starboard/android/apk/app/src/main/java/dev/cobalt/coat/StarboardBridge.java

// Copyright 2017 The Cobalt Authors. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package dev.cobalt.coat;

import static android.content.Context.AUDIO_SERVICE;
import static android.media.AudioManager.GET_DEVICES_INPUTS;
import static dev.cobalt.util.Log.TAG;

import android.annotation.SuppressLint;
import android.app.Activity;
import android.app.Service;
import android.content.Context;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.hardware.input.InputManager;
import android.media.AudioDeviceInfo;
import android.media.AudioManager;
import android.net.ConnectivityManager;
import android.net.Network;
import android.net.NetworkCapabilities;
import android.os.Build;
import android.os.Build.VERSION;
import android.util.Pair;
import android.util.Size;
import android.util.SizeF;
import android.view.Display;
import android.view.InputDevice;
import android.view.accessibility.AccessibilityManager;
import android.view.accessibility.CaptioningManager;
import androidx.annotation.Nullable;
import androidx.annotation.RequiresApi;
import dev.cobalt.account.UserAuthorizer;
import dev.cobalt.libraries.services.clientloginfo.ClientLogInfo;
import dev.cobalt.media.AudioOutputManager;
import dev.cobalt.media.CaptionSettings;
import dev.cobalt.media.CobaltMediaSession;
import dev.cobalt.media.MediaImage;
import dev.cobalt.util.DisplayUtil;
import dev.cobalt.util.Holder;
import dev.cobalt.util.Log;
import dev.cobalt.util.UsedByNative;
import java.lang.reflect.Method;
import java.net.InterfaceAddress;
import java.net.NetworkInterface;
import java.net.SocketException;
import java.util.Calendar;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Locale;
import java.util.Set;
import java.util.TimeZone;

/** Implementation of the required JNI methods called by the Starboard C++ code. */
public class StarboardBridge {

  /** Interface to be implemented by the Android Application hosting the starboard app. */
  public interface HostApplication {
    void setStarboardBridge(StarboardBridge starboardBridge);

    StarboardBridge getStarboardBridge();
  }

  private CobaltSystemConfigChangeReceiver sysConfigChangeReceiver;
  private CobaltTextToSpeechHelper ttsHelper;
  private UserAuthorizer userAuthorizer;
  private AudioOutputManager audioOutputManager;
  private CobaltMediaSession cobaltMediaSession;
  private AudioPermissionRequester audioPermissionRequester;
  private KeyboardEditor keyboardEditor;
  private NetworkStatus networkStatus;
  private ResourceOverlay resourceOverlay;

  static {
    // Even though NativeActivity already loads our library from C++,
    // we still have to load it from Java to make JNI calls into it.
    System.loadLibrary("coat");
  }

  private final Context appContext;
  private final Holder<Activity> activityHolder;
  private final Holder<Service> serviceHolder;
  private final String[] args;
  private final String startDeepLink;
  private final Runnable stopRequester =
      new Runnable() {
        @Override
        public void run() {
          requestStop(0);
        }
      };

  private volatile boolean starboardStopped = false;

  private final HashMap<String, CobaltService.Factory> cobaltServiceFactories = new HashMap<>();
  private final HashMap<String, CobaltService> cobaltServices = new HashMap<>();

  private static final TimeZone DEFAULT_TIME_ZONE = TimeZone.getTimeZone("America/Los_Angeles");
  private final long timeNanosecondsPerMicrosecond = 1000;

  private Set<Integer> supportedHdrTypesSet = new HashSet<Integer>();
  private long supportedHdrTypesSetUpdatedAt = 0;
  private final long supportedHdrTypesCacheTtlMs = 1000;

  public StarboardBridge(
      Context appContext,
      Holder<Activity> activityHolder,
      Holder<Service> serviceHolder,
      UserAuthorizer userAuthorizer,
      String[] args,
      String startDeepLink) {

