/* //device/content/providers/telephony/TelephonyProvider.java
**
** Copyright 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.providers.telephony;

import static android.provider.Telephony.Carriers.APN;
import static android.provider.Telephony.Carriers.AUTH_TYPE;
import static android.provider.Telephony.Carriers.BEARER;
import static android.provider.Telephony.Carriers.BEARER_BITMASK;
import static android.provider.Telephony.Carriers.CARRIER_DELETED;
import static android.provider.Telephony.Carriers.CARRIER_DELETED_BUT_PRESENT_IN_XML;
import static android.provider.Telephony.Carriers.CARRIER_EDITED;
import static android.provider.Telephony.Carriers.CARRIER_ENABLED;
import static android.provider.Telephony.Carriers.CONTENT_URI;
import static android.provider.Telephony.Carriers.CURRENT;
import static android.provider.Telephony.Carriers.EDITED;
import static android.provider.Telephony.Carriers.MAX_CONNS;
import static android.provider.Telephony.Carriers.MAX_CONNS_TIME;
import static android.provider.Telephony.Carriers.MCC;
import static android.provider.Telephony.Carriers.MMSC;
import static android.provider.Telephony.Carriers.MMSPORT;
import static android.provider.Telephony.Carriers.MMSPROXY;
import static android.provider.Telephony.Carriers.MNC;
import static android.provider.Telephony.Carriers.MODEM_COGNITIVE;
import static android.provider.Telephony.Carriers.MTU;
import static android.provider.Telephony.Carriers.MVNO_MATCH_DATA;
import static android.provider.Telephony.Carriers.MVNO_TYPE;
import static android.provider.Telephony.Carriers.NAME;
import static android.provider.Telephony.Carriers.NETWORK_TYPE_BITMASK;
import static android.provider.Telephony.Carriers.NUMERIC;
import static android.provider.Telephony.Carriers.OWNED_BY;
import static android.provider.Telephony.Carriers.OWNED_BY_OTHERS;
import static android.provider.Telephony.Carriers.OWNED_BY_DPC;
import static android.provider.Telephony.Carriers.PASSWORD;
import static android.provider.Telephony.Carriers.PORT;
import static android.provider.Telephony.Carriers.PROFILE_ID;
import static android.provider.Telephony.Carriers.PROTOCOL;
import static android.provider.Telephony.Carriers.PROXY;
import static android.provider.Telephony.Carriers.ROAMING_PROTOCOL;
import static android.provider.Telephony.Carriers.SERVER;
import static android.provider.Telephony.Carriers.SUBSCRIPTION_ID;
import static android.provider.Telephony.Carriers.TYPE;
import static android.provider.Telephony.Carriers.UNEDITED;
import static android.provider.Telephony.Carriers.USER;
import static android.provider.Telephony.Carriers.USER_DELETED;
import static android.provider.Telephony.Carriers.USER_DELETED_BUT_PRESENT_IN_XML;
import static android.provider.Telephony.Carriers.USER_EDITABLE;
import static android.provider.Telephony.Carriers.USER_EDITED;
import static android.provider.Telephony.Carriers.USER_VISIBLE;
import static android.provider.Telephony.Carriers.WAIT_TIME;
import static android.provider.Telephony.Carriers._ID;

import android.content.ComponentName;
import android.content.ContentProvider;
import android.content.ContentUris;
import android.content.ContentValues;
import android.content.Context;
import android.content.Intent;
import android.content.ServiceConnection;
import android.content.SharedPreferences;
import android.content.UriMatcher;
import android.content.pm.PackageManager;
import android.content.res.Resources;
import android.content.res.XmlResourceParser;
import android.database.Cursor;
import android.database.MatrixCursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteException;
import android.database.sqlite.SQLiteOpenHelper;
import android.database.sqlite.SQLiteQueryBuilder;
import android.net.Uri;
import android.os.Binder;
import android.os.Environment;
import android.os.FileUtils;
import android.os.IBinder;
import android.os.Process;
import android.os.RemoteException;
import android.os.SystemProperties;
import android.os.UserHandle;
import android.telephony.ServiceState;
import android.telephony.SubscriptionInfo;
import android.telephony.SubscriptionManager;
import android.telephony.TelephonyManager;
import android.text.TextUtils;
import android.util.Log;
import android.util.Pair;
import android.util.Xml;

import com.android.internal.annotations.GuardedBy;
import com.android.internal.annotations.VisibleForTesting;
import com.android.internal.telephony.IApnSourceService;
import com.android.internal.telephony.SubscriptionController;
import com.android.internal.util.XmlUtils;

import org.xmlpull.v1.XmlPullParser;
import org.xmlpull.v1.XmlPullParserException;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class TelephonyProvider extends ContentProvider
{
    private static final String DATABASE_NAME = "telephony.db";
    private static final int IDLE_CONNECTION_TIMEOUT_MS = 30000;
    private static final boolean DBG = true;
    private static final boolean VDBG = false; // STOPSHIP if true

    private static final int DATABASE_VERSION = 24 << 16;
    private static final int URL_UNKNOWN = 0;
    private static final int URL_TELEPHONY = 1;
    private static final int URL_CURRENT = 2;
    private static final int URL_ID = 3;
    private static final int URL_RESTOREAPN = 4;
    private static final int URL_PREFERAPN = 5;
    private static final int URL_PREFERAPN_NO_UPDATE = 6;
    private static final int URL_SIMINFO = 7;
    private static final int URL_TELEPHONY_USING_SUBID = 8;
    private static final int URL_CURRENT_USING_SUBID = 9;
    private static final int URL_RESTOREAPN_USING_SUBID = 10;
    private static final int URL_PREFERAPN_USING_SUBID = 11;
    private static final int URL_PREFERAPN_NO_UPDATE_USING_SUBID = 12;
    private static final int URL_SIMINFO_USING_SUBID = 13;
    private static final int URL_UPDATE_DB = 14;
    private static final int URL_DELETE = 15;
    private static final int URL_DPC = 16;
    private static final int URL_DPC_ID = 17;
    private static final int URL_FILTERED = 18;
    private static final int URL_ENFORCE_MANAGED = 19;


    private static final String TAG = "TelephonyProvider";
    private static final String CARRIERS_TABLE = "carriers";
    private static final String CARRIERS_TABLE_TMP = "carriers_tmp";
    private static final String SIMINFO_TABLE = "siminfo";

    private static final String PREF_FILE_APN = "preferred-apn";
    private static final String COLUMN_APN_ID = "apn_id";
    private static final String EXPLICIT_SET_CALLED = "explicit_set_called";

    private static final String PREF_FILE_FULL_APN = "preferred-full-apn";
    private static final String DB_VERSION_KEY = "version";

    private static final String BUILD_ID_FILE = "build-id";
    private static final String RO_BUILD_ID = "ro_build_id";

    private static final String ENFORCED_FILE = "dpc-apn-enforced";
    private static final String ENFORCED_KEY = "enforced";

    private static final String PREF_FILE = "telephonyprovider";
    private static final String APN_CONF_CHECKSUM = "apn_conf_checksum";

    private static final String PARTNER_APNS_PATH = "etc/apns-conf.xml";
    private static final String OEM_APNS_PATH = "telephony/apns-conf.xml";
    private static final String OTA_UPDATED_APNS_PATH = "misc/apns-conf.xml";
    private static final String OLD_APNS_PATH = "etc/old-apns-conf.xml";

    private static final String DEFAULT_PROTOCOL = "IP";
    private static final String DEFAULT_ROAMING_PROTOCOL = "IP";

    private static final UriMatcher s_urlMatcher = new UriMatcher(UriMatcher.NO_MATCH);

    private static final ContentValues s_currentNullMap;
    private static final ContentValues s_currentSetMap;

    private static final String IS_UNEDITED = EDITED + "=" + UNEDITED;
    private static final String IS_EDITED = EDITED + "!=" + UNEDITED;
    private static final String IS_USER_EDITED = EDITED + "=" + USER_EDITED;
    private static final String IS_NOT_USER_EDITED = EDITED + "!=" + USER_EDITED;
    private static final String IS_USER_DELETED = EDITED + "=" + USER_DELETED;
    private static final String IS_NOT_USER_DELETED = EDITED + "!=" + USER_DELETED;
    private static final String IS_USER_DELETED_BUT_PRESENT_IN_XML =
            EDITED + "=" + USER_DELETED_BUT_PRESENT_IN_XML;
    private static final String IS_NOT_USER_DELETED_BUT_PRESENT_IN_XML =
            EDITED + "!=" + USER_DELETED_BUT_PRESENT_IN_XML;
    private static final String IS_CARRIER_EDITED = EDITED + "=" + CARRIER_EDITED;
    private static final String IS_NOT_CARRIER_EDITED = EDITED + "!=" + CARRIER_EDITED;
    private static final String IS_CARRIER_DELETED = EDITED + "=" + CARRIER_DELETED;
    private static final String IS_NOT_CARRIER_DELETED = EDITED + "!=" + CARRIER_DELETED;
    private static final String IS_CARRIER_DELETED_BUT_PRESENT_IN_XML =
            EDITED + "=" + CARRIER_DELETED_BUT_PRESENT_IN_XML;
    private static final String IS_NOT_CARRIER_DELETED_BUT_PRESENT_IN_XML =
            EDITED + "!=" + CARRIER_DELETED_BUT_PRESENT_IN_XML;
    private static final String IS_OWNED_BY_DPC = OWNED_BY + "=" + OWNED_BY_DPC;
    private static final String IS_NOT_OWNED_BY_DPC = OWNED_BY + "!=" + OWNED_BY_DPC;

    private static final int INVALID_APN_ID = -1;
    private static final List<String> CARRIERS_UNIQUE_FIELDS = new ArrayList<String>();
    private static final Map<String, String> CARRIERS_UNIQUE_FIELDS_DEFAULTS = new HashMap();

    private static Boolean s_apnSourceServiceExists;

    protected final Object mLock = new Object();
    @GuardedBy("mLock")
    private IApnSourceService mIApnSourceService;
    private Injector mInjector;

    private boolean mManagedApnEnforced;

    static {
        // Columns not included in UNIQUE constraint: name, current, edited, user, server, password,
        // authtype, type, protocol, roaming_protocol, sub_id, modem_cognitive, max_conns,
        // wait_time, max_conns_time, mtu, bearer_bitmask, user_visible, network_type_bitmask
        CARRIERS_UNIQUE_FIELDS_DEFAULTS.put(NUMERIC, "");
        CARRIERS_UNIQUE_FIELDS_DEFAULTS.put(MCC, "");
        CARRIERS_UNIQUE_FIELDS_DEFAULTS.put(MNC, "");
        CARRIERS_UNIQUE_FIELDS_DEFAULTS.put(APN, "");
        CARRIERS_UNIQUE_FIELDS_DEFAULTS.put(PROXY, "");
        CARRIERS_UNIQUE_FIELDS_DEFAULTS.put(PORT, "");
        CARRIERS_UNIQUE_FIELDS_DEFAULTS.put(MMSPROXY, "");
        CARRIERS_UNIQUE_FIELDS_DEFAULTS.put(MMSPORT, "");
        CARRIERS_UNIQUE_FIELDS_DEFAULTS.put(MMSC, "");
        CARRIERS_UNIQUE_FIELDS_DEFAULTS.put(CARRIER_ENABLED, "1");
        CARRIERS_UNIQUE_FIELDS_DEFAULTS.put(BEARER, "0");
        CARRIERS_UNIQUE_FIELDS_DEFAULTS.put(MVNO_TYPE, "");
        CARRIERS_UNIQUE_FIELDS_DEFAULTS.put(MVNO_MATCH_DATA, "");
        CARRIERS_UNIQUE_FIELDS_DEFAULTS.put(PROFILE_ID, "0");
        CARRIERS_UNIQUE_FIELDS_DEFAULTS.put(PROTOCOL, "IP");
        CARRIERS_UNIQUE_FIELDS_DEFAULTS.put(ROAMING_PROTOCOL, "IP");
        CARRIERS_UNIQUE_FIELDS_DEFAULTS.put(USER_EDITABLE, "1");
        CARRIERS_UNIQUE_FIELDS_DEFAULTS.put(OWNED_BY, String.valueOf(OWNED_BY_OTHERS));

        CARRIERS_UNIQUE_FIELDS.addAll(CARRIERS_UNIQUE_FIELDS_DEFAULTS.keySet());
    }

    @VisibleForTesting
    public static String getStringForCarrierTableCreation(String tableName) {
        return "CREATE TABLE " + tableName +
                "(_id INTEGER PRIMARY KEY," +
                NAME + " TEXT DEFAULT ''," +
                NUMERIC + " TEXT DEFAULT ''," +
                MCC + " TEXT DEFAULT ''," +
                MNC + " TEXT DEFAULT ''," +
                APN + " TEXT DEFAULT ''," +
                USER + " TEXT DEFAULT ''," +
                SERVER + " TEXT DEFAULT ''," +
                PASSWORD + " TEXT DEFAULT ''," +
                PROXY + " TEXT DEFAULT ''," +
                PORT + " TEXT DEFAULT ''," +
                MMSPROXY + " TEXT DEFAULT ''," +
                MMSPORT + " TEXT DEFAULT ''," +
                MMSC + " TEXT DEFAULT ''," +
                AUTH_TYPE + " INTEGER DEFAULT -1," +
                TYPE + " TEXT DEFAULT ''," +
                CURRENT + " INTEGER," +
                PROTOCOL + " TEXT DEFAULT " + DEFAULT_PROTOCOL + "," +
                ROAMING_PROTOCOL + " TEXT DEFAULT " + DEFAULT_ROAMING_PROTOCOL + "," +
                CARRIER_ENABLED + " BOOLEAN DEFAULT 1," +
                BEARER + " INTEGER DEFAULT 0," +
                BEARER_BITMASK + " INTEGER DEFAULT 0," +
                NETWORK_TYPE_BITMASK + " INTEGER DEFAULT 0," +
                MVNO_TYPE + " TEXT DEFAULT ''," +
                MVNO_MATCH_DATA + " TEXT DEFAULT ''," +
                SUBSCRIPTION_ID + " INTEGER DEFAULT "
                + SubscriptionManager.INVALID_SUBSCRIPTION_ID + "," +
                PROFILE_ID + " INTEGER DEFAULT 0," +
                MODEM_COGNITIVE + " BOOLEAN DEFAULT 0," +
                MAX_CONNS + " INTEGER DEFAULT 0," +
                WAIT_TIME + " INTEGER DEFAULT 0," +
                MAX_CONNS_TIME + " INTEGER DEFAULT 0," +
                MTU + " INTEGER DEFAULT 0," +
                EDITED + " INTEGER DEFAULT " + UNEDITED + "," +
                USER_VISIBLE + " BOOLEAN DEFAULT 1," +
                USER_EDITABLE + " BOOLEAN DEFAULT 1," +
                OWNED_BY + " INTEGER DEFAULT " + OWNED_BY_OTHERS + "," +
                // Uniqueness collisions are used to trigger merge code so if a field is listed
                // here it means we will accept both (user edited + new apn_conf definition)
                // Columns not included in UNIQUE constraint: name, current, edited,
                // user, server, password, authtype, type, sub_id, modem_cognitive, max_conns,
                // wait_time, max_conns_time, mtu, bearer_bitmask, user_visible,
                // network_type_bitmask.
                "UNIQUE (" + TextUtils.join(", ", CARRIERS_UNIQUE_FIELDS) + "));";
    }

