/*
 * Copyright (C) 2006 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.phone;

import static android.Manifest.permission.READ_PHONE_STATE;

import android.app.Notification;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.app.StatusBarManager;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.content.pm.ResolveInfo;
import android.content.pm.UserInfo;
import android.content.res.Resources;
import android.net.Uri;
import android.os.PersistableBundle;
import android.os.SystemProperties;
import android.os.UserHandle;
import android.os.UserManager;
import android.preference.PreferenceManager;
import android.provider.ContactsContract.PhoneLookup;
import android.telecom.DefaultDialerManager;
import android.telecom.PhoneAccount;
import android.telecom.PhoneAccountHandle;
import android.telecom.TelecomManager;
import android.telephony.CarrierConfigManager;
import android.telephony.PhoneNumberUtils;
import android.telephony.ServiceState;
import android.telephony.SubscriptionInfo;
import android.telephony.SubscriptionManager;
import android.telephony.TelephonyManager;
import android.text.TextUtils;
import android.util.ArrayMap;
import android.util.Log;
import android.widget.Toast;

import com.android.internal.telephony.Phone;
import com.android.internal.telephony.PhoneFactory;
import com.android.internal.telephony.TelephonyCapabilities;
import com.android.internal.telephony.util.NotificationChannelController;
import com.android.phone.settings.VoicemailSettingsActivity;

import java.util.Iterator;
import java.util.List;
import java.util.Set;

/**
 * NotificationManager-related utility code for the Phone app.
 *
 * This is a singleton object which acts as the interface to the
 * framework's NotificationManager, and is used to display status bar
 * icons and control other status bar-related behavior.
 *
 * @see PhoneGlobals.notificationMgr
 */
public class NotificationMgr {
    private static final String LOG_TAG = NotificationMgr.class.getSimpleName();
    private static final boolean DBG =
            (PhoneGlobals.DBG_LEVEL >= 1) && (SystemProperties.getInt("ro.debuggable", 0) == 1);
    // Do not check in with VDBG = true, since that may write PII to the system log.
    private static final boolean VDBG = false;

    private static final String MWI_SHOULD_CHECK_VVM_CONFIGURATION_KEY_PREFIX =
            "mwi_should_check_vvm_configuration_state_";

    // notification types
    static final int MMI_NOTIFICATION = 1;
    static final int NETWORK_SELECTION_NOTIFICATION = 2;
    static final int VOICEMAIL_NOTIFICATION = 3;
    static final int CALL_FORWARD_NOTIFICATION = 4;
    static final int DATA_DISCONNECTED_ROAMING_NOTIFICATION = 5;
    static final int SELECTED_OPERATOR_FAIL_NOTIFICATION = 6;

    /** The singleton NotificationMgr instance. */
    private static NotificationMgr sInstance;

    private PhoneGlobals mApp;

    private Context mContext;
    private NotificationManager mNotificationManager;
    private StatusBarManager mStatusBarManager;
    private UserManager mUserManager;
    private Toast mToast;
    private SubscriptionManager mSubscriptionManager;
    private TelecomManager mTelecomManager;
    private TelephonyManager mTelephonyManager;

    // used to track the notification of selected network unavailable
    private boolean mSelectedUnavailableNotify = false;

    // used to track whether the message waiting indicator is visible, per subscription id.
    private ArrayMap<Integer, Boolean> mMwiVisible = new ArrayMap<Integer, Boolean>();

    /**
     * Private constructor (this is a singleton).
     * @see #init(PhoneGlobals)
     */
    private NotificationMgr(PhoneGlobals app) {
        mApp = app;
        mContext = app;
        mNotificationManager =
                (NotificationManager) app.getSystemService(Context.NOTIFICATION_SERVICE);
        mStatusBarManager =
                (StatusBarManager) app.getSystemService(Context.STATUS_BAR_SERVICE);
        mUserManager = (UserManager) app.getSystemService(Context.USER_SERVICE);
        mSubscriptionManager = SubscriptionManager.from(mContext);
        mTelecomManager = TelecomManager.from(mContext);
        mTelephonyManager = (TelephonyManager) app.getSystemService(Context.TELEPHONY_SERVICE);
    }

