/*
 * Copyright (C) 2011 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.cellbroadcastreceiver;

import static android.telephony.SmsCbMessage.MESSAGE_FORMAT_3GPP;
import static android.telephony.SmsCbMessage.MESSAGE_FORMAT_3GPP2;

import android.annotation.NonNull;
import android.app.ActivityManager;
import android.app.Notification;
import android.app.NotificationChannel;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.app.Service;
import android.content.ContentValues;
import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.content.pm.PackageManager;
import android.content.res.Resources;
import android.media.AudioAttributes;
import android.media.AudioManager;
import android.net.Uri;
import android.os.Binder;
import android.os.Bundle;
import android.os.Handler;
import android.os.IBinder;
import android.os.Looper;
import android.os.SystemProperties;
import android.os.UserHandle;
import android.preference.PreferenceManager;
import android.provider.Telephony;
import android.service.notification.StatusBarNotification;
import android.telephony.PhoneStateListener;
import android.telephony.SmsCbEtwsInfo;
import android.telephony.SmsCbMessage;
import android.telephony.SubscriptionManager;
import android.telephony.TelephonyManager;
import android.text.TextUtils;
import android.util.Log;

import com.android.cellbroadcastreceiver.CellBroadcastChannelManager.CellBroadcastChannelRange;
import com.android.cellbroadcastservice.CellBroadcastStatsLog;
import com.android.internal.annotations.VisibleForTesting;

import java.util.ArrayList;
import java.util.Locale;

/**
 * This service manages the display and animation of broadcast messages.
 * Emergency messages display with a flashing animated exclamation mark icon,
 * and an alert tone is played when the alert is first shown to the user
 * (but not when the user views a previously received broadcast).
 */
public class CellBroadcastAlertService extends Service
        implements AudioManager.OnAudioFocusChangeListener {
    private static final String TAG = "CBAlertService";

    /** Intent action to display alert dialog/notification, after verifying the alert is new. */
    @VisibleForTesting
    public static final String SHOW_NEW_ALERT_ACTION = "cellbroadcastreceiver.SHOW_NEW_ALERT";

    /** Identifier for getExtra() when adding this object to an Intent. */
    public static final String SMS_CB_MESSAGE_EXTRA =
            "com.android.cellbroadcastreceiver.SMS_CB_MESSAGE";

    /** Use the same notification ID for non-emergency alerts. */
    @VisibleForTesting
    public static final int NOTIFICATION_ID = 1;

    /**
     * Notification channel containing for non-emergency alerts.
     */
    static final String NOTIFICATION_CHANNEL_NON_EMERGENCY_ALERTS = "broadcastMessagesNonEmergency";

    /**
     * Notification channel for emergency alerts. This is used when users sneak out of the
     * noisy pop-up for a real emergency and get a notification due to not officially acknowledged
     * the alert and want to refer it back later.
     */
    static final String NOTIFICATION_CHANNEL_EMERGENCY_ALERTS = "broadcastMessages";

    /**
     * Notification channel for emergency alerts during voice call. This is used when users in a
     * voice call, emergency alert will be displayed in a notification format rather than playing
     * alert tone.
     */
    static final String NOTIFICATION_CHANNEL_EMERGENCY_ALERTS_IN_VOICECALL =
        "broadcastMessagesInVoiceCall";

    /** Intent extra for passing a SmsCbMessage */
    private static final String EXTRA_MESSAGE = "message";

    /**
     * Key for accessing message filter from SystemProperties. For testing use.
     */
    private static final String MESSAGE_FILTER_PROPERTY_KEY =
            "persist.cellbroadcast.message_filter";

    private Context mContext;

    /**
     * Alert type
     */
    public enum AlertType {
        DEFAULT,
        ETWS_DEFAULT,
        ETWS_EARTHQUAKE,
        ETWS_TSUNAMI,
        TEST,
        AREA,
        INFO,
        OTHER
    }

    private TelephonyManager mTelephonyManager;
    private AudioManager mAudioManager;

    /**
     * Do not preempt active voice call, instead post notifications and play the ringtone/vibrate
     * when the voicecall finish
     */
    private static boolean sRemindAfterCallFinish = false;


    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        mContext = getApplicationContext();
        String action = intent.getAction();
        Log.d(TAG, "onStartCommand: " + action);
        if (Telephony.Sms.Intents.ACTION_SMS_EMERGENCY_CB_RECEIVED.equals(action) ||
                Telephony.Sms.Intents.SMS_CB_RECEIVED_ACTION.equals(action)) {
            handleCellBroadcastIntent(intent);
        } else if (SHOW_NEW_ALERT_ACTION.equals(action)) {
            if (UserHandle.myUserId() == ((ActivityManager) getSystemService(
                    Context.ACTIVITY_SERVICE)).getCurrentUser()) {
                showNewAlert(intent);
            } else {
                Log.d(TAG, "Not active user, ignore the alert display");
            }
        } else {
            Log.e(TAG, "Unrecognized intent action: " + action);
        }
        return START_NOT_STICKY;
    }