    @VisibleForTesting
    public static final String CREATE_SIMINFO_TABLE_STRING = "CREATE TABLE " + SIMINFO_TABLE + "("
            + SubscriptionManager.UNIQUE_KEY_SUBSCRIPTION_ID
                + " INTEGER PRIMARY KEY AUTOINCREMENT,"
            + SubscriptionManager.ICC_ID + " TEXT NOT NULL,"
            + SubscriptionManager.SIM_SLOT_INDEX
                + " INTEGER DEFAULT " + SubscriptionManager.SIM_NOT_INSERTED + ","
            + SubscriptionManager.DISPLAY_NAME + " TEXT,"
            + SubscriptionManager.CARRIER_NAME + " TEXT,"
            + SubscriptionManager.NAME_SOURCE
                + " INTEGER DEFAULT " + SubscriptionManager.NAME_SOURCE_DEFAULT_SOURCE + ","
            + SubscriptionManager.COLOR + " INTEGER DEFAULT " + SubscriptionManager.COLOR_DEFAULT + ","
            + SubscriptionManager.NUMBER + " TEXT,"
            + SubscriptionManager.DISPLAY_NUMBER_FORMAT
                + " INTEGER NOT NULL DEFAULT " + SubscriptionManager.DISPLAY_NUMBER_DEFAULT + ","
            + SubscriptionManager.DATA_ROAMING
                + " INTEGER DEFAULT " + SubscriptionManager.DATA_ROAMING_DEFAULT + ","
            + SubscriptionManager.MCC + " INTEGER DEFAULT 0,"
            + SubscriptionManager.MNC + " INTEGER DEFAULT 0,"
            + SubscriptionManager.SIM_PROVISIONING_STATUS
                + " INTEGER DEFAULT " + SubscriptionManager.SIM_PROVISIONED + ","
            + SubscriptionManager.IS_EMBEDDED + " INTEGER DEFAULT 0,"
            + SubscriptionManager.ACCESS_RULES + " BLOB,"
            + SubscriptionManager.IS_REMOVABLE + " INTEGER DEFAULT 0,"
            + SubscriptionManager.CB_EXTREME_THREAT_ALERT + " INTEGER DEFAULT 1,"
            + SubscriptionManager.CB_SEVERE_THREAT_ALERT + " INTEGER DEFAULT 1,"
            + SubscriptionManager.CB_AMBER_ALERT + " INTEGER DEFAULT 1,"
            + SubscriptionManager.CB_EMERGENCY_ALERT + " INTEGER DEFAULT 1,"
            + SubscriptionManager.CB_ALERT_SOUND_DURATION + " INTEGER DEFAULT 4,"
            + SubscriptionManager.CB_ALERT_REMINDER_INTERVAL + " INTEGER DEFAULT 0,"
            + SubscriptionManager.CB_ALERT_VIBRATE + " INTEGER DEFAULT 1,"
            + SubscriptionManager.CB_ALERT_SPEECH + " INTEGER DEFAULT 1,"
            + SubscriptionManager.CB_ETWS_TEST_ALERT + " INTEGER DEFAULT 0,"
            + SubscriptionManager.CB_CHANNEL_50_ALERT + " INTEGER DEFAULT 1,"
            + SubscriptionManager.CB_CMAS_TEST_ALERT + " INTEGER DEFAULT 0,"
            + SubscriptionManager.CB_OPT_OUT_DIALOG + " INTEGER DEFAULT 1,"
            + SubscriptionManager.ENHANCED_4G_MODE_ENABLED + " INTEGER DEFAULT -1,"
            + SubscriptionManager.VT_IMS_ENABLED + " INTEGER DEFAULT -1,"
            + SubscriptionManager.WFC_IMS_ENABLED + " INTEGER DEFAULT -1,"
            + SubscriptionManager.WFC_IMS_MODE + " INTEGER DEFAULT -1,"
            + SubscriptionManager.WFC_IMS_ROAMING_MODE + " INTEGER DEFAULT -1,"
            + SubscriptionManager.WFC_IMS_ROAMING_ENABLED + " INTEGER DEFAULT -1"
            + ");";

    static {
        s_urlMatcher.addURI("telephony", "carriers", URL_TELEPHONY);
        s_urlMatcher.addURI("telephony", "carriers/current", URL_CURRENT);
        s_urlMatcher.addURI("telephony", "carriers/#", URL_ID);
        s_urlMatcher.addURI("telephony", "carriers/restore", URL_RESTOREAPN);
        s_urlMatcher.addURI("telephony", "carriers/preferapn", URL_PREFERAPN);
        s_urlMatcher.addURI("telephony", "carriers/preferapn_no_update", URL_PREFERAPN_NO_UPDATE);

        s_urlMatcher.addURI("telephony", "siminfo", URL_SIMINFO);

        s_urlMatcher.addURI("telephony", "carriers/subId/*", URL_TELEPHONY_USING_SUBID);
        s_urlMatcher.addURI("telephony", "carriers/current/subId/*", URL_CURRENT_USING_SUBID);
        s_urlMatcher.addURI("telephony", "carriers/restore/subId/*", URL_RESTOREAPN_USING_SUBID);
        s_urlMatcher.addURI("telephony", "carriers/preferapn/subId/*", URL_PREFERAPN_USING_SUBID);
        s_urlMatcher.addURI("telephony", "carriers/preferapn_no_update/subId/*",
                URL_PREFERAPN_NO_UPDATE_USING_SUBID);

        s_urlMatcher.addURI("telephony", "carriers/update_db", URL_UPDATE_DB);
        s_urlMatcher.addURI("telephony", "carriers/delete", URL_DELETE);

        // Only called by DevicePolicyManager to manipulate DPC records.
        s_urlMatcher.addURI("telephony", "carriers/dpc", URL_DPC);
        // Only called by DevicePolicyManager to manipulate a DPC record with certain _ID.
        s_urlMatcher.addURI("telephony", "carriers/dpc/#", URL_DPC_ID);
        // Only called by Settings app, DcTracker and other telephony components to get APN list
        // according to whether DPC records are enforced.
        s_urlMatcher.addURI("telephony", "carriers/filtered", URL_FILTERED);
        // Only Called by DevicePolicyManager to enforce DPC records.
        s_urlMatcher.addURI("telephony", "carriers/enforce_managed", URL_ENFORCE_MANAGED);

        s_currentNullMap = new ContentValues(1);
        s_currentNullMap.put(CURRENT, "0");

        s_currentSetMap = new ContentValues(1);
        s_currentSetMap.put(CURRENT, "1");
    }

    /**
     * Unit test will subclass it to inject mocks.
     */
    @VisibleForTesting
    static class Injector {
        int binderGetCallingUid() {
            return Binder.getCallingUid();
        }
    }

    public TelephonyProvider() {
        this(new Injector());
    }

    @VisibleForTesting
    public TelephonyProvider(Injector injector) {
        mInjector = injector;
    }

    private static class DatabaseHelper extends SQLiteOpenHelper {
        // Context to access resources with
        private Context mContext;

        /**
         * DatabaseHelper helper class for loading apns into a database.
         *
         * @param context of the user.
         */
        public DatabaseHelper(Context context) {
            super(context, DATABASE_NAME, null, getVersion(context));
            mContext = context;
            // Memory optimization - close idle connections after 30s of inactivity
            setIdleConnectionTimeout(IDLE_CONNECTION_TIMEOUT_MS);
        }

        private static int getVersion(Context context) {
            if (VDBG) log("getVersion:+");
            // Get the database version, combining a static schema version and the XML version
            Resources r = context.getResources();
            XmlResourceParser parser = r.getXml(com.android.internal.R.xml.apns);
            try {
                XmlUtils.beginDocument(parser, "apns");
                int publicversion = Integer.parseInt(parser.getAttributeValue(null, "version"));
                int version = DATABASE_VERSION | publicversion;
                if (VDBG) log("getVersion:- version=0x" + Integer.toHexString(version));
                return version;
            } catch (Exception e) {
                loge("Can't get version of APN database" + e + " return version=" +
                        Integer.toHexString(DATABASE_VERSION));
                return DATABASE_VERSION;
            } finally {
                parser.close();
            }
        }

        @Override
        public void onCreate(SQLiteDatabase db) {
            if (DBG) log("dbh.onCreate:+ db=" + db);
            createSimInfoTable(db);
            createCarriersTable(db, CARRIERS_TABLE);
            // if CarrierSettings app is installed, we expect it to do the initializiation instead
            if (apnSourceServiceExists(mContext)) {
                log("dbh.onCreate: Skipping apply APNs from xml.");
            } else {
                log("dbh.onCreate: Apply apns from xml.");
                initDatabase(db);
            }
            if (DBG) log("dbh.onCreate:- db=" + db);
        }

        @Override
        public void onOpen(SQLiteDatabase db) {
            if (VDBG) log("dbh.onOpen:+ db=" + db);
            try {
                // Try to access the table and create it if "no such table"
                db.query(SIMINFO_TABLE, null, null, null, null, null, null);
                if (DBG) log("dbh.onOpen: ok, queried table=" + SIMINFO_TABLE);
            } catch (SQLiteException e) {
                loge("Exception " + SIMINFO_TABLE + "e=" + e);
                if (e.getMessage().startsWith("no such table")) {
                    createSimInfoTable(db);
                }
            }
            try {
                db.query(CARRIERS_TABLE, null, null, null, null, null, null);
                if (DBG) log("dbh.onOpen: ok, queried table=" + CARRIERS_TABLE);
            } catch (SQLiteException e) {
                loge("Exception " + CARRIERS_TABLE + " e=" + e);
                if (e.getMessage().startsWith("no such table")) {
                    createCarriersTable(db, CARRIERS_TABLE);
                }
            }
            if (VDBG) log("dbh.onOpen:- db=" + db);
        }

        private void createSimInfoTable(SQLiteDatabase db) {
            if (DBG) log("dbh.createSimInfoTable:+");
            db.execSQL(CREATE_SIMINFO_TABLE_STRING);
            if (DBG) log("dbh.createSimInfoTable:-");
        }

        private void createCarriersTable(SQLiteDatabase db, String tableName) {
            // Set up the database schema
            if (DBG) log("dbh.createCarriersTable: " + tableName);
            db.execSQL(getStringForCarrierTableCreation(tableName));
            if (DBG) log("dbh.createCarriersTable:-");
        }

        private long getChecksum(File file) {
            long checksum = -1;
            try {
                checksum = FileUtils.checksumCrc32(file);
                if (DBG) log("Checksum for " + file.getAbsolutePath() + " is " + checksum);
            } catch (FileNotFoundException e) {
                loge("FileNotFoundException for " + file.getAbsolutePath() + ":" + e);
            } catch (IOException e) {
                loge("IOException for " + file.getAbsolutePath() + ":" + e);
            }
            return checksum;
        }

        private long getApnConfChecksum() {
            SharedPreferences sp = mContext.getSharedPreferences(PREF_FILE, Context.MODE_PRIVATE);
            return sp.getLong(APN_CONF_CHECKSUM, -1);
        }

        private void setApnConfChecksum(long checksum) {
            SharedPreferences sp = mContext.getSharedPreferences(PREF_FILE, Context.MODE_PRIVATE);
            SharedPreferences.Editor editor = sp.edit();
            editor.putLong(APN_CONF_CHECKSUM, checksum);
            editor.apply();
        }

        private File getApnConfFile() {
            // Environment.getRootDirectory() is a fancy way of saying ANDROID_ROOT or "/system".
            File confFile = new File(Environment.getRootDirectory(), PARTNER_APNS_PATH);
            File oemConfFile =  new File(Environment.getOemDirectory(), OEM_APNS_PATH);
            File updatedConfFile = new File(Environment.getDataDirectory(), OTA_UPDATED_APNS_PATH);
            confFile = getNewerFile(confFile, oemConfFile);
            confFile = getNewerFile(confFile, updatedConfFile);
            return confFile;
        }

        /**
         * This function computes checksum for the file to be read and compares it against the
         * last read file. DB needs to be updated only if checksum has changed, or old checksum does
         * not exist.
         * @return true if DB should be updated with new conf file, false otherwise
         */
        private boolean apnDbUpdateNeeded() {
            File confFile = getApnConfFile();
            long newChecksum = getChecksum(confFile);
            long oldChecksum = getApnConfChecksum();
            if (DBG) log("newChecksum: " + newChecksum);
            if (DBG) log("oldChecksum: " + oldChecksum);
            if (newChecksum == oldChecksum) {
                return false;
            } else {
                return true;
            }
        }

        /**
         *  This function adds APNs from xml file(s) to db. The db may or may not be empty to begin
         *  with.
         */
        private void initDatabase(SQLiteDatabase db) {
            if (VDBG) log("dbh.initDatabase:+ db=" + db);
            // Read internal APNS data
            Resources r = mContext.getResources();
            XmlResourceParser parser = r.getXml(com.android.internal.R.xml.apns);
            int publicversion = -1;
            try {
                XmlUtils.beginDocument(parser, "apns");
                publicversion = Integer.parseInt(parser.getAttributeValue(null, "version"));
                loadApns(db, parser);
            } catch (Exception e) {
                loge("Got exception while loading APN database." + e);
            } finally {
                parser.close();
            }

            // Read external APNS data (partner-provided)
            XmlPullParser confparser = null;
            File confFile = getApnConfFile();

            FileReader confreader = null;
            if (DBG) log("confFile = " + confFile);
            try {
                confreader = new FileReader(confFile);
                confparser = Xml.newPullParser();
                confparser.setInput(confreader);
                XmlUtils.beginDocument(confparser, "apns");

                // Sanity check. Force internal version and confidential versions to agree
                int confversion = Integer.parseInt(confparser.getAttributeValue(null, "version"));
                if (publicversion != confversion) {
                    log("initDatabase: throwing exception due to version mismatch");
                    throw new IllegalStateException("Internal APNS file version doesn't match "
                            + confFile.getAbsolutePath());
                }

                loadApns(db, confparser);
            } catch (FileNotFoundException e) {
                // It's ok if the file isn't found. It means there isn't a confidential file
                // Log.e(TAG, "File not found: '" + confFile.getAbsolutePath() + "'");
            } catch (Exception e) {
                loge("initDatabase: Exception while parsing '" + confFile.getAbsolutePath() + "'" +
                        e);
            } finally {
                // Get rid of user/carrier deleted entries that are not present in apn xml file.
                // Those entries have edited value USER_DELETED/CARRIER_DELETED.
                if (VDBG) {
                    log("initDatabase: deleting USER_DELETED and replacing "
                            + "DELETED_BUT_PRESENT_IN_XML with DELETED");
                }

                // Delete USER_DELETED
                db.delete(CARRIERS_TABLE, IS_USER_DELETED + " or " + IS_CARRIER_DELETED, null);

                // Change USER_DELETED_BUT_PRESENT_IN_XML to USER_DELETED
                ContentValues cv = new ContentValues();
                cv.put(EDITED, USER_DELETED);
                db.update(CARRIERS_TABLE, cv, IS_USER_DELETED_BUT_PRESENT_IN_XML, null);

                // Change CARRIER_DELETED_BUT_PRESENT_IN_XML to CARRIER_DELETED
                cv = new ContentValues();
                cv.put(EDITED, CARRIER_DELETED);
                db.update(CARRIERS_TABLE, cv, IS_CARRIER_DELETED_BUT_PRESENT_IN_XML, null);

                if (confreader != null) {
                    try {
                        confreader.close();
                    } catch (IOException e) {
                        // do nothing
                    }
                }

                // Update the stored checksum
                setApnConfChecksum(getChecksum(confFile));
            }
            if (VDBG) log("dbh.initDatabase:- db=" + db);

        }

        private File getNewerFile(File sysApnFile, File altApnFile) {
            if (altApnFile.exists()) {
                // Alternate file exists. Use the newer one.
                long altFileTime = altApnFile.lastModified();
                long currFileTime = sysApnFile.lastModified();
                if (DBG) log("APNs Timestamp: altFileTime = " + altFileTime + " currFileTime = "
                        + currFileTime);

                // To get the latest version from OEM or System image
                if (altFileTime > currFileTime) {
                    if (DBG) log("APNs Timestamp: Alternate image " + altApnFile.getPath() +
                            " is greater than System image");
                    return altApnFile;
                }
            } else {
                // No Apn in alternate image, so load it from system image.
                if (DBG) log("No APNs in OEM image = " + altApnFile.getPath() +
                        " Load APNs from system image");
            }
            return sysApnFile;
        }

        @Override
        public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
            if (DBG) {
                log("dbh.onUpgrade:+ db=" + db + " oldV=" + oldVersion + " newV=" + newVersion);
            }

            if (oldVersion < (5 << 16 | 6)) {
                // 5 << 16 is the Database version and 6 in the xml version.

