providers/telephony/MmsSmsDatabaseHelper.java

/*
 * Copyright (C) 2008 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 java.io.IOException;
import java.io.InputStream;
import java.io.FileInputStream;
import java.io.File;
import java.util.ArrayList;

import android.content.BroadcastReceiver;
import android.content.ContentValues;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.provider.BaseColumns;
import android.provider.Telephony;
import android.provider.Telephony.Mms;
import android.provider.Telephony.MmsSms;
import android.provider.Telephony.Sms;
import android.provider.Telephony.Threads;
import android.provider.Telephony.Mms.Addr;
import android.provider.Telephony.Mms.Part;
import android.provider.Telephony.Mms.Rate;
import android.provider.Telephony.MmsSms.PendingMessages;
import android.util.Log;

import com.google.android.mms.pdu.EncodedStringValue;
import com.google.android.mms.pdu.PduHeaders;

public class MmsSmsDatabaseHelper extends SQLiteOpenHelper {
    private static final String TAG = "MmsSmsDatabaseHelper";

    private static final String SMS_UPDATE_THREAD_READ_BODY =
                        "  UPDATE threads SET read = " +
                        "    CASE (SELECT COUNT(*)" +
                        "          FROM sms" +
                        "          WHERE " + Sms.READ + " = 0" +
                        "            AND " + Sms.THREAD_ID + " = threads._id)" +
                        "      WHEN 0 THEN 1" +
                        "      ELSE 0" +
                        "    END" +
                        "  WHERE threads._id = new." + Sms.THREAD_ID + "; ";

    private static final String UPDATE_THREAD_COUNT_ON_NEW =
                        "  UPDATE threads SET message_count = " +
                        "     (SELECT COUNT(sms._id) FROM sms LEFT JOIN threads " +
                        "      ON threads._id = " + Sms.THREAD_ID +
                        "      WHERE " + Sms.THREAD_ID + " = new.thread_id" +
                        "        AND sms." + Sms.TYPE + " != 3) + " +
                        "     (SELECT COUNT(pdu._id) FROM pdu LEFT JOIN threads " +
                        "      ON threads._id = " + Mms.THREAD_ID +
                        "      WHERE " + Mms.THREAD_ID + " = new.thread_id" +
                        "        AND (m_type=132 OR m_type=130 OR m_type=128)" +
                        "        AND " + Mms.MESSAGE_BOX + " != 3) " +
                        "  WHERE threads._id = new.thread_id; ";

    private static final String UPDATE_THREAD_COUNT_ON_OLD =
                        "  UPDATE threads SET message_count = " +
                        "     (SELECT COUNT(sms._id) FROM sms LEFT JOIN threads " +
                        "      ON threads._id = " + Sms.THREAD_ID +
                        "      WHERE " + Sms.THREAD_ID + " = old.thread_id" +
                        "        AND sms." + Sms.TYPE + " != 3) + " +
                        "     (SELECT COUNT(pdu._id) FROM pdu LEFT JOIN threads " +
                        "      ON threads._id = " + Mms.THREAD_ID +
                        "      WHERE " + Mms.THREAD_ID + " = old.thread_id" +
                        "        AND (m_type=132 OR m_type=130 OR m_type=128)" +
                        "        AND " + Mms.MESSAGE_BOX + " != 3) " +
                        "  WHERE threads._id = old.thread_id; ";

    private static final String SMS_UPDATE_THREAD_DATE_SNIPPET_COUNT_ON_UPDATE =
                        "BEGIN" +
                        "  UPDATE threads SET" +
                        "    date = (strftime('%s','now') * 1000), " +
                        "    snippet = new." + Sms.BODY + ", " +
                        "    snippet_cs = 0" +
                        "  WHERE threads._id = new." + Sms.THREAD_ID + "; " +
                        UPDATE_THREAD_COUNT_ON_NEW +
                        SMS_UPDATE_THREAD_READ_BODY +
                        "END;";

    private static final String PDU_UPDATE_THREAD_CONSTRAINTS =
                        "  WHEN new." + Mms.MESSAGE_TYPE + "=" +
                        PduHeaders.MESSAGE_TYPE_RETRIEVE_CONF +
                        "    OR new." + Mms.MESSAGE_TYPE + "=" +
                        PduHeaders.MESSAGE_TYPE_NOTIFICATION_IND +
                        "    OR new." + Mms.MESSAGE_TYPE + "=" +
                        PduHeaders.MESSAGE_TYPE_SEND_REQ + " ";

    // When looking in the pdu table for unread messages, only count messages that
    // are displayed to the user. The constants are defined in PduHeaders and could be used
    // here, but the string "(m_type=132 OR m_type=130 OR m_type=128)" is used throughout this
    // file and so it is used here to be consistent.
    //     m_type=128   = MESSAGE_TYPE_SEND_REQ
    //     m_type=130   = MESSAGE_TYPE_NOTIFICATION_IND
    //     m_type=132   = MESSAGE_TYPE_RETRIEVE_CONF
    private static final String PDU_UPDATE_THREAD_READ_BODY =
                        "  UPDATE threads SET read = " +
                        "    CASE (SELECT COUNT(*)" +
                        "          FROM " + MmsProvider.TABLE_PDU +
                        "          WHERE " + Mms.READ + " = 0" +
                        "            AND " + Mms.THREAD_ID + " = threads._id " +
                        "            AND (m_type=132 OR m_type=130 OR m_type=128)) " +
                        "      WHEN 0 THEN 1" +
                        "      ELSE 0" +
                        "    END" +
                        "  WHERE threads._id = new." + Mms.THREAD_ID + "; ";

    private static final String PDU_UPDATE_THREAD_DATE_SNIPPET_COUNT_ON_UPDATE =
                        "BEGIN" +
                        "  UPDATE threads SET" +
                        "    date = (strftime('%s','now') * 1000), " +
                        "    snippet = new." + Mms.SUBJECT + ", " +
                        "    snippet_cs = new." + Mms.SUBJECT_CHARSET +
                        "  WHERE threads._id = new." + Mms.THREAD_ID + "; " +
                        UPDATE_THREAD_COUNT_ON_NEW +
                        PDU_UPDATE_THREAD_READ_BODY +
                        "END;";

    private static final String UPDATE_THREAD_SNIPPET_SNIPPET_CS_ON_DELETE =
                        "  UPDATE threads SET snippet = " +
                        "   (SELECT snippet FROM" +
                        "     (SELECT date * 1000 AS date, sub AS snippet, thread_id FROM pdu" +
                        "      UNION SELECT date, body AS snippet, thread_id FROM sms)" +
                        "    WHERE thread_id = OLD.thread_id ORDER BY date DESC LIMIT 1) " +
                        "  WHERE threads._id = OLD.thread_id; " +
                        "  UPDATE threads SET snippet_cs = " +
                        "   (SELECT snippet_cs FROM" +
                        "     (SELECT date * 1000 AS date, sub_cs AS snippet_cs, thread_id FROM pdu" +
                        "      UNION SELECT date, 0 AS snippet_cs, thread_id FROM sms)" +
                        "    WHERE thread_id = OLD.thread_id ORDER BY date DESC LIMIT 1) " +
                        "  WHERE threads._id = OLD.thread_id; ";


    // When a part is inserted, if it is not text/plain or application/smil
    // (which both can exist with text-only MMSes), then there is an attachment.
    // Set has_attachment=1 in the threads table for the thread in question.
    private static final String PART_UPDATE_THREADS_ON_INSERT_TRIGGER =
                        "CREATE TRIGGER update_threads_on_insert_part " +
                        " AFTER INSERT ON part " +
                        " WHEN new.ct != 'text/plain' AND new.ct != 'application/smil' " +
                        " BEGIN " +
                        "  UPDATE threads SET has_attachment=1 WHERE _id IN " +
                        "   (SELECT pdu.thread_id FROM part JOIN pdu ON pdu._id=part.mid " +
                        "     WHERE part._id=new._id LIMIT 1); " +
                        " END";