    @Override
    public void onCreate() {
        mTelephonyManager = (TelephonyManager)
                getApplicationContext().getSystemService(Context.TELEPHONY_SERVICE);
        mTelephonyManager.listen(mPhoneStateListener, PhoneStateListener.LISTEN_CALL_STATE);
        mAudioManager = (AudioManager)
            getApplicationContext().getSystemService(Context.AUDIO_SERVICE);
    }

    @Override
    public void onDestroy() {
        // Stop listening for incoming calls.
        mTelephonyManager.listen(mPhoneStateListener, 0);

    }

    /**
     * Check if we should display the received cell broadcast message.
     *
     * @param message Cell broadcast message
     * @return True if the message should be displayed to the user
     */
    private boolean shouldDisplayMessage(SmsCbMessage message) {
        TelephonyManager tm = ((TelephonyManager) mContext.getSystemService(
                Context.TELEPHONY_SERVICE)).createForSubscriptionId(message.getSubscriptionId());
        if (tm.getEmergencyCallbackMode() && CellBroadcastSettings.getResources(
                mContext, message.getSubscriptionId()).getBoolean(R.bool.ignore_messages_in_ecbm)) {
            // Ignore the message in ECBM.
            // It is for LTE only mode. For 1xRTT, incoming pages should be ignored in the modem.
            Log.d(TAG, "ignoring alert of type " + message.getServiceCategory() + " in ECBM");
            return false;
        }
        // Check if the channel is enabled by the user or configuration.
        if (!isChannelEnabled(message)) {
            Log.d(TAG, "ignoring alert of type " + message.getServiceCategory()
                    + " by user preference");
            return false;
        }

        // Check if message body is empty
        String msgBody = message.getMessageBody();
        if (msgBody == null || msgBody.length() == 0) {
            Log.e(TAG, "Empty content or Unsupported charset");
            return false;
        }

        // Check if we need to perform language filtering.
        CellBroadcastChannelManager channelManager = new CellBroadcastChannelManager(mContext,
                message.getSubscriptionId());
        CellBroadcastChannelRange range = channelManager
                .getCellBroadcastChannelRangeFromMessage(message);
        String messageLanguage = message.getLanguageCode();
        if (range != null && range.mFilterLanguage) {
            // language filtering based on CBR second language settings
            final String secondLanguageCode =  CellBroadcastSettings.getResources(mContext,
                    SubscriptionManager.DEFAULT_SUBSCRIPTION_ID)
                    .getString(R.string.emergency_alert_second_language_code);
            if (!secondLanguageCode.isEmpty()) {
                SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);
                boolean receiveInSecondLanguage = prefs.getBoolean(
                        CellBroadcastSettings.KEY_RECEIVE_CMAS_IN_SECOND_LANGUAGE, false);
                // For DCS values that bit 6 is 1 and bit 7 is 0, language field is not defined so
                // ap receives it as null value and so alert is not shown to the user.
                // bypass language filter in this case.
                if (!TextUtils.isEmpty(messageLanguage)
                        && !secondLanguageCode.equalsIgnoreCase(messageLanguage)) {
                    Log.w(TAG, "Ignoring message in the unspecified second language:"
                            + messageLanguage);
                    return false;
                } else if (!receiveInSecondLanguage) {
                    Log.d(TAG, "Ignoring message in second language because setting is off");
                    return false;
                }
            } else {
                // language filtering based on device language settings.
                String deviceLanguage = Locale.getDefault().getLanguage();
                // Apply If the message's language does not match device's message, we don't
                // display the message.
                if (!TextUtils.isEmpty(messageLanguage)
                        && !messageLanguage.equalsIgnoreCase(deviceLanguage)) {
                    Log.d(TAG, "ignoring the alert due to language mismatch. Message lang="
                            + messageLanguage + ", device lang=" + deviceLanguage);
                    return false;
                }
            }
        }

        // Check for custom filtering
        String messageFilters = SystemProperties.get(MESSAGE_FILTER_PROPERTY_KEY, "");
        if (!TextUtils.isEmpty(messageFilters)) {
            String[] filters = messageFilters.split(",");
            for (String filter : filters) {
                if (!TextUtils.isEmpty(filter)) {
                    if (message.getMessageBody().toLowerCase().contains(filter)) {
                        Log.i(TAG, "Skipped message due to filter: " + filter);
                        return false;
                    }
                }
            }
        }

        return true;
    }

    private void handleCellBroadcastIntent(Intent intent) {
        Bundle extras = intent.getExtras();
        if (extras == null) {
            Log.e(TAG, "received SMS_CB_RECEIVED_ACTION with no extras!");
            return;
        }

