package eu.siacs.conversations.persistance;

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.DatabaseUtils;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.text.TextUtils;
import android.os.Build;
import android.os.Environment;
import android.os.SystemClock;
import android.util.Base64;
import android.util.Log;

import com.cheogram.android.WebxdcUpdate;

import com.google.common.base.Stopwatch;
import com.google.common.collect.Multimap;
import com.google.common.collect.HashMultimap;

import org.json.JSONException;
import org.json.JSONObject;
import org.whispersystems.libsignal.IdentityKey;
import org.whispersystems.libsignal.IdentityKeyPair;
import org.whispersystems.libsignal.InvalidKeyException;
import org.whispersystems.libsignal.SignalProtocolAddress;
import org.whispersystems.libsignal.state.PreKeyRecord;
import org.whispersystems.libsignal.state.SessionRecord;
import org.whispersystems.libsignal.state.SignedPreKeyRecord;

import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.IOException;
import java.security.cert.CertificateEncodingException;
import java.security.cert.CertificateException;
import java.security.cert.CertificateFactory;
import java.security.cert.X509Certificate;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.Hashtable;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.UUID;
import java.util.concurrent.CopyOnWriteArrayList;

import io.ipfs.cid.Cid;

import eu.siacs.conversations.Config;
import eu.siacs.conversations.crypto.axolotl.AxolotlService;
import eu.siacs.conversations.crypto.axolotl.FingerprintStatus;
import eu.siacs.conversations.crypto.axolotl.SQLiteAxolotlStore;
import eu.siacs.conversations.entities.Account;
import eu.siacs.conversations.entities.Contact;
import eu.siacs.conversations.entities.Conversation;
import eu.siacs.conversations.entities.DownloadableFile;
import eu.siacs.conversations.entities.Message;
import eu.siacs.conversations.entities.MucOptions;
import eu.siacs.conversations.entities.PresenceTemplate;
import eu.siacs.conversations.entities.Roster;
import eu.siacs.conversations.entities.ServiceDiscoveryResult;
import eu.siacs.conversations.services.QuickConversationsService;
import eu.siacs.conversations.services.ShortcutService;
import eu.siacs.conversations.utils.CryptoHelper;
import eu.siacs.conversations.utils.CursorUtils;
import eu.siacs.conversations.utils.FtsUtils;
import eu.siacs.conversations.utils.MimeUtils;
import eu.siacs.conversations.utils.Resolver;
import eu.siacs.conversations.xmpp.InvalidJid;
import eu.siacs.conversations.xmpp.Jid;
import eu.siacs.conversations.xmpp.mam.MamReference;

public class DatabaseBackend extends SQLiteOpenHelper {

    private static final String DATABASE_NAME = "history";
    private static final int DATABASE_VERSION = 52;

    private static boolean requiresMessageIndexRebuild = false;
    private static DatabaseBackend instance = null;
    private static final String CREATE_CONTATCS_STATEMENT = "create table "
            + Contact.TABLENAME + "(" + Contact.ACCOUNT + " TEXT, "
            + Contact.SERVERNAME + " TEXT, " + Contact.SYSTEMNAME + " TEXT,"
            + Contact.PRESENCE_NAME + " TEXT,"
            + Contact.JID + " TEXT," + Contact.KEYS + " TEXT,"
            + Contact.PHOTOURI + " TEXT," + Contact.OPTIONS + " NUMBER,"
            + Contact.SYSTEMACCOUNT + " NUMBER, " + Contact.AVATAR + " TEXT, "
            + Contact.LAST_PRESENCE + " TEXT, " + Contact.LAST_TIME + " NUMBER, "
            + Contact.RTP_CAPABILITY + " TEXT,"
            + Contact.GROUPS + " TEXT, FOREIGN KEY(" + Contact.ACCOUNT + ") REFERENCES "
            + Account.TABLENAME + "(" + Account.UUID
            + ") ON DELETE CASCADE, UNIQUE(" + Contact.ACCOUNT + ", "
            + Contact.JID + ") ON CONFLICT REPLACE);";