    // When the 'mid' column in the part table is updated, we need to run the trigger to update
    // the threads table's has_attachment column, if the part is an attachment.
    private static final String PART_UPDATE_THREADS_ON_UPDATE_TRIGGER =
                        "CREATE TRIGGER update_threads_on_update_part " +
                        " AFTER UPDATE of " + Part.MSG_ID + " ON part " +
                        " WHEN new.ct != 'text/plain' AND new.ct != 'application/smil' " +
                        " BEGIN " +
                        "  UPDATE threads SET has_attachment=1 WHERE _id IN " +
                        "   (SELECT pdu.thread_id FROM part JOIN pdu ON pdu._id=part.mid " +
                        "     WHERE part._id=new._id LIMIT 1); " +
                        " END";


    // When a part is deleted (with the same non-text/SMIL constraint as when
    // we set has_attachment), update the threads table for all threads.
    // Unfortunately we cannot update only the thread that the part was
    // attached to, as it is possible that the part has been orphaned and
    // the message it was attached to is already gone.
    private static final String PART_UPDATE_THREADS_ON_DELETE_TRIGGER =
                        "CREATE TRIGGER update_threads_on_delete_part " +
                        " AFTER DELETE ON part " +
                        " WHEN old.ct != 'text/plain' AND old.ct != 'application/smil' " +
                        " BEGIN " +
                        "  UPDATE threads SET has_attachment = " +
                        "   CASE " +
                        "    (SELECT COUNT(*) FROM part JOIN pdu " +
                        "     WHERE pdu.thread_id = threads._id " +
                        "     AND part.ct != 'text/plain' AND part.ct != 'application/smil' " +
                        "     AND part.mid = pdu._id)" +
                        "   WHEN 0 THEN 0 " +
                        "   ELSE 1 " +
                        "   END; " +
                        " END";

    // When the 'thread_id' column in the pdu table is updated, we need to run the trigger to update
    // the threads table's has_attachment column, if the message has an attachment in 'part' table
    private static final String PDU_UPDATE_THREADS_ON_UPDATE_TRIGGER =
                        "CREATE TRIGGER update_threads_on_update_pdu " +
                        " AFTER UPDATE of thread_id ON pdu " +
                        " BEGIN " +
                        "  UPDATE threads SET has_attachment=1 WHERE _id IN " +
                        "   (SELECT pdu.thread_id FROM part JOIN pdu " +
                        "     WHERE part.ct != 'text/plain' AND part.ct != 'application/smil' " +
                        "     AND part.mid = pdu._id);" +
                        " END";

    private static MmsSmsDatabaseHelper sInstance = null;
    private static boolean sTriedAutoIncrement = false;
    private static boolean sFakeLowStorageTest = false;     // for testing only

    static final String DATABASE_NAME = "mmssms.db";
    static final int DATABASE_VERSION = 55;
    private final Context mContext;
    private LowStorageMonitor mLowStorageMonitor;


    private MmsSmsDatabaseHelper(Context context) {
        super(context, DATABASE_NAME, null, DATABASE_VERSION);

        mContext = context;
    }

    /**
     * Return a singleton helper for the combined MMS and SMS
     * database.
     */
    /* package */ static synchronized MmsSmsDatabaseHelper getInstance(Context context) {
        if (sInstance == null) {
            sInstance = new MmsSmsDatabaseHelper(context);
        }
        return sInstance;
    }

    public static void updateThread(SQLiteDatabase db, long thread_id) {
        if (thread_id < 0) {
            updateAllThreads(db, null, null);
            return;
        }

        // Delete the row for this thread in the threads table if
        // there are no more messages attached to it in either
        // the sms or pdu tables.
        int rows = db.delete("threads",
                  "_id = ? AND _id NOT IN" +
                  "          (SELECT thread_id FROM sms " +
                  "           UNION SELECT thread_id FROM pdu)",
                  new String[] { String.valueOf(thread_id) });
        if (rows > 0) {
            // If this deleted a row, let's remove orphaned canonical_addresses and get outta here
            db.delete("canonical_addresses",
                    "_id NOT IN (SELECT DISTINCT recipient_ids FROM threads)", null);
            return;
        }
        // Update the message count in the threads table as the sum
        // of all messages in both the sms and pdu tables.
        db.execSQL(
            "  UPDATE threads SET message_count = " +
            "     (SELECT COUNT(sms._id) FROM sms LEFT JOIN threads " +
            "      ON threads._id = " + Sms.THREAD_ID +
            "      WHERE " + Sms.THREAD_ID + " = " + thread_id +
            "        AND sms." + Sms.TYPE + " != 3) + " +
            "     (SELECT COUNT(pdu._id) FROM pdu LEFT JOIN threads " +
            "      ON threads._id = " + Mms.THREAD_ID +
            "      WHERE " + Mms.THREAD_ID + " = " + thread_id +
            "        AND (m_type=132 OR m_type=130 OR m_type=128)" +
            "        AND " + Mms.MESSAGE_BOX + " != 3) " +
            "  WHERE threads._id = " + thread_id + ";");

        // Update the date and the snippet (and its character set) in
        // the threads table to be that of the most recent message in
        // the thread.
        db.execSQL(
            "  UPDATE threads" +
            "  SET" +
            "  date =" +
            "    (SELECT date FROM" +
            "        (SELECT date * 1000 AS date, thread_id FROM pdu" +
            "         UNION SELECT date, thread_id FROM sms)" +
            "     WHERE thread_id = " + thread_id + " ORDER BY date DESC LIMIT 1)," +
            "  snippet =" +
            "    (SELECT snippet FROM" +
            "        (SELECT date * 1000 AS date, sub AS snippet, thread_id FROM pdu" +
            "         UNION SELECT date, body AS snippet, thread_id FROM sms)" +
            "     WHERE thread_id = " + thread_id + " ORDER BY date DESC LIMIT 1)," +
            "  snippet_cs =" +
            "    (SELECT snippet_cs FROM" +
            "        (SELECT date * 1000 AS date, sub_cs AS snippet_cs, thread_id FROM pdu" +
            "         UNION SELECT date, 0 AS snippet_cs, thread_id FROM sms)" +
            "     WHERE thread_id = " + thread_id + " ORDER BY date DESC LIMIT 1)" +
            "  WHERE threads._id = " + thread_id + ";");

        // Update the error column of the thread to indicate if there
        // are any messages in it that have failed to send.
        // First check to see if there are any messages with errors in this thread.
        String query = "SELECT thread_id FROM sms WHERE type=" +
            Telephony.TextBasedSmsColumns.MESSAGE_TYPE_FAILED +
            " AND thread_id = " + thread_id +
                                " LIMIT 1";
        int setError = 0;
        Cursor c = db.rawQuery(query, null);
        if (c != null) {
            try {
                setError = c.getCount();    // Because of the LIMIT 1, count will be 1 or 0.
            } finally {
                c.close();
            }
        }
        // What's the current state of the error flag in the threads table?
        String errorQuery = "SELECT error FROM threads WHERE _id = " + thread_id;
        c = db.rawQuery(errorQuery, null);
        if (c != null) {
            try {
                if (c.moveToNext()) {
                    int curError = c.getInt(0);
                    if (curError != setError) {
                        // The current thread error column differs, update it.
                        db.execSQL("UPDATE threads SET error=" + setError +
                                " WHERE _id = " + thread_id);
                    }
                }
            } finally {
                c.close();
            }
        }
    }

    public static void updateAllThreads(SQLiteDatabase db, String where, String[] whereArgs) {
        if (where == null) {
            where = "";
        } else {
            where = "WHERE (" + where + ")";
        }
        String query = "SELECT _id FROM threads WHERE _id IN " +
                       "(SELECT DISTINCT thread_id FROM sms " + where + ")";
        Cursor c = db.rawQuery(query, whereArgs);
        if (c != null) {
            try {
                while (c.moveToNext()) {
                    updateThread(db, c.getInt(0));
                }
            } finally {
                c.close();
            }
        }
        // TODO: there are several db operations in this function. Lets wrap them in a
        // transaction to make it faster.
        // remove orphaned threads
        db.delete("threads",
                "_id NOT IN (SELECT DISTINCT thread_id FROM sms " +
                "UNION SELECT DISTINCT thread_id FROM pdu)", null);