        SmsCbMessage message = (SmsCbMessage) extras.get(EXTRA_MESSAGE);

        if (message == null) {
            Log.e(TAG, "received SMS_CB_RECEIVED_ACTION with no message extra");
            return;
        }

        if (message.getMessageFormat() == MESSAGE_FORMAT_3GPP) {
            CellBroadcastStatsLog.write(CellBroadcastStatsLog.CB_MESSAGE_REPORTED,
                    CellBroadcastStatsLog.CELL_BROADCAST_MESSAGE_REPORTED__TYPE__GSM,
                    CellBroadcastStatsLog.CELL_BROADCAST_MESSAGE_REPORTED__SOURCE__CB_RECEIVER_APP);
        } else if (message.getMessageFormat() == MESSAGE_FORMAT_3GPP2) {
            CellBroadcastStatsLog.write(CellBroadcastStatsLog.CB_MESSAGE_REPORTED,
                    CellBroadcastStatsLog.CELL_BROADCAST_MESSAGE_REPORTED__TYPE__CDMA,
                    CellBroadcastStatsLog.CELL_BROADCAST_MESSAGE_REPORTED__SOURCE__CB_RECEIVER_APP);
        }

        if (!shouldDisplayMessage(message)) {
            return;
        }

        final Intent alertIntent = new Intent(SHOW_NEW_ALERT_ACTION);
        alertIntent.setClass(this, CellBroadcastAlertService.class);
        alertIntent.putExtra(EXTRA_MESSAGE, message);

        // write to database on a background thread
        new CellBroadcastContentProvider.AsyncCellBroadcastTask(getContentResolver())
                .execute((CellBroadcastContentProvider.CellBroadcastOperation) provider -> {
                    if (provider.insertNewBroadcast(message)) {
                        // new message, show the alert or notification on UI thread
                        startService(alertIntent);
                        // mark the message as displayed to the user.
                        markMessageDisplayed(message);
                        if (CellBroadcastSettings.getResources(mContext,
                                message.getSubscriptionId())
                                .getBoolean(R.bool.enable_write_alerts_to_sms_inbox)) {
                            // TODO: Should not create the instance of channel manager everywhere.
                            CellBroadcastChannelManager channelManager =
                                    new CellBroadcastChannelManager(mContext,
                                            message.getSubscriptionId());
                            CellBroadcastChannelRange range = channelManager
                                    .getCellBroadcastChannelRangeFromMessage(message);
                            if (CellBroadcastReceiver.isTestingMode(getApplicationContext())
                                    || (range != null && range.mWriteToSmsInbox)) {
                                writeMessageToSmsInbox(message);
                            }
                        }
                        return true;
                    } else {
                        return false;
                    }
                });
    }

    /**
     * Mark the message as displayed in cell broadcast service's database.
     *
     * @param message The cell broadcast message.
     */
    private void markMessageDisplayed(SmsCbMessage message) {
        ContentValues cv = new ContentValues();
        cv.put(Telephony.CellBroadcasts.MESSAGE_DISPLAYED, 1);
        mContext.getContentResolver().update(Telephony.CellBroadcasts.CONTENT_URI, cv,
                Telephony.CellBroadcasts.RECEIVED_TIME + "=?",
                new String[] {Long.toString(message.getReceivedTime())});
    }

    private void showNewAlert(Intent intent) {
        Bundle extras = intent.getExtras();
        if (extras == null) {
            Log.e(TAG, "received SHOW_NEW_ALERT_ACTION with no extras!");
            return;
        }

        SmsCbMessage cbm = intent.getParcelableExtra(EXTRA_MESSAGE);

        if (cbm == null) {
            Log.e(TAG, "received SHOW_NEW_ALERT_ACTION with no message extra");
            return;
        }

        if (mTelephonyManager.getCallState() != TelephonyManager.CALL_STATE_IDLE
                && CellBroadcastSettings.getResources(mContext, cbm.getSubscriptionId())
                .getBoolean(R.bool.enable_alert_handling_during_call)) {
            Log.d(TAG, "CMAS received in dialing/during voicecall.");
            sRemindAfterCallFinish = true;
        }