    private static final String CREATE_DISCOVERY_RESULTS_STATEMENT = "create table "
            + ServiceDiscoveryResult.TABLENAME + "("
            + ServiceDiscoveryResult.HASH + " TEXT, "
            + ServiceDiscoveryResult.VER + " TEXT, "
            + ServiceDiscoveryResult.RESULT + " TEXT, "
            + "UNIQUE(" + ServiceDiscoveryResult.HASH + ", "
            + ServiceDiscoveryResult.VER + ") ON CONFLICT REPLACE);";

    private static final String CREATE_PRESENCE_TEMPLATES_STATEMENT = "CREATE TABLE "
            + PresenceTemplate.TABELNAME + "("
            + PresenceTemplate.UUID + " TEXT, "
            + PresenceTemplate.LAST_USED + " NUMBER,"
            + PresenceTemplate.MESSAGE + " TEXT,"
            + PresenceTemplate.STATUS + " TEXT,"
            + "UNIQUE(" + PresenceTemplate.MESSAGE + "," + PresenceTemplate.STATUS + ") ON CONFLICT REPLACE);";

    private static final String CREATE_PREKEYS_STATEMENT = "CREATE TABLE "
            + SQLiteAxolotlStore.PREKEY_TABLENAME + "("
            + SQLiteAxolotlStore.ACCOUNT + " TEXT,  "
            + SQLiteAxolotlStore.ID + " INTEGER, "
            + SQLiteAxolotlStore.KEY + " TEXT, FOREIGN KEY("
            + SQLiteAxolotlStore.ACCOUNT
            + ") REFERENCES " + Account.TABLENAME + "(" + Account.UUID + ") ON DELETE CASCADE, "
            + "UNIQUE( " + SQLiteAxolotlStore.ACCOUNT + ", "
            + SQLiteAxolotlStore.ID
            + ") ON CONFLICT REPLACE"
            + ");";

    private static final String CREATE_SIGNED_PREKEYS_STATEMENT = "CREATE TABLE "
            + SQLiteAxolotlStore.SIGNED_PREKEY_TABLENAME + "("
            + SQLiteAxolotlStore.ACCOUNT + " TEXT,  "
            + SQLiteAxolotlStore.ID + " INTEGER, "
            + SQLiteAxolotlStore.KEY + " TEXT, FOREIGN KEY("
            + SQLiteAxolotlStore.ACCOUNT
            + ") REFERENCES " + Account.TABLENAME + "(" + Account.UUID + ") ON DELETE CASCADE, "
            + "UNIQUE( " + SQLiteAxolotlStore.ACCOUNT + ", "
            + SQLiteAxolotlStore.ID
            + ") ON CONFLICT REPLACE" +
            ");";

    private static final String CREATE_SESSIONS_STATEMENT = "CREATE TABLE "
            + SQLiteAxolotlStore.SESSION_TABLENAME + "("
            + SQLiteAxolotlStore.ACCOUNT + " TEXT,  "
            + SQLiteAxolotlStore.NAME + " TEXT, "
            + SQLiteAxolotlStore.DEVICE_ID + " INTEGER, "
            + SQLiteAxolotlStore.KEY + " TEXT, FOREIGN KEY("
            + SQLiteAxolotlStore.ACCOUNT
            + ") REFERENCES " + Account.TABLENAME + "(" + Account.UUID + ") ON DELETE CASCADE, "
            + "UNIQUE( " + SQLiteAxolotlStore.ACCOUNT + ", "
            + SQLiteAxolotlStore.NAME + ", "
            + SQLiteAxolotlStore.DEVICE_ID
            + ") ON CONFLICT REPLACE"
            + ");";

