service/src/com/android/car/BluetoothDeviceConnectionPolicy.java

/*
 * Copyright (C) 2017 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.car;

import android.app.ActivityManager;
import android.bluetooth.BluetoothA2dpSink;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothHeadsetClient;
import android.bluetooth.BluetoothMapClient;
import android.bluetooth.BluetoothPbapClient;
import android.bluetooth.BluetoothProfile;
import android.car.hardware.CarPropertyValue;
import android.car.hardware.CarSensorEvent;
import android.car.hardware.CarSensorManager;
import android.car.hardware.ICarSensorEventListener;
import android.car.hardware.cabin.CarCabinManager;
import android.car.hardware.property.CarPropertyEvent;
import android.car.hardware.property.ICarPropertyEventListener;
import android.car.ICarBluetoothUserService;
import android.car.ICarUserService;

import static android.car.settings.CarSettings.Secure.KEY_BLUETOOTH_AUTOCONNECT_MUSIC_DEVICES;
import static android.car.settings.CarSettings.Secure.KEY_BLUETOOTH_AUTOCONNECT_PHONE_DEVICES;
import static android.car.settings.CarSettings.Secure.KEY_BLUETOOTH_AUTOCONNECT_MESSAGING_DEVICES;

import android.os.UserHandle;
import android.provider.Settings;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.RemoteException;
import android.util.Log;

import java.lang.StringBuilder;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.locks.ReentrantLock;


/**
 * A Bluetooth Device Connection policy that is specific to the use cases of a Car.  A car's
 * bluetooth capabilities in terms of the profiles it supports and its use cases are unique.
 * Hence the CarService manages the policy that drives when and what to connect to.
 *
 * When to connect:
 * The policy can be configured to listen to various vehicle events that are appropriate to
 * trigger a connection attempt.  Signals like door unlock/open, ignition state changes indicate
 * user entry and there by attempt to connect to their devices. This removes the need for the user
 * to manually connect his device everytime they get in a car.
 *
 * Which device to connect:
 * The policy also keeps track of the {Profile : DevicesThatCanConnectOnTheProfile} and when
 * it is time to connect, picks the device that is appropriate and available.
 * For every profile, the policy attempts to connect to the last connected device first. The policy
 * maintains a list of connect-able devices for every profile, in the order of how recently they
 * connected.  The device that successfully connects on a profile is moved to the top of the list
 * of devices for that profile, so the next time a connection attempt is made, the policy starts
 * with the last connected device first.
 */

public class BluetoothDeviceConnectionPolicy {
    private static final String TAG = "BTDevConnectionPolicy";
    private static final String SETTINGS_DELIMITER = ",";
    private static final boolean DBG = false;
    private final Context mContext;
    private boolean mInitialized = false;
    private boolean mUserSpecificInfoInitialized = false;
    private final Object mSetupLock = new Object();

    // The main data structure that holds on to the {profile:list of known and connectible devices}
    private HashMap<Integer, BluetoothDevicesInfo> mProfileToConnectableDevicesMap;

    // The foll. number of connections are what the Bluetooth services and stack supports
    // and has been tested with.  MAP and A2DP are limited to one connection only.  HFP and PBAP,
    // though having the capability to support more than 2, has been tested with 2 connections.
    private static final int NUM_SUPPORTED_PHONE_CONNECTIONS = 2; // num of HFP and PBAP connections
    private static final int NUM_SUPPORTED_MSG_CONNECTIONS = 1; // num of MAP connections
    private static final int NUM_SUPPORTED_MUSIC_CONNECTIONS = 1; // num of A2DP connections
    private Map<Integer, Integer> mNumSupportedActiveConnections;

    private BluetoothAutoConnectStateMachine mBluetoothAutoConnectStateMachine;
    private final BluetoothAdapter mBluetoothAdapter;
    private BroadcastReceiver mBluetoothBroadcastReceiver;

    private ICarUserService mCarUserService;
    private PerUserCarServiceHelper mUserServiceHelper;
    private ICarBluetoothUserService mCarBluetoothUserService;
    private ReentrantLock mCarUserServiceAccessLock;

    // Events that are listened to for triggering an auto-connect:
    // Cabin events like Door unlock coming from the Cabin Service.
    private final CarCabinService mCarCabinService;
    private final CarPropertyListener mCabinEventListener;
    // Sensor events like Ignition switch ON from the Car Sensor Service
    private final CarSensorService mCarSensorService;
    private final CarSensorEventListener mCarSensorEventListener;

    // PerUserCarService related listeners
    private final UserServiceConnectionCallback mServiceCallback;

    // The Bluetooth profiles that the CarService will try to auto-connect on.
    private final List<Integer> mProfilesToConnect;
    private static final int MAX_CONNECT_RETRIES = 1;

    private static final int PROFILE_NOT_AVAILABLE = -1;

    // Device & Profile currently being connected on
    private ConnectionParams mConnectionInFlight;

    public static BluetoothDeviceConnectionPolicy create(Context context,
            CarCabinService carCabinService, CarSensorService carSensorService,
            PerUserCarServiceHelper userServiceHelper) {
        return new BluetoothDeviceConnectionPolicy(context, carCabinService, carSensorService,
                userServiceHelper);
    }

    private BluetoothDeviceConnectionPolicy(Context context, CarCabinService carCabinService,
            CarSensorService carSensorService, PerUserCarServiceHelper userServiceHelper) {
        mContext = context;
        mCarCabinService = carCabinService;
        mCarSensorService = carSensorService;
        mUserServiceHelper = userServiceHelper;
        mCarUserServiceAccessLock = new ReentrantLock();
        mProfilesToConnect = Arrays.asList(
                BluetoothProfile.HEADSET_CLIENT, BluetoothProfile.A2DP_SINK,
                BluetoothProfile.PBAP_CLIENT, BluetoothProfile.MAP_CLIENT);
        // mNumSupportedActiveConnections is a HashMap of mProfilesToConnect and the number of
        // connections each profile supports currently.
        mNumSupportedActiveConnections = new HashMap<>(mProfilesToConnect.size());
        for (Integer profile: mProfilesToConnect) {
            switch (profile) {
                case BluetoothProfile.HEADSET_CLIENT:
                    mNumSupportedActiveConnections.put(BluetoothProfile.HEADSET_CLIENT,
                            NUM_SUPPORTED_PHONE_CONNECTIONS);
                    break;
                case BluetoothProfile.PBAP_CLIENT:
                    mNumSupportedActiveConnections.put(BluetoothProfile.PBAP_CLIENT,
                            NUM_SUPPORTED_PHONE_CONNECTIONS);
                    break;
                case BluetoothProfile.A2DP_SINK:
                    mNumSupportedActiveConnections.put(BluetoothProfile.A2DP_SINK,
                            NUM_SUPPORTED_MUSIC_CONNECTIONS);
                    break;
                case BluetoothProfile.MAP_CLIENT:
                    mNumSupportedActiveConnections.put(BluetoothProfile.MAP_CLIENT,
                            NUM_SUPPORTED_MSG_CONNECTIONS);
                    break;
            }
        }