        // Either shown the dialog, adding it to notification (non emergency, or delayed emergency),
        CellBroadcastChannelManager channelManager = new CellBroadcastChannelManager(
                mContext, cbm.getSubscriptionId());
        if (channelManager.isEmergencyMessage(cbm) && !sRemindAfterCallFinish) {
            // start alert sound / vibration / TTS and display full-screen alert
            openEmergencyAlertNotification(cbm);
        } else {
            // add notification to the bar by passing the list of unread non-emergency
            // cell broadcast messages
            ArrayList<SmsCbMessage> messageList = CellBroadcastReceiverApp
                    .addNewMessageToList(cbm);
            addToNotificationBar(cbm, messageList, this, false);
        }
    }

    /**
     * Check if the message's channel is enabled on the device.
     *
     * @param message the message to check
     * @return true if the channel is enabled on the device, otherwise false.
     */
    private boolean isChannelEnabled(SmsCbMessage message) {

        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);
        // Check if all emergency alerts are disabled.
        boolean emergencyAlertEnabled =
                prefs.getBoolean(CellBroadcastSettings.KEY_ENABLE_ALERTS_MASTER_TOGGLE, true);

        SmsCbEtwsInfo etwsInfo = message.getEtwsWarningInfo();
        if (etwsInfo != null
                && etwsInfo.getWarningType() == SmsCbEtwsInfo.ETWS_WARNING_TYPE_TEST_MESSAGE) {
            return emergencyAlertEnabled
                    && CellBroadcastSettings.isTestAlertsToggleVisible(getApplicationContext())
                    && PreferenceManager.getDefaultSharedPreferences(this)
                    .getBoolean(CellBroadcastSettings.KEY_ENABLE_TEST_ALERTS, false);
        }

        if (message.isEtwsMessage()) {
            // ETWS messages.
            // Turn on/off emergency notifications is the only way to turn on/off ETWS messages.
            return emergencyAlertEnabled;

        }

        int channel = message.getServiceCategory();

        // Check if the messages are on additional channels enabled by the resource config.
        // If those channels are enabled by the carrier, but the device is actually roaming, we
        // should not allow the messages.
        CellBroadcastChannelManager channelManager = new CellBroadcastChannelManager(
                mContext, message.getSubscriptionId());
        ArrayList<CellBroadcastChannelRange> ranges = channelManager.getCellBroadcastChannelRanges(
                R.array.additional_cbs_channels_strings);

        for (CellBroadcastChannelRange range : ranges) {
            if (range.mStartId <= channel && range.mEndId >= channel) {
                // Check if the channel is within the scope. If not, ignore the alert message.
                if (!channelManager.checkScope(range.mScope)) {
                    Log.d(TAG, "The range [" + range.mStartId + "-" + range.mEndId
                            + "] is not within the scope. mScope = " + range.mScope);
                    return false;
                }

                if (range.mAlertType == AlertType.TEST) {
                    return emergencyAlertEnabled
                            && CellBroadcastSettings.isTestAlertsToggleVisible(
                                    getApplicationContext())
                            && PreferenceManager.getDefaultSharedPreferences(this)
                            .getBoolean(CellBroadcastSettings.KEY_ENABLE_TEST_ALERTS,
                                    false);
                }

                return emergencyAlertEnabled;
            }
        }

        if (channelManager.checkCellBroadcastChannelRange(channel,
                R.array.emergency_alerts_channels_range_strings)) {
            return emergencyAlertEnabled
                    && PreferenceManager.getDefaultSharedPreferences(this).getBoolean(
                            CellBroadcastSettings.KEY_ENABLE_EMERGENCY_ALERTS, true);
        }
        // CMAS warning types
        if (channelManager.checkCellBroadcastChannelRange(channel,
                R.array.cmas_presidential_alerts_channels_range_strings)) {
            // always enabled
            return true;
        }
        if (channelManager.checkCellBroadcastChannelRange(channel,
                R.array.cmas_alert_extreme_channels_range_strings)) {
            return emergencyAlertEnabled
                    && PreferenceManager.getDefaultSharedPreferences(this).getBoolean(
                            CellBroadcastSettings.KEY_ENABLE_CMAS_EXTREME_THREAT_ALERTS, true);
        }
        if (channelManager.checkCellBroadcastChannelRange(channel,
                R.array.cmas_alerts_severe_range_strings)) {
            return emergencyAlertEnabled
                    && PreferenceManager.getDefaultSharedPreferences(this).getBoolean(
                            CellBroadcastSettings.KEY_ENABLE_CMAS_SEVERE_THREAT_ALERTS, true);
        }
        if (channelManager.checkCellBroadcastChannelRange(channel,
                R.array.cmas_amber_alerts_channels_range_strings)) {
            return emergencyAlertEnabled
                    && PreferenceManager.getDefaultSharedPreferences(this)
                            .getBoolean(CellBroadcastSettings.KEY_ENABLE_CMAS_AMBER_ALERTS, true);
        }