        // remove orphaned canonical_addresses
        db.delete("canonical_addresses",
                "_id NOT IN (SELECT DISTINCT recipient_ids FROM threads)", null);
    }

    public static int deleteOneSms(SQLiteDatabase db, int message_id) {
        int thread_id = -1;
        // Find the thread ID that the specified SMS belongs to.
        Cursor c = db.query("sms", new String[] { "thread_id" },
                            "_id=" + message_id, null, null, null, null);
        if (c != null) {
            if (c.moveToFirst()) {
                thread_id = c.getInt(0);
            }
            c.close();
        }

        // Delete the specified message.
        int rows = db.delete("sms", "_id=" + message_id, null);
        if (thread_id > 0) {
            // Update its thread.
            updateThread(db, thread_id);
        }
        return rows;
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        createMmsTables(db);
        createSmsTables(db);
        createCommonTables(db);
        createCommonTriggers(db);
        createMmsTriggers(db);
        createWordsTables(db);
        createIndices(db);
    }

    // When upgrading the database we need to populate the words
    // table with the rows out of sms and part.
    private void populateWordsTable(SQLiteDatabase db) {
        final String TABLE_WORDS = "words";
        {
            Cursor smsRows = db.query(
                    "sms",
                    new String[] { Sms._ID, Sms.BODY },
                    null,
                    null,
                    null,
                    null,
                    null);
            try {
                if (smsRows != null) {
                    smsRows.moveToPosition(-1);
                    ContentValues cv = new ContentValues();
                    while (smsRows.moveToNext()) {
                        cv.clear();

                        long id = smsRows.getLong(0);        // 0 for Sms._ID
                        String body = smsRows.getString(1);  // 1 for Sms.BODY

                        cv.put(Telephony.MmsSms.WordsTable.ID, id);
                        cv.put(Telephony.MmsSms.WordsTable.INDEXED_TEXT, body);
                        cv.put(Telephony.MmsSms.WordsTable.SOURCE_ROW_ID, id);
                        cv.put(Telephony.MmsSms.WordsTable.TABLE_ID, 1);
                        db.insert(TABLE_WORDS, Telephony.MmsSms.WordsTable.INDEXED_TEXT, cv);
                    }
                }
            } finally {
                if (smsRows != null) {
                    smsRows.close();
                }
            }
        }

        {
            Cursor mmsRows = db.query(
                    "part",
                    new String[] { Part._ID, Part.TEXT },
                    "ct = 'text/plain'",
                    null,
                    null,
                    null,
                    null);
            try {
                if (mmsRows != null) {
                    mmsRows.moveToPosition(-1);
                    ContentValues cv = new ContentValues();
                    while (mmsRows.moveToNext()) {
                        cv.clear();

                        long id = mmsRows.getLong(0);         // 0 for Part._ID
                        String body = mmsRows.getString(1);   // 1 for Part.TEXT

                        cv.put(Telephony.MmsSms.WordsTable.ID, id);
                        cv.put(Telephony.MmsSms.WordsTable.INDEXED_TEXT, body);
                        cv.put(Telephony.MmsSms.WordsTable.SOURCE_ROW_ID, id);
                        cv.put(Telephony.MmsSms.WordsTable.TABLE_ID, 1);
                        db.insert(TABLE_WORDS, Telephony.MmsSms.WordsTable.INDEXED_TEXT, cv);
                    }
                }
            } finally {
                if (mmsRows != null) {
                    mmsRows.close();
                }
            }
        }
    }

    private void createWordsTables(SQLiteDatabase db) {
        try {
            db.execSQL("CREATE VIRTUAL TABLE words USING FTS3 (_id INTEGER PRIMARY KEY, index_text TEXT, source_id INTEGER, table_to_use INTEGER);");

            // monitor the sms table
            // NOTE don't handle inserts using a trigger because it has an unwanted
            // side effect:  the value returned for the last row ends up being the
            // id of one of the trigger insert not the original row insert.
            // Handle inserts manually in the provider.
            db.execSQL("CREATE TRIGGER sms_words_update AFTER UPDATE ON sms BEGIN UPDATE words " +
                    " SET index_text = NEW.body WHERE (source_id=NEW._id AND table_to_use=1); " +
                    " END;");
            db.execSQL("CREATE TRIGGER sms_words_delete AFTER DELETE ON sms BEGIN DELETE FROM " +
                    "  words WHERE source_id = OLD._id AND table_to_use = 1; END;");

            // monitor the mms table
            db.execSQL("CREATE TRIGGER mms_words_update AFTER UPDATE ON part BEGIN UPDATE words " +
                    " SET index_text = NEW.text WHERE (source_id=NEW._id AND table_to_use=2); " +
                    " END;");
            db.execSQL("CREATE TRIGGER mms_words_delete AFTER DELETE ON part BEGIN DELETE FROM " +
                    " words WHERE source_id = OLD._id AND table_to_use = 2; END;");

            populateWordsTable(db);
        } catch (Exception ex) {
            Log.e(TAG, "got exception creating words table: " + ex.toString());
        }
    }

    private void createIndices(SQLiteDatabase db) {
        createThreadIdIndex(db);
    }

    private void createThreadIdIndex(SQLiteDatabase db) {
        try {
            db.execSQL("CREATE INDEX IF NOT EXISTS typeThreadIdIndex ON sms" +
            " (type, thread_id);");
        } catch (Exception ex) {
            Log.e(TAG, "got exception creating indices: " + ex.toString());
        }
    }

    private void createMmsTables(SQLiteDatabase db) {
        // N.B.: Whenever the columns here are changed, the columns in
        // {@ref MmsSmsProvider} must be changed to match.
        db.execSQL("CREATE TABLE " + MmsProvider.TABLE_PDU + " (" +
                   Mms._ID + " INTEGER PRIMARY KEY," +
                   Mms.THREAD_ID + " INTEGER," +
                   Mms.DATE + " INTEGER," +
                   Mms.DATE_SENT + " INTEGER DEFAULT 0," +
                   Mms.MESSAGE_BOX + " INTEGER," +
                   Mms.READ + " INTEGER DEFAULT 0," +
                   Mms.MESSAGE_ID + " TEXT," +
                   Mms.SUBJECT + " TEXT," +
                   Mms.SUBJECT_CHARSET + " INTEGER," +
                   Mms.CONTENT_TYPE + " TEXT," +
                   Mms.CONTENT_LOCATION + " TEXT," +
                   Mms.EXPIRY + " INTEGER," +
                   Mms.MESSAGE_CLASS + " TEXT," +
                   Mms.MESSAGE_TYPE + " INTEGER," +
                   Mms.MMS_VERSION + " INTEGER," +
                   Mms.MESSAGE_SIZE + " INTEGER," +
                   Mms.PRIORITY + " INTEGER," +
                   Mms.READ_REPORT + " INTEGER," +
                   Mms.REPORT_ALLOWED + " INTEGER," +
                   Mms.RESPONSE_STATUS + " INTEGER," +
                   Mms.STATUS + " INTEGER," +
                   Mms.TRANSACTION_ID + " TEXT," +
                   Mms.RETRIEVE_STATUS + " INTEGER," +
                   Mms.RETRIEVE_TEXT + " TEXT," +
                   Mms.RETRIEVE_TEXT_CHARSET + " INTEGER," +
                   Mms.READ_STATUS + " INTEGER," +
                   Mms.CONTENT_CLASS + " INTEGER," +
                   Mms.RESPONSE_TEXT + " TEXT," +
                   Mms.DELIVERY_TIME + " INTEGER," +
                   Mms.DELIVERY_REPORT + " INTEGER," +
                   Mms.LOCKED + " INTEGER DEFAULT 0," +
                   Mms.SEEN + " INTEGER DEFAULT 0" +
                   ");");