                // This change adds a new authtype column to the database.
                // The auth type column can have 4 values: 0 (None), 1 (PAP), 2 (CHAP)
                // 3 (PAP or CHAP). To avoid breaking compatibility, with already working
                // APNs, the unset value (-1) will be used. If the value is -1.
                // the authentication will default to 0 (if no user / password) is specified
                // or to 3. Currently, there have been no reported problems with
                // pre-configured APNs and hence it is set to -1 for them. Similarly,
                // if the user, has added a new APN, we set the authentication type
                // to -1.

                db.execSQL("ALTER TABLE " + CARRIERS_TABLE +
                        " ADD COLUMN authtype INTEGER DEFAULT -1;");

                oldVersion = 5 << 16 | 6;
            }
            if (oldVersion < (6 << 16 | 6)) {
                // Add protcol fields to the APN. The XML file does not change.
                db.execSQL("ALTER TABLE " + CARRIERS_TABLE +
                        " ADD COLUMN protocol TEXT DEFAULT IP;");
                db.execSQL("ALTER TABLE " + CARRIERS_TABLE +
                        " ADD COLUMN roaming_protocol TEXT DEFAULT IP;");
                oldVersion = 6 << 16 | 6;
            }
            if (oldVersion < (7 << 16 | 6)) {
                // Add carrier_enabled, bearer fields to the APN. The XML file does not change.
                db.execSQL("ALTER TABLE " + CARRIERS_TABLE +
                        " ADD COLUMN carrier_enabled BOOLEAN DEFAULT 1;");
                db.execSQL("ALTER TABLE " + CARRIERS_TABLE +
                        " ADD COLUMN bearer INTEGER DEFAULT 0;");
                oldVersion = 7 << 16 | 6;
            }
            if (oldVersion < (8 << 16 | 6)) {
                // Add mvno_type, mvno_match_data fields to the APN.
                // The XML file does not change.
                db.execSQL("ALTER TABLE " + CARRIERS_TABLE +
                        " ADD COLUMN mvno_type TEXT DEFAULT '';");
                db.execSQL("ALTER TABLE " + CARRIERS_TABLE +
                        " ADD COLUMN mvno_match_data TEXT DEFAULT '';");
                oldVersion = 8 << 16 | 6;
            }
            if (oldVersion < (9 << 16 | 6)) {
                db.execSQL("ALTER TABLE " + CARRIERS_TABLE +
                        " ADD COLUMN sub_id INTEGER DEFAULT " +
                        SubscriptionManager.INVALID_SUBSCRIPTION_ID + ";");
                oldVersion = 9 << 16 | 6;
            }
            if (oldVersion < (10 << 16 | 6)) {
                db.execSQL("ALTER TABLE " + CARRIERS_TABLE +
                        " ADD COLUMN profile_id INTEGER DEFAULT 0;");
                db.execSQL("ALTER TABLE " + CARRIERS_TABLE +
                        " ADD COLUMN modem_cognitive BOOLEAN DEFAULT 0;");
                db.execSQL("ALTER TABLE " + CARRIERS_TABLE +
                        " ADD COLUMN max_conns INTEGER DEFAULT 0;");
                db.execSQL("ALTER TABLE " + CARRIERS_TABLE +
                        " ADD COLUMN wait_time INTEGER DEFAULT 0;");
                db.execSQL("ALTER TABLE " + CARRIERS_TABLE +
                        " ADD COLUMN max_conns_time INTEGER DEFAULT 0;");
                oldVersion = 10 << 16 | 6;
            }
            if (oldVersion < (11 << 16 | 6)) {
                db.execSQL("ALTER TABLE " + CARRIERS_TABLE +
                        " ADD COLUMN mtu INTEGER DEFAULT 0;");
                oldVersion = 11 << 16 | 6;
            }
            if (oldVersion < (12 << 16 | 6)) {
                try {
                    // Try to update the siminfo table. It might not be there.
                    db.execSQL("ALTER TABLE " + SIMINFO_TABLE +
                            " ADD COLUMN " + SubscriptionManager.MCC + " INTEGER DEFAULT 0;");
                    db.execSQL("ALTER TABLE " + SIMINFO_TABLE +
                            " ADD COLUMN " + SubscriptionManager.MNC + " INTEGER DEFAULT 0;");
                } catch (SQLiteException e) {
                    if (DBG) {
                        log("onUpgrade skipping " + SIMINFO_TABLE + " upgrade. " +
                                " The table will get created in onOpen.");
                    }
                }
                oldVersion = 12 << 16 | 6;
            }
            if (oldVersion < (13 << 16 | 6)) {
                try {
                    // Try to update the siminfo table. It might not be there.
                    db.execSQL("ALTER TABLE " + SIMINFO_TABLE + " ADD COLUMN " +
                            SubscriptionManager.CARRIER_NAME + " TEXT DEFAULT '';");
                } catch (SQLiteException e) {
                    if (DBG) {
                        log("onUpgrade skipping " + SIMINFO_TABLE + " upgrade. " +
                                " The table will get created in onOpen.");
                    }
                }
                oldVersion = 13 << 16 | 6;
            }
            if (oldVersion < (14 << 16 | 6)) {
                // Do nothing. This is to avoid recreating table twice. Table is anyway recreated
                // for next version and that takes care of updates for this version as well.
                // This version added a new column user_edited to carriers db.
            }
            if (oldVersion < (15 << 16 | 6)) {
                // Most devices should be upgrading from version 13. On upgrade new db will be
                // populated from the xml included in OTA but user and carrier edited/added entries
                // need to be preserved. This new version also adds new columns EDITED and
                // BEARER_BITMASK to the table. Upgrade steps from version 13 are:
                // 1. preserve user and carrier added/edited APNs (by comparing against
                // old-apns-conf.xml included in OTA) - done in preserveUserAndCarrierApns()
                // 2. add new columns EDITED and BEARER_BITMASK (create a new table for that) - done
                // in createCarriersTable()
                // 3. copy over preserved APNs from old table to new table - done in
                // copyPreservedApnsToNewTable()
                // The only exception if upgrading from version 14 is that EDITED field is already
                // present (but is called USER_EDITED)
                /*********************************************************************************
                 * IMPORTANT NOTE: SINCE CARRIERS TABLE IS RECREATED HERE, IT WILL BE THE LATEST
                 * VERSION AFTER THIS. AS A RESULT ANY SUBSEQUENT UPDATES TO THE TABLE WILL FAIL
                 * (DUE TO COLUMN-ALREADY-EXISTS KIND OF EXCEPTION). ALL SUBSEQUENT UPDATES SHOULD
                 * HANDLE THAT GRACEFULLY.
                 *********************************************************************************/
                Cursor c;
                String[] proj = {"_id"};
                if (VDBG) {
                    c = db.query(CARRIERS_TABLE, proj, null, null, null, null, null);
                    log("dbh.onUpgrade:- before upgrading total number of rows: " + c.getCount());
                }

                // Compare db with old apns xml file so that any user or carrier edited/added
                // entries can be preserved across upgrade
                preserveUserAndCarrierApns(db);

                c = db.query(CARRIERS_TABLE, null, null, null, null, null, null);

                if (VDBG) {
                    log("dbh.onUpgrade:- after preserveUserAndCarrierApns() total number of " +
                            "rows: " + ((c == null) ? 0 : c.getCount()));
                }

                createCarriersTable(db, CARRIERS_TABLE_TMP);

                copyPreservedApnsToNewTable(db, c);
                c.close();

                db.execSQL("DROP TABLE IF EXISTS " + CARRIERS_TABLE);

                db.execSQL("ALTER TABLE " + CARRIERS_TABLE_TMP + " rename to " + CARRIERS_TABLE +
                        ";");

                if (VDBG) {
                    c = db.query(CARRIERS_TABLE, proj, null, null, null, null, null);
                    log("dbh.onUpgrade:- after upgrading total number of rows: " + c.getCount());
                    c.close();
                    c = db.query(CARRIERS_TABLE, proj, IS_UNEDITED, null, null, null, null);
                    log("dbh.onUpgrade:- after upgrading total number of rows with " + IS_UNEDITED +
                            ": " + c.getCount());
                    c.close();
                    c = db.query(CARRIERS_TABLE, proj, IS_EDITED, null, null, null, null);
                    log("dbh.onUpgrade:- after upgrading total number of rows with " + IS_EDITED +
                            ": " + c.getCount());
                    c.close();
                }

                oldVersion = 15 << 16 | 6;
            }
            if (oldVersion < (16 << 16 | 6)) {
                try {
                    // Try to update the siminfo table. It might not be there.
                    // These columns may already be present in which case execSQL will throw an
                    // exception
                    db.execSQL("ALTER TABLE " + SIMINFO_TABLE + " ADD COLUMN "
                            + SubscriptionManager.CB_EXTREME_THREAT_ALERT + " INTEGER DEFAULT 1;");
                    db.execSQL("ALTER TABLE " + SIMINFO_TABLE + " ADD COLUMN "
                            + SubscriptionManager.CB_SEVERE_THREAT_ALERT + " INTEGER DEFAULT 1;");
                    db.execSQL("ALTER TABLE " + SIMINFO_TABLE + " ADD COLUMN "
                            + SubscriptionManager.CB_AMBER_ALERT + " INTEGER DEFAULT 1;");
                    db.execSQL("ALTER TABLE " + SIMINFO_TABLE + " ADD COLUMN "
                            + SubscriptionManager.CB_EMERGENCY_ALERT + " INTEGER DEFAULT 1;");
                    db.execSQL("ALTER TABLE " + SIMINFO_TABLE + " ADD COLUMN "
                            + SubscriptionManager.CB_ALERT_SOUND_DURATION + " INTEGER DEFAULT 4;");
                    db.execSQL("ALTER TABLE " + SIMINFO_TABLE + " ADD COLUMN "
                            + SubscriptionManager.CB_ALERT_REMINDER_INTERVAL + " INTEGER DEFAULT 0;");
                    db.execSQL("ALTER TABLE " + SIMINFO_TABLE + " ADD COLUMN "
                            + SubscriptionManager.CB_ALERT_VIBRATE + " INTEGER DEFAULT 1;");
                    db.execSQL("ALTER TABLE " + SIMINFO_TABLE + " ADD COLUMN "
                            + SubscriptionManager.CB_ALERT_SPEECH + " INTEGER DEFAULT 1;");
                    db.execSQL("ALTER TABLE " + SIMINFO_TABLE + " ADD COLUMN "
                            + SubscriptionManager.CB_ETWS_TEST_ALERT + " INTEGER DEFAULT 0;");
                    db.execSQL("ALTER TABLE " + SIMINFO_TABLE + " ADD COLUMN "
                            + SubscriptionManager.CB_CHANNEL_50_ALERT + " INTEGER DEFAULT 1;");
                    db.execSQL("ALTER TABLE " + SIMINFO_TABLE + " ADD COLUMN "
                            + SubscriptionManager.CB_CMAS_TEST_ALERT + " INTEGER DEFAULT 0;");
                    db.execSQL("ALTER TABLE " + SIMINFO_TABLE + " ADD COLUMN "
                            + SubscriptionManager.CB_OPT_OUT_DIALOG + " INTEGER DEFAULT 1;");
                } catch (SQLiteException e) {
                    if (DBG) {
                        log("onUpgrade skipping " + SIMINFO_TABLE + " upgrade. " +
                                " The table will get created in onOpen.");
                    }
                }
                oldVersion = 16 << 16 | 6;
            }
            if (oldVersion < (17 << 16 | 6)) {
                Cursor c = null;
                try {
                    c = db.query(CARRIERS_TABLE, null, null, null, null, null, null,
                            String.valueOf(1));
                    if (c == null || c.getColumnIndex(USER_VISIBLE) == -1) {
                        db.execSQL("ALTER TABLE " + CARRIERS_TABLE + " ADD COLUMN " +
                                USER_VISIBLE + " BOOLEAN DEFAULT 1;");
                    } else {
                        if (DBG) {
                            log("onUpgrade skipping " + CARRIERS_TABLE + " upgrade.  Column " +
                                    USER_VISIBLE + " already exists.");
                        }
                    }
                } finally {
                    if (c != null) {
                        c.close();
                    }
                }
                oldVersion = 17 << 16 | 6;
            }
            if (oldVersion < (18 << 16 | 6)) {
                try {
                    // Try to update the siminfo table. It might not be there.
                    db.execSQL("ALTER TABLE " + SIMINFO_TABLE + " ADD COLUMN " +
                            SubscriptionManager.SIM_PROVISIONING_STATUS + " INTEGER DEFAULT " +
                            SubscriptionManager.SIM_PROVISIONED + ";");
                } catch (SQLiteException e) {
                    if (DBG) {
                        log("onUpgrade skipping " + SIMINFO_TABLE + " upgrade. " +
                                " The table will get created in onOpen.");
                    }
                }
                oldVersion = 18 << 16 | 6;
            }
            if (oldVersion < (19 << 16 | 6)) {
                // Do nothing. This is to avoid recreating table twice. Table is anyway recreated
                // for version 24 and that takes care of updates for this version as well.
                // This version added more fields protocol and roaming protocol to the primary key.
            }
            if (oldVersion < (20 << 16 | 6)) {
                try {
                    // Try to update the siminfo table. It might not be there.
                    db.execSQL("ALTER TABLE " + SIMINFO_TABLE + " ADD COLUMN " +
                            SubscriptionManager.IS_EMBEDDED + " INTEGER DEFAULT 0;");
                    db.execSQL("ALTER TABLE " + SIMINFO_TABLE + " ADD COLUMN " +
                            SubscriptionManager.ACCESS_RULES + " BLOB;");
                    db.execSQL("ALTER TABLE " + SIMINFO_TABLE + " ADD COLUMN " +
                            SubscriptionManager.IS_REMOVABLE + " INTEGER DEFAULT 0;");
                } catch (SQLiteException e) {
                    if (DBG) {
                        log("onUpgrade skipping " + SIMINFO_TABLE + " upgrade. " +
                                "The table will get created in onOpen.");
                    }
                }
                oldVersion = 20 << 16 | 6;
            }
            if (oldVersion < (21 << 16 | 6)) {
                try {
                    // Try to update the carriers table. It might not be there.
                    db.execSQL("ALTER TABLE " + CARRIERS_TABLE + " ADD COLUMN " +
                            USER_EDITABLE + " INTEGER DEFAULT 1;");
                } catch (SQLiteException e) {
                    // This is possible if the column already exists which may be the case if the
                    // table was just created as part of upgrade to version 19
                    if (DBG) {
                        log("onUpgrade skipping " + CARRIERS_TABLE + " upgrade. " +
                                "The table will get created in onOpen.");
                    }
                }
                oldVersion = 21 << 16 | 6;
            }
            if (oldVersion < (22 << 16 | 6)) {
                try {
                    // Try to update the siminfo table. It might not be there.
                    db.execSQL("ALTER TABLE " + SIMINFO_TABLE + " ADD COLUMN "
                            + SubscriptionManager.ENHANCED_4G_MODE_ENABLED
                            + " INTEGER DEFAULT -1;");
                    db.execSQL("ALTER TABLE " + SIMINFO_TABLE + " ADD COLUMN "
                            + SubscriptionManager.VT_IMS_ENABLED + " INTEGER DEFAULT -1;");
                    db.execSQL("ALTER TABLE " + SIMINFO_TABLE + " ADD COLUMN "
                            + SubscriptionManager.WFC_IMS_ENABLED + " INTEGER DEFAULT -1;");
                    db.execSQL("ALTER TABLE " + SIMINFO_TABLE + " ADD COLUMN "
                            + SubscriptionManager.WFC_IMS_MODE + " INTEGER DEFAULT -1;");
                    db.execSQL("ALTER TABLE " + SIMINFO_TABLE + " ADD COLUMN "
                            + SubscriptionManager.WFC_IMS_ROAMING_MODE + " INTEGER DEFAULT -1;");
                    db.execSQL("ALTER TABLE " + SIMINFO_TABLE + " ADD COLUMN "
                            + SubscriptionManager.WFC_IMS_ROAMING_ENABLED + " INTEGER DEFAULT -1;");
                } catch (SQLiteException e) {
                    if (DBG) {
                        log("onUpgrade skipping " + CARRIERS_TABLE + " upgrade. " +
                                "The table will get created in onOpen.");
                    }
                }
                oldVersion = 22 << 16 | 6;
            }
            if (oldVersion < (23 << 16 | 6)) {
                try {
                    db.execSQL("ALTER TABLE " + CARRIERS_TABLE + " ADD COLUMN " +
                            OWNED_BY + " INTEGER DEFAULT " + OWNED_BY_OTHERS + ";");
                } catch (SQLiteException e) {
                    if (DBG) {
                        log("onUpgrade skipping " + CARRIERS_TABLE + " upgrade. " +
                                "The table will get created in onOpen.");
                    }
                }
                oldVersion = 23 << 16 | 6;
            }
            if (oldVersion < (24 << 16 | 6)) {
                Cursor c = null;
                String[] proj = {"_id"};
                recreateDB(c, db, proj, /* version */24);
                if (VDBG) {
                    c = db.query(CARRIERS_TABLE, proj, null, null, null, null, null);
                    log("dbh.onUpgrade:- after upgrading total number of rows: " + c.getCount());
                    c.close();
                    c = db.query(CARRIERS_TABLE, proj, NETWORK_TYPE_BITMASK, null, null, null, null);
                    log("dbh.onUpgrade:- after upgrading total number of rows with "
                            + NETWORK_TYPE_BITMASK + ": " + c.getCount());
                    c.close();
                }
                oldVersion = 24 << 16 | 6;
            }
            if (DBG) {
                log("dbh.onUpgrade:- db=" + db + " oldV=" + oldVersion + " newV=" + newVersion);
            }
        }