    private static final String CREATE_IDENTITIES_STATEMENT = "CREATE TABLE "
            + SQLiteAxolotlStore.IDENTITIES_TABLENAME + "("
            + SQLiteAxolotlStore.ACCOUNT + " TEXT,  "
            + SQLiteAxolotlStore.NAME + " TEXT, "
            + SQLiteAxolotlStore.OWN + " INTEGER, "
            + SQLiteAxolotlStore.FINGERPRINT + " TEXT, "
            + SQLiteAxolotlStore.CERTIFICATE + " BLOB, "
            + SQLiteAxolotlStore.TRUST + " TEXT, "
            + SQLiteAxolotlStore.ACTIVE + " NUMBER, "
            + SQLiteAxolotlStore.LAST_ACTIVATION + " NUMBER,"
            + SQLiteAxolotlStore.KEY + " TEXT, FOREIGN KEY("
            + SQLiteAxolotlStore.ACCOUNT
            + ") REFERENCES " + Account.TABLENAME + "(" + Account.UUID + ") ON DELETE CASCADE, "
            + "UNIQUE( " + SQLiteAxolotlStore.ACCOUNT + ", "
            + SQLiteAxolotlStore.NAME + ", "
            + SQLiteAxolotlStore.FINGERPRINT
            + ") ON CONFLICT IGNORE"
            + ");";

    private static final String RESOLVER_RESULTS_TABLENAME = "resolver_results";

    private static final String CREATE_RESOLVER_RESULTS_TABLE = "create table " + RESOLVER_RESULTS_TABLENAME + "("
            + Resolver.Result.DOMAIN + " TEXT,"
            + Resolver.Result.HOSTNAME + " TEXT,"
            + Resolver.Result.IP + " BLOB,"
            + Resolver.Result.PRIORITY + " NUMBER,"
            + Resolver.Result.DIRECT_TLS + " NUMBER,"
            + Resolver.Result.AUTHENTICATED + " NUMBER,"
            + Resolver.Result.PORT + " NUMBER,"
            + "UNIQUE(" + Resolver.Result.DOMAIN + ") ON CONFLICT REPLACE"
            + ");";

    private static final String CREATE_MESSAGE_TIME_INDEX = "CREATE INDEX message_time_index ON " + Message.TABLENAME + "(" + Message.TIME_SENT + ")";
    private static final String CREATE_MESSAGE_CONVERSATION_INDEX = "CREATE INDEX message_conversation_index ON " + Message.TABLENAME + "(" + Message.CONVERSATION + ")";
    private static final String CREATE_MESSAGE_DELETED_INDEX = "CREATE INDEX message_deleted_index ON " + Message.TABLENAME + "(" + Message.DELETED + ")";
    private static final String CREATE_MESSAGE_RELATIVE_FILE_PATH_INDEX = "CREATE INDEX message_file_path_index ON " + Message.TABLENAME + "(" + Message.RELATIVE_FILE_PATH + ")";
    private static final String CREATE_MESSAGE_TYPE_INDEX = "CREATE INDEX message_type_index ON " + Message.TABLENAME + "(" + Message.TYPE + ")";

    private static final String CREATE_MESSAGE_INDEX_TABLE = "CREATE VIRTUAL TABLE messages_index USING fts4 (uuid,body,notindexed=\"uuid\",content=\"" + Message.TABLENAME + "\",tokenize='unicode61')";
    private static final String CREATE_MESSAGE_INSERT_TRIGGER = "CREATE TRIGGER after_message_insert AFTER INSERT ON " + Message.TABLENAME + " BEGIN INSERT INTO messages_index(rowid,uuid,body) VALUES(NEW.rowid,NEW.uuid,NEW.body); END;";
    private static final String CREATE_MESSAGE_UPDATE_TRIGGER = "CREATE TRIGGER after_message_update UPDATE OF uuid,body ON " + Message.TABLENAME + " BEGIN UPDATE messages_index SET body=NEW.body,uuid=NEW.uuid WHERE rowid=OLD.rowid; END;";
    private static final String CREATE_MESSAGE_DELETE_TRIGGER = "CREATE TRIGGER after_message_delete AFTER DELETE ON " + Message.TABLENAME + " BEGIN DELETE FROM messages_index WHERE rowid=OLD.rowid; END;";
    private static final String COPY_PREEXISTING_ENTRIES = "INSERT INTO messages_index(messages_index) VALUES('rebuild');";

    protected Context context;

    private DatabaseBackend(Context context) {
        super(context, DATABASE_NAME, null, DATABASE_VERSION);
        this.context = context;
        setWriteAheadLoggingEnabled(true);
    }