        if (channelManager.checkCellBroadcastChannelRange(channel,
                R.array.exercise_alert_range_strings)
                && getResources().getBoolean(R.bool.always_enable_exercise_alert)) {
            return true;
        }

        if (channelManager.checkCellBroadcastChannelRange(channel,
                R.array.required_monthly_test_range_strings)
                || channelManager.checkCellBroadcastChannelRange(channel,
                R.array.exercise_alert_range_strings)
                || channelManager.checkCellBroadcastChannelRange(channel,
                R.array.operator_defined_alert_range_strings)) {
            return emergencyAlertEnabled
                    && CellBroadcastSettings.isTestAlertsToggleVisible(getApplicationContext())
                    && PreferenceManager.getDefaultSharedPreferences(this)
                            .getBoolean(CellBroadcastSettings.KEY_ENABLE_TEST_ALERTS,
                                    false);
        }

        if (channelManager.checkCellBroadcastChannelRange(channel,
                R.array.public_safety_messages_channels_range_strings)) {
            return emergencyAlertEnabled
                    && PreferenceManager.getDefaultSharedPreferences(this)
                    .getBoolean(CellBroadcastSettings.KEY_ENABLE_PUBLIC_SAFETY_MESSAGES,
                            true);
        }

        if (channelManager.checkCellBroadcastChannelRange(channel,
                R.array.state_local_test_alert_range_strings)) {
            return emergencyAlertEnabled
                    && PreferenceManager.getDefaultSharedPreferences(this)
                    .getBoolean(CellBroadcastSettings.KEY_ENABLE_STATE_LOCAL_TEST_ALERTS,
                            false);
        }

        return true;
    }

    /**
     * Display an alert message for emergency alerts.
     * @param message the alert to display
     */
    private void openEmergencyAlertNotification(SmsCbMessage message) {
        // Close dialogs and window shade
        Intent closeDialogs = new Intent(Intent.ACTION_CLOSE_SYSTEM_DIALOGS);
        sendBroadcast(closeDialogs);

        // start audio/vibration/speech service for emergency alerts
        Intent audioIntent = new Intent(this, CellBroadcastAlertAudio.class);
        audioIntent.setAction(CellBroadcastAlertAudio.ACTION_START_ALERT_AUDIO);
        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);

        CellBroadcastChannelManager channelManager = new CellBroadcastChannelManager(
                mContext, message.getSubscriptionId());

        AlertType alertType = AlertType.DEFAULT;
        if (message.isEtwsMessage()) {
            alertType = AlertType.ETWS_DEFAULT;

            if (message.getEtwsWarningInfo() != null) {
                int warningType = message.getEtwsWarningInfo().getWarningType();

                switch (warningType) {
                    case SmsCbEtwsInfo.ETWS_WARNING_TYPE_EARTHQUAKE:
                    case SmsCbEtwsInfo.ETWS_WARNING_TYPE_EARTHQUAKE_AND_TSUNAMI:
                        alertType = AlertType.ETWS_EARTHQUAKE;
                        break;
                    case SmsCbEtwsInfo.ETWS_WARNING_TYPE_TSUNAMI:
                        alertType = AlertType.ETWS_TSUNAMI;
                        break;
                    case SmsCbEtwsInfo.ETWS_WARNING_TYPE_TEST_MESSAGE:
                        alertType = AlertType.TEST;
                        break;
                    case SmsCbEtwsInfo.ETWS_WARNING_TYPE_OTHER_EMERGENCY:
                        alertType = AlertType.OTHER;
                        break;
                }
            }
        } else {
            int channel = message.getServiceCategory();
            ArrayList<CellBroadcastChannelRange> ranges = channelManager
                    .getAllCellBroadcastChannelRanges();
            for (CellBroadcastChannelRange range : ranges) {
                if (channel >= range.mStartId && channel <= range.mEndId) {
                    alertType = range.mAlertType;
                    break;
                }
            }
        }
        CellBroadcastChannelRange range = channelManager
                .getCellBroadcastChannelRangeFromMessage(message);
        audioIntent.putExtra(CellBroadcastAlertAudio.ALERT_AUDIO_TONE_TYPE, alertType);
        audioIntent.putExtra(
                CellBroadcastAlertAudio.ALERT_AUDIO_VIBRATION_PATTERN_EXTRA,
                (range != null)
                        ? range.mVibrationPattern
                        : CellBroadcastSettings.getResources(mContext, message.getSubscriptionId())
                        .getIntArray(R.array.default_vibration_pattern));

        if (prefs.getBoolean(CellBroadcastSettings.KEY_OVERRIDE_DND, false)
                || (range != null && range.mOverrideDnd)) {
            audioIntent.putExtra(CellBroadcastAlertAudio.ALERT_AUDIO_OVERRIDE_DND_EXTRA, true);
        }