        db.execSQL("CREATE TABLE " + MmsProvider.TABLE_ADDR + " (" +
                   Addr._ID + " INTEGER PRIMARY KEY," +
                   Addr.MSG_ID + " INTEGER," +
                   Addr.CONTACT_ID + " INTEGER," +
                   Addr.ADDRESS + " TEXT," +
                   Addr.TYPE + " INTEGER," +
                   Addr.CHARSET + " INTEGER);");

        db.execSQL("CREATE TABLE " + MmsProvider.TABLE_PART + " (" +
                   Part._ID + " INTEGER PRIMARY KEY," +
                   Part.MSG_ID + " INTEGER," +
                   Part.SEQ + " INTEGER DEFAULT 0," +
                   Part.CONTENT_TYPE + " TEXT," +
                   Part.NAME + " TEXT," +
                   Part.CHARSET + " INTEGER," +
                   Part.CONTENT_DISPOSITION + " TEXT," +
                   Part.FILENAME + " TEXT," +
                   Part.CONTENT_ID + " TEXT," +
                   Part.CONTENT_LOCATION + " TEXT," +
                   Part.CT_START + " INTEGER," +
                   Part.CT_TYPE + " TEXT," +
                   Part._DATA + " TEXT," +
                   Part.TEXT + " TEXT);");

        db.execSQL("CREATE TABLE " + MmsProvider.TABLE_RATE + " (" +
                   Rate.SENT_TIME + " INTEGER);");

        db.execSQL("CREATE TABLE " + MmsProvider.TABLE_DRM + " (" +
                   BaseColumns._ID + " INTEGER PRIMARY KEY," +
                   "_data TEXT);");
    }

    private void createMmsTriggers(SQLiteDatabase db) {
        // Cleans up parts when a MM is deleted.
        db.execSQL("CREATE TRIGGER part_cleanup DELETE ON " + MmsProvider.TABLE_PDU + " " +
                   "BEGIN " +
                   "  DELETE FROM " + MmsProvider.TABLE_PART +
                   "  WHERE " + Part.MSG_ID + "=old._id;" +
                   "END;");

        // Cleans up address info when a MM is deleted.
        db.execSQL("CREATE TRIGGER addr_cleanup DELETE ON " + MmsProvider.TABLE_PDU + " " +
                   "BEGIN " +
                   "  DELETE FROM " + MmsProvider.TABLE_ADDR +
                   "  WHERE " + Addr.MSG_ID + "=old._id;" +
                   "END;");

        // Delete obsolete delivery-report, read-report while deleting their
        // associated Send.req.
        db.execSQL("CREATE TRIGGER cleanup_delivery_and_read_report " +
                   "AFTER DELETE ON " + MmsProvider.TABLE_PDU + " " +
                   "WHEN old." + Mms.MESSAGE_TYPE + "=" + PduHeaders.MESSAGE_TYPE_SEND_REQ + " " +
                   "BEGIN " +
                   "  DELETE FROM " + MmsProvider.TABLE_PDU +
                   "  WHERE (" + Mms.MESSAGE_TYPE + "=" + PduHeaders.MESSAGE_TYPE_DELIVERY_IND +
                   "    OR " + Mms.MESSAGE_TYPE + "=" + PduHeaders.MESSAGE_TYPE_READ_ORIG_IND +
                   ")" +
                   "    AND " + Mms.MESSAGE_ID + "=old." + Mms.MESSAGE_ID + "; " +
                   "END;");

        // Update threads table to indicate whether attachments exist when
        // parts are inserted or deleted.
        db.execSQL(PART_UPDATE_THREADS_ON_INSERT_TRIGGER);
        db.execSQL(PART_UPDATE_THREADS_ON_UPDATE_TRIGGER);
        db.execSQL(PART_UPDATE_THREADS_ON_DELETE_TRIGGER);
        db.execSQL(PDU_UPDATE_THREADS_ON_UPDATE_TRIGGER);
    }

    private void createSmsTables(SQLiteDatabase db) {
        // N.B.: Whenever the columns here are changed, the columns in
        // {@ref MmsSmsProvider} must be changed to match.
        db.execSQL("CREATE TABLE sms (" +
                   "_id INTEGER PRIMARY KEY," +
                   "thread_id INTEGER," +
                   "address TEXT," +
                   "person INTEGER," +
                   "date INTEGER," +
                   "date_sent INTEGER DEFAULT 0," +
                   "protocol INTEGER," +
                   "read INTEGER DEFAULT 0," +
                   "status INTEGER DEFAULT -1," + // a TP-Status value
                                                  // or -1 if it
                                                  // status hasn't
                                                  // been received
                   "type INTEGER," +
                   "reply_path_present INTEGER," +
                   "subject TEXT," +
                   "body TEXT," +
                   "service_center TEXT," +
                   "locked INTEGER DEFAULT 0," +
                   "error_code INTEGER DEFAULT 0," +
                   "seen INTEGER DEFAULT 0" +
                   ");");

        /**
         * This table is used by the SMS dispatcher to hold
         * incomplete partial messages until all the parts arrive.
         */
        db.execSQL("CREATE TABLE raw (" +
                   "_id INTEGER PRIMARY KEY," +
                   "date INTEGER," +
                   "reference_number INTEGER," + // one per full message
                   "count INTEGER," + // the number of parts
                   "sequence INTEGER," + // the part number of this message
                   "destination_port INTEGER," +
                   "address TEXT," +
                   "pdu TEXT);"); // the raw PDU for this part

        db.execSQL("CREATE TABLE attachments (" +
                   "sms_id INTEGER," +
                   "content_url TEXT," +
                   "offset INTEGER);");

        /**
         * This table is used by the SMS dispatcher to hold pending
         * delivery status report intents.
         */
        db.execSQL("CREATE TABLE sr_pending (" +
                   "reference_number INTEGER," +
                   "action TEXT," +
                   "data TEXT);");
    }

    private void createCommonTables(SQLiteDatabase db) {
        // TODO Ensure that each entry is removed when the last use of
        // any address equivalent to its address is removed.

        /**
         * This table maps the first instance seen of any particular
         * MMS/SMS address to an ID, which is then used as its
         * canonical representation.  If the same address or an
         * equivalent address (as determined by our Sqlite
         * PHONE_NUMBERS_EQUAL extension) is seen later, this same ID
         * will be used.
         */
        db.execSQL("CREATE TABLE canonical_addresses (" +
                   "_id INTEGER PRIMARY KEY," +
                   "address TEXT);");

        /**
         * This table maps the subject and an ordered set of recipient
         * IDs, separated by spaces, to a unique thread ID.  The IDs
         * come from the canonical_addresses table.  This works
         * because messages are considered to be part of the same
         * thread if they have the same subject (or a null subject)
         * and the same set of recipients.
         */
        db.execSQL("CREATE TABLE threads (" +
                   Threads._ID + " INTEGER PRIMARY KEY AUTOINCREMENT," +
                   Threads.DATE + " INTEGER DEFAULT 0," +
                   Threads.MESSAGE_COUNT + " INTEGER DEFAULT 0," +
                   Threads.RECIPIENT_IDS + " TEXT," +
                   Threads.SNIPPET + " TEXT," +
                   Threads.SNIPPET_CHARSET + " INTEGER DEFAULT 0," +
                   Threads.READ + " INTEGER DEFAULT 1," +
                   Threads.TYPE + " INTEGER DEFAULT 0," +
                   Threads.ERROR + " INTEGER DEFAULT 0," +
                   Threads.HAS_ATTACHMENT + " INTEGER DEFAULT 0);");