        private void recreateDB(Cursor c, SQLiteDatabase db, String[] proj, int version) {
            // Upgrade steps are:
            // 1. Create a temp table- done in createCarriersTable()
            // 2. copy over APNs from old table to new table - done in copyDataToTmpTable()
            // 3. Drop the existing table.
            // 4. Copy over the tmp table.
            if (VDBG) {
                c = db.query(CARRIERS_TABLE, proj, null, null, null, null, null);
                log("dbh.onUpgrade:- before upgrading total number of rows: " + c.getCount());
                c.close();
            }

            c = db.query(CARRIERS_TABLE, null, null, null, null, null, null);

            if (VDBG) {
                log("dbh.onUpgrade:- starting data copy of existing rows: " +
                        + ((c == null) ? 0 : c.getCount()));
            }

            db.execSQL("DROP TABLE IF EXISTS " + CARRIERS_TABLE_TMP);

            createCarriersTable(db, CARRIERS_TABLE_TMP);

            copyDataToTmpTable(db, c);
            c.close();

            db.execSQL("DROP TABLE IF EXISTS " + CARRIERS_TABLE);

            db.execSQL("ALTER TABLE " + CARRIERS_TABLE_TMP + " rename to " + CARRIERS_TABLE + ";");
        }

        private void preserveUserAndCarrierApns(SQLiteDatabase db) {
            if (VDBG) log("preserveUserAndCarrierApns");
            XmlPullParser confparser;
            File confFile = new File(Environment.getRootDirectory(), OLD_APNS_PATH);
            FileReader confreader = null;
            try {
                confreader = new FileReader(confFile);
                confparser = Xml.newPullParser();
                confparser.setInput(confreader);
                XmlUtils.beginDocument(confparser, "apns");

                deleteMatchingApns(db, confparser);
            } catch (FileNotFoundException e) {
                // This function is called only when upgrading db to version 15. Details about the
                // upgrade are mentioned in onUpgrade(). This file missing means user/carrier added
                // APNs cannot be preserved. Log an error message so that OEMs know they need to
                // include old apns file for comparison.
                loge("PRESERVEUSERANDCARRIERAPNS: " + OLD_APNS_PATH +
                        " NOT FOUND. IT IS NEEDED TO UPGRADE FROM OLDER VERSIONS OF APN " +
                        "DB WHILE PRESERVING USER/CARRIER ADDED/EDITED ENTRIES.");
            } catch (Exception e) {
                loge("preserveUserAndCarrierApns: Exception while parsing '" +
                        confFile.getAbsolutePath() + "'" + e);
            } finally {
                if (confreader != null) {
                    try {
                        confreader.close();
                    } catch (IOException e) {
                        // do nothing
                    }
                }
            }
        }

        private void deleteMatchingApns(SQLiteDatabase db, XmlPullParser parser) {
            if (VDBG) log("deleteMatchingApns");
            if (parser != null) {
                if (VDBG) log("deleteMatchingApns: parser != null");
                try {
                    XmlUtils.nextElement(parser);
                    while (parser.getEventType() != XmlPullParser.END_DOCUMENT) {
                        ContentValues row = getRow(parser);
                        if (row == null) {
                            throw new XmlPullParserException("Expected 'apn' tag", parser, null);
                        }
                        deleteRow(db, row);
                        XmlUtils.nextElement(parser);
                    }
                } catch (XmlPullParserException e) {
                    loge("deleteMatchingApns: Got XmlPullParserException while deleting apns." + e);
                } catch (IOException e) {
                    loge("deleteMatchingApns: Got IOException while deleting apns." + e);
                } catch (SQLException e) {
                    loge("deleteMatchingApns: Got SQLException while deleting apns." + e);
                }
            }
        }

        private String queryValFirst(String field) {
            return field + "=?";
        }

        private String queryVal(String field) {
            return " and " + field + "=?";
        }

        private String queryValOrNull(String field) {
            return " and (" + field + "=? or " + field + " is null)";
        }

        private String queryVal2OrNull(String field) {
            return " and (" + field + "=? or " + field + "=? or " + field + " is null)";
        }

        private void deleteRow(SQLiteDatabase db, ContentValues values) {
            if (VDBG) log("deleteRow");
            String where = queryValFirst(NUMERIC) +
                    queryVal(MNC) +
                    queryVal(MNC) +
                    queryValOrNull(APN) +
                    queryValOrNull(USER) +
                    queryValOrNull(SERVER) +
                    queryValOrNull(PASSWORD) +
                    queryValOrNull(PROXY) +
                    queryValOrNull(PORT) +
                    queryValOrNull(MMSPROXY) +
                    queryValOrNull(MMSPORT) +
                    queryValOrNull(MMSC) +
                    queryValOrNull(AUTH_TYPE) +
                    queryValOrNull(TYPE) +
                    queryValOrNull(PROTOCOL) +
                    queryValOrNull(ROAMING_PROTOCOL) +
                    queryVal2OrNull(CARRIER_ENABLED) +
                    queryValOrNull(BEARER) +
                    queryValOrNull(MVNO_TYPE) +
                    queryValOrNull(MVNO_MATCH_DATA) +
                    queryValOrNull(PROFILE_ID) +
                    queryVal2OrNull(MODEM_COGNITIVE) +
                    queryValOrNull(MAX_CONNS) +
                    queryValOrNull(WAIT_TIME) +
                    queryValOrNull(MAX_CONNS_TIME) +
                    queryValOrNull(MTU);
            String[] whereArgs = new String[29];
            int i = 0;
            whereArgs[i++] = values.getAsString(NUMERIC);
            whereArgs[i++] = values.getAsString(MCC);
            whereArgs[i++] = values.getAsString(MNC);
            whereArgs[i++] = values.getAsString(NAME);
            whereArgs[i++] = values.containsKey(APN) ?
                    values.getAsString(APN) : "";
            whereArgs[i++] = values.containsKey(USER) ?
                    values.getAsString(USER) : "";
            whereArgs[i++] = values.containsKey(SERVER) ?
                    values.getAsString(SERVER) : "";
            whereArgs[i++] = values.containsKey(PASSWORD) ?
                    values.getAsString(PASSWORD) : "";
            whereArgs[i++] = values.containsKey(PROXY) ?
                    values.getAsString(PROXY) : "";
            whereArgs[i++] = values.containsKey(PORT) ?
                    values.getAsString(PORT) : "";
            whereArgs[i++] = values.containsKey(MMSPROXY) ?
                    values.getAsString(MMSPROXY) : "";
            whereArgs[i++] = values.containsKey(MMSPORT) ?
                    values.getAsString(MMSPORT) : "";
            whereArgs[i++] = values.containsKey(MMSC) ?
                    values.getAsString(MMSC) : "";
            whereArgs[i++] = values.containsKey(AUTH_TYPE) ?
                    values.getAsString(AUTH_TYPE) : "-1";
            whereArgs[i++] = values.containsKey(TYPE) ?
                    values.getAsString(TYPE) : "";
            whereArgs[i++] = values.containsKey(PROTOCOL) ?
                    values.getAsString(PROTOCOL) : DEFAULT_PROTOCOL;
            whereArgs[i++] = values.containsKey(ROAMING_PROTOCOL) ?
                    values.getAsString(ROAMING_PROTOCOL) : DEFAULT_ROAMING_PROTOCOL;

            if (values.containsKey(CARRIER_ENABLED) &&
                    (values.getAsString(CARRIER_ENABLED).
                            equalsIgnoreCase("false") ||
                            values.getAsString(CARRIER_ENABLED).equals("0"))) {
                whereArgs[i++] = "false";
                whereArgs[i++] = "0";
            } else {
                whereArgs[i++] = "true";
                whereArgs[i++] = "1";
            }

            whereArgs[i++] = values.containsKey(BEARER) ?
                    values.getAsString(BEARER) : "0";
            whereArgs[i++] = values.containsKey(MVNO_TYPE) ?
                    values.getAsString(MVNO_TYPE) : "";
            whereArgs[i++] = values.containsKey(MVNO_MATCH_DATA) ?
                    values.getAsString(MVNO_MATCH_DATA) : "";
            whereArgs[i++] = values.containsKey(PROFILE_ID) ?
                    values.getAsString(PROFILE_ID) : "0";

            if (values.containsKey(MODEM_COGNITIVE) &&
                    (values.getAsString(MODEM_COGNITIVE).
                            equalsIgnoreCase("true") ||
                            values.getAsString(MODEM_COGNITIVE).equals("1"))) {
                whereArgs[i++] = "true";
                whereArgs[i++] = "1";
            } else {
                whereArgs[i++] = "false";
                whereArgs[i++] = "0";
            }

            whereArgs[i++] = values.containsKey(MAX_CONNS) ?
                    values.getAsString(MAX_CONNS) : "0";
            whereArgs[i++] = values.containsKey(WAIT_TIME) ?
                    values.getAsString(WAIT_TIME) : "0";
            whereArgs[i++] = values.containsKey(MAX_CONNS_TIME) ?
                    values.getAsString(MAX_CONNS_TIME) : "0";
            whereArgs[i++] = values.containsKey(MTU) ?
                    values.getAsString(MTU) : "0";

            if (VDBG) {
                log("deleteRow: where: " + where);

                StringBuilder builder = new StringBuilder();
                for (String s : whereArgs) {
                    builder.append(s + ", ");
                }

                log("deleteRow: whereArgs: " + builder.toString());
            }
            db.delete(CARRIERS_TABLE, where, whereArgs);
        }

        private void copyDataToTmpTable(SQLiteDatabase db, Cursor c) {
            // Move entries from CARRIERS_TABLE to CARRIERS_TABLE_TMP
            if (c != null) {
                while (c.moveToNext()) {
                    ContentValues cv = new ContentValues();
                    copyApnValuesV17(cv, c);
                    // Sync bearer bitmask and network type bitmask
                    getNetworkTypeBitmaskFromCursor(cv, c);
                    try {
                        db.insertWithOnConflict(CARRIERS_TABLE_TMP, null, cv,
                                SQLiteDatabase.CONFLICT_ABORT);
                        if (VDBG) {
                            log("dbh.copyPreservedApnsToNewTable: db.insert returned >= 0; " +
                                    "insert successful for cv " + cv);
                        }
                    } catch (SQLException e) {
                        if (VDBG)
                            log("dbh.copyPreservedApnsToNewTable insertWithOnConflict exception " +
                                    e + " for cv " + cv);
                    }
                }
            }
        }

        private void copyApnValuesV17(ContentValues cv, Cursor c) {
            // Include only non-null values in cv so that null values can be replaced
            // with default if there's a default value for the field

            // String vals
            getStringValueFromCursor(cv, c, NAME);
            getStringValueFromCursor(cv, c, NUMERIC);
            getStringValueFromCursor(cv, c, MCC);
            getStringValueFromCursor(cv, c, MNC);
            getStringValueFromCursor(cv, c, APN);
            getStringValueFromCursor(cv, c, USER);
            getStringValueFromCursor(cv, c, SERVER);
            getStringValueFromCursor(cv, c, PASSWORD);
            getStringValueFromCursor(cv, c, PROXY);
            getStringValueFromCursor(cv, c, PORT);
            getStringValueFromCursor(cv, c, MMSPROXY);
            getStringValueFromCursor(cv, c, MMSPORT);
            getStringValueFromCursor(cv, c, MMSC);
            getStringValueFromCursor(cv, c, TYPE);
            getStringValueFromCursor(cv, c, PROTOCOL);
            getStringValueFromCursor(cv, c, ROAMING_PROTOCOL);
            getStringValueFromCursor(cv, c, MVNO_TYPE);
            getStringValueFromCursor(cv, c, MVNO_MATCH_DATA);

            // bool/int vals
            getIntValueFromCursor(cv, c, AUTH_TYPE);
            getIntValueFromCursor(cv, c, CURRENT);
            getIntValueFromCursor(cv, c, CARRIER_ENABLED);
            getIntValueFromCursor(cv, c, BEARER);
            getIntValueFromCursor(cv, c, SUBSCRIPTION_ID);
            getIntValueFromCursor(cv, c, PROFILE_ID);
            getIntValueFromCursor(cv, c, MODEM_COGNITIVE);
            getIntValueFromCursor(cv, c, MAX_CONNS);
            getIntValueFromCursor(cv, c, WAIT_TIME);
            getIntValueFromCursor(cv, c, MAX_CONNS_TIME);
            getIntValueFromCursor(cv, c, MTU);
            getIntValueFromCursor(cv, c, BEARER_BITMASK);
            getIntValueFromCursor(cv, c, EDITED);
            getIntValueFromCursor(cv, c, USER_VISIBLE);
        }


        private void copyPreservedApnsToNewTable(SQLiteDatabase db, Cursor c) {
            // Move entries from CARRIERS_TABLE to CARRIERS_TABLE_TMP
            if (c != null) {
                String[] persistApnsForPlmns = mContext.getResources().getStringArray(
                        R.array.persist_apns_for_plmn);
                while (c.moveToNext()) {
                    ContentValues cv = new ContentValues();
                    String val;
                    // Using V17 copy function for V15 upgrade. This should be fine since it handles
                    // columns that may not exist properly (getStringValueFromCursor() and
                    // getIntValueFromCursor() handle column index -1)
                    copyApnValuesV17(cv, c);
                    // Change bearer to a bitmask
                    String bearerStr = c.getString(c.getColumnIndex(BEARER));
                    if (!TextUtils.isEmpty(bearerStr)) {
                        int bearer_bitmask = ServiceState.getBitmaskForTech(
                                Integer.parseInt(bearerStr));
                        cv.put(BEARER_BITMASK, bearer_bitmask);

                        int networkTypeBitmask = ServiceState.getBitmaskForTech(
                                ServiceState.rilRadioTechnologyToNetworkType(
                                        Integer.parseInt(bearerStr)));
                        cv.put(NETWORK_TYPE_BITMASK, networkTypeBitmask);
                    }

                    int userEditedColumnIdx = c.getColumnIndex("user_edited");
                    if (userEditedColumnIdx != -1) {
                        String user_edited = c.getString(userEditedColumnIdx);
                        if (!TextUtils.isEmpty(user_edited)) {
                            cv.put(EDITED, new Integer(user_edited));
                        }
                    } else {
                        cv.put(EDITED, CARRIER_EDITED);
                    }

