(String hostname) {
+    return Single.defer(() -> {
+      if (!serverConnectivityList.containsKey(hostname)) {
+        return Single.error(new IllegalArgumentException("hostname not found"));
+      }
+      serverConnectivityList.put(hostname, ServerConnectivity.STATE_DISCONNECTING);
+
+      if (serviceInterface != null) {
+        return serviceInterface.disconnectFromServer(hostname);
+      } else {
+        return Single.error(new IllegalStateException("not prepared"));
+      }
+    });
+  }
+}

app/src/main/java/chat/rocket/android/service/RealmBasedServerInfo.java

+package chat.rocket.android.service;
+
+import android.support.annotation.Nullable;
+import android.text.TextUtils;
+import io.realm.RealmObject;
+import io.realm.annotations.PrimaryKey;
+
+import org.json.JSONObject;
+
+import java.util.ArrayList;
+import java.util.List;
+import chat.rocket.android.realm_helper.RealmHelper;
+import chat.rocket.android.realm_helper.RealmStore;
+
+/**
+ * Backend implementation to store ServerInfo.
+ */
+public class RealmBasedServerInfo extends RealmObject {
+  private static final String DB_NAME = "serverlist";
+
+  @PrimaryKey private String hostname;
+  private String name;
+  private String session;
+  private boolean insecure;
+
+  interface ColumnName {
+    String HOSTNAME = "hostname";
+    String NAME = "name";
+    String SESSION = "session";
+    String INSECURE = "insecure";
+  }
+
+  ServerInfo getServerInfo() {
+    return new ServerInfo(hostname, name, session, insecure);
+  }
+
+  static RealmHelper getRealm() {
+    return RealmStore.getOrCreate(DB_NAME);
+  }
+
+  static void addOrUpdate(String hostname, String name) {
+    getRealm().executeTransaction(realm ->
+        realm.createOrUpdateObjectFromJson(RealmBasedServerInfo.class, new JSONObject()
+            .put(ColumnName.HOSTNAME, hostname)
+            .put(ColumnName.NAME, TextUtils.isEmpty(name) ? JSONObject.NULL : name)));
+  }
+
+  static void remove(String hostname) {
+    getRealm().executeTransaction(realm -> {
+      realm.where(RealmBasedServerInfo.class).equalTo(ColumnName.HOSTNAME, hostname)
+          .findAll()
+          .deleteAllFromRealm();
+      return null;
+    });
+  }
+
+  static void updateSession(String hostname, String session) {
+    RealmBasedServerInfo impl = getRealm().executeTransactionForRead(realm ->
+        realm.where(RealmBasedServerInfo.class).equalTo(ColumnName.HOSTNAME, hostname).findFirst());
+
+    if (impl != null) {
+      impl.session = session;
+      getRealm().executeTransaction(realm -> {
+        realm.copyToRealmOrUpdate(impl);
+        return null;
+      });
+    }
+  }
+
+  static @Nullable ServerInfo getServerInfoForHost(String hostname) {
+    RealmBasedServerInfo impl = getRealm().executeTransactionForRead(realm ->
+        realm.where(RealmBasedServerInfo.class).equalTo(ColumnName.HOSTNAME, hostname).findFirst());
+    return impl == null ? null : impl.getServerInfo();
+  }
+
+  static void setInsecure(String hostname, boolean insecure) {
+    RealmBasedServerInfo impl = getRealm().executeTransactionForRead(realm ->
+        realm.where(RealmBasedServerInfo.class).equalTo(ColumnName.HOSTNAME, hostname).findFirst());
+
+    if (impl != null) {
+      impl.insecure = insecure;
+      getRealm().executeTransaction(realm -> {
+        realm.copyToRealmOrUpdate(impl);
+        return null;
+      });
+    }
+  }
+
+  static List<ServerInfo> getServerInfoList() {
+    List<RealmBasedServerInfo> results = getRealm().executeTransactionForReadResults(realm ->
+        realm.where(RealmBasedServerInfo.class).findAll());
+    ArrayList<ServerInfo> list = new ArrayList<>();
+    for (RealmBasedServerInfo impl : results) {
+      list.add(impl.getServerInfo());
+    }
+    return list;
+  }
+}

app/src/main/java/chat/rocket/android/service/RocketChatService.java

@@ -3,140 +3,112 @@ package chat.rocket.android.service;
 import android.app.Service;
 import android.content.Context;
 import android.content.Intent;
+import android.content.ServiceConnection;
+import android.os.Binder;
 import android.os.IBinder;
 import android.support.annotation.Nullable;
-import io.realm.RealmResults;
 
 import java.util.HashMap;
-import java.util.List;
-import bolts.Task;
-import chat.rocket.android.helper.LogcatIfError;
-import chat.rocket.android.model.ServerConfig;
-import chat.rocket.android.realm_helper.RealmHelper;
-import chat.rocket.android.realm_helper.RealmListObserver;
-import chat.rocket.android.realm_helper.RealmStore;
+import java.util.concurrent.TimeUnit;
+import hugo.weaving.DebugLog;
+import rx.Observable;
+import rx.Single;
 
 /**
  * Background service for Rocket.Chat.Application class.
  */
-public class RocketChatService extends Service {
+public class RocketChatService extends Service implements ConnectivityServiceInterface {
 
-  private RealmHelper realmHelper;
+  private ConnectivityManagerInternal connectivityManager;
   private HashMap<String, RocketChatWebSocketThread> webSocketThreads;
-  private RealmListObserver<ServerConfig> connectionRequiredServerConfigObserver;
+
+  public class LocalBinder extends Binder {
+    ConnectivityServiceInterface getServiceInterface() {
+      return RocketChatService.this;
+    }
+  }
+
+  private final LocalBinder localBinder = new LocalBinder();
 