    /**
     * Initialize the singleton NotificationMgr instance.
     *
     * This is only done once, at startup, from PhoneApp.onCreate().
     * From then on, the NotificationMgr instance is available via the
     * PhoneApp's public "notificationMgr" field, which is why there's no
     * getInstance() method here.
     */
    /* package */ static NotificationMgr init(PhoneGlobals app) {
        synchronized (NotificationMgr.class) {
            if (sInstance == null) {
                sInstance = new NotificationMgr(app);
            } else {
                Log.wtf(LOG_TAG, "init() called multiple times!  sInstance = " + sInstance);
            }
            return sInstance;
        }
    }

    /** The projection to use when querying the phones table */
    static final String[] PHONES_PROJECTION = new String[] {
        PhoneLookup.NUMBER,
        PhoneLookup.DISPLAY_NAME,
        PhoneLookup._ID
    };

    /**
     * Re-creates the message waiting indicator (voicemail) notification if it is showing.  Used to
     * refresh the voicemail intent on the indicator when the user changes it via the voicemail
     * settings screen.  The voicemail notification sound is suppressed.
     *
     * @param subId The subscription Id.
     */
    /* package */ void refreshMwi(int subId) {
        // In a single-sim device, subId can be -1 which means "no sub id".  In this case we will
        // reference the single subid stored in the mMwiVisible map.
        if (subId == SubscriptionManager.INVALID_SUBSCRIPTION_ID) {
            if (mMwiVisible.keySet().size() == 1) {
                Set<Integer> keySet = mMwiVisible.keySet();
                Iterator<Integer> keyIt = keySet.iterator();
                if (!keyIt.hasNext()) {
                    return;
                }
                subId = keyIt.next();
            }
        }
        if (mMwiVisible.containsKey(subId)) {
            boolean mwiVisible = mMwiVisible.get(subId);
            if (mwiVisible) {
                mApp.notifier.updatePhoneStateListeners(true);
            }
        }
    }

    public void setShouldCheckVisualVoicemailConfigurationForMwi(int subId, boolean enabled) {
        if (!SubscriptionManager.isValidSubscriptionId(subId)) {
            Log.e(LOG_TAG, "setShouldCheckVisualVoicemailConfigurationForMwi: invalid subId"
                    + subId);
            return;
        }

        PreferenceManager.getDefaultSharedPreferences(mContext).edit()
                .putBoolean(MWI_SHOULD_CHECK_VVM_CONFIGURATION_KEY_PREFIX + subId, enabled)
                .apply();
    }

    private boolean shouldCheckVisualVoicemailConfigurationForMwi(int subId) {
        if (!SubscriptionManager.isValidSubscriptionId(subId)) {
            Log.e(LOG_TAG, "shouldCheckVisualVoicemailConfigurationForMwi: invalid subId" + subId);
            return true;
        }
        return PreferenceManager
                .getDefaultSharedPreferences(mContext)
                .getBoolean(MWI_SHOULD_CHECK_VVM_CONFIGURATION_KEY_PREFIX + subId, true);
    }
    /**
     * Updates the message waiting indicator (voicemail) notification.
     *
     * @param visible true if there are messages waiting
     */
    /* package */ void updateMwi(int subId, boolean visible) {
        updateMwi(subId, visible, false /* isRefresh */);
    }

    /**
     * Updates the message waiting indicator (voicemail) notification.
     *
     * @param subId the subId to update.
     * @param visible true if there are messages waiting
     * @param isRefresh {@code true} if the notification is a refresh and the user should not be
     * notified again.
     */
    void updateMwi(int subId, boolean visible, boolean isRefresh) {
        if (!PhoneGlobals.sVoiceCapable) {
            // Do not show the message waiting indicator on devices which are not voice capable.
            // These events *should* be blocked at the telephony layer for such devices.
            Log.w(LOG_TAG, "Called updateMwi() on non-voice-capable device! Ignoring...");
            return;
        }

