WIP: Fix issue where emulator connects to the wrong host upon reconnect

firebase-database/gradle.properties

@@ -13,5 +13,5 @@
 # limitations under the License.
 
 version=21.0.0
-latestReleasedVersion=20.3.1
+latestReleasedVersion=20.3.2
 android.enableUnitTestBinaryResources=true

firebase-database/src/androidTest/java/com/google/firebase/database/connection/ConnectionTest.java

@@ -66,7 +66,7 @@ public void onCacheHost(String s) {}
             IntegrationTestValues.getNamespace(),
             /*secure=*/ true);
     DatabaseConfig config = IntegrationTestHelpers.newFrozenTestConfig();
-    Connection conn = new Connection(config.getConnectionContext(), info, null, del, null, "");
+    Connection conn = new Connection(config.getConnectionContext(), info, null, del, null, "", false);
     conn.open();
     IntegrationTestHelpers.waitFor(valSemaphore);
   }

firebase-database/src/androidTest/java/com/google/firebase/database/core/SynchronousConnection.java

@@ -55,7 +55,7 @@ public SynchronousConnection(String host) {
     RepoInfo repoInfo = parsed.repoInfo;
     HostInfo hostInfo = new HostInfo(repoInfo.host, repoInfo.namespace, repoInfo.secure);
 
-    connection = new PersistentConnectionImpl(context.getConnectionContext(), hostInfo, this);
+    connection = new PersistentConnectionImpl(context.getConnectionContext(), hostInfo, this, false);
     this.connectSemaphore = new Semaphore(0);
   }
 

firebase-database/src/main/java/com/google/firebase/database/FirebaseDatabase.java

@@ -313,12 +313,13 @@ public synchronized void setPersistenceCacheSizeBytes(long cacheSizeInBytes) {
    * @param port the emulator port (for example, 9000)
    */
   public void useEmulator(@NonNull String host, int port) {
+    System.out.println("Using Emulator");
     if (this.repo != null) {
       throw new IllegalStateException(
           "Cannot call useEmulator() after instance has already been initialized.");
     }
-
     this.emulatorSettings = new EmulatedServiceSettings(host, port);
+    this.config.setUsingEmulator(true);
   }
 
   /** @return The semver version for this build of the Firebase Database client */

firebase-database/src/main/java/com/google/firebase/database/android/AndroidPlatform.java

@@ -114,8 +114,9 @@ public PersistentConnection newPersistentConnection(
       ConnectionContext connectionContext,
       HostInfo info,
       PersistentConnection.Delegate delegate) {
+
     final PersistentConnection connection =
-        new PersistentConnectionImpl(connectionContext, info, delegate);
+        new PersistentConnectionImpl(connectionContext, info, delegate, context.isUsingEmulator());
 
     // TODO: Ideally we would remove this listener at some point, but right now
     // there's no cleanup path for PersistentConnection (or Repo, etc.). They live forever.

firebase-database/src/main/java/com/google/firebase/database/connection/Connection.java

@@ -70,18 +70,22 @@ private enum State {
   private State state;
   private final LogWrapper logger;
 
+  private boolean isUsingEmulator;
+
   public Connection(
       ConnectionContext context,
       HostInfo hostInfo,
       String cachedHost,
       Delegate delegate,
       String optLastSessionId,
-      String appCheckToken) {
+      String appCheckToken,
+      boolean isUsingEmulator) {
     long connId = connectionIds++;
     this.hostInfo = hostInfo;
     this.delegate = delegate;
     this.logger = new LogWrapper(context.getLogger(), "Connection", "conn_" + connId);
     this.state = State.REALTIME_CONNECTING;
+    this.isUsingEmulator = isUsingEmulator;
     this.conn =
         new WebsocketConnection(
             context, hostInfo, cachedHost, appCheckToken, this, optLastSessionId);
@@ -205,7 +209,9 @@ private void onConnectionShutdown(String reason) {
   private void onHandshake(Map<String, Object> handshake) {
     long timestamp = (Long) handshake.get(SERVER_HELLO_TIMESTAMP);
     String host = (String) handshake.get(SERVER_HELLO_HOST);
-    delegate.onCacheHost(host);
+    if(!this.isUsingEmulator) {
+      delegate.onCacheHost(host);
+    }
     String sessionId = (String) handshake.get(SERVER_HELLO_SESSION_ID);
 
     if (state == State.REALTIME_CONNECTING) {

firebase-database/src/main/java/com/google/firebase/database/connection/PersistentConnectionImpl.java