   /**
    * ensure RocketChatService alive.
    */
-  public static void keepAlive(Context context) {
+  /*package*/ static void keepAlive(Context context) {
     context.startService(new Intent(context, RocketChatService.class));
   }
 
+  public static void bind(Context context, ServiceConnection serviceConnection) {
+    context.bindService(
+        new Intent(context, RocketChatService.class), serviceConnection, Context.BIND_AUTO_CREATE);
+  }
+
+  public static void unbind(Context context, ServiceConnection serviceConnection) {
+    context.unbindService(serviceConnection);
+  }
+
   @Override
   public void onCreate() {
     super.onCreate();
-    webSocketThreads = new HashMap<>();
-    realmHelper = RealmStore.getDefault();
-    connectionRequiredServerConfigObserver = realmHelper
-        .createListObserver(realm -> realm.where(ServerConfig.class)
-            .isNotNull(ServerConfig.HOSTNAME)
-            .equalTo(ServerConfig.STATE, ServerConfig.STATE_READY)
-            .findAll())
-        .setOnUpdateListener(this::connectToServerWithServerConfig);
-
-    refreshServerConfigState();
-  }
 
-  private void refreshServerConfigState() {
-    realmHelper.executeTransaction(realm -> {
-      RealmResults<ServerConfig> configs = realm.where(ServerConfig.class)
-          .notEqualTo(ServerConfig.STATE, ServerConfig.STATE_READY)
-          .findAll();
-      for (ServerConfig config : configs) {
-        config.setState(ServerConfig.STATE_READY);
-      }
-      return null;
-    }).continueWith(new LogcatIfError());
-    ;
+    connectivityManager = ConnectivityManager.getInstanceForInternal(getApplicationContext());
+    connectivityManager.resetConnectivityStateList();
+    webSocketThreads = new HashMap<>();
   }
 
   @Override
   public int onStartCommand(Intent intent, int flags, int startId) {
-    List<ServerConfig> configs = realmHelper.executeTransactionForReadResults(realm ->
-        realm.where(ServerConfig.class)
-            .equalTo(ServerConfig.STATE, ServerConfig.STATE_CONNECTED)
-            .findAll());
-    for (ServerConfig config : configs) {
-      String serverConfigId = config.getServerConfigId();
-      if (webSocketThreads.containsKey(serverConfigId)) {
-        RocketChatWebSocketThread thread = webSocketThreads.get(serverConfigId);
-        if (thread != null) {
-          thread.keepAlive();
-        }
-      }
-    }
-
-    realmHelper.executeTransaction(realm -> {
-      RealmResults<ServerConfig> targetConfigs = realm
-          .where(ServerConfig.class)
-          .beginGroup()
-          .equalTo(ServerConfig.STATE, ServerConfig.STATE_CONNECTION_ERROR)
-          .or()
-          .isNotNull(ServerConfig.ERROR)
-          .endGroup()
-          .isNotNull(ServerConfig.SESSION)
-          .findAll();
-      for (ServerConfig config : targetConfigs) {
-        config.setState(ServerConfig.STATE_READY);
-        config.setError(null);
-      }
-      return null;
-    }).onSuccessTask(task -> {
-      connectionRequiredServerConfigObserver.sub();
-      return null;
-    });
+    connectivityManager.ensureConnections();
     return START_NOT_STICKY;
   }
 
-  private void connectToServerWithServerConfig(List<ServerConfig> configList) {
-    if (configList.isEmpty()) {
-      return;
-    }
-
-    ServerConfig config = configList.get(0);
-    final String serverConfigId = config.getServerConfigId();
-    ServerConfig.updateState(serverConfigId, ServerConfig.STATE_CONNECTING)
-        .onSuccessTask(task -> createWebSocketThread(config))
-        .onSuccessTask(task -> {
-          RocketChatWebSocketThread thread = task.getResult();
-          if (thread != null) {
-            thread.keepAlive();
-          }
-          return ServerConfig.updateState(serverConfigId, ServerConfig.STATE_CONNECTED);
-        }).continueWith(new LogcatIfError());
+  @Override
+  public Single<Boolean> ensureConnectionToServer(String hostname) { //called via binder.
+    return getOrCreateWebSocketThread(hostname)
+        .doOnError(err -> {
+          webSocketThreads.remove(hostname);
+          connectivityManager.notifyConnectionLost(hostname, ConnectivityManagerInternal.REASON_NETWORK_ERROR);
+        })
+        .flatMap(webSocketThreads -> webSocketThreads.keepAlive());
   }
 
-  private Task<RocketChatWebSocketThread> createWebSocketThread(final ServerConfig config) {
-    final String serverConfigId = config.getServerConfigId();
-    webSocketThreads.put(serverConfigId, null);
-    return RocketChatWebSocketThread.getStarted(getApplicationContext(), config)
-        .onSuccessTask(task -> {
-          webSocketThreads.put(serverConfigId, task.getResult());
-          return task;
-        });
+  @Override
+  public Single<Boolean> disconnectFromServer(String hostname) { //called via binder.
+    return Single.defer(() -> {
+      if (!webSocketThreads.containsKey(hostname)) {
+        return Single.just(true);
+      }
+
+      RocketChatWebSocketThread thread = webSocketThreads.get(hostname);
+      if (thread != null) {
+        return thread.terminate();
+      } else {
+        return Observable.timer(1, TimeUnit.SECONDS).toSingle()
+            .flatMap(_val -> disconnectFromServer(hostname));
+      }
+    });
   }
 