        Phone phone = PhoneGlobals.getPhone(subId);
        Log.i(LOG_TAG, "updateMwi(): subId " + subId + " update to " + visible);
        mMwiVisible.put(subId, visible);

        if (visible) {
            if (phone == null) {
                Log.w(LOG_TAG, "Found null phone for: " + subId);
                return;
            }

            SubscriptionInfo subInfo = mSubscriptionManager.getActiveSubscriptionInfo(subId);
            if (subInfo == null) {
                Log.w(LOG_TAG, "Found null subscription info for: " + subId);
                return;
            }

            int resId = android.R.drawable.stat_notify_voicemail;
            if (mTelephonyManager.getPhoneCount() > 1) {
                resId = (phone.getPhoneId() == 0) ? R.drawable.stat_notify_voicemail_sub1
                        : R.drawable.stat_notify_voicemail_sub2;
            }

            // This Notification can get a lot fancier once we have more
            // information about the current voicemail messages.
            // (For example, the current voicemail system can't tell
            // us the caller-id or timestamp of a message, or tell us the
            // message count.)

            // But for now, the UI is ultra-simple: if the MWI indication
            // is supposed to be visible, just show a single generic
            // notification.

            String notificationTitle = mContext.getString(R.string.notification_voicemail_title);
            String vmNumber = phone.getVoiceMailNumber();
            if (DBG) log("- got vm number: '" + vmNumber + "'");

            // The voicemail number may be null because:
            //   (1) This phone has no voicemail number.
            //   (2) This phone has a voicemail number, but the SIM isn't ready yet. This may
            //       happen when the device first boots if we get a MWI notification when we
            //       register on the network before the SIM has loaded. In this case, the
            //       SubscriptionListener in CallNotifier will update this once the SIM is loaded.
            if ((vmNumber == null) && !phone.getIccRecordsLoaded()) {
                if (DBG) log("- Null vm number: SIM records not loaded (yet)...");
                return;
            }

            Integer vmCount = null;

            if (TelephonyCapabilities.supportsVoiceMessageCount(phone)) {
                vmCount = phone.getVoiceMessageCount();
                String titleFormat = mContext.getString(R.string.notification_voicemail_title_count);
                notificationTitle = String.format(titleFormat, vmCount);
            }

            // This pathway only applies to PSTN accounts; only SIMS have subscription ids.
            PhoneAccountHandle phoneAccountHandle = PhoneUtils.makePstnPhoneAccountHandle(phone);

            Intent intent;
            String notificationText;
            boolean isSettingsIntent = TextUtils.isEmpty(vmNumber);

            if (isSettingsIntent) {
                notificationText = mContext.getString(
                        R.string.notification_voicemail_no_vm_number);

                // If the voicemail number if unknown, instead of calling voicemail, take the user
                // to the voicemail settings.
                notificationText = mContext.getString(
                        R.string.notification_voicemail_no_vm_number);
                intent = new Intent(VoicemailSettingsActivity.ACTION_ADD_VOICEMAIL);
                intent.putExtra(SubscriptionInfoHelper.SUB_ID_EXTRA, subId);
                intent.setClass(mContext, VoicemailSettingsActivity.class);
            } else {
                if (mTelephonyManager.getPhoneCount() > 1) {
                    notificationText = subInfo.getDisplayName().toString();
                } else {
                    notificationText = String.format(
                            mContext.getString(R.string.notification_voicemail_text_format),
                            PhoneNumberUtils.formatNumber(vmNumber));
                }
                intent = new Intent(
                        Intent.ACTION_CALL, Uri.fromParts(PhoneAccount.SCHEME_VOICEMAIL, "",
                                null));
                intent.putExtra(TelecomManager.EXTRA_PHONE_ACCOUNT_HANDLE, phoneAccountHandle);
            }