    // Make sure the JNI stack is properly initialized first as there is
    // race condition as soon as any of the following objects creates a new thread.
    nativeInitialize();

    this.appContext = appContext;
    this.activityHolder = activityHolder;
    this.serviceHolder = serviceHolder;
    this.args = args;
    this.startDeepLink = startDeepLink;
    this.sysConfigChangeReceiver = new CobaltSystemConfigChangeReceiver(appContext, stopRequester);
    this.ttsHelper = new CobaltTextToSpeechHelper(appContext);
    this.userAuthorizer = userAuthorizer;
    this.audioOutputManager = new AudioOutputManager(appContext);
    this.cobaltMediaSession =
        new CobaltMediaSession(appContext, activityHolder, audioOutputManager);
    this.audioPermissionRequester = new AudioPermissionRequester(appContext, activityHolder);
    this.networkStatus = new NetworkStatus(appContext);
    this.resourceOverlay = new ResourceOverlay(appContext);
  }

  private native boolean nativeInitialize();

  private native long nativeSbTimeGetMonotonicNow();

  protected void onActivityStart(Activity activity, KeyboardEditor keyboardEditor) {
    activityHolder.set(activity);
    this.keyboardEditor = keyboardEditor;
    sysConfigChangeReceiver.setForeground(true);

    // TODO: v0_1231sd2 is the default value used for testing,
    // delete it once we verify it can be queried in QOE system.
    if (!isReleaseBuild()) {
      ClientLogInfo.setClientInfo("v0_1231sd2");
    }
  }

  protected void onActivityStop(Activity activity) {
    if (activityHolder.get() == activity) {
      activityHolder.set(null);
    }
    sysConfigChangeReceiver.setForeground(false);
  }

  protected void onActivityDestroy(Activity activity) {
    if (starboardStopped) {
      // We can't restart the starboard app, so kill the process for a clean start next time.
      Log.i(TAG, "Activity destroyed after shutdown; killing app.");
      System.exit(0);
    } else {
      Log.i(TAG, "Activity destroyed without shutdown; app suspended in background.");
    }
  }

  protected void onServiceStart(Service service) {
    serviceHolder.set(service);
  }

  protected void onServiceDestroy(Service service) {
    if (serviceHolder.get() == service) {
      serviceHolder.set(null);
    }
  }

  @SuppressWarnings("unused")
  @UsedByNative
  protected void startMediaPlaybackService() {
    if (cobaltMediaSession == null || !cobaltMediaSession.isActive()) {
      Log.w(TAG, "Do not start a MediaPlaybackService when the MediSsession is null or inactive.");
      return;
    }

    Service service = serviceHolder.get();
    if (service == null) {
      if (appContext == null) {
        Log.w(TAG, "Activiy already destroyed.");
        return;
      }
      Log.i(TAG, "Cold start - Instantiating a MediaPlaybackService.");
      Intent intent = new Intent(appContext, MediaPlaybackService.class);
      try {
        if (VERSION.SDK_INT >= 26) {
          appContext.startForegroundService(intent);
        } else {
          appContext.startService(intent);
        }
      } catch (SecurityException e) {
        Log.e(TAG, "Failed to start MediaPlaybackService with intent.", e);
        return;
      }
    } else {
      Log.i(TAG, "Warm start - Restarting the MediaPlaybackService.");
      ((MediaPlaybackService) service).startService();
    }
  }

  @SuppressWarnings("unused")
  @UsedByNative
  protected void stopMediaPlaybackService() {
    Service service = serviceHolder.get();
    if (service != null) {
      Log.i(TAG, "Stopping the MediaPlaybackService.");
      ((MediaPlaybackService) service).stopService();
    }
  }

  @SuppressWarnings("unused")
  @UsedByNative
  protected void beforeStartOrResume() {
    Log.i(TAG, "Prepare to resume");
    // Bring our platform services to life before resuming so that they're ready to deal with
    // whatever the web app wants to do with them as part of its start/resume logic.
    cobaltMediaSession.resume();
    networkStatus.beforeStartOrResume();
    for (CobaltService service : cobaltServices.values()) {
      service.beforeStartOrResume();
    }
  }

  @SuppressWarnings("unused")
  @UsedByNative
  protected void beforeSuspend() {
    try {
      Log.i(TAG, "Prepare to suspend");
      // We want the MediaSession to be deactivated immediately before suspending so that by the
      // time, the launcher is visible our "Now Playing" card is already gone. Then Cobalt and
      // the web app can take their time suspending after that.
      cobaltMediaSession.suspend();
      networkStatus.beforeSuspend();
      for (CobaltService service : cobaltServices.values()) {
        service.beforeSuspend();
      }
      // We need to stop MediaPlaybackService before suspending so that this foreground service
      // would not prevent releasing activity's memory consumption.
      stopMediaPlaybackService();
    } catch (Throwable e) {
      Log.i(TAG, "Caught exception in beforeSuspend: " + e.getMessage());
    }
  }