    private static ContentValues createFingerprintStatusContentValues(FingerprintStatus.Trust trust, boolean active) {
        ContentValues values = new ContentValues();
        values.put(SQLiteAxolotlStore.TRUST, trust.toString());
        values.put(SQLiteAxolotlStore.ACTIVE, active ? 1 : 0);
        return values;
    }

    public static boolean requiresMessageIndexRebuild() {
        return requiresMessageIndexRebuild;
    }

    public void rebuildMessagesIndex() {
        final SQLiteDatabase db = getWritableDatabase();
        final Stopwatch stopwatch = Stopwatch.createStarted();
        db.execSQL(COPY_PREEXISTING_ENTRIES);
        Log.d(Config.LOGTAG,"rebuilt message index in "+ stopwatch.stop().toString());
    }

    public static synchronized DatabaseBackend getInstance(Context context) {
        if (instance == null) {
            instance = new DatabaseBackend(context);
        }
        return instance;
    }

    protected void cheogramMigrate(SQLiteDatabase db) {
        db.beginTransaction();

        try {
            Cursor cursor = db.rawQuery("PRAGMA cheogram.user_version", null);
            cursor.moveToNext();
            int cheogramVersion = cursor.getInt(0);
            cursor.close();

            if(cheogramVersion < 1) {
                // No cross-DB foreign keys unfortunately
                db.execSQL(
                    "CREATE TABLE cheogram." + Message.TABLENAME + "(" +
                    Message.UUID + " TEXT PRIMARY KEY, " +
                    "subject TEXT" +
                    ")"
                );
                db.execSQL("PRAGMA cheogram.user_version = 1");
            }

            if(cheogramVersion < 2) {
                db.execSQL(
                    "ALTER TABLE cheogram." + Message.TABLENAME + " " +
                    "ADD COLUMN oobUri TEXT"
                );
                db.execSQL(
                    "ALTER TABLE cheogram." + Message.TABLENAME + " " +
                    "ADD COLUMN fileParams TEXT"
                );
                db.execSQL("PRAGMA cheogram.user_version = 2");
            }

            if(cheogramVersion < 3) {
                db.execSQL(
                    "ALTER TABLE cheogram." + Message.TABLENAME + " " +
                    "ADD COLUMN payloads TEXT"
                );
                db.execSQL("PRAGMA cheogram.user_version = 3");
            }

            if(cheogramVersion < 4) {
                db.execSQL(
                    "CREATE TABLE cheogram.cids (" +
                    "cid TEXT NOT NULL PRIMARY KEY," +
                    "path TEXT NOT NULL" +
                    ")"
                );
                db.execSQL("PRAGMA cheogram.user_version = 4");
            }

            if(cheogramVersion < 5) {
                db.execSQL(
                    "ALTER TABLE cheogram." + Message.TABLENAME + " " +
                    "ADD COLUMN timeReceived NUMBER"
                );
                db.execSQL("CREATE INDEX cheogram.message_time_received_index ON " + Message.TABLENAME + " (timeReceived)");
                db.execSQL("PRAGMA cheogram.user_version = 5");
            }

            if(cheogramVersion < 6) {
                db.execSQL(
                    "CREATE TABLE cheogram.blocked_media (" +
                    "cid TEXT NOT NULL PRIMARY KEY" +
                    ")"
                );
                db.execSQL("PRAGMA cheogram.user_version = 6");
            }

            if(cheogramVersion < 7) {
                db.execSQL(
                    "ALTER TABLE cheogram.cids " +
                    "ADD COLUMN url TEXT"
                );
                db.execSQL("PRAGMA cheogram.user_version = 7");
            }

            if(cheogramVersion < 8) {
                db.execSQL(
                    "CREATE TABLE cheogram.webxdc_updates (" +
                    "serial INTEGER PRIMARY KEY AUTOINCREMENT, " +
                    Message.CONVERSATION + " TEXT NOT NULL, " +
                    "sender TEXT NOT NULL, " +
                    "thread TEXT NOT NULL, " +
                    "threadParent TEXT, " +
                    "info TEXT, " +
                    "document TEXT, " +
                    "summary TEXT, " +
                    "payload TEXT" +
                    ")"
                );
                db.execSQL("CREATE INDEX cheogram.webxdc_index ON webxdc_updates (" + Message.CONVERSATION + ", thread)");
                db.execSQL("PRAGMA cheogram.user_version = 8");
				}