-  @Override
-  public void onDestroy() {
-    if (connectionRequiredServerConfigObserver != null) {
-      connectionRequiredServerConfigObserver.unsub();
-    }
-    super.onDestroy();
+  @DebugLog
+  private Single<RocketChatWebSocketThread> getOrCreateWebSocketThread(String hostname) {
+    return Single.defer(() -> {
+      if (webSocketThreads.containsKey(hostname)) {
+        RocketChatWebSocketThread thread = webSocketThreads.get(hostname);
+        if (thread != null) {
+          return Single.just(thread);
+        } else {
+          return Observable.timer(1, TimeUnit.SECONDS).toSingle()
+              .flatMap(_val -> getOrCreateWebSocketThread(hostname));
+        }
+      }
+      webSocketThreads.put(hostname, null);
+      return RocketChatWebSocketThread.getStarted(getApplicationContext(), hostname)
+          .doOnSuccess(thread -> webSocketThreads.put(hostname, thread));
+    });
   }
 
   @Nullable
   @Override
   public IBinder onBind(Intent intent) {
-    return null;
+    return localBinder;
   }
 }

app/src/main/java/chat/rocket/android/service/ServerConnectivity.java

+package chat.rocket.android.service;
+
+/**
+ * pair with server's hostname and its connectivity state.
+ */
+public class ServerConnectivity {
+  public static final int STATE_CONNECTED = 1;
+  public static final int STATE_DISCONNECTED = 2;
+  /*package*/ static final int STATE_CONNECTING = 3;
+  /*package*/ static final int STATE_DISCONNECTING = 4;
+
+  public final String hostname;
+  public final int state;
+
+  public ServerConnectivity(String hostname, int state) {
+    this.hostname = hostname;
+    this.state = state;
+  }
+}

app/src/main/java/chat/rocket/android/service/ServerInfo.java

+package chat.rocket.android.service;
+
+
+/**
+ * Stores information just for required for initializing connectivity manager.
+ */
+public class ServerInfo {
+  public final String hostname;
+  public final String name;
+  /*package*/ final String session;
+  public final boolean insecure;
+
+  public ServerInfo(String hostname, String name, String session, boolean insecure) {
+    this.hostname = hostname;
+    this.name = name;
+    this.session = session;
+    this.insecure = insecure;
+  }
+}

app/src/main/java/chat/rocket/android/service/ddp/AbstractDDPDocEventSubscriber.java

@@ -9,10 +9,10 @@ import org.json.JSONException;
 import org.json.JSONObject;
 
 import java.util.Iterator;
-import chat.rocket.android.api.DDPClientWrapper;
 import chat.rocket.android.helper.LogcatIfError;
 import chat.rocket.android.log.RCLog;
 import chat.rocket.android.realm_helper.RealmHelper;
+import chat.rocket.android.service.DDPClientRef;
 import chat.rocket.android.service.Registrable;
 import chat.rocket.android_ddp.DDPSubscription;
 import rx.Subscription;
@@ -21,17 +21,17 @@ public abstract class AbstractDDPDocEventSubscriber implements Registrable {
   protected final Context context;
   protected final String hostname;
   protected final RealmHelper realmHelper;
-  protected final DDPClientWrapper ddpClient;
+  protected final DDPClientRef ddpClientRef;
   private boolean isUnsubscribed;
   private String subscriptionId;
   private Subscription rxSubscription;
 
   protected AbstractDDPDocEventSubscriber(Context context, String hostname,
-                                          RealmHelper realmHelper, DDPClientWrapper ddpClient) {
+                                          RealmHelper realmHelper, DDPClientRef ddpClientRef) {
     this.context = context;
     this.hostname = hostname;
     this.realmHelper = realmHelper;
-    this.ddpClient = ddpClient;
+    this.ddpClientRef = ddpClientRef;
   }
 
   protected abstract String getSubscriptionName();
@@ -66,9 +66,9 @@ public abstract class AbstractDDPDocEventSubscriber implements Registrable {
       // just ignore.
     }
 
-    ddpClient.subscribe(getSubscriptionName(), params).onSuccess(task -> {
+    ddpClientRef.get().subscribe(getSubscriptionName(), params).onSuccess(task -> {
       if (isUnsubscribed) {
-        ddpClient.unsubscribe(task.getResult().id).continueWith(new LogcatIfError());
+        ddpClientRef.get().unsubscribe(task.getResult().id).continueWith(new LogcatIfError());
       } else {
         subscriptionId = task.getResult().id;
       }
@@ -95,7 +95,7 @@ public abstract class AbstractDDPDocEventSubscriber implements Registrable {
   }
 
   protected Subscription subscribe() {
-    return ddpClient.getSubscriptionCallback()
+    return ddpClientRef.get().getSubscriptionCallback()
         .filter(event -> event instanceof DDPSubscription.DocEvent)
         .cast(DDPSubscription.DocEvent.class)
         .filter(event -> isTarget(event.collection))
@@ -182,7 +182,7 @@ public abstract class AbstractDDPDocEventSubscriber implements Registrable {
       rxSubscription.unsubscribe();
     }
     if (!TextUtils.isEmpty(subscriptionId)) {
-      ddpClient.unsubscribe(subscriptionId).continueWith(new LogcatIfError());
+      ddpClientRef.get().unsubscribe(subscriptionId).continueWith(new LogcatIfError());
     }
   }
 }

app/src/main/java/chat/rocket/android/service/ddp/base/AbstractBaseSubscriber.java

@@ -3,14 +3,14 @@ package chat.rocket.android.service.ddp.base;
 import android.content.Context;
 import org.json.JSONArray;
 
-import chat.rocket.android.api.DDPClientWrapper;
 import chat.rocket.android.realm_helper.RealmHelper;
+import chat.rocket.android.service.DDPClientRef;
 import chat.rocket.android.service.ddp.AbstractDDPDocEventSubscriber;
 
 abstract class AbstractBaseSubscriber extends AbstractDDPDocEventSubscriber {
   protected AbstractBaseSubscriber(Context context, String hostname, RealmHelper realmHelper,
-                                   DDPClientWrapper ddpClient) {
-    super(context, hostname, realmHelper, ddpClient);
+                                   DDPClientRef ddpClientRef) {
+    super(context, hostname, realmHelper, ddpClientRef);
   }
 