            PendingIntent pendingIntent =
                    PendingIntent.getActivity(mContext, subId /* requestCode */, intent, 0);

            Resources res = mContext.getResources();
            PersistableBundle carrierConfig = PhoneGlobals.getInstance().getCarrierConfigForSubId(
                    subId);
            Notification.Builder builder = new Notification.Builder(mContext);
            builder.setSmallIcon(resId)
                    .setWhen(System.currentTimeMillis())
                    .setColor(subInfo.getIconTint())
                    .setContentTitle(notificationTitle)
                    .setContentText(notificationText)
                    .setContentIntent(pendingIntent)
                    .setColor(res.getColor(R.color.dialer_theme_color))
                    .setOngoing(carrierConfig.getBoolean(
                            CarrierConfigManager.KEY_VOICEMAIL_NOTIFICATION_PERSISTENT_BOOL))
                    .setChannel(NotificationChannelController.CHANNEL_ID_VOICE_MAIL)
                    .setOnlyAlertOnce(isRefresh);

            final Notification notification = builder.build();
            List<UserInfo> users = mUserManager.getUsers(true);
            for (int i = 0; i < users.size(); i++) {
                final UserInfo user = users.get(i);
                final UserHandle userHandle = user.getUserHandle();
                if (!mUserManager.hasUserRestriction(
                        UserManager.DISALLOW_OUTGOING_CALLS, userHandle)
                        && !user.isManagedProfile()) {
                    if (!maybeSendVoicemailNotificationUsingDefaultDialer(phone, vmCount, vmNumber,
                            pendingIntent, isSettingsIntent, userHandle, isRefresh)) {
                        mNotificationManager.notifyAsUser(
                                Integer.toString(subId) /* tag */,
                                VOICEMAIL_NOTIFICATION,
                                notification,
                                userHandle);
                    }
                }
            }
        } else {
            List<UserInfo> users = mUserManager.getUsers(true /* excludeDying */);
            for (int i = 0; i < users.size(); i++) {
                final UserInfo user = users.get(i);
                final UserHandle userHandle = user.getUserHandle();
                if (!mUserManager.hasUserRestriction(
                        UserManager.DISALLOW_OUTGOING_CALLS, userHandle)
                        && !user.isManagedProfile()) {
                    if (!maybeSendVoicemailNotificationUsingDefaultDialer(phone, 0, null, null,
                            false, userHandle, isRefresh)) {
                        mNotificationManager.cancelAsUser(
                                Integer.toString(subId) /* tag */,
                                VOICEMAIL_NOTIFICATION,
                                userHandle);
                    }
                }
            }
        }
    }

    /**
     * Sends a broadcast with the voicemail notification information to the default dialer. This
     * method is also used to indicate to the default dialer when to clear the
     * notification. A pending intent can be passed to the default dialer to indicate an action to
     * be taken as it would by a notification produced in this class.
     * @param phone The phone the notification is sent from
     * @param count The number of pending voicemail messages to indicate on the notification. A
     *              Value of 0 is passed here to indicate that the notification should be cleared.
     * @param number The voicemail phone number if specified.
     * @param pendingIntent The intent that should be passed as the action to be taken.
     * @param isSettingsIntent {@code true} to indicate the pending intent is to launch settings.
     *                         otherwise, {@code false} to indicate the intent launches voicemail.
     * @param userHandle The user to receive the notification. Each user can have their own default
     *                   dialer.
     * @return {@code true} if the default was notified of the notification.
     */
    private boolean maybeSendVoicemailNotificationUsingDefaultDialer(Phone phone, Integer count,
            String number, PendingIntent pendingIntent, boolean isSettingsIntent,
            UserHandle userHandle, boolean isRefresh) {