        // Listen to Cabin events for triggering auto connect
        mCabinEventListener = new CarPropertyListener();
        mCarSensorEventListener = new CarSensorEventListener();
        // Listen to User switching to connect to per User device.
        mServiceCallback = new UserServiceConnectionCallback();
        mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
        if (mBluetoothAdapter == null) {
            Log.w(TAG, "No Bluetooth Adapter Available");
        }
    }

    /**
     * ConnectionParams - parameters/objects relevant to the bluetooth connection calls.
     * This encapsulates the information that is passed around across different methods in the
     * policy. Contains the bluetooth device {@link BluetoothDevice} and the list of profiles that
     * we want that device to connect on.
     * Used as the currency that methods use to talk to each other in the policy.
     */
    public static class ConnectionParams {
        private BluetoothDevice mBluetoothDevice;
        private Integer mBluetoothProfile;

        public ConnectionParams() {
            // default constructor
        }

        public ConnectionParams(Integer profile) {
            mBluetoothProfile = profile;
        }

        public ConnectionParams(Integer profile, BluetoothDevice device) {
            mBluetoothProfile = profile;
            mBluetoothDevice = device;
        }

        // getters & Setters
        public void setBluetoothDevice(BluetoothDevice device) {
            mBluetoothDevice = device;
        }

        public void setBluetoothProfile(Integer profile) {
            mBluetoothProfile = profile;
        }

        public BluetoothDevice getBluetoothDevice() {
            return mBluetoothDevice;
        }

        public Integer getBluetoothProfile() {
            return mBluetoothProfile;
        }
    }

    /**
     * BluetoothBroadcastReceiver receives the bluetooth related intents that are relevant to
     * connection
     * and bonding state changes.  Reports the information to the {@link
     * BluetoothDeviceConnectionPolicy}
     * for it update its status.
     */
    public class BluetoothBroadcastReceiver extends BroadcastReceiver {
        @Override
        public void onReceive(Context context, Intent intent) {
            String action = intent.getAction();
            BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
            if (DBG) {
                if (device != null) {
                    Log.d(TAG, "Received Intent for device: " + device.getName() + action);
                } else {
                    Log.d(TAG, "Received Intent no device: " + action);
                }
            }
            ConnectionParams connectParams;
            if (BluetoothDevice.ACTION_BOND_STATE_CHANGED.equals(action)) {
                int bondState = intent.getIntExtra(BluetoothDevice.EXTRA_BOND_STATE,
                        BluetoothDevice.ERROR);
                updateBondState(device, bondState);

            } else if (BluetoothA2dpSink.ACTION_CONNECTION_STATE_CHANGED.equals(action)) {
                connectParams = new ConnectionParams(BluetoothProfile.A2DP_SINK, device);
                int currState = intent.getIntExtra(BluetoothProfile.EXTRA_STATE,
                        BluetoothProfile.STATE_DISCONNECTED);
                notifyConnectionStatus(connectParams, currState);

            } else if (BluetoothHeadsetClient.ACTION_CONNECTION_STATE_CHANGED.equals(action)) {
                connectParams = new ConnectionParams(BluetoothProfile.HEADSET_CLIENT, device);
                int currState = intent.getIntExtra(BluetoothProfile.EXTRA_STATE,
                        BluetoothProfile.STATE_DISCONNECTED);
                notifyConnectionStatus(connectParams, currState);

            } else if (BluetoothPbapClient.ACTION_CONNECTION_STATE_CHANGED.equals(action)) {
                connectParams = new ConnectionParams(BluetoothProfile.PBAP_CLIENT, device);
                int currState = intent.getIntExtra(BluetoothProfile.EXTRA_STATE,
                        BluetoothProfile.STATE_DISCONNECTED);
                notifyConnectionStatus(connectParams, currState);

            } else if (BluetoothMapClient.ACTION_CONNECTION_STATE_CHANGED.equals(action)) {
                connectParams = new ConnectionParams(BluetoothProfile.MAP_CLIENT, device);
                int currState = intent.getIntExtra(BluetoothProfile.EXTRA_STATE,
                        BluetoothProfile.STATE_DISCONNECTED);
                notifyConnectionStatus(connectParams, currState);

            } else if (BluetoothAdapter.ACTION_STATE_CHANGED.equals(action)) {
                int currState = intent.getIntExtra(BluetoothAdapter.EXTRA_STATE, -1);
                if (DBG) {
                    Log.d(TAG, "Bluetooth Adapter State: " + currState);
                }
                if (currState == BluetoothAdapter.STATE_ON) {
                    // Read from Settings which devices to connect to and populate
                    // mProfileToConnectableDevicesMap
                    readAndRebuildDeviceMapFromSettings();
                    initiateConnection();
                } else if (currState == BluetoothAdapter.STATE_OFF) {
                    // Write currently connected device snapshot to file.
                    writeDeviceInfoToSettings();
                    resetBluetoothDevicesConnectionInfo();
                }
            }
        }
    }

    /**
     * Cleanup state and reinitialize whenever we connect to the PerUserCarService.
     * This happens in init() and whenever the PerUserCarService is restarted on User Switch Events
     */
    private class UserServiceConnectionCallback implements PerUserCarServiceHelper.ServiceCallback {
        @Override
        public void onServiceConnected(ICarUserService carUserService) {
            if (mCarUserServiceAccessLock != null) {
                mCarUserServiceAccessLock.lock();
                try {
                    mCarUserService = carUserService;
                } finally {
                    mCarUserServiceAccessLock.unlock();
                }
            }
            if (DBG) {
                Log.d(TAG, "Connected to PerUserCarService");
            }
            // re-initialize for current user.
            initializeUserSpecificInfo();
        }