   @Override

app/src/main/java/chat/rocket/android/service/ddp/base/ActiveUsersSubscriber.java

@@ -2,21 +2,20 @@ package chat.rocket.android.service.ddp.base;
 
 import android.content.Context;
 import io.realm.RealmObject;
-
 import org.json.JSONException;
 import org.json.JSONObject;
 
-import chat.rocket.android.api.DDPClientWrapper;
 import chat.rocket.android.model.ddp.User;
 import chat.rocket.android.realm_helper.RealmHelper;
+import chat.rocket.android.service.DDPClientRef;
 
 /**
  * "activeUsers" subscriber.
  */
 public class ActiveUsersSubscriber extends AbstractBaseSubscriber {
   public ActiveUsersSubscriber(Context context, String hostname, RealmHelper realmHelper,
-                               DDPClientWrapper ddpClient) {
-    super(context, hostname, realmHelper, ddpClient);
+                               DDPClientRef ddpClientRef) {
+    super(context, hostname, realmHelper, ddpClientRef);
   }
 
   @Override

app/src/main/java/chat/rocket/android/service/ddp/base/LoginServiceConfigurationSubscriber.java

@@ -3,17 +3,17 @@ package chat.rocket.android.service.ddp.base;
 import android.content.Context;
 import io.realm.RealmObject;
 
-import chat.rocket.android.api.DDPClientWrapper;
 import chat.rocket.android.model.ddp.MeteorLoginServiceConfiguration;
 import chat.rocket.android.realm_helper.RealmHelper;
+import chat.rocket.android.service.DDPClientRef;
 
 /**
  * meteor.loginServiceConfiguration subscriber
  */
 public class LoginServiceConfigurationSubscriber extends AbstractBaseSubscriber {
   public LoginServiceConfigurationSubscriber(Context context, String hostname,
-                                             RealmHelper realmHelper, DDPClientWrapper ddpClient) {
-    super(context, hostname, realmHelper, ddpClient);
+                                             RealmHelper realmHelper, DDPClientRef ddpClientRef) {
+    super(context, hostname, realmHelper, ddpClientRef);
   }
 
   @Override

app/src/main/java/chat/rocket/android/service/ddp/base/UserDataSubscriber.java

@@ -2,21 +2,20 @@ package chat.rocket.android.service.ddp.base;
 
 import android.content.Context;
 import io.realm.RealmObject;
-
 import org.json.JSONException;
 import org.json.JSONObject;
 
-import chat.rocket.android.api.DDPClientWrapper;
 import chat.rocket.android.model.ddp.User;
 import chat.rocket.android.realm_helper.RealmHelper;
+import chat.rocket.android.service.DDPClientRef;
 
 /**
  * "userData" subscriber.
  */
 public class UserDataSubscriber extends AbstractBaseSubscriber {
   public UserDataSubscriber(Context context, String hostname, RealmHelper realmHelper,
-                            DDPClientWrapper ddpClient) {
-    super(context, hostname, realmHelper, ddpClient);
+                            DDPClientRef ddpClientRef) {
+    super(context, hostname, realmHelper, ddpClientRef);
   }
 
   @Override

app/src/main/java/chat/rocket/android/service/ddp/stream/AbstractStreamNotifyEventSubscriber.java

@@ -5,18 +5,18 @@ import org.json.JSONArray;
 import org.json.JSONException;
 import org.json.JSONObject;
 
-import chat.rocket.android.api.DDPClientWrapper;
 import chat.rocket.android.helper.LogcatIfError;
 import chat.rocket.android.log.RCLog;
 import chat.rocket.android.realm_helper.RealmHelper;
+import chat.rocket.android.service.DDPClientRef;
 import chat.rocket.android.service.ddp.AbstractDDPDocEventSubscriber;
 import chat.rocket.android_ddp.DDPSubscription;
 
 abstract class AbstractStreamNotifyEventSubscriber extends AbstractDDPDocEventSubscriber {
   protected AbstractStreamNotifyEventSubscriber(Context context, String hostname,
                                                 RealmHelper realmHelper,
-                                                DDPClientWrapper ddpClient) {
-    super(context, hostname, realmHelper, ddpClient);
+                                                DDPClientRef ddpClientRef) {
+    super(context, hostname, realmHelper, ddpClientRef);
   }
 
   @Override

app/src/main/java/chat/rocket/android/service/ddp/stream/AbstractStreamNotifyUserEventSubscriber.java

@@ -2,16 +2,16 @@ package chat.rocket.android.service.ddp.stream;
 
 import android.content.Context;
 
-import chat.rocket.android.api.DDPClientWrapper;
 import chat.rocket.android.realm_helper.RealmHelper;
+import chat.rocket.android.service.DDPClientRef;
 
 abstract class AbstractStreamNotifyUserEventSubscriber extends AbstractStreamNotifyEventSubscriber {
   protected final String userId;
 
   protected AbstractStreamNotifyUserEventSubscriber(Context context, String hostname,
                                                     RealmHelper realmHelper,
-                                                    DDPClientWrapper ddpClient, String userId) {
-    super(context, hostname, realmHelper, ddpClient);
+                                                    DDPClientRef ddpClientRef, String userId) {
+    super(context, hostname, realmHelper, ddpClientRef);
     this.userId = userId;
   }
 

app/src/main/java/chat/rocket/android/service/ddp/stream/StreamNotifyUserSubscriptionsChanged.java

@@ -5,15 +5,15 @@ import io.realm.RealmObject;
 import org.json.JSONException;
 import org.json.JSONObject;
 