            if(cheogramVersion < 9) {
                db.execSQL(
                    "ALTER TABLE cheogram.webxdc_updates " +
                    "ADD COLUMN message_id TEXT"
                );
                db.execSQL("CREATE UNIQUE INDEX cheogram.webxdc_message_id_index ON webxdc_updates (" + Message.CONVERSATION + ", message_id)");
                db.execSQL("PRAGMA cheogram.user_version = 9");
            }

            if(cheogramVersion < 10) {
                db.execSQL(
                    "CREATE TABLE cheogram.muted_participants (" +
                    "muc_jid TEXT NOT NULL, " +
                    "occupant_id TEXT NOT NULL, " +
                    "nick TEXT NOT NULL," +
                    "PRIMARY KEY (muc_jid, occupant_id)" +
                    ")"
                );
                db.execSQL(
                    "ALTER TABLE cheogram." + Message.TABLENAME + " " +
                    "ADD COLUMN occupant_id TEXT"
                );
                db.execSQL("PRAGMA cheogram.user_version = 10");
            }

            if(cheogramVersion < 11) {
                if (Build.VERSION.SDK_INT >= 34) {
                    db.execSQL(
                        "ALTER TABLE cheogram.muted_participants " +
                        "DROP COLUMN nick"
                    );
                } else {
                    db.execSQL("DROP TABLE cheogram.muted_participants");
                    db.execSQL(
                        "CREATE TABLE cheogram.muted_participants (" +
                        "muc_jid TEXT NOT NULL, " +
                        "occupant_id TEXT NOT NULL, " +
                        "PRIMARY KEY (muc_jid, occupant_id)" +
                        ")"
                    );
                }
                db.execSQL("PRAGMA cheogram.user_version = 11");
            }

            db.setTransactionSuccessful();
        } finally {
            db.endTransaction();
        }
    }