        if (shouldManageNotificationThroughDefaultDialer(userHandle)) {
            Intent intent = getShowVoicemailIntentForDefaultDialer(userHandle);
            intent.setFlags(Intent.FLAG_RECEIVER_FOREGROUND);
            intent.setAction(TelephonyManager.ACTION_SHOW_VOICEMAIL_NOTIFICATION);
            intent.putExtra(TelephonyManager.EXTRA_PHONE_ACCOUNT_HANDLE,
                    PhoneUtils.makePstnPhoneAccountHandle(phone));
            intent.putExtra(TelephonyManager.EXTRA_IS_REFRESH, isRefresh);
            if (count != null) {
                intent.putExtra(TelephonyManager.EXTRA_NOTIFICATION_COUNT, count);
            }

            // Additional information about the voicemail notification beyond the count is only
            // present when the count not specified or greater than 0. The value of 0 represents
            // clearing the notification, which does not require additional information.
            if (count == null || count > 0) {
                if (!TextUtils.isEmpty(number)) {
                    intent.putExtra(TelephonyManager.EXTRA_VOICEMAIL_NUMBER, number);
                }

                if (pendingIntent != null) {
                    intent.putExtra(isSettingsIntent
                            ? TelephonyManager.EXTRA_LAUNCH_VOICEMAIL_SETTINGS_INTENT
                            : TelephonyManager.EXTRA_CALL_VOICEMAIL_INTENT,
                            pendingIntent);
                }
            }
            mContext.sendBroadcastAsUser(intent, userHandle, READ_PHONE_STATE);
            return true;
        }

        return false;
    }

    private Intent getShowVoicemailIntentForDefaultDialer(UserHandle userHandle) {
        String dialerPackage = DefaultDialerManager
                .getDefaultDialerApplication(mContext, userHandle.getIdentifier());
        return new Intent(TelephonyManager.ACTION_SHOW_VOICEMAIL_NOTIFICATION)
                .setPackage(dialerPackage);
    }

    private boolean shouldManageNotificationThroughDefaultDialer(UserHandle userHandle) {
        Intent intent = getShowVoicemailIntentForDefaultDialer(userHandle);
        if (intent == null) {
            return false;
        }

        List<ResolveInfo> receivers = mContext.getPackageManager()
                .queryBroadcastReceivers(intent, 0);
        return receivers.size() > 0;
    }

    /**
     * Updates the message call forwarding indicator notification.
     *
     * @param visible true if call forwarding enabled
     */

     /* package */ void updateCfi(int subId, boolean visible) {
        updateCfi(subId, visible, false /* isRefresh */);
    }

    /**
     * Updates the message call forwarding indicator notification.
     *
     * @param visible true if call forwarding enabled
     */
    /* package */ void updateCfi(int subId, boolean visible, boolean isRefresh) {
        logi("updateCfi: subId= " + subId + ", visible=" + (visible ? "Y" : "N"));
        if (visible) {
            // If Unconditional Call Forwarding (forward all calls) for VOICE
            // is enabled, just show a notification.  We'll default to expanded
            // view for now, so the there is less confusion about the icon.  If
            // it is deemed too weird to have CF indications as expanded views,
            // then we'll flip the flag back.

            // TODO: We may want to take a look to see if the notification can
            // display the target to forward calls to.  This will require some
            // effort though, since there are multiple layers of messages that
            // will need to propagate that information.

            SubscriptionInfo subInfo = mSubscriptionManager.getActiveSubscriptionInfo(subId);
            if (subInfo == null) {
                Log.w(LOG_TAG, "Found null subscription info for: " + subId);
                return;
            }

            String notificationTitle;
            int resId = R.drawable.stat_sys_phone_call_forward;
            if (mTelephonyManager.getPhoneCount() > 1) {
                int slotId = SubscriptionManager.getSlotIndex(subId);
                resId = (slotId == 0) ? R.drawable.stat_sys_phone_call_forward_sub1
                        : R.drawable.stat_sys_phone_call_forward_sub2;
                notificationTitle = subInfo.getDisplayName().toString();
            } else {
                notificationTitle = mContext.getString(R.string.labelCF);
            }