        @Override
        public void onPreUnbind() {
            if (DBG) {
                Log.d(TAG, "Before Unbinding from UserService");
            }
            try {
                if (mCarBluetoothUserService != null) {
                    mCarBluetoothUserService.closeBluetoothConnectionProxy();
                }
            } catch (RemoteException e) {
                Log.e(TAG,
                        "Remote Exception during closeBluetoothConnectionProxy(): " + e.getMessage());
            }
            // Clean up information related to user who went background.
            cleanupUserSpecificInfo();
        }
        @Override
        public void onServiceDisconnected() {
            if (DBG) {
                Log.d(TAG, "Disconnected from PerUserCarService");
            }
            if (mCarUserServiceAccessLock != null) {
                mCarUserServiceAccessLock.lock();
                try {
                    mCarBluetoothUserService = null;
                    mCarUserService = null;
                } finally {
                    mCarUserServiceAccessLock.unlock();
                }
            }
        }
    }

    /**
     * Gets the Per User Car Bluetooth Service (ICarBluetoothService) from the PerUserCarService
     * which acts as a top level Service running in the current user context.
     * Also sets up the connection proxy objects required to communicate with the Bluetooth
     * Profile Services.
     * @return ICarBluetoothUserService running in current user
     */
    private ICarBluetoothUserService setupBluetoothUserService() {
        ICarBluetoothUserService carBluetoothUserService = null;
        if (mCarUserService != null) {
            try {
                carBluetoothUserService = mCarUserService.getBluetoothUserService();
                if (carBluetoothUserService != null) {
                    if (DBG) {
                        Log.d(TAG, "Got CarBTUsrSvc");
                    }
                    carBluetoothUserService.setupBluetoothConnectionProxy();
                }
            } catch (RemoteException e) {
                Log.e(TAG, "Remote Service Exception on ServiceConnection Callback: "
                        + e.getMessage());
            }
        } else {
            if (DBG) {
                Log.d(TAG, "PerUserCarService not connected");
            }
        }
        return carBluetoothUserService;
    }

    /**
     * Setup the Bluetooth profile service connections and Vehicle Event listeners.
     * and start the state machine -{@link BluetoothAutoConnectStateMachine}
     */
    public synchronized void init() {
        if (DBG) {
            Log.d(TAG, "init()");
        }
        // Initialize information specific to current user.
        initializeUserSpecificInfo();
        // Listen to various events coming from the vehicle.
        setupEventListenersLocked();
        mInitialized = true;
    }

    /**
     * Setup and initialize information that is specific per User account, which involves:
     * 1. Reading the list of devices to connect for current user and initialize the deviceMap
     * with that information.
     * 2. Register a BroadcastReceiver for bluetooth related events for the current user.
     * 3. Start and bind to {@link PerUserCarService} as current user.
     * 4. Start the {@link BluetoothAutoConnectStateMachine}
     */
    private void initializeUserSpecificInfo() {
        synchronized (mSetupLock) {
            if (DBG) {
                Log.d(TAG, "initializeUserSpecificInfo()");
            }
            if (mUserSpecificInfoInitialized) {
                if (DBG) {
                    Log.d(TAG, "Already Initialized");
                }
                return;
            }
            mBluetoothAutoConnectStateMachine = BluetoothAutoConnectStateMachine.make(this);
            readAndRebuildDeviceMapFromSettings();
            setupBluetoothEventsIntentFilterLocked();

            mConnectionInFlight = new ConnectionParams();
            // Get the BluetoothUserService and also setup the Bluetooth Connection Proxy for
            // all profiles.
            mCarBluetoothUserService = setupBluetoothUserService();
            mUserSpecificInfoInitialized = true;
        }
    }

    /**
     * Setting up the Intent filter for Bluetooth related broadcasts
     * This includes knowing when the
     * 1. Bluetooth Adapter turned on/off
     * 2. Bonding State of a device changes
     * 3. A specific profile's connection state changes.
     */
    private void setupBluetoothEventsIntentFilterLocked() {
        mBluetoothBroadcastReceiver = new BluetoothBroadcastReceiver();
        IntentFilter profileFilter = new IntentFilter();
        profileFilter.addAction(BluetoothDevice.ACTION_BOND_STATE_CHANGED);
        profileFilter.addAction(BluetoothA2dpSink.ACTION_CONNECTION_STATE_CHANGED);
        profileFilter.addAction(BluetoothHeadsetClient.ACTION_CONNECTION_STATE_CHANGED);
        profileFilter.addAction(BluetoothPbapClient.ACTION_CONNECTION_STATE_CHANGED);
        profileFilter.addAction(BluetoothMapClient.ACTION_CONNECTION_STATE_CHANGED);
        profileFilter.addAction(BluetoothAdapter.ACTION_STATE_CHANGED);
        mContext.registerReceiverAsUser(mBluetoothBroadcastReceiver, UserHandle.CURRENT,
                profileFilter, null, null);
    }

    /**
     * Initialize the {@link #mProfileToConnectableDevicesMap}.
     * {@link #mProfileToConnectableDevicesMap} stores the profile:DeviceList information.  This
     * method retrieves it from persistent memory.
     */
    private synchronized void initDeviceMap() {
        if (mProfileToConnectableDevicesMap == null) {
            mProfileToConnectableDevicesMap = new HashMap<>();
            for (Integer profile : mProfilesToConnect) {
                // Build the BluetoothDevicesInfo for this profile.
                BluetoothDevicesInfo devicesInfo = new BluetoothDevicesInfo(profile,
                        mNumSupportedActiveConnections.get(profile));
                mProfileToConnectableDevicesMap.put(profile, devicesInfo);
            }
            if (DBG) {
                Log.d(TAG, "Created a new empty Device Map");
            }
        }
    }