                    // New EDITED column. Default value (UNEDITED) will
                    // be used for all rows except for non-mvno entries for plmns indicated
                    // by resource: those will be set to CARRIER_EDITED to preserve
                    // their current values
                    val = c.getString(c.getColumnIndex(NUMERIC));
                    for (String s : persistApnsForPlmns) {
                        if (!TextUtils.isEmpty(val) && val.equals(s) &&
                                (!cv.containsKey(MVNO_TYPE) ||
                                        TextUtils.isEmpty(cv.getAsString(MVNO_TYPE)))) {
                            if (userEditedColumnIdx == -1) {
                                cv.put(EDITED, CARRIER_EDITED);
                            } else { // if (oldVersion == 14) -- if db had user_edited column
                                if (cv.getAsInteger(EDITED) == USER_EDITED) {
                                    cv.put(EDITED, CARRIER_EDITED);
                                }
                            }

                            break;
                        }
                    }

                    try {
                        db.insertWithOnConflict(CARRIERS_TABLE_TMP, null, cv,
                                SQLiteDatabase.CONFLICT_ABORT);
                        if (VDBG) {
                            log("dbh.copyPreservedApnsToNewTable: db.insert returned >= 0; " +
                                    "insert successful for cv " + cv);
                        }
                    } catch (SQLException e) {
                        if (VDBG)
                            log("dbh.copyPreservedApnsToNewTable insertWithOnConflict exception " +
                                    e + " for cv " + cv);
                        // Insertion failed which could be due to a conflict. Check if that is
                        // the case and merge the entries
                        Cursor oldRow = DatabaseHelper.selectConflictingRow(db,
                                CARRIERS_TABLE_TMP, cv);
                        if (oldRow != null) {
                            ContentValues mergedValues = new ContentValues();
                            mergeFieldsAndUpdateDb(db, CARRIERS_TABLE_TMP, oldRow, cv,
                                    mergedValues, true, mContext);
                            oldRow.close();
                        }
                    }
                }
            }
        }

        private void getStringValueFromCursor(ContentValues cv, Cursor c, String key) {
            int columnIndex = c.getColumnIndex(key);
            if (columnIndex != -1) {
                String fromCursor = c.getString(columnIndex);
                if (!TextUtils.isEmpty(fromCursor)) {
                    cv.put(key, fromCursor);
                }
            }
        }

        /**
         * If NETWORK_TYPE_BITMASK does not exist (upgrade from version 23 to version 24), generate
         * NETWORK_TYPE_BITMASK with the use of BEARER_BITMASK. If NETWORK_TYPE_BITMASK existed
         * (upgrade from version 24 to forward), always map NETWORK_TYPE_BITMASK to BEARER_BITMASK.
         */
        private void getNetworkTypeBitmaskFromCursor(ContentValues cv, Cursor c) {
            int columnIndex = c.getColumnIndex(NETWORK_TYPE_BITMASK);
            if (columnIndex != -1) {
                getStringValueFromCursor(cv, c, NETWORK_TYPE_BITMASK);
                // Map NETWORK_TYPE_BITMASK to BEARER_BITMASK if NETWORK_TYPE_BITMASK existed;
                String fromCursor = c.getString(columnIndex);
                if (!TextUtils.isEmpty(fromCursor) && fromCursor.matches("\\d+")) {
                    int networkBitmask = Integer.valueOf(fromCursor);
                    int bearerBitmask = ServiceState.convertNetworkTypeBitmaskToBearerBitmask(
                            networkBitmask);
                    cv.put(BEARER_BITMASK, String.valueOf(bearerBitmask));
                }
                return;
            }
            columnIndex = c.getColumnIndex(BEARER_BITMASK);
            if (columnIndex != -1) {
                String fromCursor = c.getString(columnIndex);
                if (!TextUtils.isEmpty(fromCursor) && fromCursor.matches("\\d+")) {
                    int bearerBitmask = Integer.valueOf(fromCursor);
                    int networkBitmask = ServiceState.convertBearerBitmaskToNetworkTypeBitmask(
                            bearerBitmask);
                    cv.put(NETWORK_TYPE_BITMASK, String.valueOf(networkBitmask));
                }
            }
        }

        private void getIntValueFromCursor(ContentValues cv, Cursor c, String key) {
            int columnIndex = c.getColumnIndex(key);
            if (columnIndex != -1) {
                String fromCursor = c.getString(columnIndex);
                if (!TextUtils.isEmpty(fromCursor)) {
                    try {
                        cv.put(key, new Integer(fromCursor));
                    } catch (NumberFormatException nfe) {
                        // do nothing
                    }
                }
            }
        }

        /**
         * Gets the next row of apn values.
         *
         * @param parser the parser
         * @return the row or null if it's not an apn
         */
        private ContentValues getRow(XmlPullParser parser) {
            if (!"apn".equals(parser.getName())) {
                return null;
            }

            ContentValues map = new ContentValues();

            String mcc = parser.getAttributeValue(null, "mcc");
            String mnc = parser.getAttributeValue(null, "mnc");
            String numeric = mcc + mnc;

            map.put(NUMERIC, numeric);
            map.put(MCC, mcc);
            map.put(MNC, mnc);
            map.put(NAME, parser.getAttributeValue(null, "carrier"));

            // do not add NULL to the map so that default values can be inserted in db
            addStringAttribute(parser, "apn", map, APN);
            addStringAttribute(parser, "user", map, USER);
            addStringAttribute(parser, "server", map, SERVER);
            addStringAttribute(parser, "password", map, PASSWORD);
            addStringAttribute(parser, "proxy", map, PROXY);
            addStringAttribute(parser, "port", map, PORT);
            addStringAttribute(parser, "mmsproxy", map, MMSPROXY);
            addStringAttribute(parser, "mmsport", map, MMSPORT);
            addStringAttribute(parser, "mmsc", map, MMSC);

            String apnType = parser.getAttributeValue(null, "type");
            if (apnType != null) {
                // Remove spaces before putting it in the map.
                apnType = apnType.replaceAll("\\s+", "");
                map.put(TYPE, apnType);
            }

            addStringAttribute(parser, "protocol", map, PROTOCOL);
            addStringAttribute(parser, "roaming_protocol", map, ROAMING_PROTOCOL);

            addIntAttribute(parser, "authtype", map, AUTH_TYPE);
            addIntAttribute(parser, "bearer", map, BEARER);
            addIntAttribute(parser, "profile_id", map, PROFILE_ID);
            addIntAttribute(parser, "max_conns", map, MAX_CONNS);
            addIntAttribute(parser, "wait_time", map, WAIT_TIME);
            addIntAttribute(parser, "max_conns_time", map, MAX_CONNS_TIME);
            addIntAttribute(parser, "mtu", map, MTU);


            addBoolAttribute(parser, "carrier_enabled", map, CARRIER_ENABLED);
            addBoolAttribute(parser, "modem_cognitive", map, MODEM_COGNITIVE);
            addBoolAttribute(parser, "user_visible", map, USER_VISIBLE);
            addBoolAttribute(parser, "user_editable", map, USER_EDITABLE);

            int networkTypeBitmask = 0;
            String networkTypeList = parser.getAttributeValue(null, "network_type_bitmask");
            if (networkTypeList != null) {
                networkTypeBitmask = ServiceState.getBitmaskFromString(networkTypeList);
            }
            map.put(NETWORK_TYPE_BITMASK, networkTypeBitmask);

            int bearerBitmask = 0;
            if (networkTypeList != null) {
                bearerBitmask =
                        ServiceState.convertNetworkTypeBitmaskToBearerBitmask(networkTypeBitmask);
            } else {
                String bearerList = parser.getAttributeValue(null, "bearer_bitmask");
                if (bearerList != null) {
                    bearerBitmask = ServiceState.getBitmaskFromString(bearerList);
                }
                // Update the network type bitmask to keep them sync.
                networkTypeBitmask = ServiceState.convertBearerBitmaskToNetworkTypeBitmask(
                        bearerBitmask);
                map.put(NETWORK_TYPE_BITMASK, networkTypeBitmask);
            }
            map.put(BEARER_BITMASK, bearerBitmask);

            String mvno_type = parser.getAttributeValue(null, "mvno_type");
            if (mvno_type != null) {
                String mvno_match_data = parser.getAttributeValue(null, "mvno_match_data");
                if (mvno_match_data != null) {
                    map.put(MVNO_TYPE, mvno_type);
                    map.put(MVNO_MATCH_DATA, mvno_match_data);
                }
            }

            return map;
        }

        private void addStringAttribute(XmlPullParser parser, String att,
                                        ContentValues map, String key) {
            String val = parser.getAttributeValue(null, att);
            if (val != null) {
                map.put(key, val);
            }
        }

        private void addIntAttribute(XmlPullParser parser, String att,
                                     ContentValues map, String key) {
            String val = parser.getAttributeValue(null, att);
            if (val != null) {
                map.put(key, Integer.parseInt(val));
            }
        }

        private void addBoolAttribute(XmlPullParser parser, String att,
                                      ContentValues map, String key) {
            String val = parser.getAttributeValue(null, att);
            if (val != null) {
                map.put(key, Boolean.parseBoolean(val));
            }
        }

        /*
         * Loads apns from xml file into the database
         *
         * @param db the sqlite database to write to
         * @param parser the xml parser
         *
         */
        private void loadApns(SQLiteDatabase db, XmlPullParser parser) {
            if (parser != null) {
                try {
                    db.beginTransaction();
                    XmlUtils.nextElement(parser);
                    while (parser.getEventType() != XmlPullParser.END_DOCUMENT) {
                        ContentValues row = getRow(parser);
                        if (row == null) {
                            throw new XmlPullParserException("Expected 'apn' tag", parser, null);
                        }
                        insertAddingDefaults(db, row);
                        XmlUtils.nextElement(parser);
                    }
                    db.setTransactionSuccessful();
                } catch (XmlPullParserException e) {
                    loge("Got XmlPullParserException while loading apns." + e);
                } catch (IOException e) {
                    loge("Got IOException while loading apns." + e);
                } catch (SQLException e) {
                    loge("Got SQLException while loading apns." + e);
                } finally {
                    db.endTransaction();
                }
            }
        }

        static public ContentValues setDefaultValue(ContentValues values) {
            if (!values.containsKey(SUBSCRIPTION_ID)) {
                int subId = SubscriptionManager.getDefaultSubscriptionId();
                values.put(SUBSCRIPTION_ID, subId);
            }

            return values;
        }

        private void insertAddingDefaults(SQLiteDatabase db, ContentValues row) {
            row = setDefaultValue(row);
            try {
                db.insertWithOnConflict(CARRIERS_TABLE, null, row, SQLiteDatabase.CONFLICT_ABORT);
                if (VDBG) log("dbh.insertAddingDefaults: db.insert returned >= 0; insert " +
                        "successful for cv " + row);
            } catch (SQLException e) {
                if (VDBG) log("dbh.insertAddingDefaults: exception " + e);
                // Insertion failed which could be due to a conflict. Check if that is the case and
                // update edited field accordingly.
                // Search for the exact same entry and update edited field.
                // If it is USER_EDITED/CARRIER_EDITED change it to UNEDITED,
                // and if USER/CARRIER_DELETED change it to USER/CARRIER_DELETED_BUT_PRESENT_IN_XML.
                Cursor oldRow = selectConflictingRow(db, CARRIERS_TABLE, row);
                if (oldRow != null) {
                    // Update the row
                    ContentValues mergedValues = new ContentValues();
                    int edited = oldRow.getInt(oldRow.getColumnIndex(EDITED));
                    int old_edited = edited;
                    if (edited != UNEDITED) {
                        if (edited == USER_DELETED) {
                            // USER_DELETED_BUT_PRESENT_IN_XML indicates entry has been deleted
                            // by user but present in apn xml file.
                            edited = USER_DELETED_BUT_PRESENT_IN_XML;
                        } else if (edited == CARRIER_DELETED) {
                            // CARRIER_DELETED_BUT_PRESENT_IN_XML indicates entry has been deleted
                            // by user but present in apn xml file.
                            edited = CARRIER_DELETED_BUT_PRESENT_IN_XML;
                        }
                        mergedValues.put(EDITED, edited);
                    }

                    mergeFieldsAndUpdateDb(db, CARRIERS_TABLE, oldRow, row, mergedValues, false,
                            mContext);

                    if (VDBG) log("dbh.insertAddingDefaults: old edited = " + old_edited
                            + " new edited = " + edited);

                    oldRow.close();
                }
            }
        }

        public static void mergeFieldsAndUpdateDb(SQLiteDatabase db, String table, Cursor oldRow,
                                                  ContentValues newRow, ContentValues mergedValues,
                                                  boolean onUpgrade, Context context) {
            if (newRow.containsKey(TYPE)) {
                // Merge the types
                String oldType = oldRow.getString(oldRow.getColumnIndex(TYPE));
                String newType = newRow.getAsString(TYPE);

                if (!oldType.equalsIgnoreCase(newType)) {
                    if (oldType.equals("") || newType.equals("")) {
                        newRow.put(TYPE, "");
                    } else {
                        String[] oldTypes = oldType.toLowerCase().split(",");
                        String[] newTypes = newType.toLowerCase().split(",");

                        if (VDBG) {
                            log("mergeFieldsAndUpdateDb: Calling separateRowsNeeded() oldType=" +
                                    oldType + " old bearer=" + oldRow.getInt(oldRow.getColumnIndex(
                                    BEARER_BITMASK)) +  " old networkType=" +
                                    oldRow.getInt(oldRow.getColumnIndex(NETWORK_TYPE_BITMASK)) +
                                    " old profile_id=" + oldRow.getInt(oldRow.getColumnIndex(
                                    PROFILE_ID)) + " newRow " + newRow);
                        }

                        // If separate rows are needed, do not need to merge any further
                        if (separateRowsNeeded(db, table, oldRow, newRow, context, oldTypes,
                                newTypes)) {
                            if (VDBG) log("mergeFieldsAndUpdateDb: separateRowsNeeded() returned " +
                                    "true");
                            return;
                        }

                        // Merge the 2 types
                        ArrayList<String> mergedTypes = new ArrayList<String>();
                        mergedTypes.addAll(Arrays.asList(oldTypes));
                        for (String s : newTypes) {
                            if (!mergedTypes.contains(s.trim())) {
                                mergedTypes.add(s);
                            }
                        }
                        StringBuilder mergedType = new StringBuilder();
                        for (int i = 0; i < mergedTypes.size(); i++) {
                            mergedType.append((i == 0 ? "" : ",") + mergedTypes.get(i));
                        }
                        newRow.put(TYPE, mergedType.toString());
                    }
                }
                mergedValues.put(TYPE, newRow.getAsString(TYPE));
            }

            if (newRow.containsKey(BEARER_BITMASK)) {
                int oldBearer = oldRow.getInt(oldRow.getColumnIndex(BEARER_BITMASK));
                int newBearer = newRow.getAsInteger(BEARER_BITMASK);
                if (oldBearer != newBearer) {
                    if (oldBearer == 0 || newBearer == 0) {
                        newRow.put(BEARER_BITMASK, 0);
                    } else {
                        newRow.put(BEARER_BITMASK, (oldBearer | newBearer));
                    }
                }
                mergedValues.put(BEARER_BITMASK, newRow.getAsInteger(BEARER_BITMASK));
            }

            if (newRow.containsKey(NETWORK_TYPE_BITMASK)) {
                int oldBitmask = oldRow.getInt(oldRow.getColumnIndex(NETWORK_TYPE_BITMASK));
                int newBitmask = newRow.getAsInteger(NETWORK_TYPE_BITMASK);
                if (oldBitmask != newBitmask) {
                    if (oldBitmask == 0 || newBitmask == 0) {
                        newRow.put(NETWORK_TYPE_BITMASK, 0);
                    } else {
                        newRow.put(NETWORK_TYPE_BITMASK, (oldBitmask | newBitmask));
                    }
                }
                mergedValues.put(NETWORK_TYPE_BITMASK, newRow.getAsInteger(NETWORK_TYPE_BITMASK));
            }

            if (newRow.containsKey(BEARER_BITMASK)
                    && newRow.containsKey(NETWORK_TYPE_BITMASK)) {
                syncBearerBitmaskAndNetworkTypeBitmask(mergedValues);
            }

            if (!onUpgrade) {
                mergedValues.putAll(newRow);
            }

            if (mergedValues.size() > 0) {
                db.update(table, mergedValues, "_id=" + oldRow.getInt(oldRow.getColumnIndex("_id")),
                        null);
            }
        }

        private static boolean separateRowsNeeded(SQLiteDatabase db, String table, Cursor oldRow,
                                                  ContentValues newRow, Context context,
                                                  String[] oldTypes, String[] newTypes) {
            // If this APN falls under persist_apns_for_plmn, and the
            // only difference between old type and new type is that one has dun, and
            // the APNs have profile_id 0 or not set, then set the profile_id to 1 for
            // the dun APN/remove dun from type. This will ensure both oldRow and newRow exist
            // separately in db.