-import chat.rocket.android.api.DDPClientWrapper;
 import chat.rocket.android.model.ddp.RoomSubscription;
 import chat.rocket.android.realm_helper.RealmHelper;
+import chat.rocket.android.service.DDPClientRef;
 
 public class StreamNotifyUserSubscriptionsChanged extends AbstractStreamNotifyUserEventSubscriber {
   public StreamNotifyUserSubscriptionsChanged(Context context, String hostname,
-                                              RealmHelper realmHelper, DDPClientWrapper ddpClient,
+                                              RealmHelper realmHelper, DDPClientRef ddpClientRef,
                                               String userId) {
-    super(context, hostname, realmHelper, ddpClient, userId);
+    super(context, hostname, realmHelper, ddpClientRef, userId);
   }
 
   @Override

app/src/main/java/chat/rocket/android/service/ddp/stream/StreamRoomMessage.java

@@ -5,9 +5,9 @@ import io.realm.RealmObject;
 import org.json.JSONException;
 import org.json.JSONObject;
 
-import chat.rocket.android.api.DDPClientWrapper;
 import chat.rocket.android.model.ddp.Message;
 import chat.rocket.android.realm_helper.RealmHelper;
+import chat.rocket.android.service.DDPClientRef;
 
 /**
  * stream-room-message subscriber.
@@ -16,8 +16,8 @@ public class StreamRoomMessage extends AbstractStreamNotifyEventSubscriber {
   private String roomId;
 
   public StreamRoomMessage(Context context, String hostname,
-                           RealmHelper realmHelper, DDPClientWrapper ddpClient, String roomId) {
-    super(context, hostname, realmHelper, ddpClient);
+                           RealmHelper realmHelper, DDPClientRef ddpClientRef, String roomId) {
+    super(context, hostname, realmHelper, ddpClientRef);
     this.roomId = roomId;
   }
 

app/src/main/java/chat/rocket/android/service/internal/StreamRoomMessageManager.java

@@ -4,8 +4,8 @@ import android.content.Context;
 import android.os.Handler;
 import android.os.Looper;
 
-import chat.rocket.android.api.DDPClientWrapper;
 import chat.rocket.android.realm_helper.RealmHelper;
+import chat.rocket.android.service.DDPClientRef;
 import chat.rocket.android.service.Registrable;
 import chat.rocket.android.service.ddp.stream.StreamRoomMessage;
 
@@ -16,17 +16,17 @@ public class StreamRoomMessageManager implements Registrable {
   private final Context context;
   private final String hostname;
   private final RealmHelper realmHelper;
-  private final DDPClientWrapper ddpClient;
+  private final DDPClientRef ddpClientRef;
   private final AbstractRocketChatCacheObserver cacheObserver;
   private final Handler handler;
   private StreamRoomMessage streamRoomMessage;
 
   public StreamRoomMessageManager(Context context, String hostname,
-                                  RealmHelper realmHelper, DDPClientWrapper ddpClient) {
+                                  RealmHelper realmHelper, DDPClientRef ddpClientRef) {
     this.context = context;
     this.hostname = hostname;
     this.realmHelper = realmHelper;
-    this.ddpClient = ddpClient;
+    this.ddpClientRef = ddpClientRef;
 
     cacheObserver = new AbstractRocketChatCacheObserver(context, realmHelper) {
       @Override
@@ -40,7 +40,7 @@ public class StreamRoomMessageManager implements Registrable {
 
   private void registerStreamNotifyMessage(String roomId) {
     handler.post(() -> {
-      streamRoomMessage = new StreamRoomMessage(context, hostname, realmHelper, ddpClient, roomId);
+      streamRoomMessage = new StreamRoomMessage(context, hostname, realmHelper, ddpClientRef, roomId);
       streamRoomMessage.register();
     });
   }

app/src/main/java/chat/rocket/android/service/observer/AbstractModelObserver.java

@@ -3,9 +3,9 @@ package chat.rocket.android.service.observer;
 import android.content.Context;
 import io.realm.RealmObject;
 
-import chat.rocket.android.api.DDPClientWrapper;
 import chat.rocket.android.realm_helper.RealmHelper;
 import chat.rocket.android.realm_helper.RealmListObserver;
+import chat.rocket.android.service.DDPClientRef;
 import chat.rocket.android.service.Registrable;
 
 abstract class AbstractModelObserver<T extends RealmObject>
@@ -14,15 +14,15 @@ abstract class AbstractModelObserver<T extends RealmObject>
   protected final Context context;
   protected final String hostname;
   protected final RealmHelper realmHelper;
-  protected final DDPClientWrapper ddpClient;
+  protected final DDPClientRef ddpClientRef;
   private final RealmListObserver observer;
 
   protected AbstractModelObserver(Context context, String hostname,
-                                  RealmHelper realmHelper, DDPClientWrapper ddpClient) {
+                                  RealmHelper realmHelper, DDPClientRef ddpClientRef) {
     this.context = context;
     this.hostname = hostname;
     this.realmHelper = realmHelper;
-    this.ddpClient = ddpClient;
+    this.ddpClientRef = ddpClientRef;
     observer = realmHelper.createListObserver(this).setOnUpdateListener(this);
   }
 

app/src/main/java/chat/rocket/android/service/observer/CurrentUserObserver.java

@@ -6,11 +6,11 @@ import io.realm.RealmResults;
 
 import java.util.ArrayList;
 import java.util.List;
-import chat.rocket.android.api.DDPClientWrapper;
 import chat.rocket.android.api.MethodCallHelper;
 import chat.rocket.android.helper.LogcatIfError;
 import chat.rocket.android.model.ddp.User;
 import chat.rocket.android.realm_helper.RealmHelper;
+import chat.rocket.android.service.DDPClientRef;
 import chat.rocket.android.service.Registrable;
 import chat.rocket.android.service.ddp.stream.StreamNotifyUserSubscriptionsChanged;
 import hugo.weaving.DebugLog;
@@ -24,9 +24,9 @@ public class CurrentUserObserver extends AbstractModelObserver<User> {
   private ArrayList<Registrable> listeners;
 
   public CurrentUserObserver(Context context, String hostname,
-                             RealmHelper realmHelper, DDPClientWrapper ddpClient) {
-    super(context, hostname, realmHelper, ddpClient);
-    methodCall = new MethodCallHelper(realmHelper, ddpClient);
+                             RealmHelper realmHelper, DDPClientRef ddpClientRef) {
+    super(context, hostname, realmHelper, ddpClientRef);
+    methodCall = new MethodCallHelper(realmHelper, ddpClientRef);
     currentUserExists = false;
   }
 