            Notification.Builder builder = new Notification.Builder(mContext)
                    .setSmallIcon(resId)
                    .setColor(subInfo.getIconTint())
                    .setContentTitle(notificationTitle)
                    .setContentText(mContext.getString(R.string.sum_cfu_enabled_indicator))
                    .setShowWhen(false)
                    .setOngoing(true)
                    .setChannel(NotificationChannelController.CHANNEL_ID_CALL_FORWARD)
                    .setOnlyAlertOnce(isRefresh);

            Intent intent = new Intent(Intent.ACTION_MAIN);
            intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TOP);
            intent.setClassName("com.android.phone", "com.android.phone.CallFeaturesSetting");
            SubscriptionInfoHelper.addExtrasToIntent(
                    intent, mSubscriptionManager.getActiveSubscriptionInfo(subId));
            builder.setContentIntent(PendingIntent.getActivity(mContext, subId /* requestCode */,
                    intent, 0));
            mNotificationManager.notifyAsUser(
                    Integer.toString(subId) /* tag */,
                    CALL_FORWARD_NOTIFICATION,
                    builder.build(),
                    UserHandle.ALL);
        } else {
            List<UserInfo> users = mUserManager.getUsers(true);
            for (UserInfo user : users) {
                if (user.isManagedProfile()) {
                    continue;
                }
                UserHandle userHandle = user.getUserHandle();
                mNotificationManager.cancelAsUser(
                        Integer.toString(subId) /* tag */,
                        CALL_FORWARD_NOTIFICATION,
                        userHandle);
            }
        }
    }

    /**
     * Shows the "data disconnected due to roaming" notification, which
     * appears when you lose data connectivity because you're roaming and
     * you have the "data roaming" feature turned off.
     */
    void showDataDisconnectedRoaming() {
        if (DBG) log("showDataDisconnectedRoaming()...");

        // "Mobile network settings" screen / dialog
        Intent intent = new Intent(mContext, com.android.phone.MobileNetworkSettings.class);
        PendingIntent contentIntent = PendingIntent.getActivity(mContext, 0, intent, 0);

        final CharSequence contentText = mContext.getText(R.string.roaming_reenable_message);

        final Notification.Builder builder = new Notification.Builder(mContext)
                .setSmallIcon(android.R.drawable.stat_sys_warning)
                .setContentTitle(mContext.getText(R.string.roaming_notification_title))
                .setColor(mContext.getResources().getColor(R.color.dialer_theme_color))
                .setContentText(contentText)
                .setChannel(NotificationChannelController.CHANNEL_ID_MOBILE_DATA_STATUS)
                .setContentIntent(contentIntent);
        final Notification notif =
                new Notification.BigTextStyle(builder).bigText(contentText).build();
        mNotificationManager.notifyAsUser(
                null /* tag */, DATA_DISCONNECTED_ROAMING_NOTIFICATION, notif, UserHandle.ALL);
    }

    /**
     * Turns off the "data disconnected due to roaming" notification.
     */
    /* package */ void hideDataDisconnectedRoaming() {
        if (DBG) log("hideDataDisconnectedRoaming()...");
        mNotificationManager.cancel(DATA_DISCONNECTED_ROAMING_NOTIFICATION);
    }

    /**
     * Display the network selection "no service" notification
     * @param operator is the numeric operator number
     * @param subId is the subscription ID
     */
    private void showNetworkSelection(String operator, int subId) {
        if (DBG) log("showNetworkSelection(" + operator + ")...");

        Notification.Builder builder = new Notification.Builder(mContext)
                .setSmallIcon(android.R.drawable.stat_sys_warning)
                .setContentTitle(mContext.getString(R.string.notification_network_selection_title))
                .setContentText(
                        mContext.getString(R.string.notification_network_selection_text, operator))
                .setShowWhen(false)
                .setOngoing(true)
                .setChannel(NotificationChannelController.CHANNEL_ID_ALERT);