            boolean match = false;

            // Check if APN falls under persist_apns_for_plmn
            String[] persistApnsForPlmns = context.getResources().getStringArray(
                    R.array.persist_apns_for_plmn);
            for (String s : persistApnsForPlmns) {
                if (s.equalsIgnoreCase(newRow.getAsString(NUMERIC))) {
                    match = true;
                    break;
                }
            }

            if (!match) return false;

            // APN falls under persist_apns_for_plmn
            // Check if only difference between old type and new type is that
            // one has dun
            ArrayList<String> oldTypesAl = new ArrayList<String>(Arrays.asList(oldTypes));
            ArrayList<String> newTypesAl = new ArrayList<String>(Arrays.asList(newTypes));
            ArrayList<String> listWithDun = null;
            ArrayList<String> listWithoutDun = null;
            boolean dunInOld = false;
            if (oldTypesAl.size() == newTypesAl.size() + 1) {
                listWithDun = oldTypesAl;
                listWithoutDun = newTypesAl;
                dunInOld = true;
            } else if (oldTypesAl.size() + 1 == newTypesAl.size()) {
                listWithDun = newTypesAl;
                listWithoutDun = oldTypesAl;
            } else {
                return false;
            }

            if (listWithDun.contains("dun") && !listWithoutDun.contains("dun")) {
                listWithoutDun.add("dun");
                if (!listWithDun.containsAll(listWithoutDun)) {
                    return false;
                }

                // Only difference between old type and new type is that
                // one has dun
                // Check if profile_id is 0/not set
                if (oldRow.getInt(oldRow.getColumnIndex(PROFILE_ID)) == 0) {
                    if (dunInOld) {
                        // Update oldRow to remove dun from its type field
                        ContentValues updateOldRow = new ContentValues();
                        StringBuilder sb = new StringBuilder();
                        boolean first = true;
                        for (String s : listWithDun) {
                            if (!s.equalsIgnoreCase("dun")) {
                                sb.append(first ? s : "," + s);
                                first = false;
                            }
                        }
                        String updatedType = sb.toString();
                        if (VDBG) {
                            log("separateRowsNeeded: updating type in oldRow to " + updatedType);
                        }
                        updateOldRow.put(TYPE, updatedType);
                        db.update(table, updateOldRow,
                                "_id=" + oldRow.getInt(oldRow.getColumnIndex("_id")), null);
                        return true;
                    } else {
                        if (VDBG) log("separateRowsNeeded: adding profile id 1 to newRow");
                        // Update newRow to set profile_id to 1
                        newRow.put(PROFILE_ID, new Integer(1));
                    }
                } else {
                    return false;
                }

                // If match was found, both oldRow and newRow need to exist
                // separately in db. Add newRow to db.
                try {
                    db.insertWithOnConflict(table, null, newRow, SQLiteDatabase.CONFLICT_REPLACE);
                    if (VDBG) log("separateRowsNeeded: added newRow with profile id 1 to db");
                    return true;
                } catch (SQLException e) {
                    loge("Exception on trying to add new row after updating profile_id");
                }
            }

            return false;
        }

        public static Cursor selectConflictingRow(SQLiteDatabase db, String table,
                                                  ContentValues row) {
            // Conflict is possible only when numeric, mcc, mnc (fields without any default value)
            // are set in the new row
            if (!row.containsKey(NUMERIC) || !row.containsKey(MCC) || !row.containsKey(MNC)) {
                loge("dbh.selectConflictingRow: called for non-conflicting row: " + row);
                return null;
            }

            String[] columns = { "_id",
                    TYPE,
                    EDITED,
                    BEARER_BITMASK,
                    NETWORK_TYPE_BITMASK,
                    PROFILE_ID };
            String selection = TextUtils.join("=? AND ", CARRIERS_UNIQUE_FIELDS) + "=?";
            int i = 0;
            String[] selectionArgs = new String[CARRIERS_UNIQUE_FIELDS.size()];
            for (String field : CARRIERS_UNIQUE_FIELDS) {
                if (CARRIER_ENABLED.equals(field)) {
                    // for CARRIER_ENABLED we overwrite the value "false" with "0"
                    selectionArgs[i++] = row.containsKey(CARRIER_ENABLED) &&
                            (row.getAsString(CARRIER_ENABLED).equals("0") ||
                                    row.getAsString(CARRIER_ENABLED).equals("false")) ?
                            "0" : CARRIERS_UNIQUE_FIELDS_DEFAULTS.get(CARRIER_ENABLED);
                } else {
                    selectionArgs[i++] = row.containsKey(field) ?
                            row.getAsString(field) : CARRIERS_UNIQUE_FIELDS_DEFAULTS.get(field);
                }
            }

            Cursor c = db.query(table, columns, selection, selectionArgs, null, null, null);

            if (c != null) {
                if (c.getCount() == 1) {
                    if (VDBG) log("dbh.selectConflictingRow: " + c.getCount() + " conflicting " +
                            "row found");
                    if (c.moveToFirst()) {
                        return c;
                    } else {
                        loge("dbh.selectConflictingRow: moveToFirst() failed");
                    }
                } else {
                    loge("dbh.selectConflictingRow: Expected 1 but found " + c.getCount() +
                            " matching rows found for cv " + row);
                }
                c.close();
            } else {
                loge("dbh.selectConflictingRow: Error - c is null; no matching row found for " +
                        "cv " + row);
            }

            return null;
        }
    }

    /**
     * These methods can be overridden in a subclass for testing TelephonyProvider using an
     * in-memory database.
     */
    SQLiteDatabase getReadableDatabase() {
        return mOpenHelper.getReadableDatabase();
    }
    SQLiteDatabase getWritableDatabase() {
        return mOpenHelper.getWritableDatabase();
    }
    void initDatabaseWithDatabaseHelper(SQLiteDatabase db) {
        mOpenHelper.initDatabase(db);
    }
    boolean needApnDbUpdate() {
        return mOpenHelper.apnDbUpdateNeeded();
    }

    private static boolean apnSourceServiceExists(Context context) {
        if (s_apnSourceServiceExists != null) {
            return s_apnSourceServiceExists;
        }
        try {
            String service = context.getResources().getString(R.string.apn_source_service);
            if (TextUtils.isEmpty(service)) {
                s_apnSourceServiceExists = false;
            } else {
                s_apnSourceServiceExists = context.getPackageManager().getServiceInfo(
                        ComponentName.unflattenFromString(service), 0)
                        != null;
            }
        } catch (PackageManager.NameNotFoundException e) {
            s_apnSourceServiceExists = false;
        }
        return s_apnSourceServiceExists;
    }

    private void restoreApnsWithService() {
        Context context = getContext();
        Resources r = context.getResources();
        ServiceConnection connection = new ServiceConnection() {
            @Override
            public void onServiceConnected(ComponentName className,
                    IBinder service) {
                log("restoreApnsWithService: onServiceConnected");
                synchronized (mLock) {
                    mIApnSourceService = IApnSourceService.Stub.asInterface(service);
                    mLock.notifyAll();
                }
            }

            @Override
            public void onServiceDisconnected(ComponentName arg0) {
                loge("mIApnSourceService has disconnected unexpectedly");
                synchronized (mLock) {
                    mIApnSourceService = null;
                }
            }
        };

        Intent intent = new Intent(IApnSourceService.class.getName());
        intent.setComponent(ComponentName.unflattenFromString(
                r.getString(R.string.apn_source_service)));
        log("binding to service to restore apns, intent=" + intent);
        try {
            if (context.bindService(intent, connection, Context.BIND_AUTO_CREATE)) {
                synchronized (mLock) {
                    while (mIApnSourceService == null) {
                        try {
                            mLock.wait();
                        } catch (InterruptedException e) {
                            loge("Error while waiting for service connection: " + e);
                        }
                    }
                    try {
                        ContentValues[] values = mIApnSourceService.getApns();
                        if (values != null) {
                            // we use the unsynchronized insert because this function is called
                            // within the syncrhonized function delete()
                            unsynchronizedBulkInsert(CONTENT_URI, values);
                            log("restoreApnsWithService: restored");
                        }
                    } catch (RemoteException e) {
                        loge("Error applying apns from service: " + e);
                    }
                }
            } else {
                loge("unable to bind to service from intent=" + intent);
            }
        } catch (SecurityException e) {
            loge("Error applying apns from service: " + e);
        } finally {
            if (connection != null) {
                context.unbindService(connection);
            }
            synchronized (mLock) {
                mIApnSourceService = null;
            }
        }
    }


    @Override
    public boolean onCreate() {
        mOpenHelper = new DatabaseHelper(getContext());

        if (!apnSourceServiceExists(getContext())) {
            // Call getReadableDatabase() to make sure onUpgrade is called
            if (VDBG) log("onCreate: calling getReadableDatabase to trigger onUpgrade");
            SQLiteDatabase db = getReadableDatabase();

            // Update APN db on build update
            String newBuildId = SystemProperties.get("ro.build.id", null);
            if (!TextUtils.isEmpty(newBuildId)) {
                // Check if build id has changed
                SharedPreferences sp = getContext().getSharedPreferences(BUILD_ID_FILE,
                        Context.MODE_PRIVATE);
                String oldBuildId = sp.getString(RO_BUILD_ID, "");
                if (!newBuildId.equals(oldBuildId)) {
                    if (DBG) log("onCreate: build id changed from " + oldBuildId + " to " +
                            newBuildId);

                    // Get rid of old preferred apn shared preferences
                    SubscriptionManager sm = SubscriptionManager.from(getContext());
                    if (sm != null) {
                        List<SubscriptionInfo> subInfoList = sm.getAllSubscriptionInfoList();
                        for (SubscriptionInfo subInfo : subInfoList) {
                            SharedPreferences spPrefFile = getContext().getSharedPreferences(
                                    PREF_FILE_APN + subInfo.getSubscriptionId(), Context.MODE_PRIVATE);
                            if (spPrefFile != null) {
                                SharedPreferences.Editor editor = spPrefFile.edit();
                                editor.clear();
                                editor.apply();
                            }
                        }
                    }

                    // Update APN DB
                    updateApnDb();
                } else {
                    if (VDBG) log("onCreate: build id did not change: " + oldBuildId);
                }
                sp.edit().putString(RO_BUILD_ID, newBuildId).apply();
            } else {
                if (VDBG) log("onCreate: newBuildId is empty");
            }
        }

        SharedPreferences sp = getContext().getSharedPreferences(ENFORCED_FILE,
                Context.MODE_PRIVATE);
        mManagedApnEnforced = sp.getBoolean(ENFORCED_KEY, false);

        if (VDBG) log("onCreate:- ret true");

        return true;
    }

    private synchronized boolean isManagedApnEnforced() {
        return mManagedApnEnforced;
    }

    private void setManagedApnEnforced(boolean enforced) {
        SharedPreferences sp = getContext().getSharedPreferences(ENFORCED_FILE,
                Context.MODE_PRIVATE);
        SharedPreferences.Editor editor = sp.edit();
        editor.putBoolean(ENFORCED_KEY, enforced);
        editor.apply();
        synchronized (this) {
            mManagedApnEnforced = enforced;
        }
    }

    private void setPreferredApnId(Long id, int subId, boolean saveApn) {
        SharedPreferences sp = getContext().getSharedPreferences(PREF_FILE_APN,
                Context.MODE_PRIVATE);
        SharedPreferences.Editor editor = sp.edit();
        editor.putLong(COLUMN_APN_ID + subId, id != null ? id : INVALID_APN_ID);
        // This is for debug purposes. It indicates if this APN was set by DcTracker or user (true)
        // or if this was restored from APN saved in PREF_FILE_FULL_APN (false).
        editor.putBoolean(EXPLICIT_SET_CALLED + subId, saveApn);
        editor.apply();
        if (id == null || id.longValue() == INVALID_APN_ID) {
            deletePreferredApn(subId);
        } else {
            // If id is not invalid, and saveApn is true, save the actual APN in PREF_FILE_FULL_APN
            // too.
            if (saveApn) {
                setPreferredApn(id, subId);
            }
        }
    }

    private long getPreferredApnId(int subId, boolean checkApnSp) {
        SharedPreferences sp = getContext().getSharedPreferences(PREF_FILE_APN,
                Context.MODE_PRIVATE);
        long apnId = sp.getLong(COLUMN_APN_ID + subId, INVALID_APN_ID);
        if (apnId == INVALID_APN_ID && checkApnSp) {
            apnId = getPreferredApnIdFromApn(subId);
            if (apnId != INVALID_APN_ID) {
                setPreferredApnId(apnId, subId, false);
            }
        }
        return apnId;
    }

    private void deletePreferredApnId() {
        SharedPreferences sp = getContext().getSharedPreferences(PREF_FILE_APN,
                Context.MODE_PRIVATE);

        // Before deleting, save actual preferred apns (not the ids) in a separate SP.
        // NOTE: This code to call setPreferredApn() can be removed since the function is now called
        // from setPreferredApnId(). However older builds (pre oc-mr1) do not have that change, so
        // when devices upgrade from those builds and this function is called, this code is needed
        // otherwise the preferred APN will be lost.
        Map<String, ?> allPrefApnId = sp.getAll();
        for (String key : allPrefApnId.keySet()) {
            // extract subId from key by removing COLUMN_APN_ID
            try {
                int subId = Integer.parseInt(key.replace(COLUMN_APN_ID, ""));
                long apnId = getPreferredApnId(subId, false);
                if (apnId != INVALID_APN_ID) {
                    setPreferredApn(apnId, subId);
                }
            } catch (Exception e) {
                loge("Skipping over key " + key + " due to exception " + e);
            }
        }

        SharedPreferences.Editor editor = sp.edit();
        editor.clear();
        editor.apply();
    }

    private void setPreferredApn(Long id, int subId) {
        log("setPreferredApn: _id " + id + " subId " + subId);
        SQLiteDatabase db = getWritableDatabase();
        // query all unique fields from id
        String[] proj = CARRIERS_UNIQUE_FIELDS.toArray(new String[CARRIERS_UNIQUE_FIELDS.size()]);