        /**
         * This table stores the queue of messages to be sent/downloaded.
         */
        db.execSQL("CREATE TABLE " + MmsSmsProvider.TABLE_PENDING_MSG +" (" +
                   PendingMessages._ID + " INTEGER PRIMARY KEY," +
                   PendingMessages.PROTO_TYPE + " INTEGER," +
                   PendingMessages.MSG_ID + " INTEGER," +
                   PendingMessages.MSG_TYPE + " INTEGER," +
                   PendingMessages.ERROR_TYPE + " INTEGER," +
                   PendingMessages.ERROR_CODE + " INTEGER," +
                   PendingMessages.RETRY_INDEX + " INTEGER NOT NULL DEFAULT 0," +
                   PendingMessages.DUE_TIME + " INTEGER," +
                   PendingMessages.LAST_TRY + " INTEGER);");

    }

    // TODO Check the query plans for these triggers.
    private void createCommonTriggers(SQLiteDatabase db) {
        // Updates threads table whenever a message is added to pdu.
        db.execSQL("CREATE TRIGGER pdu_update_thread_on_insert AFTER INSERT ON " +
                   MmsProvider.TABLE_PDU + " " +
                   PDU_UPDATE_THREAD_CONSTRAINTS +
                   PDU_UPDATE_THREAD_DATE_SNIPPET_COUNT_ON_UPDATE);

        // Updates threads table whenever a message is added to sms.
        db.execSQL("CREATE TRIGGER sms_update_thread_on_insert AFTER INSERT ON sms " +
                   SMS_UPDATE_THREAD_DATE_SNIPPET_COUNT_ON_UPDATE);

        // Updates threads table whenever a message in pdu is updated.
        db.execSQL("CREATE TRIGGER pdu_update_thread_date_subject_on_update AFTER" +
                   "  UPDATE OF " + Mms.DATE + ", " + Mms.SUBJECT + ", " + Mms.MESSAGE_BOX +
                   "  ON " + MmsProvider.TABLE_PDU + " " +
                   PDU_UPDATE_THREAD_CONSTRAINTS +
                   PDU_UPDATE_THREAD_DATE_SNIPPET_COUNT_ON_UPDATE);

        // Updates threads table whenever a message in sms is updated.
        db.execSQL("CREATE TRIGGER sms_update_thread_date_subject_on_update AFTER" +
                   "  UPDATE OF " + Sms.DATE + ", " + Sms.BODY + ", " + Sms.TYPE +
                   "  ON sms " +
                   SMS_UPDATE_THREAD_DATE_SNIPPET_COUNT_ON_UPDATE);

        // Updates threads table whenever a message in pdu is updated.
        db.execSQL("CREATE TRIGGER pdu_update_thread_read_on_update AFTER" +
                   "  UPDATE OF " + Mms.READ +
                   "  ON " + MmsProvider.TABLE_PDU + " " +
                   PDU_UPDATE_THREAD_CONSTRAINTS +
                   "BEGIN " +
                   PDU_UPDATE_THREAD_READ_BODY +
                   "END;");

        // Updates threads table whenever a message in sms is updated.
        db.execSQL("CREATE TRIGGER sms_update_thread_read_on_update AFTER" +
                   "  UPDATE OF " + Sms.READ +
                   "  ON sms " +
                   "BEGIN " +
                   SMS_UPDATE_THREAD_READ_BODY +
                   "END;");

        // Update threads table whenever a message in pdu is deleted
        db.execSQL("CREATE TRIGGER pdu_update_thread_on_delete " +
                   "AFTER DELETE ON pdu " +
                   "BEGIN " +
                   "  UPDATE threads SET " +
                   "     date = (strftime('%s','now') * 1000)" +
                   "  WHERE threads._id = old." + Mms.THREAD_ID + "; " +
                   UPDATE_THREAD_COUNT_ON_OLD +
                   UPDATE_THREAD_SNIPPET_SNIPPET_CS_ON_DELETE +
                   "END;");

        // As of DATABASE_VERSION 55, we've removed these triggers that delete empty threads.
        // These triggers interfere with saving drafts on brand new threads. Instead of
        // triggers cleaning up empty threads, the empty threads should be cleaned up by
        // an explicit call to delete with Threads.OBSOLETE_THREADS_URI.

//        // When the last message in a thread is deleted, these
//        // triggers ensure that the entry for its thread ID is removed
//        // from the threads table.
//        db.execSQL("CREATE TRIGGER delete_obsolete_threads_pdu " +
//                   "AFTER DELETE ON pdu " +
//                   "BEGIN " +
//                   "  DELETE FROM threads " +
//                   "  WHERE " +
//                   "    _id = old.thread_id " +
//                   "    AND _id NOT IN " +
//                   "    (SELECT thread_id FROM sms " +
//                   "     UNION SELECT thread_id from pdu); " +
//                   "END;");
//
//        db.execSQL("CREATE TRIGGER delete_obsolete_threads_when_update_pdu " +
//                   "AFTER UPDATE OF " + Mms.THREAD_ID + " ON pdu " +
//                   "WHEN old." + Mms.THREAD_ID + " != new." + Mms.THREAD_ID + " " +
//                   "BEGIN " +
//                   "  DELETE FROM threads " +
//                   "  WHERE " +
//                   "    _id = old.thread_id " +
//                   "    AND _id NOT IN " +
//                   "    (SELECT thread_id FROM sms " +
//                   "     UNION SELECT thread_id from pdu); " +
//                   "END;");

        // Insert pending status for M-Notification.ind or M-ReadRec.ind
        // when they are inserted into Inbox/Outbox.
        db.execSQL("CREATE TRIGGER insert_mms_pending_on_insert " +
                   "AFTER INSERT ON pdu " +
                   "WHEN new." + Mms.MESSAGE_TYPE + "=" + PduHeaders.MESSAGE_TYPE_NOTIFICATION_IND +
                   "  OR new." + Mms.MESSAGE_TYPE + "=" + PduHeaders.MESSAGE_TYPE_READ_REC_IND +
                   " " +
                   "BEGIN " +
                   "  INSERT INTO " + MmsSmsProvider.TABLE_PENDING_MSG +
                   "    (" + PendingMessages.PROTO_TYPE + "," +
                   "     " + PendingMessages.MSG_ID + "," +
                   "     " + PendingMessages.MSG_TYPE + "," +
                   "     " + PendingMessages.ERROR_TYPE + "," +
                   "     " + PendingMessages.ERROR_CODE + "," +
                   "     " + PendingMessages.RETRY_INDEX + "," +
                   "     " + PendingMessages.DUE_TIME + ") " +
                   "  VALUES " +
                   "    (" + MmsSms.MMS_PROTO + "," +
                   "      new." + BaseColumns._ID + "," +
                   "      new." + Mms.MESSAGE_TYPE + ",0,0,0,0);" +
                   "END;");

        // Insert pending status for M-Send.req when it is moved into Outbox.
        db.execSQL("CREATE TRIGGER insert_mms_pending_on_update " +
                   "AFTER UPDATE ON pdu " +
                   "WHEN new." + Mms.MESSAGE_TYPE + "=" + PduHeaders.MESSAGE_TYPE_SEND_REQ +
                   "  AND new." + Mms.MESSAGE_BOX + "=" + Mms.MESSAGE_BOX_OUTBOX +
                   "  AND old." + Mms.MESSAGE_BOX + "!=" + Mms.MESSAGE_BOX_OUTBOX + " " +
                   "BEGIN " +
                   "  INSERT INTO " + MmsSmsProvider.TABLE_PENDING_MSG +
                   "    (" + PendingMessages.PROTO_TYPE + "," +
                   "     " + PendingMessages.MSG_ID + "," +
                   "     " + PendingMessages.MSG_TYPE + "," +
                   "     " + PendingMessages.ERROR_TYPE + "," +
                   "     " + PendingMessages.ERROR_CODE + "," +
                   "     " + PendingMessages.RETRY_INDEX + "," +
                   "     " + PendingMessages.DUE_TIME + ") " +
                   "  VALUES " +
                   "    (" + MmsSms.MMS_PROTO + "," +
                   "      new." + BaseColumns._ID + "," +
                   "      new." + Mms.MESSAGE_TYPE + ",0,0,0,0);" +
                   "END;");