  @SuppressWarnings("unused")
  @UsedByNative
  protected void afterStopped() {
    starboardStopped = true;
    ttsHelper.shutdown();
    userAuthorizer.shutdown();
    for (CobaltService service : cobaltServices.values()) {
      service.afterStopped();
    }
    Activity activity = activityHolder.get();
    if (activity != null) {
      // Wait until the activity is destroyed to exit.
      Log.i(TAG, "Shutdown in foreground; finishing Activity and removing task.");
      activity.finishAndRemoveTask();
    } else {
      // We can't restart the starboard app, so kill the process for a clean start next time.
      Log.i(TAG, "Shutdown in background; killing app without removing task.");
      System.exit(0);
    }
  }

  @SuppressWarnings("unused")
  @UsedByNative
  public void requestStop(int errorLevel) {
    if (!starboardStopped) {
      Log.i(TAG, "Request to stop");
      nativeStopApp(errorLevel);
    }
  }

  private native void nativeStopApp(int errorLevel);

  @SuppressWarnings("unused")
  @UsedByNative
  public void requestSuspend() {
    Activity activity = activityHolder.get();
    if (activity != null) {
      Log.i(TAG, "Request to suspend");
      activity.finish();
    }
  }

  public boolean onSearchRequested() {
    return nativeOnSearchRequested();
  }

  private native boolean nativeOnSearchRequested();

  @SuppressWarnings("unused")
  @UsedByNative
  public Context getApplicationContext() {
    return appContext;
  }

  @SuppressWarnings("unused")
  @UsedByNative
  void raisePlatformError(@PlatformError.ErrorType int errorType, long data) {
    PlatformError error = new PlatformError(activityHolder, errorType, data);
    error.raise();
  }

  /** Returns true if the native code is compiled for release (i.e. 'gold' build). */
  public static boolean isReleaseBuild() {
    return nativeIsReleaseBuild();
  }

  private static native boolean nativeIsReleaseBuild();

  protected Holder<Activity> getActivityHolder() {
    return activityHolder;
  }

  @SuppressWarnings("unused")
  @UsedByNative
  protected String[] getArgs() {
    return args;
  }

  /** Returns the URL from the Intent that started the app. */
  @SuppressWarnings("unused")
  @UsedByNative
  protected String getStartDeepLink() {
    return startDeepLink;
  }

  /** Sends an event to the web app to navigate to the given URL */
  public void handleDeepLink(String url) {
    nativeHandleDeepLink(url);
  }

  private native void nativeHandleDeepLink(String url);

  /**
   * Returns the absolute path to the directory where application specific files should be written.
   * May be overridden for use cases that need to segregate storage.
   */
  @SuppressWarnings("unused")
  @UsedByNative
  protected String getFilesAbsolutePath() {
    return appContext.getFilesDir().getAbsolutePath();
  }

  /**
   * Returns the absolute path to the application specific cache directory on the filesystem. May be
   * overridden for use cases that need to segregate storage.
   */
  @SuppressWarnings("unused")
  @UsedByNative
  protected String getCacheAbsolutePath() {
    return appContext.getCacheDir().getAbsolutePath();
  }

  /**
   * Returns non-loopback network interface address and its netmask, or null if none.
   *
   * <p>A Java function to help implement Starboard's SbSocketGetLocalInterfaceAddress.
   */
  @SuppressWarnings("unused")
  @UsedByNative
  Pair<byte[], byte[]> getLocalInterfaceAddressAndNetmask(boolean wantIPv6) {
    try {
      Enumeration<NetworkInterface> it = NetworkInterface.getNetworkInterfaces();

      while (it.hasMoreElements()) {
        NetworkInterface ni = it.nextElement();
        if (ni.isLoopback()) {
          continue;
        }
        if (!ni.isUp()) {
          continue;
        }
        if (ni.isPointToPoint()) {
          continue;
        }

        for (InterfaceAddress ia : ni.getInterfaceAddresses()) {
          byte[] address = ia.getAddress().getAddress();
          boolean isIPv6 = (address.length > 4);
          if (isIPv6 == wantIPv6) {
            // Convert the network prefix length to a network mask.
            int prefix = ia.getNetworkPrefixLength();
            byte[] netmask = new byte[address.length];
            for (int i = 0; i < netmask.length; i++) {
              if (prefix == 0) {
                netmask[i] = 0;
              } else if (prefix >= 8) {
                netmask[i] = (byte) 0xFF;
                prefix -= 8;
              } else {
                netmask[i] = (byte) (0xFF << (8 - prefix));
                prefix = 0;
              }
            }
            return new Pair<>(address, netmask);
          }
        }
      }
    } catch (SocketException ex) {
      // TODO should we have a logging story that strips logs for production?
      Log.w(TAG, "sbSocketGetLocalInterfaceAddress exception", ex);
      return null;
    }
    return null;
  }