    /**
     * Setting up Listeners to the various events we are interested in listening to for initiating
     * Bluetooth connection attempts.
     */
    private void setupEventListenersLocked() {
        // Setting up a listener for events from CarCabinService
        // For now, we listen to door unlock signal coming from {@link CarCabinService},
        // and Ignition state START from {@link CarSensorService}
        mCarCabinService.registerListener(mCabinEventListener);
        mCarSensorService.registerOrUpdateSensorListener(
                CarSensorManager.SENSOR_TYPE_IGNITION_STATE, 0, mCarSensorEventListener);
        mUserServiceHelper.registerServiceCallback(mServiceCallback);
    }

    /**
     * Handles events coming in from the {@link CarCabinService}
     * The events that can trigger Bluetooth Scanning from CarCabinService is Door Unlock.
     * Upon receiving the event that is of interest, initiate a connection attempt by calling
     * the policy {@link BluetoothDeviceConnectionPolicy}
     */
    private class CarPropertyListener extends ICarPropertyEventListener.Stub {
        @Override
        public void onEvent(CarPropertyEvent event) throws RemoteException {
            if (DBG) {
                Log.d(TAG, "Cabin change Event : " + event.getEventType());
            }
            Boolean locked;
            CarPropertyValue value = event.getCarPropertyValue();
            Object o = value.getValue();

            if (value.getPropertyId() == CarCabinManager.ID_DOOR_LOCK) {
                if (o instanceof Boolean) {
                    locked = (Boolean) o;
                    if (DBG) {
                        Log.d(TAG, "Door Lock: " + locked);
                    }
                    // Attempting a connection only on a door unlock
                    if (!locked) {
                        initiateConnection();
                    }
                }
            }
        }
    }

    /**
     * Handles events coming in from the {@link CarSensorService}
     * The events that can trigger Bluetooth Scanning from CarSensorService is Ignition START.
     * Upon receiving the event that is of interest, initiate a connection attempt by calling
     * the policy {@link BluetoothDeviceConnectionPolicy}
     */
    private class CarSensorEventListener extends ICarSensorEventListener.Stub {
        @Override
        public void onSensorChanged(List<CarSensorEvent> events) throws RemoteException {
            if (events != null & !events.isEmpty()) {
                CarSensorEvent event = events.get(0);
                if (DBG) {
                    Log.d(TAG, "Sensor event Type : " + event.sensorType);
                }
                if (event.sensorType == CarSensorManager.SENSOR_TYPE_IGNITION_STATE) {
                    if (DBG) {
                        Log.d(TAG, "Sensor value : " + event.intValues[0]);
                    }
                    if (event.intValues[0] == CarSensorEvent.IGNITION_STATE_START) {
                        initiateConnection();
                    }
                }
            }
        }
    }

    /**
     * Clean up slate. Close the Bluetooth profile service connections and quit the state machine -
     * {@link BluetoothAutoConnectStateMachine}
     */
    public synchronized void release() {
        if (DBG) {
            Log.d(TAG, "release()");
        }
        mInitialized = false;
        writeDeviceInfoToSettings();
        cleanupUserSpecificInfo();
        closeEventListeners();
    }

    /**
     * Clean up information related to user who went background.
     */
    private void cleanupUserSpecificInfo() {
        synchronized (mSetupLock) {
            if (DBG) {
                Log.d(TAG, "cleanupUserSpecificInfo()");
            }
            if (!mUserSpecificInfoInitialized) {
                if (DBG) {
                    Log.d(TAG, "User specific Info Not initialized..Not cleaning up");
                }
                return;
            }
            mUserSpecificInfoInitialized = false;
            // quit the state machine
            mBluetoothAutoConnectStateMachine.doQuit();
            mProfileToConnectableDevicesMap = null;
            mConnectionInFlight = null;
            if (mBluetoothBroadcastReceiver != null) {
                mContext.unregisterReceiver(mBluetoothBroadcastReceiver);
                mBluetoothBroadcastReceiver = null;
            }
        }
    }

    /**
     * Unregister the listeners to the various Vehicle events coming from other parts of the
     * CarService
     */
    private void closeEventListeners() {
        if (DBG) {
            Log.d(TAG, "closeEventListeners()");
        }
        mCarCabinService.unregisterListener(mCabinEventListener);
        mCarSensorService.unregisterSensorListener(CarSensorManager.SENSOR_TYPE_IGNITION_STATE,
                mCarSensorEventListener);
        mUserServiceHelper.unregisterServiceCallback(mServiceCallback);
    }

    /**
     * Resets the {@link BluetoothDevicesInfo#mConnectionInfo} of all the profiles to start from
     * a clean slate.  The ConnectionInfo has all the book keeping information regarding the state
     * of connection attempts - like which device in the device list for the profile is the next
     * to try connecting etc.
     * This method does not clear the {@link BluetoothDevicesInfo#mDeviceInfoList} like the {@link
     * #resetProfileToConnectableDevicesMap()} method does.
     */
    private synchronized void resetBluetoothDevicesConnectionInfo() {
        if (DBG) {
            Log.d(TAG, "Resetting ConnectionInfo for all profiles");
        }
        for (BluetoothDevicesInfo devInfo : mProfileToConnectableDevicesMap.values()) {
            devInfo.resetConnectionInfoLocked();
        }
    }

    /**
     * Resets the {@link #mProfileToConnectableDevicesMap} to a clean and empty slate.
     */
    public synchronized void resetProfileToConnectableDevicesMap() {
        if (DBG) {
            Log.d(TAG, "Resetting the mProfilesToConnectableDevicesMap");
        }
        for (BluetoothDevicesInfo devInfo : mProfileToConnectableDevicesMap.values()) {
            devInfo.resetDeviceListLocked();
        }
    }

    /**
     * Returns the list of profiles that the Autoconnection policy attempts to connect on
     *
     * @return profile list.
     */
    public synchronized List<Integer> getProfilesToConnect() {
        return mProfilesToConnect;
    }

    /**
     * Add a new Profile to the list of To Be Connected profiles.
     *
     * @param profile - ProfileInfo of the new profile to be added.
     */
    public synchronized void addProfile(Integer profile) {
        mProfilesToConnect.add(profile);
    }