        Cursor c = db.query(CARRIERS_TABLE, proj, "_id=" + id, null, null, null, null);
        if (c != null) {
            if (c.getCount() == 1) {
                c.moveToFirst();
                SharedPreferences sp = getContext().getSharedPreferences(PREF_FILE_FULL_APN,
                        Context.MODE_PRIVATE);
                SharedPreferences.Editor editor = sp.edit();
                // store values of all unique fields to SP
                for (String key : CARRIERS_UNIQUE_FIELDS) {
                    editor.putString(key + subId, c.getString(c.getColumnIndex(key)));
                }
                // also store the version number
                editor.putString(DB_VERSION_KEY + subId, "" + DATABASE_VERSION);
                editor.apply();
            } else {
                log("setPreferredApn: # matching APNs found " + c.getCount());
            }
            c.close();
        } else {
            log("setPreferredApn: No matching APN found");
        }
    }

    private long getPreferredApnIdFromApn(int subId) {
        log("getPreferredApnIdFromApn: for subId " + subId);
        SQLiteDatabase db = getWritableDatabase();
        String where = TextUtils.join("=? and ", CARRIERS_UNIQUE_FIELDS) + "=?";
        String[] whereArgs = new String[CARRIERS_UNIQUE_FIELDS.size()];
        SharedPreferences sp = getContext().getSharedPreferences(PREF_FILE_FULL_APN,
                Context.MODE_PRIVATE);
        long apnId = INVALID_APN_ID;
        int i = 0;
        for (String key : CARRIERS_UNIQUE_FIELDS) {
            whereArgs[i] = sp.getString(key + subId, null);
            if (whereArgs[i] == null) {
                return INVALID_APN_ID;
            }
            i++;
        }
        Cursor c = db.query(CARRIERS_TABLE, new String[]{"_id"}, where, whereArgs, null, null,
                null);
        if (c != null) {
            if (c.getCount() == 1) {
                c.moveToFirst();
                apnId = c.getInt(c.getColumnIndex("_id"));
            } else {
                log("getPreferredApnIdFromApn: returning INVALID. # matching APNs found " +
                        c.getCount());
            }
            c.close();
        } else {
            log("getPreferredApnIdFromApn: returning INVALID. No matching APN found");
        }
        return apnId;
    }

    private void deletePreferredApn(int subId) {
        log("deletePreferredApn: for subId " + subId);
        SharedPreferences sp = getContext().getSharedPreferences(PREF_FILE_FULL_APN,
                Context.MODE_PRIVATE);
        if (sp.contains(DB_VERSION_KEY + subId)) {
            log("deletePreferredApn: apn is stored. Deleting it now for subId " + subId);
            SharedPreferences.Editor editor = sp.edit();
            editor.remove(DB_VERSION_KEY + subId);
            for (String key : CARRIERS_UNIQUE_FIELDS) {
                editor.remove(key + subId);
            }
            editor.apply();
        }
    }

    boolean isCallingFromSystemUid() {
        return mInjector.binderGetCallingUid() == Process.SYSTEM_UID;
    }

    void ensureCallingFromSystemUid(String message) {
        if (!isCallingFromSystemUid()) {
            throw new SecurityException(message);
        }
    }

    @Override
    public synchronized Cursor query(Uri url, String[] projectionIn, String selection,
            String[] selectionArgs, String sort) {
        if (VDBG) log("query: url=" + url + ", projectionIn=" + projectionIn + ", selection="
            + selection + "selectionArgs=" + selectionArgs + ", sort=" + sort);
        TelephonyManager mTelephonyManager =
                (TelephonyManager)getContext().getSystemService(Context.TELEPHONY_SERVICE);
        int subId = SubscriptionManager.getDefaultSubscriptionId();
        String subIdString;
        SQLiteQueryBuilder qb = new SQLiteQueryBuilder();
        qb.setStrict(true); // a little protection from injection attacks
        qb.setTables(CARRIERS_TABLE);

        List<String> constraints = new ArrayList<String>();

        int match = s_urlMatcher.match(url);
        switch (match) {
            case URL_TELEPHONY_USING_SUBID: {
                subIdString = url.getLastPathSegment();
                try {
                    subId = Integer.parseInt(subIdString);
                } catch (NumberFormatException e) {
                    loge("NumberFormatException" + e);
                    return null;
                }
                if (DBG) log("subIdString = " + subIdString + " subId = " + subId);
                constraints.add(NUMERIC + " = '" + mTelephonyManager.getSimOperator(subId) + "'");
                constraints.add(SUBSCRIPTION_ID + "=" + subIdString);
            }
            // intentional fall through from above case
            case URL_TELEPHONY: {
                constraints.add(IS_NOT_OWNED_BY_DPC);
                break;
            }

            case URL_CURRENT_USING_SUBID: {
                subIdString = url.getLastPathSegment();
                try {
                    subId = Integer.parseInt(subIdString);
                } catch (NumberFormatException e) {
                    loge("NumberFormatException" + e);
                    return null;
                }
                if (DBG) log("subIdString = " + subIdString + " subId = " + subId);
                constraints.add(SUBSCRIPTION_ID + "=" + subIdString);
            }
            //intentional fall through from above case
            case URL_CURRENT: {
                constraints.add("current IS NOT NULL");
                constraints.add(IS_NOT_OWNED_BY_DPC);
                // do not ignore the selection since MMS may use it.
                //selection = null;
                break;
            }

            case URL_ID: {
                constraints.add("_id = " + url.getPathSegments().get(1));
                constraints.add(IS_NOT_OWNED_BY_DPC);
                break;
            }

            case URL_PREFERAPN_USING_SUBID:
            case URL_PREFERAPN_NO_UPDATE_USING_SUBID: {
                subIdString = url.getLastPathSegment();
                try {
                    subId = Integer.parseInt(subIdString);
                } catch (NumberFormatException e) {
                    loge("NumberFormatException" + e);
                    return null;
                }
                if (DBG) log("subIdString = " + subIdString + " subId = " + subId);
                constraints.add(SUBSCRIPTION_ID + "=" + subIdString);
            }
            //intentional fall through from above case
            case URL_PREFERAPN:
            case URL_PREFERAPN_NO_UPDATE: {
                constraints.add("_id = " + getPreferredApnId(subId, true));
                break;
            }

            case URL_DPC: {
                ensureCallingFromSystemUid("URL_DPC called from non SYSTEM_UID.");
                // DPC query only returns DPC records.
                constraints.add(IS_OWNED_BY_DPC);
                break;
            }

            case URL_FILTERED: {
                if(isManagedApnEnforced()) {
                    // If enforced, return DPC records only.
                    constraints.add(IS_OWNED_BY_DPC);
                } else {
                    // Otherwise return non-DPC records only.
                    constraints.add(IS_NOT_OWNED_BY_DPC);
                }
                break;
            }

            case URL_ENFORCE_MANAGED: {
                ensureCallingFromSystemUid("URL_ENFORCE_MANAGED called from non SYSTEM_UID.");
                MatrixCursor cursor = new MatrixCursor(new String[]{ENFORCED_KEY});
                cursor.addRow(new Object[]{isManagedApnEnforced() ? 1 : 0});
                return cursor;
            }

            case URL_SIMINFO: {
                qb.setTables(SIMINFO_TABLE);
                break;
            }

            default: {
                return null;
            }
        }

        // appendWhere doesn't add ANDs so we do it ourselves
        if (constraints.size() > 0) {
            qb.appendWhere(TextUtils.join(" AND ", constraints));
        }

        if (match != URL_SIMINFO) {
            if (projectionIn != null) {
                for (String column : projectionIn) {
                    if (TYPE.equals(column) ||
                            MMSC.equals(column) ||
                            MMSPROXY.equals(column) ||
                            MMSPORT.equals(column) ||
                            APN.equals(column)) {
                        // noop
                    } else {
                        checkPermission();
                        break;
                    }
                }
            } else {
                // null returns all columns, so need permission check
                checkPermission();
            }
        }

        SQLiteDatabase db = getReadableDatabase();
        Cursor ret = null;
        try {
            // Exclude entries marked deleted
            if (CARRIERS_TABLE.equals(qb.getTables())) {
                if (TextUtils.isEmpty(selection)) {
                    selection = "";
                } else {
                    selection += " and ";
                }
                selection += IS_NOT_USER_DELETED + " and " +
                        IS_NOT_USER_DELETED_BUT_PRESENT_IN_XML + " and " +
                        IS_NOT_CARRIER_DELETED + " and " +
                        IS_NOT_CARRIER_DELETED_BUT_PRESENT_IN_XML;
                if (VDBG) log("query: selection modified to " + selection);
            }
            ret = qb.query(db, projectionIn, selection, selectionArgs, null, null, sort);
        } catch (SQLException e) {
            loge("got exception when querying: " + e);
        }
        if (ret != null)
            ret.setNotificationUri(getContext().getContentResolver(), url);
        return ret;
    }

    @Override
    public String getType(Uri url)
    {
        switch (s_urlMatcher.match(url)) {
        case URL_TELEPHONY:
        case URL_TELEPHONY_USING_SUBID:
            return "vnd.android.cursor.dir/telephony-carrier";

        case URL_ID:
            return "vnd.android.cursor.item/telephony-carrier";

        case URL_PREFERAPN_USING_SUBID:
        case URL_PREFERAPN_NO_UPDATE_USING_SUBID:
        case URL_PREFERAPN:
        case URL_PREFERAPN_NO_UPDATE:
            return "vnd.android.cursor.item/telephony-carrier";

        default:
            throw new IllegalArgumentException("Unknown URL " + url);
        }
    }

    /**
     * Insert an array of ContentValues and call notifyChange at the end.
     */
    @Override
    public synchronized int bulkInsert(Uri url, ContentValues[] values) {
        return unsynchronizedBulkInsert(url, values);
    }

    /**
     * Do a bulk insert while inside a synchronized function. This is typically not safe and should
     * only be done when you are sure there will be no conflict.
     */
    private int unsynchronizedBulkInsert(Uri url, ContentValues[] values) {
        int count = 0;
        boolean notify = false;
        for (ContentValues value : values) {
            Pair<Uri, Boolean> rowAndNotify = insertSingleRow(url, value);
            if (rowAndNotify.first != null) {
                count++;
            }
            if (rowAndNotify.second == true) {
                notify = true;
            }
        }
        if (notify) {
            getContext().getContentResolver().notifyChange(CONTENT_URI, null,
                    true, UserHandle.USER_ALL);
        }
        return count;
    }

    @Override
    public synchronized Uri insert(Uri url, ContentValues initialValues) {
        Pair<Uri, Boolean> rowAndNotify = insertSingleRow(url, initialValues);
        if (rowAndNotify.second) {
            getContext().getContentResolver().notifyChange(CONTENT_URI, null,
                    true, UserHandle.USER_ALL);
        }
        return rowAndNotify.first;
    }

    /**
     * Internal insert function to prevent code duplication for URL_TELEPHONY and URL_DPC.
     *
     * @param values the value that caller wants to insert
     * @return a pair in which the first element refers to the Uri for the row inserted, the second
     *         element refers to whether sends out nofitication.
     */
    private Pair<Uri, Boolean> insertRowWithValue(ContentValues values) {
        Uri result = null;
        boolean notify = false;
        SQLiteDatabase db = getWritableDatabase();

        try {
            // Replace on conflict so that if same APN is present in db with edited
            // as UNEDITED or USER/CARRIER_DELETED, it is replaced with
            // edited USER/CARRIER_EDITED
            long rowID = db.insertWithOnConflict(CARRIERS_TABLE, null, values,
                    SQLiteDatabase.CONFLICT_ABORT);
            if (rowID >= 0) {
                result = ContentUris.withAppendedId(CONTENT_URI, rowID);
                notify = true;
            }
            if (VDBG) log("insert: inserted " + values.toString() + " rowID = " + rowID);
        } catch (SQLException e) {
            log("insert: exception " + e);
            // Insertion failed which could be due to a conflict. Check if that is the case
            // and merge the entries
            Cursor oldRow = DatabaseHelper.selectConflictingRow(db, CARRIERS_TABLE, values);
            if (oldRow != null) {
                ContentValues mergedValues = new ContentValues();
                DatabaseHelper.mergeFieldsAndUpdateDb(db, CARRIERS_TABLE, oldRow, values,
                        mergedValues, false, getContext());
                oldRow.close();
                notify = true;
            }
        }
        return Pair.create(result, notify);
    }

    private Pair<Uri, Boolean> insertSingleRow(Uri url, ContentValues initialValues) {
        Uri result = null;
        int subId = SubscriptionManager.getDefaultSubscriptionId();

        checkPermission();
        syncBearerBitmaskAndNetworkTypeBitmask(initialValues);

        boolean notify = false;
        SQLiteDatabase db = getWritableDatabase();
        int match = s_urlMatcher.match(url);
        switch (match)
        {
            case URL_TELEPHONY_USING_SUBID:
            {
                String subIdString = url.getLastPathSegment();
                try {
                    subId = Integer.parseInt(subIdString);
                } catch (NumberFormatException e) {
                    loge("NumberFormatException" + e);
                    return Pair.create(result, notify);
                }
                if (DBG) log("subIdString = " + subIdString + " subId = " + subId);
            }
            //intentional fall through from above case

            case URL_TELEPHONY:
            {
                ContentValues values;
                if (initialValues != null) {
                    values = new ContentValues(initialValues);
                } else {
                    values = new ContentValues();
                }

                values.put(SUBSCRIPTION_ID, subId);
                values = DatabaseHelper.setDefaultValue(values);
                if (!values.containsKey(EDITED)) {
                    values.put(EDITED, CARRIER_EDITED);
                }
                // Owned_by should be others if inserted via general uri.
                values.put(OWNED_BY, OWNED_BY_OTHERS);

                Pair<Uri, Boolean> ret = insertRowWithValue(values);
                result = ret.first;
                notify = ret.second;
                break;
            }

            case URL_CURRENT_USING_SUBID:
            {
                String subIdString = url.getLastPathSegment();
                try {
                    subId = Integer.parseInt(subIdString);
                } catch (NumberFormatException e) {
                    loge("NumberFormatException" + e);
                    return Pair.create(result, notify);
                }
                if (DBG) log("subIdString = " + subIdString + " subId = " + subId);
                // FIXME use subId in the query
            }
            //intentional fall through from above case

            case URL_CURRENT:
            {
                // zero out the previous operator
                db.update(CARRIERS_TABLE, s_currentNullMap, CURRENT + "!=0", null);

                String numeric = initialValues.getAsString(NUMERIC);
                int updated = db.update(CARRIERS_TABLE, s_currentSetMap,
                        NUMERIC + " = '" + numeric + "'", null);

                if (updated > 0)
                {
                    if (VDBG) log("Setting numeric '" + numeric + "' to be the current operator");
                }
                else
                {
                    loge("Failed setting numeric '" + numeric + "' to the current operator");
                }
                break;
            }

            case URL_PREFERAPN_USING_SUBID:
            case URL_PREFERAPN_NO_UPDATE_USING_SUBID:
            {
                String subIdString = url.getLastPathSegment();
                try {
                    subId = Integer.parseInt(subIdString);
                } catch (NumberFormatException e) {
                    loge("NumberFormatException" + e);
                    return Pair.create(result, notify);
                }
                if (DBG) log("subIdString = " + subIdString + " subId = " + subId);
            }
            //intentional fall through from above case

            case URL_PREFERAPN:
            case URL_PREFERAPN_NO_UPDATE:
            {
                if (initialValues != null) {
                    if(initialValues.containsKey(COLUMN_APN_ID)) {
                        setPreferredApnId(initialValues.getAsLong(COLUMN_APN_ID), subId, true);
                    }
                }
                break;
            }

            case URL_DPC: {
                ensureCallingFromSystemUid("URL_DPC called from non SYSTEM_UID.");

                ContentValues values;
                if (initialValues != null) {
                    values = new ContentValues(initialValues);
                } else {
                    values = new ContentValues();
                }

                // Owned_by should be DPC if inserted via URL_DPC.
                values.put(OWNED_BY, OWNED_BY_DPC);
                // DPC records should not be user editable.
                values.put(USER_EDITABLE, false);
                Pair<Uri, Boolean> ret = insertRowWithValue(values);
                result = ret.first;
                notify = ret.second;
                break;
            }

            case URL_SIMINFO: {
               long id = db.insert(SIMINFO_TABLE, null, initialValues);
               result = ContentUris.withAppendedId(SubscriptionManager.CONTENT_URI, id);
               break;
            }
        }

        return Pair.create(result, notify);
    }

    @Override
    public synchronized int delete(Uri url, String where, String[] whereArgs) {
        int count = 0;
        int subId = SubscriptionManager.getDefaultSubscriptionId();
        String userOrCarrierEdited = ") and (" +
                IS_USER_EDITED +  " or " +
                IS_CARRIER_EDITED + ")";
        String notUserOrCarrierEdited = ") and (" +
                IS_NOT_USER_EDITED +  " and " +
                IS_NOT_CARRIER_EDITED + ")";
        String unedited = ") and " + IS_UNEDITED;
        ContentValues cv = new ContentValues();
        cv.put(EDITED, USER_DELETED);

        checkPermission();