@@ -62,7 +62,7 @@ public class CurrentUserObserver extends AbstractModelObserver<User> {
     methodCall.getRoomSubscriptions().onSuccess(task -> {
       if (listeners != null) {
         Registrable listener = new StreamNotifyUserSubscriptionsChanged(
-            context, hostname, realmHelper, ddpClient, userId);
+            context, hostname, realmHelper, ddpClientRef, userId);
         listener.register();
         listeners.add(listener);
       }

app/src/main/java/chat/rocket/android/service/observer/FileUploadingToS3Observer.java

@@ -11,7 +11,6 @@ import java.io.IOException;
 import java.io.InputStream;
 import java.util.List;
 import bolts.Task;
-import chat.rocket.android.api.DDPClientWrapper;
 import chat.rocket.android.api.FileUploadingHelper;
 import chat.rocket.android.helper.LogcatIfError;
 import chat.rocket.android.helper.OkHttpHelper;
@@ -19,6 +18,7 @@ import chat.rocket.android.log.RCLog;
 import chat.rocket.android.model.SyncState;
 import chat.rocket.android.model.internal.FileUploading;
 import chat.rocket.android.realm_helper.RealmHelper;
+import chat.rocket.android.service.DDPClientRef;
 import okhttp3.MediaType;
 import okhttp3.MultipartBody;
 import okhttp3.Request;
@@ -35,9 +35,9 @@ public class FileUploadingToS3Observer extends AbstractModelObserver<FileUploadi
   private FileUploadingHelper methodCall;
 
   public FileUploadingToS3Observer(Context context, String hostname,
-                                   RealmHelper realmHelper, DDPClientWrapper ddpClient) {
-    super(context, hostname, realmHelper, ddpClient);
-    methodCall = new FileUploadingHelper(realmHelper, ddpClient);
+                                   RealmHelper realmHelper, DDPClientRef ddpClientRef) {
+    super(context, hostname, realmHelper, ddpClientRef);
+    methodCall = new FileUploadingHelper(realmHelper, ddpClientRef);
 
     realmHelper.executeTransaction(realm -> {
       // resume pending operations.

app/src/main/java/chat/rocket/android/service/observer/FileUploadingWithUfsObserver.java

@@ -9,7 +9,6 @@ import org.json.JSONObject;
 import java.io.InputStream;
 import java.util.List;
 import bolts.Task;
-import chat.rocket.android.api.DDPClientWrapper;
 import chat.rocket.android.api.FileUploadingHelper;
 import chat.rocket.android.helper.LogcatIfError;
 import chat.rocket.android.helper.OkHttpHelper;
@@ -19,6 +18,7 @@ import chat.rocket.android.model.ddp.User;
 import chat.rocket.android.model.internal.FileUploading;
 import chat.rocket.android.model.internal.Session;
 import chat.rocket.android.realm_helper.RealmHelper;
+import chat.rocket.android.service.DDPClientRef;
 import okhttp3.MediaType;
 import okhttp3.Request;
 import okhttp3.RequestBody;
@@ -31,9 +31,9 @@ public class FileUploadingWithUfsObserver extends AbstractModelObserver<FileUplo
   private FileUploadingHelper methodCall;
 
   public FileUploadingWithUfsObserver(Context context, String hostname,
-                                      RealmHelper realmHelper, DDPClientWrapper ddpClient) {
-    super(context, hostname, realmHelper, ddpClient);
-    methodCall = new FileUploadingHelper(realmHelper, ddpClient);
+                                      RealmHelper realmHelper, DDPClientRef ddpClientRef) {
+    super(context, hostname, realmHelper, ddpClientRef);
+    methodCall = new FileUploadingHelper(realmHelper, ddpClientRef);
 
     realmHelper.executeTransaction(realm -> {
       // resume pending operations.

app/src/main/java/chat/rocket/android/service/observer/GcmPushRegistrationObserver.java

@@ -11,7 +11,6 @@ import java.io.IOException;
 import java.util.List;
 import bolts.Task;
 import chat.rocket.android.RocketChatCache;
-import chat.rocket.android.api.DDPClientWrapper;
 import chat.rocket.android.api.RaixPushHelper;
 import chat.rocket.android.helper.LogcatIfError;
 import chat.rocket.android.model.SyncState;
@@ -20,6 +19,7 @@ import chat.rocket.android.model.ddp.PublicSettingsConstants;
 import chat.rocket.android.model.ddp.User;
 import chat.rocket.android.model.internal.GcmPushRegistration;
 import chat.rocket.android.realm_helper.RealmHelper;
+import chat.rocket.android.service.DDPClientRef;
 
 /**
  * call raix:push-update if needed.
@@ -27,8 +27,8 @@ import chat.rocket.android.realm_helper.RealmHelper;
 public class GcmPushRegistrationObserver extends AbstractModelObserver<GcmPushRegistration> {
   public GcmPushRegistrationObserver(Context context, String hostname,
                                         RealmHelper realmHelper,
-                                        DDPClientWrapper ddpClient) {
-    super(context, hostname, realmHelper, ddpClient);
+                                        DDPClientRef ddpClientRef) {
+    super(context, hostname, realmHelper, ddpClientRef);
   }
 
   @Override
@@ -75,7 +75,7 @@ public class GcmPushRegistrationObserver extends AbstractModelObserver<GcmPushRe
     final String userId = currentUser != null ? currentUser.getId() : null;
     final String pushId = RocketChatCache.getOrCreatePushId(context);
 