    /**
     * Add or remove a device based on the bonding state change.
     *
     * @param device    - device to add/remove
     * @param bondState - current bonding state
     */
    private void updateBondState(BluetoothDevice device, int bondState) {
        if (device == null) {
            Log.e(TAG, "updateBondState: device Null");
            return;
        }
        if (DBG) {
            Log.d(TAG, "BondState :" + bondState + " Device: " + device.getName());
        }
        // Bonded devices are added to a profile's device list after the device CONNECTS on the
        // profile.  When unpaired, we remove the device from all of the profiles' device list.
        if (bondState == BluetoothDevice.BOND_NONE) {
            for (Integer profile : mProfilesToConnect) {
                removeDeviceFromProfile(device, profile);
            }
        }

    }

    /**
     * Add a new device to the list of devices connect-able on the given profile
     *
     * @param device  - Bluetooth device to be added
     * @param profile - profile to add the device to.
     */
    private synchronized void addDeviceToProfile(BluetoothDevice device, Integer profile) {
        BluetoothDevicesInfo devInfo = mProfileToConnectableDevicesMap.get(profile);
        if (devInfo == null) {
            if (DBG) {
                Log.d(TAG, "Creating devInfo for profile: " + profile);
            }
            devInfo = new BluetoothDevicesInfo(profile);
            mProfileToConnectableDevicesMap.put(profile, devInfo);
        }
        devInfo.addDeviceLocked(device);
    }

    /**
     * Remove the device from the list of devices connect-able on the gievn profile.
     *
     * @param device  - Bluetooth device to be removed
     * @param profile - profile to remove the device from
     */
    private synchronized void removeDeviceFromProfile(BluetoothDevice device, Integer profile) {
        BluetoothDevicesInfo devInfo = mProfileToConnectableDevicesMap.get(profile);
        if (devInfo != null) {
            devInfo.removeDeviceLocked(device);
        }
    }

    /**
     * Initiate a bluetooth connection.
     */
    private void initiateConnection() {
        // Make sure the bluetooth adapter is available & enabled.
        if (mBluetoothAdapter == null) {
            Log.w(TAG, "Bluetooth Adapter null");
            return;
        }

        if (mBluetoothAdapter.isEnabled()) {
            if (isDeviceMapEmpty()) {
                if (DBG) {
                    Log.d(TAG, "Device Map is empty. Nothing to connect to");
                }
                return;
            }
            resetDeviceAvailableToConnect();
            if (DBG) {
                Log.d(TAG, "initiateConnection() Reset Device Availability");
            }
            mBluetoothAutoConnectStateMachine.sendMessage(BluetoothAutoConnectStateMachine
                    .CONNECT);
        } else {
            if (DBG) {
                Log.d(TAG, "Bluetooth Adapter not enabled.");
            }
        }
    }

    /**
     * Find an unconnected profile and find a device to connect on it.
     * Finds the appropriate device for the profile from the information available in
     * {@link #mProfileToConnectableDevicesMap}
     *
     * @return true - if we found a device to connect on for any of the {@link #mProfilesToConnect}
     * false - if we cannot find a device to connect to or if we are not ready to connect yet.
     */
    public synchronized boolean findDeviceToConnect() {
        if (mBluetoothAdapter == null || !mBluetoothAdapter.isEnabled()
                || mProfileToConnectableDevicesMap == null || !mInitialized) {
            if (DBG) {
                if (mProfileToConnectableDevicesMap == null) {
                    Log.d(TAG, "findDeviceToConnect(): Device Map null");
                } else {
                    Log.d(TAG, "findDeviceToConnect(): BT Adapter not enabled");
                }
            }
            return false;
        }
        boolean connectingToADevice = false;
        // Get the first unconnected profile that we can try to make a connection
        Integer nextProfile = getNextProfileToConnectLocked();
        // Keep going through the profiles until we find a device that we can connect to
        while (nextProfile != PROFILE_NOT_AVAILABLE) {
            if (DBG) {
                Log.d(TAG, "connectToProfile(): " + nextProfile);
            }
            // find a device that is next in line for a connection attempt for that profile
            // and try connecting to it.
            connectingToADevice = connectToNextDeviceInQueueLocked(nextProfile);
            // If we found a device to connect, break out of the loop
            if (connectingToADevice) {
                if (DBG) {
                    Log.d(TAG, "Found device to connect to");
                }
                BluetoothDeviceConnectionPolicy.ConnectionParams btParams =
                        new BluetoothDeviceConnectionPolicy.ConnectionParams(
                                mConnectionInFlight.getBluetoothProfile(),
                                mConnectionInFlight.getBluetoothDevice());
                // set up a time out
                mBluetoothAutoConnectStateMachine.sendMessageDelayed(
                        BluetoothAutoConnectStateMachine.CONNECT_TIMEOUT, btParams,
                        BluetoothAutoConnectStateMachine.CONNECTION_TIMEOUT_MS);
                break;
            } else {
                // result will be false, if there are no more devices to connect
                // or if the ProfileProxy objects are null (ServiceConnection
                // not yet established for this profile)
                if (DBG) {
                    Log.d(TAG, "No more device to connect on Profile: " + nextProfile);
                }
                nextProfile = getNextProfileToConnectLocked();
            }
        }
        return connectingToADevice;
    }

    /**
     * Get the first unconnected profile.
     *
     * @return profile to connect.
     * Special return value 0 if
     * 1. all profiles have been connected on.
     * 2. no profile connected but no nearby known device that can be connected to
     */
    private Integer getNextProfileToConnectLocked() {
        for (Integer profile : mProfilesToConnect) {
            BluetoothDevicesInfo devInfo = mProfileToConnectableDevicesMap.get(profile);
            if (devInfo != null) {
                if (devInfo.isProfileConnectableLocked()) {
                    return profile;
                }
            } else {
                Log.e(TAG, "Unexpected: devInfo null for profile: " + profile);
            }
        }
        // Reaching here denotes all profiles are connected or No devices available for any profile
        if (DBG) {
            Log.d(TAG, "No disconnected profiles");
        }
        return PROFILE_NOT_AVAILABLE;
    }