        SQLiteDatabase db = getWritableDatabase();
        int match = s_urlMatcher.match(url);
        switch (match)
        {
            case URL_DELETE:
            {
                // Delete preferred APN for all subIds
                deletePreferredApnId();
                // Delete unedited entries
                count = db.delete(CARRIERS_TABLE, "(" + where + unedited + " and " +
                        IS_NOT_OWNED_BY_DPC, whereArgs);
                break;
            }

            case URL_TELEPHONY_USING_SUBID:
            {
                 String subIdString = url.getLastPathSegment();
                 try {
                     subId = Integer.parseInt(subIdString);
                 } catch (NumberFormatException e) {
                     loge("NumberFormatException" + e);
                     throw new IllegalArgumentException("Invalid subId " + url);
                 }
                 if (DBG) log("subIdString = " + subIdString + " subId = " + subId);
                // FIXME use subId in query
            }
            //intentional fall through from above case

            case URL_TELEPHONY:
            {
                // Delete user/carrier edited entries
                count = db.delete(CARRIERS_TABLE, "(" + where + userOrCarrierEdited
                        + " and " + IS_NOT_OWNED_BY_DPC, whereArgs);
                // Otherwise mark as user deleted instead of deleting
                count += db.update(CARRIERS_TABLE, cv, "(" + where +
                        notUserOrCarrierEdited + " and " + IS_NOT_OWNED_BY_DPC, whereArgs);
                break;
            }

            case URL_CURRENT_USING_SUBID: {
                String subIdString = url.getLastPathSegment();
                try {
                    subId = Integer.parseInt(subIdString);
                } catch (NumberFormatException e) {
                    loge("NumberFormatException" + e);
                    throw new IllegalArgumentException("Invalid subId " + url);
                }
                if (DBG) log("subIdString = " + subIdString + " subId = " + subId);
                // FIXME use subId in query
            }
            //intentional fall through from above case

            case URL_CURRENT:
            {
                // Delete user/carrier edited entries
                count = db.delete(CARRIERS_TABLE, "(" + where + userOrCarrierEdited
                        + " and " + IS_NOT_OWNED_BY_DPC, whereArgs);
                // Otherwise mark as user deleted instead of deleting
                count += db.update(CARRIERS_TABLE, cv, "(" + where +
                        notUserOrCarrierEdited + " and " + IS_NOT_OWNED_BY_DPC, whereArgs);
                break;
            }

            case URL_ID:
            {
                // Delete user/carrier edited entries
                count = db.delete(CARRIERS_TABLE,
                        "(" + _ID + "=?" + userOrCarrierEdited +
                                " and " + IS_NOT_OWNED_BY_DPC,
                        new String[] { url.getLastPathSegment() });
                // Otherwise mark as user deleted instead of deleting
                count += db.update(CARRIERS_TABLE, cv,
                        "(" + _ID + "=?" + notUserOrCarrierEdited +
                                " and " + IS_NOT_OWNED_BY_DPC,
                        new String[]{url.getLastPathSegment() });
                break;
            }

            case URL_RESTOREAPN_USING_SUBID: {
                String subIdString = url.getLastPathSegment();
                try {
                    subId = Integer.parseInt(subIdString);
                } catch (NumberFormatException e) {
                    loge("NumberFormatException" + e);
                    throw new IllegalArgumentException("Invalid subId " + url);
                }
                if (DBG) log("subIdString = " + subIdString + " subId = " + subId);
                // FIXME use subId in query
            }
            case URL_RESTOREAPN: {
                count = 1;
                restoreDefaultAPN(subId);
                break;
            }

            case URL_PREFERAPN_USING_SUBID:
            case URL_PREFERAPN_NO_UPDATE_USING_SUBID: {
                String subIdString = url.getLastPathSegment();
                try {
                    subId = Integer.parseInt(subIdString);
                } catch (NumberFormatException e) {
                    loge("NumberFormatException" + e);
                    throw new IllegalArgumentException("Invalid subId " + url);
                }
                if (DBG) log("subIdString = " + subIdString + " subId = " + subId);
            }
            //intentional fall through from above case

            case URL_PREFERAPN:
            case URL_PREFERAPN_NO_UPDATE:
            {
                setPreferredApnId((long)INVALID_APN_ID, subId, true);
                if ((match == URL_PREFERAPN) || (match == URL_PREFERAPN_USING_SUBID)) count = 1;
                break;
            }

            case URL_DPC_ID: {
                ensureCallingFromSystemUid("URL_DPC_ID called from non SYSTEM_UID.");

                // Only delete if owned by DPC.
                count = db.delete(CARRIERS_TABLE, "(" + _ID + "=?)" + " and " + IS_OWNED_BY_DPC,
                        new String[] { url.getLastPathSegment() });
                break;
            }

            case URL_SIMINFO: {
                count = db.delete(SIMINFO_TABLE, where, whereArgs);
                break;
            }

            case URL_UPDATE_DB: {
                updateApnDb();
                count = 1;
                break;
            }

            default: {
                throw new UnsupportedOperationException("Cannot delete that URL: " + url);
            }
        }

        if (count > 0) {
            getContext().getContentResolver().notifyChange(CONTENT_URI, null,
                    true, UserHandle.USER_ALL);
        }

        return count;
    }

    @Override
    public synchronized int update(Uri url, ContentValues values, String where, String[] whereArgs)
    {
        int count = 0;
        int uriType = URL_UNKNOWN;
        int subId = SubscriptionManager.getDefaultSubscriptionId();

        checkPermission();
        syncBearerBitmaskAndNetworkTypeBitmask(values);

        SQLiteDatabase db = getWritableDatabase();
        int match = s_urlMatcher.match(url);
        switch (match)
        {
            case URL_TELEPHONY_USING_SUBID:
            {
                 String subIdString = url.getLastPathSegment();
                 try {
                     subId = Integer.parseInt(subIdString);
                 } catch (NumberFormatException e) {
                     loge("NumberFormatException" + e);
                     throw new IllegalArgumentException("Invalid subId " + url);
                 }
                 if (DBG) log("subIdString = " + subIdString + " subId = " + subId);
                //FIXME use subId in the query
            }
            //intentional fall through from above case

            case URL_TELEPHONY:
            {
                if (!values.containsKey(EDITED)) {
                    values.put(EDITED, CARRIER_EDITED);
                }

                // Replace on conflict so that if same APN is present in db with edited
                // as UNEDITED or USER/CARRIER_DELETED, it is replaced with
                // edited USER/CARRIER_EDITED
                count = db.updateWithOnConflict(CARRIERS_TABLE, values, where +
                                " and " + IS_NOT_OWNED_BY_DPC, whereArgs,
                        SQLiteDatabase.CONFLICT_REPLACE);
                break;
            }

            case URL_CURRENT_USING_SUBID:
            {
                String subIdString = url.getLastPathSegment();
                try {
                    subId = Integer.parseInt(subIdString);
                } catch (NumberFormatException e) {
                    loge("NumberFormatException" + e);
                    throw new IllegalArgumentException("Invalid subId " + url);
                }
                if (DBG) log("subIdString = " + subIdString + " subId = " + subId);
                //FIXME use subId in the query
            }
            //intentional fall through from above case

            case URL_CURRENT:
            {
                if (!values.containsKey(EDITED)) {
                    values.put(EDITED, CARRIER_EDITED);
                }
                // Replace on conflict so that if same APN is present in db with edited
                // as UNEDITED or USER/CARRIER_DELETED, it is replaced with
                // edited USER/CARRIER_EDITED
                count = db.updateWithOnConflict(CARRIERS_TABLE, values, where +
                                " and " + IS_NOT_OWNED_BY_DPC,
                        whereArgs, SQLiteDatabase.CONFLICT_REPLACE);
                break;
            }

            case URL_ID:
            {
                if (where != null || whereArgs != null) {
                    throw new UnsupportedOperationException(
                            "Cannot update URL " + url + " with a where clause");
                }
                if (!values.containsKey(EDITED)) {
                    values.put(EDITED, CARRIER_EDITED);
                }

                try {
                    count = db.updateWithOnConflict(CARRIERS_TABLE, values,
                        _ID + "=?" + " and " + IS_NOT_OWNED_BY_DPC,
                        new String[] { url.getLastPathSegment() }, SQLiteDatabase.CONFLICT_ABORT);
                } catch (SQLException e) {
                    // Update failed which could be due to a conflict. Check if that is
                    // the case and merge the entries
                    Cursor oldRow = DatabaseHelper.selectConflictingRow(db, CARRIERS_TABLE, values);
                    if (oldRow != null) {
                        ContentValues mergedValues = new ContentValues();
                        DatabaseHelper.mergeFieldsAndUpdateDb(db, CARRIERS_TABLE, oldRow, values,
                                mergedValues, false, getContext());
                        oldRow.close();
                    }
                }
                break;
            }

            case URL_PREFERAPN_USING_SUBID:
            case URL_PREFERAPN_NO_UPDATE_USING_SUBID:
            {
                String subIdString = url.getLastPathSegment();
                try {
                    subId = Integer.parseInt(subIdString);
                } catch (NumberFormatException e) {
                    loge("NumberFormatException" + e);
                    throw new IllegalArgumentException("Invalid subId " + url);
                }
                if (DBG) log("subIdString = " + subIdString + " subId = " + subId);
            }

            case URL_PREFERAPN:
            case URL_PREFERAPN_NO_UPDATE:
            {
                if (values != null) {
                    if (values.containsKey(COLUMN_APN_ID)) {
                        setPreferredApnId(values.getAsLong(COLUMN_APN_ID), subId, true);
                        if ((match == URL_PREFERAPN) ||
                                (match == URL_PREFERAPN_USING_SUBID)) {
                            count = 1;
                        }
                    }
                }
                break;
            }

            case URL_DPC_ID:
            {
                ensureCallingFromSystemUid("URL_DPC_ID called from non SYSTEM_UID.");

                if (where != null || whereArgs != null) {
                    throw new UnsupportedOperationException(
                            "Cannot update URL " + url + " with a where clause");
                }
                count = db.updateWithOnConflict(CARRIERS_TABLE, values,
                        _ID + "=?" + " and " + IS_OWNED_BY_DPC,
                        new String[] { url.getLastPathSegment() }, SQLiteDatabase.CONFLICT_REPLACE);
                break;
            }

            case URL_ENFORCE_MANAGED: {
                ensureCallingFromSystemUid("URL_ENFORCE_MANAGED called from non SYSTEM_UID.");
                if (values != null) {
                    if (values.containsKey(ENFORCED_KEY)) {
                        setManagedApnEnforced(values.getAsBoolean(ENFORCED_KEY));
                        count = 1;
                    }
                }
                break;
            }

            case URL_SIMINFO: {
                count = db.update(SIMINFO_TABLE, values, where, whereArgs);
                uriType = URL_SIMINFO;
                break;
            }

            default: {
                throw new UnsupportedOperationException("Cannot update that URL: " + url);
            }
        }

        if (count > 0) {
            switch (uriType) {
                case URL_SIMINFO:
                    getContext().getContentResolver().notifyChange(
                            SubscriptionManager.CONTENT_URI, null, true, UserHandle.USER_ALL);
                    break;
                default:
                    getContext().getContentResolver().notifyChange(
                            CONTENT_URI, null, true, UserHandle.USER_ALL);
            }
        }

        return count;
    }

    private void checkPermission() {
        int status = getContext().checkCallingOrSelfPermission(
                "android.permission.WRITE_APN_SETTINGS");
        if (status == PackageManager.PERMISSION_GRANTED) {
            return;
        }

        PackageManager packageManager = getContext().getPackageManager();
        String[] packages = packageManager.getPackagesForUid(Binder.getCallingUid());

        TelephonyManager telephonyManager =
                (TelephonyManager) getContext().getSystemService(Context.TELEPHONY_SERVICE);
        for (String pkg : packages) {
            if (telephonyManager.checkCarrierPrivilegesForPackage(pkg) ==
                    TelephonyManager.CARRIER_PRIVILEGE_STATUS_HAS_ACCESS) {
                return;
            }
        }
        throw new SecurityException("No permission to write APN settings");
    }

    private DatabaseHelper mOpenHelper;

    private void restoreDefaultAPN(int subId) {
        SQLiteDatabase db = getWritableDatabase();

        try {
            db.delete(CARRIERS_TABLE, IS_NOT_OWNED_BY_DPC, null);
        } catch (SQLException e) {
            loge("got exception when deleting to restore: " + e);
        }

        // delete preferred apn ids and preferred apns (both stored in diff SharedPref) for all
        // subIds
        SharedPreferences spApnId = getContext().getSharedPreferences(PREF_FILE_APN,
                Context.MODE_PRIVATE);
        SharedPreferences.Editor editorApnId = spApnId.edit();
        editorApnId.clear();
        editorApnId.apply();

        SharedPreferences spApn = getContext().getSharedPreferences(PREF_FILE_FULL_APN,
                Context.MODE_PRIVATE);
        SharedPreferences.Editor editorApn = spApn.edit();
        editorApn.clear();
        editorApn.apply();

        if (apnSourceServiceExists(getContext())) {
            restoreApnsWithService();
        } else {
            initDatabaseWithDatabaseHelper(db);
        }
    }

    private synchronized void updateApnDb() {
        if (apnSourceServiceExists(getContext())) {
            loge("called updateApnDb when apn source service exists");
            return;
        }

        if (!needApnDbUpdate()) {
            log("Skipping apn db update since apn-conf has not changed.");
            return;
        }

        SQLiteDatabase db = getWritableDatabase();

        // Delete preferred APN for all subIds
        deletePreferredApnId();

        // Delete entries in db
        try {
            if (VDBG) log("updateApnDb: deleting edited=UNEDITED entries");
            db.delete(CARRIERS_TABLE, IS_UNEDITED + " and " + IS_NOT_OWNED_BY_DPC, null);
        } catch (SQLException e) {
            loge("got exception when deleting to update: " + e);
        }

        initDatabaseWithDatabaseHelper(db);

        // Notify listereners of DB change since DB has been updated
        getContext().getContentResolver().notifyChange(
                CONTENT_URI, null, true, UserHandle.USER_ALL);

    }

    /**
     * Sync the bearer bitmask and network type bitmask when inserting and updating.
     * Since bearerBitmask is deprecating, map the networkTypeBitmask to bearerBitmask if
     * networkTypeBitmask was provided. But if networkTypeBitmask was not provided, map the
     * bearerBitmask to networkTypeBitmask.
     */
    private static void syncBearerBitmaskAndNetworkTypeBitmask(ContentValues values) {
        if (values.containsKey(NETWORK_TYPE_BITMASK)) {
            int convertedBitmask = ServiceState.convertNetworkTypeBitmaskToBearerBitmask(
                    values.getAsInteger(NETWORK_TYPE_BITMASK));
            if (values.containsKey(BEARER_BITMASK)
                    && convertedBitmask != values.getAsInteger(BEARER_BITMASK)) {
                loge("Network type bitmask and bearer bitmask are not compatible.");
            }
            values.put(BEARER_BITMASK, ServiceState.convertNetworkTypeBitmaskToBearerBitmask(
                    values.getAsInteger(NETWORK_TYPE_BITMASK)));
        } else {
            if (values.containsKey(BEARER_BITMASK)) {
                int convertedBitmask = ServiceState.convertBearerBitmaskToNetworkTypeBitmask(
                        values.getAsInteger(BEARER_BITMASK));
                values.put(NETWORK_TYPE_BITMASK, convertedBitmask);
            }
        }
    }

    /**
     * Log with debug
     *
     * @param s is string log
     */
    private static void log(String s) {
        Log.d(TAG, s);
    }

    private static void loge(String s) {
        Log.e(TAG, s);
    }
}