    @Override
    public void onConfigure(SQLiteDatabase db) {
        db.execSQL("PRAGMA foreign_keys=ON");
        db.rawQuery("PRAGMA secure_delete=ON", null).close();
        db.execSQL("ATTACH DATABASE ? AS cheogram", new Object[]{context.getDatabasePath("cheogram").getPath()});
        cheogramMigrate(db);
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        db.execSQL("create table " + Account.TABLENAME + "(" + Account.UUID + " TEXT PRIMARY KEY,"
                + Account.USERNAME + " TEXT,"
                + Account.SERVER + " TEXT,"
                + Account.PASSWORD + " TEXT,"
                + Account.DISPLAY_NAME + " TEXT, "
                + Account.STATUS + " TEXT,"
                + Account.STATUS_MESSAGE + " TEXT,"
                + Account.ROSTERVERSION + " TEXT,"
                + Account.OPTIONS + " NUMBER, "
                + Account.AVATAR + " TEXT, "
                + Account.KEYS + " TEXT, "
                + Account.HOSTNAME + " TEXT, "
                + Account.RESOURCE + " TEXT,"
                + Account.PINNED_MECHANISM + " TEXT,"
                + Account.PINNED_CHANNEL_BINDING + " TEXT,"
                + Account.FAST_MECHANISM + " TEXT,"
                + Account.FAST_TOKEN + " TEXT,"
                + Account.PORT + " NUMBER DEFAULT 5222)");
        db.execSQL("create table " + Conversation.TABLENAME + " ("
                + Conversation.UUID + " TEXT PRIMARY KEY, " + Conversation.NAME
                + " TEXT, " + Conversation.CONTACT + " TEXT, "
                + Conversation.ACCOUNT + " TEXT, " + Conversation.CONTACTJID
                + " TEXT, " + Conversation.CREATED + " NUMBER, "
                + Conversation.STATUS + " NUMBER, " + Conversation.MODE
                + " NUMBER, " + Conversation.ATTRIBUTES + " TEXT, FOREIGN KEY("
                + Conversation.ACCOUNT + ") REFERENCES " + Account.TABLENAME
                + "(" + Account.UUID + ") ON DELETE CASCADE);");
        db.execSQL("create table " + Message.TABLENAME + "( " + Message.UUID
                + " TEXT PRIMARY KEY, " + Message.CONVERSATION + " TEXT, "
                + Message.TIME_SENT + " NUMBER, " + Message.COUNTERPART
                + " TEXT, " + Message.TRUE_COUNTERPART + " TEXT,"
                + Message.BODY + " TEXT, " + Message.ENCRYPTION + " NUMBER, "
                + Message.STATUS + " NUMBER," + Message.TYPE + " NUMBER, "
                + Message.RELATIVE_FILE_PATH + " TEXT, "
                + Message.SERVER_MSG_ID + " TEXT, "
                + Message.FINGERPRINT + " TEXT, "
                + Message.CARBON + " INTEGER, "
                + Message.EDITED + " TEXT, "
                + Message.READ + " NUMBER DEFAULT 1, "
                + Message.OOB + " INTEGER, "
                + Message.ERROR_MESSAGE + " TEXT,"
                + Message.READ_BY_MARKERS + " TEXT,"
                + Message.MARKABLE + " NUMBER DEFAULT 0,"
                + Message.DELETED + " NUMBER DEFAULT 0,"
                + Message.BODY_LANGUAGE + " TEXT,"
                + Message.OCCUPANT_ID + " TEXT,"
                + Message.REACTIONS + " TEXT,"
                + Message.REMOTE_MSG_ID + " TEXT, FOREIGN KEY("
                + Message.CONVERSATION + ") REFERENCES "
                + Conversation.TABLENAME + "(" + Conversation.UUID
                + ") ON DELETE CASCADE);");
        db.execSQL(CREATE_MESSAGE_TIME_INDEX);
        db.execSQL(CREATE_MESSAGE_CONVERSATION_INDEX);
        db.execSQL(CREATE_MESSAGE_DELETED_INDEX);
        db.execSQL(CREATE_MESSAGE_RELATIVE_FILE_PATH_INDEX);
        db.execSQL(CREATE_MESSAGE_TYPE_INDEX);
        db.execSQL(CREATE_CONTATCS_STATEMENT);
        db.execSQL(CREATE_DISCOVERY_RESULTS_STATEMENT);
        db.execSQL(CREATE_SESSIONS_STATEMENT);
        db.execSQL(CREATE_PREKEYS_STATEMENT);
        db.execSQL(CREATE_SIGNED_PREKEYS_STATEMENT);
        db.execSQL(CREATE_IDENTITIES_STATEMENT);
        db.execSQL(CREATE_PRESENCE_TEMPLATES_STATEMENT);
        db.execSQL(CREATE_RESOLVER_RESULTS_TABLE);
        db.execSQL(CREATE_MESSAGE_INDEX_TABLE);
        db.execSQL(CREATE_MESSAGE_INSERT_TRIGGER);
        db.execSQL(CREATE_MESSAGE_UPDATE_TRIGGER);
        db.execSQL(CREATE_MESSAGE_DELETE_TRIGGER);
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        if (oldVersion < 2 && newVersion >= 2) {