        // When a message is moved out of Outbox, delete its pending status.
        db.execSQL("CREATE TRIGGER delete_mms_pending_on_update " +
                   "AFTER UPDATE ON " + MmsProvider.TABLE_PDU + " " +
                   "WHEN old." + Mms.MESSAGE_BOX + "=" + Mms.MESSAGE_BOX_OUTBOX +
                   "  AND new." + Mms.MESSAGE_BOX + "!=" + Mms.MESSAGE_BOX_OUTBOX + " " +
                   "BEGIN " +
                   "  DELETE FROM " + MmsSmsProvider.TABLE_PENDING_MSG +
                   "  WHERE " + PendingMessages.MSG_ID + "=new._id; " +
                   "END;");

        // Delete pending status for a message when it is deleted.
        db.execSQL("CREATE TRIGGER delete_mms_pending_on_delete " +
                   "AFTER DELETE ON " + MmsProvider.TABLE_PDU + " " +
                   "BEGIN " +
                   "  DELETE FROM " + MmsSmsProvider.TABLE_PENDING_MSG +
                   "  WHERE " + PendingMessages.MSG_ID + "=old._id; " +
                   "END;");

        // TODO Add triggers for SMS retry-status management.

        // Update the error flag of threads when the error type of
        // a pending MM is updated.
        db.execSQL("CREATE TRIGGER update_threads_error_on_update_mms " +
                   "  AFTER UPDATE OF err_type ON pending_msgs " +
                   "  WHEN (OLD.err_type < 10 AND NEW.err_type >= 10)" +
                   "    OR (OLD.err_type >= 10 AND NEW.err_type < 10) " +
                   "BEGIN" +
                   "  UPDATE threads SET error = " +
                   "    CASE" +
                   "      WHEN NEW.err_type >= 10 THEN error + 1" +
                   "      ELSE error - 1" +
                   "    END " +
                   "  WHERE _id =" +
                   "   (SELECT DISTINCT thread_id" +
                   "    FROM pdu" +
                   "    WHERE _id = NEW.msg_id); " +
                   "END;");

        // Update the error flag of threads when delete pending message.
        db.execSQL("CREATE TRIGGER update_threads_error_on_delete_mms " +
                   "  BEFORE DELETE ON pdu" +
                   "  WHEN OLD._id IN (SELECT DISTINCT msg_id" +
                   "                   FROM pending_msgs" +
                   "                   WHERE err_type >= 10) " +
                   "BEGIN " +
                   "  UPDATE threads SET error = error - 1" +
                   "  WHERE _id = OLD.thread_id; " +
                   "END;");

        // Update the error flag of threads while moving an MM out of Outbox,
        // which was failed to be sent permanently.
        db.execSQL("CREATE TRIGGER update_threads_error_on_move_mms " +
                   "  BEFORE UPDATE OF msg_box ON pdu " +
                   "  WHEN (OLD.msg_box = 4 AND NEW.msg_box != 4) " +
                   "  AND (OLD._id IN (SELECT DISTINCT msg_id" +
                   "                   FROM pending_msgs" +
                   "                   WHERE err_type >= 10)) " +
                   "BEGIN " +
                   "  UPDATE threads SET error = error - 1" +
                   "  WHERE _id = OLD.thread_id; " +
                   "END;");

        // Update the error flag of threads after a text message was
        // failed to send/receive.
        db.execSQL("CREATE TRIGGER update_threads_error_on_update_sms " +
                   "  AFTER UPDATE OF type ON sms" +
                   "  WHEN (OLD.type != 5 AND NEW.type = 5)" +
                   "    OR (OLD.type = 5 AND NEW.type != 5) " +
                   "BEGIN " +
                   "  UPDATE threads SET error = " +
                   "    CASE" +
                   "      WHEN NEW.type = 5 THEN error + 1" +
                   "      ELSE error - 1" +
                   "    END " +
                   "  WHERE _id = NEW.thread_id; " +
                   "END;");
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int currentVersion) {
        Log.w(TAG, "Upgrading database from version " + oldVersion
                + " to " + currentVersion + ".");

        switch (oldVersion) {
        case 40:
            if (currentVersion <= 40) {
                return;
            }

            db.beginTransaction();
            try {
                upgradeDatabaseToVersion41(db);
                db.setTransactionSuccessful();
            } catch (Throwable ex) {
                Log.e(TAG, ex.getMessage(), ex);
                break;
            } finally {
                db.endTransaction();
            }
            // fall through
        case 41:
            if (currentVersion <= 41) {
                return;
            }

            db.beginTransaction();
            try {
                upgradeDatabaseToVersion42(db);
                db.setTransactionSuccessful();
            } catch (Throwable ex) {
                Log.e(TAG, ex.getMessage(), ex);
                break;
            } finally {
                db.endTransaction();
            }
            // fall through
        case 42:
            if (currentVersion <= 42) {
                return;
            }

            db.beginTransaction();
            try {
                upgradeDatabaseToVersion43(db);
                db.setTransactionSuccessful();
            } catch (Throwable ex) {
                Log.e(TAG, ex.getMessage(), ex);
                break;
            } finally {
                db.endTransaction();
            }
            // fall through
        case 43:
            if (currentVersion <= 43) {
                return;
            }

            db.beginTransaction();
            try {
                upgradeDatabaseToVersion44(db);
                db.setTransactionSuccessful();
            } catch (Throwable ex) {
                Log.e(TAG, ex.getMessage(), ex);
                break;
            } finally {
                db.endTransaction();
            }
            // fall through
        case 44:
            if (currentVersion <= 44) {
                return;
            }

            db.beginTransaction();
            try {
                upgradeDatabaseToVersion45(db);
                db.setTransactionSuccessful();
            } catch (Throwable ex) {
                Log.e(TAG, ex.getMessage(), ex);
                break;
            } finally {
                db.endTransaction();
            }
            // fall through
        case 45:
            if (currentVersion <= 45) {
                return;
            }
            db.beginTransaction();
            try {
                upgradeDatabaseToVersion46(db);
                db.setTransactionSuccessful();
            } catch (Throwable ex) {
                Log.e(TAG, ex.getMessage(), ex);
                break;
            } finally {
                db.endTransaction();
            }
            // fall through
        case 46:
            if (currentVersion <= 46) {
                return;
            }

            db.beginTransaction();
            try {
                upgradeDatabaseToVersion47(db);
                db.setTransactionSuccessful();
            } catch (Throwable ex) {
                Log.e(TAG, ex.getMessage(), ex);
                break;
            } finally {
                db.endTransaction();
            }
            // fall through
        case 47:
            if (currentVersion <= 47) {
                return;
            }

            db.beginTransaction();
            try {
                upgradeDatabaseToVersion48(db);
                db.setTransactionSuccessful();
            } catch (Throwable ex) {
                Log.e(TAG, ex.getMessage(), ex);
                break;
            } finally {
                db.endTransaction();
            }
            // fall through
        case 48:
            if (currentVersion <= 48) {
                return;
            }

            db.beginTransaction();
            try {
                createWordsTables(db);
                db.setTransactionSuccessful();
            } catch (Throwable ex) {
                Log.e(TAG, ex.getMessage(), ex);
                break;
            } finally {
                db.endTransaction();
            }
            // fall through
        case 49:
            if (currentVersion <= 49) {
                return;
            }
            db.beginTransaction();
            try {
                createThreadIdIndex(db);
                db.setTransactionSuccessful();
            } catch (Throwable ex) {
                Log.e(TAG, ex.getMessage(), ex);
                break; // force to destroy all old data;
            } finally {
                db.endTransaction();
            }
            // fall through
        case 50:
            if (currentVersion <= 50) {
                return;
            }