        String messageBody = message.getMessageBody();

        audioIntent.putExtra(CellBroadcastAlertAudio.ALERT_AUDIO_MESSAGE_BODY, messageBody);

        String language = message.getLanguageCode();

        Log.d(TAG, "Message language = " + language);
        audioIntent.putExtra(CellBroadcastAlertAudio.ALERT_AUDIO_MESSAGE_LANGUAGE,
                language);

        audioIntent.putExtra(CellBroadcastAlertAudio.ALERT_AUDIO_SUB_INDEX,
                message.getSubscriptionId());
        audioIntent.putExtra(CellBroadcastAlertAudio.ALERT_AUDIO_DURATION,
                (range != null) ? range.mAlertDuration : -1);
        startService(audioIntent);

        ArrayList<SmsCbMessage> messageList = new ArrayList<>();
        messageList.add(message);

        // For FEATURE_WATCH, the dialog doesn't make sense from a UI/UX perspective
        if (getPackageManager().hasSystemFeature(PackageManager.FEATURE_WATCH)) {
            addToNotificationBar(message, messageList, this, false);
        } else {
            Intent alertDialogIntent = createDisplayMessageIntent(this,
                    CellBroadcastAlertDialog.class, messageList);
            alertDialogIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
            startActivity(alertDialogIntent);
        }

    }

    /**
     * Add the new alert to the notification bar (non-emergency alerts), or launch a
     * high-priority immediate intent for emergency alerts.
     * @param message the alert to display
     */
    static void addToNotificationBar(SmsCbMessage message,
                                     ArrayList<SmsCbMessage> messageList, Context context,
                                     boolean fromSaveState) {
        Resources res = CellBroadcastSettings.getResources(context, message.getSubscriptionId());
        int channelTitleId = CellBroadcastResources.getDialogTitleResource(context, message);
        CharSequence channelName = context.getText(channelTitleId);
        String messageBody = message.getMessageBody();
        final NotificationManager notificationManager =
                (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
        createNotificationChannels(context);

        boolean isWatch = context.getPackageManager()
                .hasSystemFeature(PackageManager.FEATURE_WATCH);
        // Create intent to show the new messages when user selects the notification.
        Intent intent;
        if (isWatch) {
            // For FEATURE_WATCH we want to mark as read
            intent = createMarkAsReadIntent(context, message.getReceivedTime());
        } else {
            // For anything else we handle it normally
            intent = createDisplayMessageIntent(context, CellBroadcastAlertDialog.class,
                    messageList);
        }

        intent.putExtra(CellBroadcastAlertDialog.FROM_NOTIFICATION_EXTRA, true);
        intent.putExtra(CellBroadcastAlertDialog.FROM_SAVE_STATE_NOTIFICATION_EXTRA, fromSaveState);

        PendingIntent pi;
        if (isWatch) {
            pi = PendingIntent.getBroadcast(context, 0, intent, 0);
        } else {
            pi = PendingIntent.getActivity(context, NOTIFICATION_ID, intent,
                    PendingIntent.FLAG_ONE_SHOT | PendingIntent.FLAG_UPDATE_CURRENT);
        }
        CellBroadcastChannelManager channelManager = new CellBroadcastChannelManager(
                context, message.getSubscriptionId());

        String channelId = channelManager.isEmergencyMessage(message)
                ? NOTIFICATION_CHANNEL_EMERGENCY_ALERTS : NOTIFICATION_CHANNEL_NON_EMERGENCY_ALERTS;
        if (channelId == NOTIFICATION_CHANNEL_EMERGENCY_ALERTS && sRemindAfterCallFinish) {
            channelId = NOTIFICATION_CHANNEL_EMERGENCY_ALERTS_IN_VOICECALL;
        }

        boolean nonSwipeableNotification = message.isEmergencyMessage()
                && CellBroadcastSettings.getResources(context, message.getSubscriptionId())
                .getBoolean(R.bool.non_swipeable_notification) || sRemindAfterCallFinish;