@@ -327,10 +327,13 @@ private enum ConnectionState {
   private long lastWriteTimestamp;
   private boolean hasOnDisconnects;
 
+  private boolean isUsingEmulator;
+
   public PersistentConnectionImpl(
-      ConnectionContext context, HostInfo info, final Delegate delegate) {
+      ConnectionContext context, HostInfo info, final Delegate delegate, boolean isUsingEmulator) {
     this.delegate = delegate;
     this.context = context;
+    this.isUsingEmulator = isUsingEmulator;
     this.executorService = context.getExecutorService();
     this.authTokenProvider = context.getAuthTokenProvider();
     this.appCheckTokenProvider = context.getAppCheckTokenProvider();
@@ -829,7 +832,7 @@ public void openNetworkConnection(String authToken, String appCheckToken) {
     this.connectionState = ConnectionState.Connecting;
     realtime =
         new Connection(
-            this.context, this.hostInfo, this.cachedHost, this, this.lastSessionId, appCheckToken);
+            this.context, this.hostInfo, this.cachedHost, this, this.lastSessionId, appCheckToken, this.isUsingEmulator);
     realtime.open();
   }
 

firebase-database/src/main/java/com/google/firebase/database/core/Context.java

@@ -54,6 +54,8 @@ public class Context {
 
   private Platform platform;
 
+  protected boolean isUsingEmulator = false;
+
   private Platform getPlatform() {
     if (platform == null) {
       initializeAndroidPlatform();
@@ -65,6 +67,10 @@ private synchronized void initializeAndroidPlatform() {
     platform = new AndroidPlatform(this.firebaseApp);
   }
 
+  public boolean isUsingEmulator() {
+    return this.isUsingEmulator;
+  }
+
   public boolean isFrozen() {
     return frozen;
   }
@@ -139,6 +145,7 @@ public LogWrapper getLogger(String component, String prefix) {
     return new LogWrapper(logger, component, prefix);
   }
 
+  // TODO(mtewani): fill this in instead of repoinfo
   public ConnectionContext getConnectionContext() {
     return new ConnectionContext(
         this.getLogger(),
@@ -211,8 +218,9 @@ public TokenProvider getAppCheckTokenProvider() {
     return this.appCheckTokenProvider;
   }
 
+
   public PersistentConnection newPersistentConnection(
-      HostInfo info, PersistentConnection.Delegate delegate) {
+          HostInfo info, PersistentConnection.Delegate delegate) {
     return getPlatform().newPersistentConnection(this, this.getConnectionContext(), info, delegate);
   }
 

firebase-database/src/main/java/com/google/firebase/database/core/DatabaseConfig.java

@@ -173,6 +173,14 @@ public synchronized void setPersistenceCacheSizeBytes(long cacheSizeInBytes) {
     this.cacheSize = cacheSizeInBytes;
   }
 
+  /**
+   * @hide
+   * @param isUsingEmulator
+   */
+  public synchronized void setUsingEmulator(boolean isUsingEmulator) {
+    this.isUsingEmulator = isUsingEmulator;
+  }
+
   public synchronized void setFirebaseApp(FirebaseApp app) {
     this.firebaseApp = app;
   }

firebase-database/src/main/java/com/google/firebase/database/core/RepoInfo.java

@@ -28,6 +28,7 @@ public final class RepoInfo {
   public String namespace;
   public String internalHost;
 
+
   @Override
   public String toString() {
     return "http" + (secure ? "s" : "") + "://" + host;