    /**
     * Try to connect to the next device in the device list for the given profile.
     *
     * @param profile - profile to connect on
     * @return - true if we found a device to connect on for this profile
     * false - if we cannot find a device to connect to.
     */
    private boolean connectToNextDeviceInQueueLocked(Integer profile) {
        // Get the Device Information for the given profile and find the next device to connect on
        boolean connecting = true;
        boolean proxyAvailable = true;
        BluetoothDevice devToConnect = null;
        BluetoothDevicesInfo devInfo = mProfileToConnectableDevicesMap.get(profile);
        if (devInfo == null) {
            Log.e(TAG, "Unexpected: No device Queue for this profile: " + profile);
            return false;
        }
        // Check if the Bluetooth profile service's proxy object is available before
        // attempting to connect.
        if (mCarBluetoothUserService == null) {
            mCarBluetoothUserService = setupBluetoothUserService();
        }
        if (mCarBluetoothUserService != null) {
            try {
                if (!mCarBluetoothUserService.isBluetoothConnectionProxyAvailable(profile)) {
                    // proxy unavailable.
                    if (DBG) {
                        Log.d(TAG,
                                "Proxy for Bluetooth Profile Service Unavailable: " + profile);
                    }
                    proxyAvailable = false;
                }
            } catch (RemoteException e) {
                Log.e(TAG, "Car BT Service Remote Exception.");
                proxyAvailable = false;
            }
        } else {
            Log.d(TAG, "CarBluetoothUserSvc null.  Car service not bound to PerUserCarSvc.");
            proxyAvailable = false;
        }

        if (proxyAvailable) {
            // Get the next device in the device list for this profile.
            devToConnect = devInfo.getNextDeviceInQueueLocked();
            if (devToConnect != null) {
                // deviceAvailable && proxyAvailable
                try {
                    if (mCarBluetoothUserService != null) {
                        mCarBluetoothUserService.bluetoothConnectToProfile((int) profile,
                                devToConnect);
                    } else {
                        Log.e(TAG, "CarBluetoothUserSvc null");
                        connecting = false;
                    }
                } catch (RemoteException e) {
                    Log.e(TAG, "Remote User Service stopped responding: " + e.getMessage());
                    connecting = false;
                }
            } else {
                // device unavailable
                if (DBG) {
                    Log.d(TAG, "No paired nearby device to connect to for profile: " + profile);
                }
                connecting = false;
            }
        } else {
            connecting = false;
        }

        if (connecting && devToConnect != null) {
            devInfo.setConnectionStateLocked(devToConnect, BluetoothProfile.STATE_CONNECTING);
            // Increment the retry count & cache what is being connected to
            // This method is already called from a synchronized context.
            mConnectionInFlight.setBluetoothDevice(devToConnect);
            mConnectionInFlight.setBluetoothProfile(profile);
            devInfo.incrementRetryCountLocked();
            if (DBG) {
                Log.d(TAG, "Increment Retry to: " + devInfo.getRetryCountLocked());
            }
        } else {
            // reset the mConnectionInFlight
            mConnectionInFlight.setBluetoothProfile(0);
            mConnectionInFlight.setBluetoothDevice(null);
            devInfo.setDeviceAvailableToConnectLocked(false);
        }
        return connecting;
    }

    /**
     * Update the device connection status for a profile and also notify the state machine.
     * This gets called from {@link BluetoothBroadcastReceiver} when it receives a Profile's
     * CONNECTION_STATE_CHANGED intent.
     *
     * @param params       - {@link ConnectionParams} device and profile list info
     * @param currentState - connection result to update
     */
    private void notifyConnectionStatus(ConnectionParams params, int currentState) {
        // Update the profile's BluetoothDevicesInfo.
        boolean isConnected;
        switch (currentState) {
            case BluetoothProfile.STATE_DISCONNECTED: {
                isConnected = false;
                break;
            }

            case BluetoothProfile.STATE_CONNECTED: {
                isConnected = true;
                break;
            }

            default: {
                if (DBG) {
                    Log.d(TAG, "notifyConnectionStatus() Ignoring state: " + currentState);
                }
                return;
            }

        }

        boolean updateSuccessful = updateDeviceConnectionStatus(params, isConnected);
        if (updateSuccessful) {
            if (isConnected) {
                mBluetoothAutoConnectStateMachine.sendMessage(
                        BluetoothAutoConnectStateMachine.DEVICE_CONNECTED,
                        params);
            } else {
                mBluetoothAutoConnectStateMachine.sendMessage(
                        BluetoothAutoConnectStateMachine.DEVICE_DISCONNECTED,
                        params);
            }
        }
    }

    /**
     * Update the profile's {@link BluetoothDevicesInfo} with the result of the connection
     * attempt.  This gets called from the {@link BluetoothAutoConnectStateMachine} when the
     * connection attempt times out or from {@link BluetoothBroadcastReceiver} when it receives
     * a Profile's CONNECTION_STATE_CHANGED intent.
     *
     * @param params     - {@link ConnectionParams} device and profile list info
     * @param didConnect - connection result to update
     */
    public synchronized boolean updateDeviceConnectionStatus(ConnectionParams params,
            boolean didConnect) {
        if (params == null || params.getBluetoothDevice() == null) {
            Log.e(TAG, "updateDeviceConnectionStatus: null params");
            return false;
        }
        // Get the profile to update
        Integer profileToUpdate = params.getBluetoothProfile();
        BluetoothDevice deviceThatConnected = params.getBluetoothDevice();
        if (DBG) {
            Log.d(TAG, "Profile: " + profileToUpdate + " Connected: " + didConnect + " on "
                    + deviceThatConnected.getName());
        }

        // If the connection update is on a different profile or device (a very rare possibility),
        // it is handled automatically.  Just logging it here.
        if (DBG) {
            if (mConnectionInFlight != null && mConnectionInFlight.getBluetoothProfile() != null) {
                if (profileToUpdate.equals(mConnectionInFlight.getBluetoothProfile()) == false) {
                    Log.d(TAG, "Updating profile " + profileToUpdate
                            + " different from connection in flight "
                            + mConnectionInFlight.getBluetoothProfile());
                }
            }

            if (mConnectionInFlight != null && mConnectionInFlight.getBluetoothDevice() != null) {
                if (deviceThatConnected.equals(mConnectionInFlight.getBluetoothDevice()) == false) {
                    Log.d(TAG, "Updating device: " + deviceThatConnected.getName()
                            + " different from connection in flight: "
                            + mConnectionInFlight.getBluetoothDevice().getName());