        // use default sound/vibration/lights for non-emergency broadcasts
        Notification.Builder builder =
                new Notification.Builder(context, channelId)
                        .setSmallIcon(R.drawable.ic_warning_googred)
                        .setTicker(channelName)
                        .setWhen(System.currentTimeMillis())
                        .setCategory(Notification.CATEGORY_SYSTEM)
                        .setPriority(Notification.PRIORITY_HIGH)
                        .setColor(res.getColor(R.color.notification_color))
                        .setVisibility(Notification.VISIBILITY_PUBLIC)
                        .setOngoing(nonSwipeableNotification);

        if (isWatch) {
            builder.setDeleteIntent(pi);
            // FEATURE_WATCH/CWH devices see this as priority
            builder.setVibrate(new long[]{0});
        } else {
            builder.setContentIntent(pi);
            // This will break vibration on FEATURE_WATCH, so use it for anything else
            builder.setDefaults(Notification.DEFAULT_ALL);
        }

        // increment unread alert count (decremented when user dismisses alert dialog)
        int unreadCount = messageList.size();
        if (unreadCount > 1) {
            // use generic count of unread broadcasts if more than one unread
            builder.setContentTitle(context.getString(R.string.notification_multiple_title));
            builder.setContentText(context.getString(R.string.notification_multiple, unreadCount));
        } else {
            builder.setContentTitle(channelName)
                    .setContentText(messageBody)
                    .setStyle(new Notification.BigTextStyle()
                            .bigText(messageBody));
        }

        notificationManager.notify(NOTIFICATION_ID, builder.build());

        // FEATURE_WATCH devices do not have global sounds for notifications; only vibrate.
        // TW requires sounds for 911/919
        // Emergency messages use a different audio playback and display path. Since we use
        // addToNotification for the emergency display on FEATURE WATCH devices vs the
        // Alert Dialog, it will call this and override the emergency audio tone.
        if (isWatch && !channelManager.isEmergencyMessage(message)) {
            if (res.getBoolean(R.bool.watch_enable_non_emergency_audio)) {
                // start audio/vibration/speech service for non emergency alerts
                Intent audioIntent = new Intent(context, CellBroadcastAlertAudio.class);
                audioIntent.setAction(CellBroadcastAlertAudio.ACTION_START_ALERT_AUDIO);
                audioIntent.putExtra(CellBroadcastAlertAudio.ALERT_AUDIO_TONE_TYPE,
                        AlertType.OTHER);
                context.startService(audioIntent);
            }
        }

    }

    /**
     * Creates the notification channel and registers it with NotificationManager. If a channel
     * with the same ID is already registered, NotificationManager will ignore this call.
     */
    static void createNotificationChannels(Context context) {
        NotificationManager notificationManager =
                (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
        notificationManager.createNotificationChannel(
                new NotificationChannel(
                        NOTIFICATION_CHANNEL_EMERGENCY_ALERTS,
                        context.getString(R.string.notification_channel_emergency_alerts),
                        NotificationManager.IMPORTANCE_LOW));
        final NotificationChannel nonEmergency = new NotificationChannel(
                NOTIFICATION_CHANNEL_NON_EMERGENCY_ALERTS,
                context.getString(R.string.notification_channel_broadcast_messages),
                NotificationManager.IMPORTANCE_DEFAULT);
        nonEmergency.enableVibration(true);
        notificationManager.createNotificationChannel(nonEmergency);

        final NotificationChannel emergencyAlertInVoiceCall = new NotificationChannel(
            NOTIFICATION_CHANNEL_EMERGENCY_ALERTS_IN_VOICECALL,
            context.getString(R.string.notification_channel_broadcast_messages_in_voicecall),
            NotificationManager.IMPORTANCE_HIGH);
        emergencyAlertInVoiceCall.enableVibration(true);
        notificationManager.createNotificationChannel(emergencyAlertInVoiceCall);
    }

    private static Intent createDisplayMessageIntent(Context context, Class intentClass,
            ArrayList<SmsCbMessage> messageList) {
        // Trigger the list activity to fire up a dialog that shows the received messages
        Intent intent = new Intent(context, intentClass);
        intent.putParcelableArrayListExtra(CellBroadcastAlertService.SMS_CB_MESSAGE_EXTRA,
                messageList);
        return intent;
    }

    /**
     * Creates a delete intent that calls to the {@link CellBroadcastReceiver} in order to mark
     * a message as read
     *
     * @param context context of the caller
     * @param deliveryTime time the message was sent in order to mark as read
     * @return delete intent to add to the pending intent
     */
    static Intent createMarkAsReadIntent(Context context, long deliveryTime) {
        Intent deleteIntent = new Intent(context, CellBroadcastInternalReceiver.class);
        deleteIntent.setAction(CellBroadcastReceiver.ACTION_MARK_AS_READ);
        deleteIntent.putExtra(CellBroadcastReceiver.EXTRA_DELIVERY_TIME, deliveryTime);
        return deleteIntent;
    }