-    return new RaixPushHelper(realmHelper, ddpClient)
+    return new RaixPushHelper(realmHelper, ddpClientRef)
         .pushUpdate(pushId, gcmToken, userId);
   }
 

app/src/main/java/chat/rocket/android/service/observer/GetUsersOfRoomsProcedureObserver.java

@@ -7,12 +7,12 @@ import org.json.JSONObject;
 
 import java.util.List;
 import bolts.Task;
-import chat.rocket.android.api.DDPClientWrapper;
 import chat.rocket.android.api.MethodCallHelper;
 import chat.rocket.android.log.RCLog;
 import chat.rocket.android.model.SyncState;
 import chat.rocket.android.model.internal.GetUsersOfRoomsProcedure;
 import chat.rocket.android.realm_helper.RealmHelper;
+import chat.rocket.android.service.DDPClientRef;
 
 /**
  * Model observer for executing getUsersOfRooms.
@@ -23,9 +23,9 @@ public class GetUsersOfRoomsProcedureObserver
   private final MethodCallHelper methodCall;
 
   public GetUsersOfRoomsProcedureObserver(Context context, String hostname,
-                                          RealmHelper realmHelper, DDPClientWrapper ddpClient) {
-    super(context, hostname, realmHelper, ddpClient);
-    methodCall = new MethodCallHelper(realmHelper, ddpClient);
+                                          RealmHelper realmHelper, DDPClientRef ddpClientRef) {
+    super(context, hostname, realmHelper, ddpClientRef);
+    methodCall = new MethodCallHelper(realmHelper, ddpClientRef);
   }
 
   @Override

app/src/main/java/chat/rocket/android/service/observer/LoadMessageProcedureObserver.java

@@ -8,13 +8,13 @@ import org.json.JSONObject;
 
 import java.util.List;
 import bolts.Task;
-import chat.rocket.android.api.DDPClientWrapper;
 import chat.rocket.android.api.MethodCallHelper;
 import chat.rocket.android.log.RCLog;
 import chat.rocket.android.model.SyncState;
 import chat.rocket.android.model.ddp.Message;
 import chat.rocket.android.model.internal.LoadMessageProcedure;
 import chat.rocket.android.realm_helper.RealmHelper;
+import chat.rocket.android.service.DDPClientRef;
 
 /**
  * Background process for loading messages.
@@ -24,9 +24,9 @@ public class LoadMessageProcedureObserver extends AbstractModelObserver<LoadMess
   private final MethodCallHelper methodCall;
 
   public LoadMessageProcedureObserver(Context context, String hostname,
-                                      RealmHelper realmHelper, DDPClientWrapper ddpClient) {
-    super(context, hostname, realmHelper, ddpClient);
-    methodCall = new MethodCallHelper(realmHelper, ddpClient);
+                                      RealmHelper realmHelper, DDPClientRef ddpClientRef) {
+    super(context, hostname, realmHelper, ddpClientRef);
+    methodCall = new MethodCallHelper(realmHelper, ddpClientRef);
   }
 
   @Override

app/src/main/java/chat/rocket/android/service/observer/MethodCallObserver.java

@@ -6,12 +6,12 @@ import io.realm.RealmResults;
 import org.json.JSONObject;
 
 import java.util.List;
-import chat.rocket.android.api.DDPClientWrapper;
 import chat.rocket.android.helper.CheckSum;
 import chat.rocket.android.helper.LogcatIfError;
 import chat.rocket.android.model.SyncState;
 import chat.rocket.android.model.internal.MethodCall;
 import chat.rocket.android.realm_helper.RealmHelper;
+import chat.rocket.android.service.DDPClientRef;
 import chat.rocket.android_ddp.DDPClientCallback;
 
 /**
@@ -25,8 +25,8 @@ public class MethodCallObserver extends AbstractModelObserver<MethodCall> {
    * constructor.
    */
   public MethodCallObserver(Context context, String hostname,
-                            RealmHelper realmHelper, DDPClientWrapper ddpClient) {
-    super(context, hostname, realmHelper, ddpClient);
+                            RealmHelper realmHelper, DDPClientRef ddpClientRef) {
+    super(context, hostname, realmHelper, ddpClientRef);
     realmHelper.executeTransaction(realm -> {
       // resume pending operations.
       RealmResults<MethodCall> pendingMethodCalls = realm.where(MethodCall.class)
@@ -97,7 +97,7 @@ public class MethodCallObserver extends AbstractModelObserver<MethodCall> {
             .put(MethodCall.ID, methodCallId)
             .put(MethodCall.SYNC_STATE, SyncState.SYNCING))
     ).onSuccessTask(task ->
-        ddpClient.rpc(methodCallId, methodName, params, timeout)
+        ddpClientRef.get().rpc(methodCallId, methodName, params, timeout)
             .onSuccessTask(_task -> realmHelper.executeTransaction(realm -> {
               String json = _task.getResult().result;
               return realm.createOrUpdateObjectFromJson(MethodCall.class, new JSONObject()

app/src/main/java/chat/rocket/android/service/observer/NewMessageObserver.java

@@ -6,13 +6,13 @@ import io.realm.RealmResults;
 import org.json.JSONObject;
 
 import java.util.List;
-import chat.rocket.android.api.DDPClientWrapper;
 import chat.rocket.android.api.MethodCallHelper;
 import chat.rocket.android.helper.LogcatIfError;
 import chat.rocket.android.log.RCLog;
 import chat.rocket.android.model.SyncState;
 import chat.rocket.android.model.ddp.Message;
 import chat.rocket.android.realm_helper.RealmHelper;
+import chat.rocket.android.service.DDPClientRef;
 