                }
            }
        }
        BluetoothDevicesInfo devInfo = null;
        devInfo = mProfileToConnectableDevicesMap.get(profileToUpdate);
        if (devInfo == null) {
            Log.e(TAG, "Unexpected: devInfo null for profile: " + profileToUpdate);
            return false;
        }

        boolean retry = canRetryConnection(profileToUpdate);
        // Update the status and also if a retry attempt can be made if the
        // connection timed out in the previous attempt.
        if (DBG) {
            Log.d(TAG, "Retry? : " + retry);
        }
        devInfo.updateConnectionStatusLocked(deviceThatConnected, didConnect, retry);
        // Write to persistent memory to have the latest snapshot available
        writeDeviceInfoToSettings(params);
        return true;
    }

    /**
     * Returns if we can retry connection attempt on the given profile for the device that is
     * currently in the head of the queue.
     *
     * @param profile - Profile to check
     */
    private synchronized boolean canRetryConnection(Integer profile) {
        BluetoothDevicesInfo devInfo = mProfileToConnectableDevicesMap.get(profile);
        if (devInfo == null) {
            Log.e(TAG, "Unexpected: No device Queue for this profile: " + profile);
            return false;
        }
        if (devInfo.getRetryCountLocked() < MAX_CONNECT_RETRIES) {
            return true;
        } else {
            return false;
        }
    }

    /**
     * Helper method to see if there are any connect-able devices on any of the
     * profiles.
     *
     * @return true - if {@link #mProfileToConnectableDevicesMap} does not have any devices for any
     * profiles.
     * false - if {@link #mProfileToConnectableDevicesMap} has a device for at least one profile.
     */
    private synchronized boolean isDeviceMapEmpty() {
        boolean empty = true;
        for (Integer profile : mProfilesToConnect) {
            BluetoothDevicesInfo devInfo = mProfileToConnectableDevicesMap.get(profile);
            if (devInfo != null) {
                if (devInfo.getNumberOfPairedDevicesLocked() != 0) {
                    if (DBG) {
                        Log.d(TAG, "Device map not empty. Profile: " + profile + " has "
                                + devInfo.getNumberOfPairedDevicesLocked() + " paired devices");
                    }
                    empty = false;
                    break;
                }
            }
        }
        return empty;
    }

    /**
     * Reset the Device Available to Connect information for all profiles to Available.
     * If in a previous connection attempt, we failed to connect on all devices for a profile,
     * we would update deviceAvailableToConnect for that profile to false.  That information
     * is used to deduce if we should move to the next profile. If marked false, we will not
     * try to connect on that profile anymore as part of that connection attempt.
     * However, when we get another connection trigger from the vehicle, we need to reset the
     * deviceAvailableToConnect information so we can start the connection attempts all over
     * again.
     */
    private synchronized void resetDeviceAvailableToConnect() {
        for (BluetoothDevicesInfo devInfo : mProfileToConnectableDevicesMap.values()) {
            devInfo.setDeviceAvailableToConnectLocked(true);
        }
    }

    /**
     * Utility function - Prints the Profile: list of devices information to log
     * Caller should wrap a DBG around this, since this is for debugging purpose.
     *
     * @param writer - PrintWriter
     */
    private synchronized void printDeviceMap(PrintWriter writer) {
        if (mProfileToConnectableDevicesMap == null) {
            return;
        }
        for (BluetoothDevicesInfo devInfo : mProfileToConnectableDevicesMap.values()) {
            writer.print("Profile: " + devInfo.getProfileLocked() + "\t");
            writer.print("Active Connections: " + devInfo.getNumberOfActiveConnectionsLocked());
            writer.println();
            List<BluetoothDevicesInfo.DeviceInfo> deviceInfoList = devInfo.getDeviceInfoList();
            if (deviceInfoList != null) {
                for (BluetoothDevicesInfo.DeviceInfo devicesInfo : deviceInfoList) {
                    if (devicesInfo.getBluetoothDevice() != null) {
                        writer.print(devicesInfo.getBluetoothDevice().getName() + ":");
                        writer.print(devicesInfo.getConnectionState() + "\t");
                    }
                }
                writer.println();
            }
        }
    }

    /**
     * Write the device list for all bluetooth profiles that connected.
     *
     * @return true if the write was successful, false otherwise
     */
    private synchronized boolean writeDeviceInfoToSettings() {
        ConnectionParams params;
        boolean writeResult;
        for (Integer profile : mProfilesToConnect) {
            params = new ConnectionParams(profile);
            writeResult = writeDeviceInfoToSettings(params);
            if (!writeResult) {
                Log.e(TAG, "Error writing Device Info for profile:" + profile);
                return writeResult;
            }
        }
        return true;
    }

    /**
     * Write information about which devices connected on which profile to Settings.Secure.
     * Essentially the list of devices that a profile can connect on the next auto-connect
     * attempt.
     *
     * @param params - ConnectionParams indicating which bluetooth profile to write this
     *               information
     *               for.
     * @return true if the write was successful, false otherwise
     */
    public synchronized boolean writeDeviceInfoToSettings(ConnectionParams params) {
        boolean writeSuccess = true;
        Integer profileToUpdate = params.getBluetoothProfile();

        if (mProfileToConnectableDevicesMap == null) {
            writeSuccess = false;
        } else {
            List<String> deviceNames = new ArrayList<>();
            BluetoothDevicesInfo devicesInfo = mProfileToConnectableDevicesMap.get(profileToUpdate);
            StringBuilder sb = new StringBuilder();
            String delimiter = ""; // start off with no delimiter.