            db.beginTransaction();
            try {
                upgradeDatabaseToVersion51(db);
                db.setTransactionSuccessful();
            } catch (Throwable ex) {
                Log.e(TAG, ex.getMessage(), ex);
                break;
            } finally {
                db.endTransaction();
            }
            // fall through
        case 51:
            if (currentVersion <= 51) {
                return;
            }
            // 52 was adding a new meta_data column, but that was removed.
            // fall through
        case 52:
            if (currentVersion <= 52) {
                return;
            }

            db.beginTransaction();
            try {
                upgradeDatabaseToVersion53(db);
                db.setTransactionSuccessful();
            } catch (Throwable ex) {
                Log.e(TAG, ex.getMessage(), ex);
                break;
            } finally {
                db.endTransaction();
            }
            // fall through
        case 53:
            if (currentVersion <= 53) {
                return;
            }

            db.beginTransaction();
            try {
                upgradeDatabaseToVersion54(db);
                db.setTransactionSuccessful();
            } catch (Throwable ex) {
                Log.e(TAG, ex.getMessage(), ex);
                break;
            } finally {
                db.endTransaction();
            }
            // fall through
        case 54:
            if (currentVersion <= 54) {
                return;
            }

            db.beginTransaction();
            try {
                upgradeDatabaseToVersion55(db);
                db.setTransactionSuccessful();
            } catch (Throwable ex) {
                Log.e(TAG, ex.getMessage(), ex);
                break;
            } finally {
                db.endTransaction();
            }
            return;
        }

        Log.e(TAG, "Destroying all old data.");
        dropAll(db);
        onCreate(db);
    }

    private void dropAll(SQLiteDatabase db) {
        // Clean the database out in order to start over from scratch.
        // We don't need to drop our triggers here because SQLite automatically
        // drops a trigger when its attached database is dropped.
        db.execSQL("DROP TABLE IF EXISTS canonical_addresses");
        db.execSQL("DROP TABLE IF EXISTS threads");
        db.execSQL("DROP TABLE IF EXISTS " + MmsSmsProvider.TABLE_PENDING_MSG);
        db.execSQL("DROP TABLE IF EXISTS sms");
        db.execSQL("DROP TABLE IF EXISTS raw");
        db.execSQL("DROP TABLE IF EXISTS attachments");
        db.execSQL("DROP TABLE IF EXISTS thread_ids");
        db.execSQL("DROP TABLE IF EXISTS sr_pending");
        db.execSQL("DROP TABLE IF EXISTS " + MmsProvider.TABLE_PDU + ";");
        db.execSQL("DROP TABLE IF EXISTS " + MmsProvider.TABLE_ADDR + ";");
        db.execSQL("DROP TABLE IF EXISTS " + MmsProvider.TABLE_PART + ";");
        db.execSQL("DROP TABLE IF EXISTS " + MmsProvider.TABLE_RATE + ";");
        db.execSQL("DROP TABLE IF EXISTS " + MmsProvider.TABLE_DRM + ";");
    }

    private void upgradeDatabaseToVersion41(SQLiteDatabase db) {
        db.execSQL("DROP TRIGGER IF EXISTS update_threads_error_on_move_mms");
        db.execSQL("CREATE TRIGGER update_threads_error_on_move_mms " +
                   "  BEFORE UPDATE OF msg_box ON pdu " +
                   "  WHEN (OLD.msg_box = 4 AND NEW.msg_box != 4) " +
                   "  AND (OLD._id IN (SELECT DISTINCT msg_id" +
                   "                   FROM pending_msgs" +
                   "                   WHERE err_type >= 10)) " +
                   "BEGIN " +
                   "  UPDATE threads SET error = error - 1" +
                   "  WHERE _id = OLD.thread_id; " +
                   "END;");
    }

    private void upgradeDatabaseToVersion42(SQLiteDatabase db) {
        db.execSQL("DROP TRIGGER IF EXISTS sms_update_thread_on_delete");
        db.execSQL("DROP TRIGGER IF EXISTS delete_obsolete_threads_sms");
        db.execSQL("DROP TRIGGER IF EXISTS update_threads_error_on_delete_sms");
    }

    private void upgradeDatabaseToVersion43(SQLiteDatabase db) {
        // Add 'has_attachment' column to threads table.
        db.execSQL("ALTER TABLE threads ADD COLUMN has_attachment INTEGER DEFAULT 0");

        updateThreadsAttachmentColumn(db);

        // Add insert and delete triggers for keeping it up to date.
        db.execSQL(PART_UPDATE_THREADS_ON_INSERT_TRIGGER);
        db.execSQL(PART_UPDATE_THREADS_ON_DELETE_TRIGGER);
    }

    private void upgradeDatabaseToVersion44(SQLiteDatabase db) {
        updateThreadsAttachmentColumn(db);

        // add the update trigger for keeping the threads up to date.
        db.execSQL(PART_UPDATE_THREADS_ON_UPDATE_TRIGGER);
    }

    private void upgradeDatabaseToVersion45(SQLiteDatabase db) {
        // Add 'locked' column to sms table.
        db.execSQL("ALTER TABLE sms ADD COLUMN " + Sms.LOCKED + " INTEGER DEFAULT 0");

        // Add 'locked' column to pdu table.
        db.execSQL("ALTER TABLE pdu ADD COLUMN " + Mms.LOCKED + " INTEGER DEFAULT 0");
    }

    private void upgradeDatabaseToVersion46(SQLiteDatabase db) {
        // add the "text" column for caching inline text (e.g. strings) instead of
        // putting them in an external file
        db.execSQL("ALTER TABLE part ADD COLUMN " + Part.TEXT + " TEXT");

        Cursor textRows = db.query(
                "part",
                new String[] { Part._ID, Part._DATA, Part.TEXT},
                "ct = 'text/plain' OR ct == 'application/smil'",
                null,
                null,
                null,
                null);
        ArrayList<String> filesToDelete = new ArrayList<String>();
        try {
            db.beginTransaction();
            if (textRows != null) {
                int partDataColumn = textRows.getColumnIndex(Part._DATA);

                // This code is imperfect in that we can't guarantee that all the
                // backing files get deleted.  For example if the system aborts after
                // the database is updated but before we complete the process of
                // deleting files.
                while (textRows.moveToNext()) {
                    String path = textRows.getString(partDataColumn);
                    if (path != null) {
                        try {
                            InputStream is = new FileInputStream(path);
                            byte [] data = new byte[is.available()];
                            is.read(data);
                            EncodedStringValue v = new EncodedStringValue(data);
                            db.execSQL("UPDATE part SET " + Part._DATA + " = NULL, " +
                                    Part.TEXT + " = ?", new String[] { v.getString() });
                            is.close();
                            filesToDelete.add(path);
                        } catch (IOException e) {
                            // TODO Auto-generated catch block
                            e.printStackTrace();
                        }
                    }
                }
            }
            db.setTransactionSuccessful();
        } finally {
            db.endTransaction();
            for (String pathToDelete : filesToDelete) {
                try {
                    (new File(pathToDelete)).delete();
                } catch (SecurityException ex) {
                    Log.e(TAG, "unable to clean up old mms file for " + pathToDelete, ex);
                }
            }
            if (textRows != null) {
                textRows.close();
            }
        }
    }

    private void upgradeDatabaseToVersion47(SQLiteDatabase db) {
        updateThreadsAttachmentColumn(db);

