content: /*
   * Copyright (C) 2018 The Android Open Source Project
   *
   * 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 com.android.server.deviceidle;
  
  import android.bluetooth.BluetoothAdapter;
  import android.bluetooth.BluetoothDevice;
  import android.bluetooth.BluetoothManager;
  import android.bluetooth.BluetoothProfile;
  import android.content.BroadcastReceiver;
  import android.content.Context;
  import android.content.Intent;
  import android.content.IntentFilter;
  import android.os.Handler;
  import android.os.Message;
  
  import com.android.internal.annotations.GuardedBy;
  import com.android.internal.annotations.VisibleForTesting;
  import com.android.server.DeviceIdleController;
  
  /**
   * Track whether there are any active Bluetooth devices connected.
   */
  public class BluetoothConstraint implements IDeviceIdleConstraint {
      private static final String TAG = BluetoothConstraint.class.getSimpleName();
      private static final long INACTIVITY_TIMEOUT_MS = 20 * 60 * 1000L;
  
      private final Context mContext;
      private final Handler mHandler;
      private final DeviceIdleController.LocalService mLocalService;
      private final BluetoothManager mBluetoothManager;
  
      private volatile boolean mConnected = true;
      private volatile boolean mMonitoring = false;
  
      public BluetoothConstraint(
              Context context, Handler handler, DeviceIdleController.LocalService localService) {
          mContext = context;
          mHandler = handler;
          mLocalService = localService;
          mBluetoothManager = mContext.getSystemService(BluetoothManager.class);
      }
  
      @Override
      public synchronized void startMonitoring() {
          // Start by assuming we have a connected bluetooth device.
          mConnected = true;
          mMonitoring = true;
  
          // Register a receiver to get updates on bluetooth devices disconnecting or the
          // adapter state changing.
          IntentFilter filter = new IntentFilter();
          filter.addAction(BluetoothDevice.ACTION_ACL_DISCONNECTED);
          filter.addAction(BluetoothDevice.ACTION_ACL_CONNECTED);
          filter.addAction(BluetoothAdapter.ACTION_STATE_CHANGED);
          mContext.registerReceiver(mReceiver, filter);
  
          // Some devices will try to stay connected indefinitely. Set a timeout to ignore them.
          mHandler.sendMessageDelayed(
                  Message.obtain(mHandler, mTimeoutCallback), INACTIVITY_TIMEOUT_MS);
  
          // Now we have the receiver registered, make a direct check for connected devices.
          updateAndReportActiveLocked();
      }
  
      @Override
      public synchronized void stopMonitoring() {
          mContext.unregisterReceiver(mReceiver);
          mHandler.removeCallbacks(mTimeoutCallback);
          mMonitoring = false;
      }
  
      private synchronized void cancelMonitoringDueToTimeout() {
          if (mMonitoring) {
              mMonitoring = false;
              mLocalService.onConstraintStateChanged(this, /* active= */ false);
          }
      }
  
      /**
       * Check the latest data from BluetoothManager and let DeviceIdleController know whether we
       * have connected devices (for example TV remotes / gamepads) and thus want to stay awake.
       */
      @GuardedBy("this")
      private void updateAndReportActiveLocked() {
          final boolean connected = isBluetoothConnected(mBluetoothManager);
          if (connected != mConnected) {
              mConnected = connected;
              // If we lost all of our connections, we are on track to going into idle state.
              mLocalService.onConstraintStateChanged(this, /* active= */ mConnected);
          }
      }
  
      /**
       * True if the bluetooth adapter exists, is enabled, and has at least one GATT device connected.
       */
      @VisibleForTesting
      static boolean isBluetoothConnected(BluetoothManager bluetoothManager) {
          BluetoothAdapter adapter = bluetoothManager.getAdapter();
          if (adapter != null && adapter.isEnabled()) {
              return bluetoothManager.getConnectedDevices(BluetoothProfile.GATT).size() > 0;
          }
          return false;
      }
  
      /**
       * Registered in {@link #startMonitoring()}, unregistered in {@link #stopMonitoring()}.
       */
      @VisibleForTesting
      final BroadcastReceiver mReceiver = new BroadcastReceiver() {
          @Override
          public void onReceive(Context context, Intent intent) {
              if (BluetoothDevice.ACTION_ACL_CONNECTED.equals(intent.getAction())) {
                  mLocalService.exitIdle("bluetooth");
              } else {
                  updateAndReportActiveLocked();
              }
          }
      };
  
      private final Runnable mTimeoutCallback = () -> cancelMonitoringDueToTimeout();
  }
  