            // Iterate through the List<BluetoothDevice> and build a String that is
            // names of all devices to be connected for this profile joined together and
            // delimited by a delimiter (its a ',' here)
            if (devicesInfo != null && devicesInfo.getDeviceList() != null) {
                for (BluetoothDevice device : devicesInfo.getDeviceList()) {
                    sb.append(delimiter);
                    sb.append(device.getAddress());
                    delimiter = SETTINGS_DELIMITER;
                }

            }
            // joinedDeviceNames has something like "22:22:33:44:55:AB,22:23:xx:xx:xx:xx"
            // mac addresses of connectable devices separated by a delimiter
            String joinedDeviceNames = sb.toString();
            Log.d(TAG, "Profile: " + profileToUpdate + " Writing: " + joinedDeviceNames);

            long userId = ActivityManager.getCurrentUser();
            switch (profileToUpdate) {
                case BluetoothProfile.A2DP_SINK:
                    Settings.Secure.putStringForUser(mContext.getContentResolver(),
                            KEY_BLUETOOTH_AUTOCONNECT_MUSIC_DEVICES,
                            joinedDeviceNames, (int) userId);
                    break;

                case BluetoothProfile.HEADSET_CLIENT:
                    Settings.Secure.putStringForUser(mContext.getContentResolver(),
                            KEY_BLUETOOTH_AUTOCONNECT_PHONE_DEVICES,
                            joinedDeviceNames, (int) userId);
                    break;

                case BluetoothProfile.PBAP_CLIENT:
                    // use the phone
                    break;

                case BluetoothProfile.MAP_CLIENT:
                    Settings.Secure.putStringForUser(mContext.getContentResolver(),
                            KEY_BLUETOOTH_AUTOCONNECT_MESSAGING_DEVICES,
                            joinedDeviceNames, (int) userId);
                    break;

            }
        }
        return writeSuccess;
    }

    /**
     * Read the device information from Settings.Secure and populate the
     * {@link #mProfileToConnectableDevicesMap}
     *
     * Device MAC addresses are written to Settings.Secure delimited by a ','.
     * Ex: android.car.BLUETOOTH_AUTOCONNECT_PHONE_DEVICES: xx:xx:xx:xx:xx:xx,yy:yy:yy:yy:yy
     * denotes that two devices with addresses xx:xx:xx:xx:xx:xx & yy:yy:yy:yy:yy:yy were connected
     * as phones (in HFP and PBAP profiles) the last time this user was logged in.
     *
     * @return - true if the read was successful, false if 1. BT Adapter not enabled 2. No prior
     * bonded devices 3. No information stored in Settings for this user.
     */
    public synchronized boolean readAndRebuildDeviceMapFromSettings() {
        List<String> deviceList;
        String devices = null;
        // Create and initialize mProfileToConnectableDevicesMap if needed.
        initDeviceMap();
        if (mBluetoothAdapter != null) {
            if (DBG) {
                Log.d(TAG,
                        "Number of Bonded devices:" + mBluetoothAdapter.getBondedDevices().size());
            }
            if (mBluetoothAdapter.getBondedDevices().isEmpty()) {
                if (DBG) {
                    Log.d(TAG, "No Bonded Devices available. Quit rebuilding");
                }
                return false;
            }
        }
        // Read from Settings.Secure for the current user.  There are 3 keys 1 each for Phone
        // (HFP & PBAP), 1 for Music (A2DP) and 1 for Messaging device (MAP)
        long userId = ActivityManager.getCurrentUser();
        for (Integer profile : mProfilesToConnect) {
            switch (profile) {
                case BluetoothProfile.A2DP_SINK:
                    devices = Settings.Secure.getStringForUser(mContext.getContentResolver(),
                            KEY_BLUETOOTH_AUTOCONNECT_MUSIC_DEVICES, (int) userId);
                    break;
                case BluetoothProfile.PBAP_CLIENT:
                    // fall through
                case BluetoothProfile.HEADSET_CLIENT:
                    devices = Settings.Secure.getStringForUser(mContext.getContentResolver(),
                            KEY_BLUETOOTH_AUTOCONNECT_PHONE_DEVICES, (int) userId);
                    break;
                case BluetoothProfile.MAP_CLIENT:
                    devices = Settings.Secure.getStringForUser(mContext.getContentResolver(),
                            KEY_BLUETOOTH_AUTOCONNECT_MESSAGING_DEVICES, (int) userId);
                    break;
                default:
                    Log.e(TAG, "Unexpected profile");
                    break;
            }

            if (devices == null) {
                if (DBG) {
                    Log.d(TAG, "No device information stored in Settings");
                }
                return false;
            }
            if (DBG) {
                Log.d(TAG, "Devices in Settings: " + devices);
            }
            // Get a list of Device Mac Addresses from the value
            deviceList = Arrays.asList(devices.split(SETTINGS_DELIMITER));
            if (deviceList == null) {
                return false;
            }
            BluetoothDevicesInfo devicesInfo = mProfileToConnectableDevicesMap.get(profile);
            // Do we have a bonded device with this name?  If so, get it and populate the device
            // map.
            for (String address : deviceList) {
                BluetoothDevice deviceToAdd = getBondedDeviceWithGivenName(address);
                if (deviceToAdd != null) {
                    devicesInfo.addDeviceLocked(deviceToAdd);
                } else {
                    if (DBG) {
                        Log.d(TAG, "No device with name " + address + " found in bonded devices");
                    }
                }
            }
            mProfileToConnectableDevicesMap.put(profile, devicesInfo);
        }
        return true;
    }

    /**
     * Given the device name, find the corresponding {@link BluetoothDevice} from the list of
     * Bonded devices.
     *
     * @param name Bluetooth Device name
     */
    private BluetoothDevice getBondedDeviceWithGivenName(String name) {
        if (mBluetoothAdapter == null) {
            if (DBG) {
                Log.d(TAG, "Bluetooth Adapter Null");
            }
            return null;
        }
        if (name == null) {
            Log.w(TAG, "getBondedDeviceWithGivenName() Passing in a null name");
            return null;
        }
        if (DBG) {
            Log.d(TAG, "Looking for bonded device: " + name);
        }
        BluetoothDevice btDevice = null;
        Set<BluetoothDevice> bondedDevices = mBluetoothAdapter.getBondedDevices();
        for (BluetoothDevice bd : bondedDevices) {
            if (name.equals(bd.getAddress())) {
                btDevice = bd;
                break;
            }
        }
        return btDevice;
    }


    public void dump(PrintWriter writer) {
        writer.println("*BluetoothDeviceConnectionPolicy*");
        printDeviceMap(writer);
        mBluetoothAutoConnectStateMachine.dump(writer);
    }
}