  @SuppressWarnings("unused")
  @UsedByNative
  CobaltTextToSpeechHelper getTextToSpeechHelper() {
    return ttsHelper;
  }

  /**
   * @return A new CaptionSettings object with the current system caption settings.
   */
  @SuppressWarnings("unused")
  @UsedByNative
  CaptionSettings getCaptionSettings() {
    CaptioningManager cm =
        (CaptioningManager) appContext.getSystemService(Context.CAPTIONING_SERVICE);
    return new CaptionSettings(cm);
  }

  /** Java-layer implementation of SbSystemGetLocaleId. */
  @SuppressWarnings("unused")
  @UsedByNative
  String systemGetLocaleId() {
    return Locale.getDefault().toLanguageTag();
  }

  @SuppressWarnings("unused")
  @UsedByNative
  String getTimeZoneId() {
    Locale locale = Locale.getDefault();
    Calendar calendar = Calendar.getInstance(locale);
    TimeZone timeZone = DEFAULT_TIME_ZONE;
    if (calendar != null) {
      timeZone = calendar.getTimeZone();
    }
    return timeZone.getID();
  }

  @SuppressWarnings("unused")
  @UsedByNative
  SizeF getDisplayDpi() {
    return DisplayUtil.getDisplayDpi();
  }

  @SuppressWarnings("unused")
  @UsedByNative
  Size getDisplaySize() {
    return DisplayUtil.getSystemDisplaySize();
  }

  @SuppressWarnings("unused")
  @UsedByNative
  public ResourceOverlay getResourceOverlay() {
    return resourceOverlay;
  }

  @Nullable
  private static String getSystemProperty(String name) {
    try {
      @SuppressLint("PrivateApi")
      Class<?> systemProperties = Class.forName("android.os.SystemProperties");
      Method getMethod = systemProperties.getMethod("get", String.class);
      return (String) getMethod.invoke(systemProperties, name);
    } catch (Exception e) {
      Log.e(TAG, "Failed to read system property " + name, e);
      return null;
    }
  }

  @SuppressWarnings("unused")
  @UsedByNative
  Size getDeviceResolution() {
    String displaySize =
        android.os.Build.VERSION.SDK_INT < 28
            ? getSystemProperty("sys.display-size")
            : getSystemProperty("vendor.display-size");

    if (displaySize == null) {
      return getDisplaySize();
    }

    String[] sizes = displaySize.split("x");
    if (sizes.length != 2) {
      return getDisplaySize();
    }

    try {
      return new Size(Integer.parseInt(sizes[0]), Integer.parseInt(sizes[1]));
    } catch (NumberFormatException e) {
      return getDisplaySize();
    }
  }

  @SuppressWarnings("unused")
  @UsedByNative
  boolean isNetworkConnected() {
    return networkStatus.isConnected();
  }

  /**
   * Checks if there is no microphone connected to the system.
   *
   * @return true if no device is connected.
   */
  @SuppressWarnings("unused")
  @UsedByNative
  public boolean isMicrophoneDisconnected() {
    if (Build.VERSION.SDK_INT >= 23) {
      return !isMicrophoneConnectedV23();
    } else {
      // There is no way of checking for a connected microphone/device before API 23, so cannot
      // guarantee that no microphone is connected.
      return false;
    }
  }

  @RequiresApi(23)
  private boolean isMicrophoneConnectedV23() {
    // A check specifically for microphones is not available before API 28, so it is assumed that a
    // connected input audio device is a microphone.
    AudioManager audioManager = (AudioManager) appContext.getSystemService(AUDIO_SERVICE);
    AudioDeviceInfo[] devices = audioManager.getDevices(GET_DEVICES_INPUTS);
    if (devices.length > 0) {
      return true;
    }

    // fallback to check for BT voice capable RCU
    InputManager inputManager = (InputManager) appContext.getSystemService(Context.INPUT_SERVICE);
    final int[] inputDeviceIds = inputManager.getInputDeviceIds();
    for (int inputDeviceId : inputDeviceIds) {
      final InputDevice inputDevice = inputManager.getInputDevice(inputDeviceId);
      final boolean hasMicrophone = inputDevice.hasMicrophone();
      if (hasMicrophone) {
        return true;
      }
    }
    return false;
  }