        // create the target network operators settings intent
        Intent intent = new Intent(Intent.ACTION_MAIN);
        intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK |
                Intent.FLAG_ACTIVITY_RESET_TASK_IF_NEEDED);
        // Use MobileNetworkSettings to handle the selection intent
        intent.setComponent(new ComponentName(
                mContext.getString(R.string.mobile_network_settings_package),
                mContext.getString(R.string.mobile_network_settings_class)));
        intent.putExtra(GsmUmtsOptions.EXTRA_SUB_ID, subId);
        builder.setContentIntent(PendingIntent.getActivity(mContext, 0, intent, 0));
        mNotificationManager.notifyAsUser(
                null /* tag */,
                SELECTED_OPERATOR_FAIL_NOTIFICATION,
                builder.build(),
                UserHandle.ALL);
    }

    /**
     * Turn off the network selection "no service" notification
     */
    private void cancelNetworkSelection() {
        if (DBG) log("cancelNetworkSelection()...");
        mNotificationManager.cancelAsUser(
                null /* tag */, SELECTED_OPERATOR_FAIL_NOTIFICATION, UserHandle.ALL);
    }

    /**
     * Update notification about no service of user selected operator
     *
     * @param serviceState Phone service state
     * @param subId The subscription ID
     */
    void updateNetworkSelection(int serviceState, int subId) {
        int phoneId = SubscriptionManager.getPhoneId(subId);
        Phone phone = SubscriptionManager.isValidPhoneId(phoneId) ?
                PhoneFactory.getPhone(phoneId) : PhoneFactory.getDefaultPhone();
        if (TelephonyCapabilities.supportsNetworkSelection(phone)) {
            if (SubscriptionManager.isValidSubscriptionId(subId)) {
                SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(mContext);
                String selectedNetworkOperatorName =
                        sp.getString(Phone.NETWORK_SELECTION_NAME_KEY + subId, "");
                // get the shared preference of network_selection.
                // empty is auto mode, otherwise it is the operator alpha name
                // in case there is no operator name, check the operator numeric
                if (TextUtils.isEmpty(selectedNetworkOperatorName)) {
                    selectedNetworkOperatorName =
                            sp.getString(Phone.NETWORK_SELECTION_KEY + subId, "");
                }
                boolean isManualSelection;
                // if restoring manual selection is controlled by framework, then get network
                // selection from shared preference, otherwise get from real network indicators.
                boolean restoreSelection = !mContext.getResources().getBoolean(
                        com.android.internal.R.bool.skip_restoring_network_selection);
                if (restoreSelection) {
                    isManualSelection = !TextUtils.isEmpty(selectedNetworkOperatorName);
                } else {
                    isManualSelection = phone.getServiceStateTracker().mSS.getIsManualSelection();
                }

                if (DBG) {
                    log("updateNetworkSelection()..." + "state = " + serviceState + " new network "
                            + (isManualSelection ? selectedNetworkOperatorName : ""));
                }

                if (serviceState == ServiceState.STATE_OUT_OF_SERVICE && isManualSelection) {
                    showNetworkSelection(selectedNetworkOperatorName, subId);
                    mSelectedUnavailableNotify = true;
                } else {
                    if (mSelectedUnavailableNotify) {
                        cancelNetworkSelection();
                        mSelectedUnavailableNotify = false;
                    }
                }
            } else {
                if (DBG) log("updateNetworkSelection()..." + "state = " +
                        serviceState + " not updating network due to invalid subId " + subId);
            }
        }
    }

    /* package */ void postTransientNotification(int notifyId, CharSequence msg) {
        if (mToast != null) {
            mToast.cancel();
        }

        mToast = Toast.makeText(mContext, msg, Toast.LENGTH_LONG);
        mToast.show();
    }

    private void log(String msg) {
        Log.d(LOG_TAG, msg);
    }

    private void logi(String msg) {
        Log.i(LOG_TAG, msg);
    }
}