    @VisibleForTesting
    @Override
    public IBinder onBind(Intent intent) {
        return new LocalBinder();
    }

    @VisibleForTesting
    class LocalBinder extends Binder {
        public CellBroadcastAlertService getService() {
            return CellBroadcastAlertService.this;
        }
    }

    @Override
    public void onAudioFocusChange(int focusChange) {
        if(focusChange == AudioManager.AUDIOFOCUS_GAIN) {
            Log.d(TAG, "audio focus released from voice call, play pending alert if needed");
            mAudioManager.abandonAudioFocus(this);
            playPendingAlert();
        }
    }

    /**
     * Remove previous unread notifications and play stored unread
     * emergency messages after voice call finish.
     */
    private final PhoneStateListener mPhoneStateListener = new PhoneStateListener(
        new Handler(Looper.getMainLooper())::post) {
        @Override
        public void onCallStateChanged(int state, String incomingNumber) {

            switch (state) {
                case TelephonyManager.CALL_STATE_IDLE:
                    Log.d(TAG, "onCallStateChanged: CALL_STATE_IDLE");
                    // check if audio focus was released by voice call. This is to avoid possible
                    // race conditions that voice call did not release audio focus while alert is
                    // playing at the same time (out-of-rhythm)
                    if (mAudioManager == null) {
                        mAudioManager = (AudioManager)
                            getApplicationContext().getSystemService(Context.AUDIO_SERVICE);
                    }
                    int audioFocusResult = mAudioManager.requestAudioFocus(
                            CellBroadcastAlertService.this::onAudioFocusChange,
                            new AudioAttributes.Builder().setLegacyStreamType(
                                    AudioManager.STREAM_ALARM).build(),
                            AudioManager.AUDIOFOCUS_GAIN_TRANSIENT,
                            AudioManager.AUDIOFOCUS_FLAG_DELAY_OK);
                    if (audioFocusResult == AudioManager.AUDIOFOCUS_REQUEST_GRANTED) {
                        Log.d(TAG, "audio focus released from voice call, "
                                + "play pending alert if needed");
                        mAudioManager.abandonAudioFocus(
                                CellBroadcastAlertService.this::onAudioFocusChange);
                        playPendingAlert();
                    } else {
                        Log.d(TAG, "wait for audio focus release after call");
                    }
                    break;

                default:
                    Log.d(TAG, "onCallStateChanged: other state = " + state);
                    break;
            }
        }
    };

    private void playPendingAlert() {
        if (sRemindAfterCallFinish) {
            sRemindAfterCallFinish = false;
            NotificationManager notificationManager = (NotificationManager)
                    getApplicationContext().getSystemService(
                            Context.NOTIFICATION_SERVICE);

            StatusBarNotification[] notificationList =
                    notificationManager.getActiveNotifications();

            if(notificationList != null && notificationList.length >0) {
                notificationManager.cancel(CellBroadcastAlertService.NOTIFICATION_ID);
                ArrayList<SmsCbMessage> newMessageList =
                        CellBroadcastReceiverApp.getNewMessageList();

                for (int i = 0; i < newMessageList.size(); i++) {
                    openEmergencyAlertNotification(newMessageList.get(i));
                }
            }
            CellBroadcastReceiverApp.clearNewMessageList();
        }
    }

    /**
     * Write displayed cellbroadcast messages to sms inbox
     *
     * @param message The cell broadcast message.
     */
    private void writeMessageToSmsInbox(@NonNull SmsCbMessage message) {
        // composing SMS
        ContentValues cv = new ContentValues();
        cv.put(Telephony.Sms.Inbox.BODY, message.getMessageBody());
        cv.put(Telephony.Sms.Inbox.DATE, message.getReceivedTime());
        cv.put(Telephony.Sms.Inbox.SUBSCRIPTION_ID, message.getSubscriptionId());
        cv.put(Telephony.Sms.Inbox.SUBJECT, CellBroadcastResources.getDialogTitleResource(mContext,
                message));
        cv.put(Telephony.Sms.Inbox.ADDRESS, mContext.getString(R.string.sms_cb_sender_name));
        // store all cellbroadcast messages in the same thread.
        cv.put(Telephony.Sms.Inbox.THREAD_ID, Telephony.Threads.getOrCreateThreadId(mContext,
                mContext.getString(R.string.sms_cb_sender_name)));
        Uri uri = mContext.getContentResolver().insert(Telephony.Sms.Inbox.CONTENT_URI, cv);
        if (uri == null) {
            Log.e(TAG, "writeMessageToSmsInbox: failed");
        } else {
            Log.d(TAG, "writeMessageToSmsInbox: succeed uri = " + uri);
        }
    }
}