  /**
   * Checks if the microphone is muted.
   *
   * @return true if the microphone mute is on.
   */
  @SuppressWarnings("unused")
  @UsedByNative
  public boolean isMicrophoneMute() {
    AudioManager audioManager = (AudioManager) appContext.getSystemService(AUDIO_SERVICE);
    return audioManager.isMicrophoneMute();
  }

  /**
   * @return true if we have an active network connection and it's on an wireless network.
   */
  @SuppressWarnings("unused")
  @UsedByNative
  boolean isCurrentNetworkWireless() {
    if (Build.VERSION.SDK_INT >= 23) {
      return isCurrentNetworkWirelessV23();
    } else {
      return isCurrentNetworkWirelessDeprecated();
    }
  }

  @SuppressWarnings("deprecation")
  private boolean isCurrentNetworkWirelessDeprecated() {
    ConnectivityManager connMgr =
        (ConnectivityManager) appContext.getSystemService(Context.CONNECTIVITY_SERVICE);
    android.net.NetworkInfo activeInfo = connMgr.getActiveNetworkInfo();
    if (activeInfo == null) {
      return false;
    }
    switch (activeInfo.getType()) {
      case ConnectivityManager.TYPE_ETHERNET:
        return false;
      default:
        // Consider anything that's not definitely wired to be wireless.
        // For example, TYPE_VPN is ambiguous, but it's highly likely to be
        // over wifi.
        return true;
    }
  }

  @RequiresApi(23)
  private boolean isCurrentNetworkWirelessV23() {
    ConnectivityManager connMgr =
        (ConnectivityManager) appContext.getSystemService(Context.CONNECTIVITY_SERVICE);
    Network activeNetwork = connMgr.getActiveNetwork();
    if (activeNetwork == null) {
      return false;
    }
    NetworkCapabilities activeCapabilities = connMgr.getNetworkCapabilities(activeNetwork);
    if (activeCapabilities == null) {
      return false;
    }
    // Consider anything that's not definitely wired to be wireless.
    return !activeCapabilities.hasTransport(NetworkCapabilities.TRANSPORT_ETHERNET);
  }

  /**
   * @return true if the user has enabled accessibility high contrast text in the operating system.
   */
  @SuppressWarnings("unused")
  @UsedByNative
  boolean isAccessibilityHighContrastTextEnabled() {
    AccessibilityManager am =
        (AccessibilityManager) appContext.getSystemService(Context.ACCESSIBILITY_SERVICE);

    try {
      Method m = AccessibilityManager.class.getDeclaredMethod("isHighTextContrastEnabled");

      return m.invoke(am) == Boolean.TRUE;
    } catch (ReflectiveOperationException ex) {
      return false;
    }
  }

  /** Returns Java layer implementation for AndroidUserAuthorizer */
  @SuppressWarnings("unused")
  @UsedByNative
  public UserAuthorizer getUserAuthorizer() {
    return userAuthorizer;
  }

  @SuppressWarnings("unused")
  @UsedByNative
  void updateMediaSession(
      int playbackState,
      long actions,
      long positionMs,
      float speed,
      String title,
      String artist,
      String album,
      MediaImage[] artwork,
      long duration) {
    cobaltMediaSession.updateMediaSession(
        playbackState, actions, positionMs, speed, title, artist, album, artwork, duration);
  }

  /** Returns string for kSbSystemPropertyUserAgentAuxField */
  @SuppressWarnings("unused")
  @UsedByNative
  protected String getUserAgentAuxField() {
    StringBuilder sb = new StringBuilder();

    String packageName = appContext.getApplicationInfo().packageName;
    sb.append(packageName);
    sb.append('/');

    try {
      sb.append(appContext.getPackageManager().getPackageInfo(packageName, 0).versionName);
    } catch (PackageManager.NameNotFoundException ex) {
      // Should never happen
      Log.e(TAG, "Can't find our own package", ex);
    }

    return sb.toString();
  }

  @SuppressWarnings("unused")
  @UsedByNative
  AudioOutputManager getAudioOutputManager() {
    return audioOutputManager;
  }

  /** Returns Java layer implementation for KeyboardEditor */
  @SuppressWarnings("unused")
  @UsedByNative
  KeyboardEditor getKeyboardEditor() {
    return keyboardEditor;
  }