        // add the update trigger for keeping the threads up to date.
        db.execSQL(PDU_UPDATE_THREADS_ON_UPDATE_TRIGGER);
    }

    private void upgradeDatabaseToVersion48(SQLiteDatabase db) {
        // Add 'error_code' column to sms table.
        db.execSQL("ALTER TABLE sms ADD COLUMN error_code INTEGER DEFAULT 0");
    }

    private void upgradeDatabaseToVersion51(SQLiteDatabase db) {
        db.execSQL("ALTER TABLE sms add COLUMN seen INTEGER DEFAULT 0");
        db.execSQL("ALTER TABLE pdu add COLUMN seen INTEGER DEFAULT 0");

        try {
            // update the existing sms and pdu tables so the new "seen" column is the same as
            // the "read" column for each row.
            ContentValues contentValues = new ContentValues();
            contentValues.put("seen", 1);
            int count = db.update("sms", contentValues, "read=1", null);
            Log.d(TAG, "[MmsSmsDb] upgradeDatabaseToVersion51: updated " + count +
                    " rows in sms table to have READ=1");
            count = db.update("pdu", contentValues, "read=1", null);
            Log.d(TAG, "[MmsSmsDb] upgradeDatabaseToVersion51: updated " + count +
                    " rows in pdu table to have READ=1");
        } catch (Exception ex) {
            Log.e(TAG, "[MmsSmsDb] upgradeDatabaseToVersion51 caught ", ex);
        }
    }

    private void upgradeDatabaseToVersion53(SQLiteDatabase db) {
        db.execSQL("DROP TRIGGER IF EXISTS pdu_update_thread_read_on_update");

        // Updates threads table whenever a message in pdu is updated.
        db.execSQL("CREATE TRIGGER pdu_update_thread_read_on_update AFTER" +
                   "  UPDATE OF " + Mms.READ +
                   "  ON " + MmsProvider.TABLE_PDU + " " +
                   PDU_UPDATE_THREAD_CONSTRAINTS +
                   "BEGIN " +
                   PDU_UPDATE_THREAD_READ_BODY +
                   "END;");
    }

    private void upgradeDatabaseToVersion54(SQLiteDatabase db) {
        // Add 'date_sent' column to sms table.
        db.execSQL("ALTER TABLE sms ADD COLUMN " + Sms.DATE_SENT + " INTEGER DEFAULT 0");

        // Add 'date_sent' column to pdu table.
        db.execSQL("ALTER TABLE pdu ADD COLUMN " + Mms.DATE_SENT + " INTEGER DEFAULT 0");
    }

    private void upgradeDatabaseToVersion55(SQLiteDatabase db) {
        // Drop removed triggers
        db.execSQL("DROP TRIGGER IF EXISTS delete_obsolete_threads_pdu");
        db.execSQL("DROP TRIGGER IF EXISTS delete_obsolete_threads_when_update_pdu");
    }

    @Override
    public synchronized SQLiteDatabase getWritableDatabase() {
        SQLiteDatabase db = super.getWritableDatabase();

        if (!sTriedAutoIncrement) {
            sTriedAutoIncrement = true;
            boolean hasAutoIncrement = hasAutoIncrement(db);
            Log.d(TAG, "[getWritableDatabase] hasAutoIncrement: " + hasAutoIncrement);
            if (!hasAutoIncrement) {
                db.beginTransaction();
                try {
                    if (false && sFakeLowStorageTest) {
                        Log.d(TAG, "[getWritableDatabase] mFakeLowStorageTest is true " +
                                " - fake exception");
                        throw new Exception("FakeLowStorageTest");
                    }
                    upgradeThreadsTableToAutoIncrement(db);
                    db.setTransactionSuccessful();

                    if (mLowStorageMonitor != null) {
                        // We've already updated the database. This receiver is no longer necessary.
                        Log.d(TAG, "Unregistering mLowStorageMonitor - we've upgraded");
                        mContext.unregisterReceiver(mLowStorageMonitor);
                        mLowStorageMonitor = null;
                    }
                } catch (Throwable ex) {
                    Log.e(TAG, "Failed to add autoIncrement: " + ex.getMessage(), ex);

                    if (sFakeLowStorageTest) {
                        sFakeLowStorageTest = false;
                    }

                    // We failed, perhaps because of low storage. Turn on a receiver to watch for
                    // storage space.
                    if (mLowStorageMonitor == null) {
                        Log.d(TAG, "[getWritableDatabase] turning on storage monitor");
                        mLowStorageMonitor = new LowStorageMonitor();
                        IntentFilter intentFilter = new IntentFilter();
                        intentFilter.addAction(Intent.ACTION_DEVICE_STORAGE_LOW);
                        intentFilter.addAction(Intent.ACTION_DEVICE_STORAGE_OK);
                        mContext.registerReceiver(mLowStorageMonitor, intentFilter);
                    }
                } finally {
                    db.endTransaction();
                }
            }
        }
        return db;
    }

    private boolean hasAutoIncrement(SQLiteDatabase db) {
        boolean result = false;
        String query = "SELECT sql FROM sqlite_master WHERE type='table' AND name='threads'";
        Cursor c = db.rawQuery(query, null);
        if (c != null) {
            try {
                if (c.moveToFirst()) {
                    String schema = c.getString(0);
                    result = schema != null ? schema.contains("AUTOINCREMENT") : false;
                    Log.d(TAG, "[MmsSmsDb] hasAutoIncrement: " + schema + " result: " + result);
                }
            } finally {
                c.close();
            }
        }
        return result;
    }

    // upgradeThreadsTableToAutoIncrement() is called to add the AUTOINCREMENT keyword to
    // the threads table. This could fail if the user has a lot of conversations and not enough
    // storage to make a copy of the threads table. That's ok. This upgrade is optional. It'll
    // be called again next time the device is rebooted.
    private void upgradeThreadsTableToAutoIncrement(SQLiteDatabase db) {
        if (hasAutoIncrement(db)) {
            Log.d(TAG, "[MmsSmsDb] upgradeThreadsTableToAutoIncrement: already upgraded");
            return;
        }
        Log.d(TAG, "[MmsSmsDb] upgradeThreadsTableToAutoIncrement: upgrading");

        // Make the _id of the threads table autoincrement so we never re-use thread ids
        // Have to create a new temp threads table. Copy all the info from the old table.
        // Drop the old table and rename the new table to that of the old.
        db.execSQL("CREATE TABLE threads_temp (" +
                Threads._ID + " INTEGER PRIMARY KEY AUTOINCREMENT," +
                Threads.DATE + " INTEGER DEFAULT 0," +
                Threads.MESSAGE_COUNT + " INTEGER DEFAULT 0," +
                Threads.RECIPIENT_IDS + " TEXT," +
                Threads.SNIPPET + " TEXT," +
                Threads.SNIPPET_CHARSET + " INTEGER DEFAULT 0," +
                Threads.READ + " INTEGER DEFAULT 1," +
                Threads.TYPE + " INTEGER DEFAULT 0," +
                Threads.ERROR + " INTEGER DEFAULT 0," +
                Threads.HAS_ATTACHMENT + " INTEGER DEFAULT 0);");

        db.execSQL("INSERT INTO threads_temp SELECT * from threads;");
        db.execSQL("DROP TABLE threads;");
        db.execSQL("ALTER TABLE threads_temp RENAME TO threads;");
    }

    private class LowStorageMonitor extends BroadcastReceiver {

        public LowStorageMonitor() {
        }

        public void onReceive(Context context, Intent intent) {
            String action = intent.getAction();

            Log.d(TAG, "[LowStorageMonitor] onReceive intent " + action);

            if (Intent.ACTION_DEVICE_STORAGE_OK.equals(action)) {
                sTriedAutoIncrement = false;    // try to upgrade on the next getWriteableDatabase
            }
        }
    }

    private void updateThreadsAttachmentColumn(SQLiteDatabase db) {
        // Set the values of that column correctly based on the current
        // contents of the database.
        db.execSQL("UPDATE threads SET has_attachment=1 WHERE _id IN " +
                   "  (SELECT DISTINCT pdu.thread_id FROM part " +
                   "   JOIN pdu ON pdu._id=part.mid " +
                   "   WHERE part.ct != 'text/plain' AND part.ct != 'application/smil')");
    }
}