 /**
  * Observe messages for sending.
@@ -22,9 +22,9 @@ public class NewMessageObserver extends AbstractModelObserver<Message> {
   private final MethodCallHelper methodCall;
 
   public NewMessageObserver(Context context, String hostname,
-                            RealmHelper realmHelper, DDPClientWrapper ddpClient) {
-    super(context, hostname, realmHelper, ddpClient);
-    methodCall = new MethodCallHelper(realmHelper, ddpClient);
+                            RealmHelper realmHelper, DDPClientRef ddpClientRef) {
+    super(context, hostname, realmHelper, ddpClientRef);
+    methodCall = new MethodCallHelper(realmHelper, ddpClientRef);
 
     realmHelper.executeTransaction(realm -> {
       // resume pending operations.

app/src/main/java/chat/rocket/android/service/observer/PushSettingsObserver.java

@@ -5,17 +5,17 @@ import io.realm.Realm;
 import io.realm.RealmResults;
 
 import java.util.List;
-import chat.rocket.android.api.DDPClientWrapper;
 import chat.rocket.android.helper.GcmPushSettingHelper;
 import chat.rocket.android.model.ddp.PublicSetting;
 import chat.rocket.android.model.internal.GcmPushRegistration;
 import chat.rocket.android.realm_helper.RealmHelper;
+import chat.rocket.android.service.DDPClientRef;
 
 public class PushSettingsObserver extends AbstractModelObserver<PublicSetting> {
 
   public PushSettingsObserver(Context context, String hostname,
-                              RealmHelper realmHelper, DDPClientWrapper ddpClient) {
-    super(context, hostname, realmHelper, ddpClient);
+                              RealmHelper realmHelper, DDPClientRef ddpClientRef) {
+    super(context, hostname, realmHelper, ddpClientRef);
   }
 
   @Override

app/src/main/java/chat/rocket/android/service/observer/SessionObserver.java

@@ -6,7 +6,6 @@ import io.realm.RealmResults;
 
 import java.util.List;
 import chat.rocket.android.RocketChatCache;
-import chat.rocket.android.api.DDPClientWrapper;
 import chat.rocket.android.api.RaixPushHelper;
 import chat.rocket.android.helper.LogcatIfError;
 import chat.rocket.android.model.internal.GetUsersOfRoomsProcedure;
@@ -14,6 +13,7 @@ import chat.rocket.android.model.internal.LoadMessageProcedure;
 import chat.rocket.android.model.internal.MethodCall;
 import chat.rocket.android.model.internal.Session;
 import chat.rocket.android.realm_helper.RealmHelper;
+import chat.rocket.android.service.DDPClientRef;
 import chat.rocket.android.service.internal.StreamRoomMessageManager;
 import hugo.weaving.DebugLog;
 
@@ -29,12 +29,12 @@ public class SessionObserver extends AbstractModelObserver<Session> {
    * constructor.
    */
   public SessionObserver(Context context, String hostname,
-                         RealmHelper realmHelper, DDPClientWrapper ddpClient) {
-    super(context, hostname, realmHelper, ddpClient);
+                         RealmHelper realmHelper, DDPClientRef ddpClientRef) {
+    super(context, hostname, realmHelper, ddpClientRef);
     count = 0;
 
-    streamNotifyMessage = new StreamRoomMessageManager(context, hostname, realmHelper, ddpClient);
-    pushHelper = new RaixPushHelper(realmHelper, ddpClient);
+    streamNotifyMessage = new StreamRoomMessageManager(context, hostname, realmHelper, ddpClientRef);
+    pushHelper = new RaixPushHelper(realmHelper, ddpClientRef);
   }
 
   @Override

app/src/main/java/chat/rocket/android/service/observer/TokenLoginObserver.java

@@ -5,20 +5,20 @@ import io.realm.Realm;
 import io.realm.RealmResults;
 
 import java.util.List;
-import chat.rocket.android.api.DDPClientWrapper;
 import chat.rocket.android.api.MethodCallHelper;
 import chat.rocket.android.helper.LogcatIfError;
 import chat.rocket.android.model.internal.Session;
 import chat.rocket.android.realm_helper.RealmHelper;
+import chat.rocket.android.service.DDPClientRef;
 
 public class TokenLoginObserver extends AbstractModelObserver<Session> {
 
   private final MethodCallHelper methodCall;
 
   public TokenLoginObserver(Context context, String hostname,
-                            RealmHelper realmHelper, DDPClientWrapper ddpClient) {
-    super(context, hostname, realmHelper, ddpClient);
-    methodCall = new MethodCallHelper(realmHelper, ddpClient);
+                            RealmHelper realmHelper, DDPClientRef ddpClientRef) {
+    super(context, hostname, realmHelper, ddpClientRef);
+    methodCall = new MethodCallHelper(realmHelper, ddpClientRef);
   }
 
   @Override

app/src/main/res/values/strings.xml

@@ -33,7 +33,6 @@
     <string name="fragment_login_password">Password</string>
     <string name="fragment_retry_login_retry_title">RETRY</string>
     <string name="fragment_retry_login_error_title">Connection Error</string>
-    <string name="add_server_activity_waiting_server">Connecting to server…</string>
     <string name="server_config_activity_authenticating">Authenticating…</string>
     <string name="home_fragment_title">Rocket.Chat - Home</string>
     <string name="fragment_sidebar_main_unread_rooms_title">UNREAD ROOMS</string>

dependencies.gradle

@@ -13,7 +13,7 @@ ext {
   supportAppCompat = "com.android.support:appcompat-v7:$supportVersion"
   supportDesign = "com.android.support:design:$supportVersion"
 
-  rxJava = 'io.reactivex:rxjava:1.2.2'
+  rxJava = 'io.reactivex:rxjava:1.2.3'
   boltsTask = 'com.parse.bolts:bolts-tasks:1.4.0'
   okhttp3 = 'com.squareup.okhttp3:okhttp:3.5.0'
   picasso = 'com.squareup.picasso:picasso:2.5.2'