  /** Returns Java layer implementation for AudioPermissionRequester */
  @SuppressWarnings("unused")
  @UsedByNative
  AudioPermissionRequester getAudioPermissionRequester() {
    return audioPermissionRequester;
  }

  void onActivityResult(int requestCode, int resultCode, Intent data) {
    userAuthorizer.onActivityResult(requestCode, resultCode, data);
  }

  void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
    userAuthorizer.onRequestPermissionsResult(requestCode, permissions, grantResults);
    audioPermissionRequester.onRequestPermissionsResult(requestCode, permissions, grantResults);
  }

  @SuppressWarnings("unused")
  @UsedByNative
  public void resetVideoSurface() {
    Activity activity = activityHolder.get();
    if (activity instanceof CobaltActivity) {
      ((CobaltActivity) activity).resetVideoSurface();
    }
  }

  @SuppressWarnings("unused")
  @UsedByNative
  public void setVideoSurfaceBounds(final int x, final int y, final int width, final int height) {
    Activity activity = activityHolder.get();
    if (activity instanceof CobaltActivity) {
      ((CobaltActivity) activity).setVideoSurfaceBounds(x, y, width, height);
    }
  }

  long supportedHdrTypesSetUpdatedAtNs;

  private void refreshHdrTypesCacheIfNecessary() {
    if (System.currentTimeMillis() - supportedHdrTypesSetUpdatedAt < supportedHdrTypesCacheTtlMs) {
      // Cache is up to date.
      return;
    }
    supportedHdrTypesSet.clear();
    supportedHdrTypesSetUpdatedAt = System.currentTimeMillis();

    Display defaultDisplay = DisplayUtil.getDefaultDisplay();
    if (defaultDisplay == null) {
      return;
    }

    Display.HdrCapabilities hdrCapabilities = defaultDisplay.getHdrCapabilities();
    if (hdrCapabilities == null) {
      return;
    }

    int[] supportedHdrTypes = hdrCapabilities.getSupportedHdrTypes();
    if (supportedHdrTypes == null) {
      return;
    }

    for (int supportedType : supportedHdrTypes) {
      supportedHdrTypesSet.add(supportedType);
    }
  }

  /**
   * Check if hdrType is supported by the current default display. See
   * https://developer.android.com/reference/android/view/Display.HdrCapabilities.html for valid
   * values.
   */
  @RequiresApi(24)
  @SuppressWarnings("unused")
  @UsedByNative
  public boolean isHdrTypeSupported(int hdrType) {
    if (android.os.Build.VERSION.SDK_INT < 24) {
      return false;
    }

    synchronized (this) {
      refreshHdrTypesCacheIfNecessary();
      return supportedHdrTypesSet.contains(hdrType);
    }
  }

  /** Return the CobaltMediaSession. */
  public CobaltMediaSession cobaltMediaSession() {
    return cobaltMediaSession;
  }

  public void registerCobaltService(CobaltService.Factory factory) {
    cobaltServiceFactories.put(factory.getServiceName(), factory);
  }

  @SuppressWarnings("unused")
  @UsedByNative
  boolean hasCobaltService(String serviceName) {
    return cobaltServiceFactories.get(serviceName) != null;
  }

  @SuppressWarnings("unused")
  @UsedByNative
  CobaltService openCobaltService(long nativeService, String serviceName) {
    if (cobaltServices.get(serviceName) != null) {
      // Attempting to re-open an already open service fails.
      Log.e(TAG, String.format("Cannot open already open service %s", serviceName));
      return null;
    }
    final CobaltService.Factory factory = cobaltServiceFactories.get(serviceName);
    if (factory == null) {
      Log.e(TAG, String.format("Cannot open unregistered service %s", serviceName));
      return null;
    }
    CobaltService service = factory.createCobaltService(nativeService);
    if (service != null) {
      service.receiveStarboardBridge(this);
      cobaltServices.put(serviceName, service);
    }
    return service;
  }

  @SuppressWarnings("unused")
  @UsedByNative
  void closeCobaltService(String serviceName) {
    cobaltServices.remove(serviceName);
  }

  /** Returns the application start timestamp. */
  @SuppressWarnings("unused")
  @UsedByNative
  protected long getAppStartTimestamp() {
    Activity activity = activityHolder.get();
    if (activity instanceof CobaltActivity) {
      long javaStartTimestamp = ((CobaltActivity) activity).getAppStartTimestamp();
      long cppTimestamp = nativeSbTimeGetMonotonicNow();
      long javaStopTimestamp = System.nanoTime();
      return cppTimestamp
          - (javaStartTimestamp - javaStopTimestamp) / timeNanosecondsPerMicrosecond;
    }
    return 0;
  }
}