            db.execSQL("update " + Account.TABLENAME + " set "
                    + Account.OPTIONS + " = " + Account.OPTIONS + " | 8");
        }
        if (oldVersion < 3 && newVersion >= 3) {
            db.execSQL("ALTER TABLE " + Message.TABLENAME + " ADD COLUMN "
                    + Message.TYPE + " NUMBER");
        }
        if (oldVersion < 5 && newVersion >= 5) {
            db.execSQL("DROP TABLE " + Contact.TABLENAME);
            db.execSQL(CREATE_CONTATCS_STATEMENT);
            db.execSQL("UPDATE " + Account.TABLENAME + " SET "
                    + Account.ROSTERVERSION + " = NULL");
        }
        if (oldVersion < 6 && newVersion >= 6) {
            db.execSQL("ALTER TABLE " + Message.TABLENAME + " ADD COLUMN "
                    + Message.TRUE_COUNTERPART + " TEXT");
        }
        if (oldVersion < 7 && newVersion >= 7) {
            db.execSQL("ALTER TABLE " + Message.TABLENAME + " ADD COLUMN "
                    + Message.REMOTE_MSG_ID + " TEXT");
            db.execSQL("ALTER TABLE " + Contact.TABLENAME + " ADD COLUMN "
                    + Contact.AVATAR + " TEXT");
            db.execSQL("ALTER TABLE " + Account.TABLENAME + " ADD COLUMN "
                    + Account.AVATAR + " TEXT");
        }
        if (oldVersion < 8 && newVersion >= 8) {
            db.execSQL("ALTER TABLE " + Conversation.TABLENAME + " ADD COLUMN "
                    + Conversation.ATTRIBUTES + " TEXT");
        }
        if (oldVersion < 9 && newVersion >= 9) {
            db.execSQL("ALTER TABLE " + Contact.TABLENAME + " ADD COLUMN "
                    + Contact.LAST_TIME + " NUMBER");
            db.execSQL("ALTER TABLE " + Contact.TABLENAME + " ADD COLUMN "
                    + Contact.LAST_PRESENCE + " TEXT");
        }
        if (oldVersion < 10 && newVersion >= 10) {
            db.execSQL("ALTER TABLE " + Message.TABLENAME + " ADD COLUMN "
                    + Message.RELATIVE_FILE_PATH + " TEXT");
        }
        if (oldVersion < 11 && newVersion >= 11) {
            db.execSQL("ALTER TABLE " + Contact.TABLENAME + " ADD COLUMN "
                    + Contact.GROUPS + " TEXT");
            db.execSQL("delete from " + Contact.TABLENAME);
            db.execSQL("update " + Account.TABLENAME + " set " + Account.ROSTERVERSION + " = NULL");
        }
        if (oldVersion < 12 && newVersion >= 12) {
            db.execSQL("ALTER TABLE " + Message.TABLENAME + " ADD COLUMN "
                    + Message.SERVER_MSG_ID + " TEXT");
        }
        if (oldVersion < 13 && newVersion >= 13) {
            db.execSQL("delete from " + Contact.TABLENAME);
            db.execSQL("update " + Account.TABLENAME + " set " + Account.ROSTERVERSION + " = NULL");
        }
        if (oldVersion < 14 && newVersion >= 14) {
            canonicalizeJids(db);
        }
        if (oldVersion < 15 && newVersion >= 15) {
            recreateAxolotlDb(db);
            db.execSQL("ALTER TABLE " + Message.TABLENAME + " ADD COLUMN "
                    + Message.FINGERPRINT + " TEXT");
        }
        if (oldVersion < 16 && newVersion >= 16) {
            db.execSQL("ALTER TABLE " + Message.TABLENAME + " ADD COLUMN "
                    + Message.CARBON + " INTEGER");
        }
        if (oldVersion < 19 && newVersion >= 19) {
            db.execSQL("ALTER TABLE " + Account.TABLENAME + " ADD COLUMN " + Account.DISPLAY_NAME + " TEXT");
        }
        if (oldVersion < 20 && newVersion >= 20) {
            db.execSQL("ALTER TABLE " + Account.TABLENAME + " ADD COLUMN " + Account.HOSTNAME + " TEXT");
            db.execSQL("ALTER TABLE " + Account.TABLENAME + " ADD COLUMN " + Account.PORT + " NUMBER DEFAULT 5222");
        }
        if (oldVersion < 26 && newVersion >= 26) {
            db.execSQL("ALTER TABLE " + Account.TABLENAME + " ADD COLUMN " + Account.STATUS + " TEXT");
            db.execSQL("ALTER TABLE " + Account.TABLENAME + " ADD COLUMN " + Account.STATUS_MESSAGE + " TEXT");
        }
        if (oldVersion < 40 && newVersion >= 40) {
            db.execSQL("ALTER TABLE " + Account.TABLENAME + " ADD COLUMN " + Account.RESOURCE + " TEXT");
        }
        /* Any migrations that alter the Account table need to happen BEFORE this migration, as it
         * depends on account de-serialization.
         */
        if (oldVersion < 17 && newVersion >= 17 && newVersion < 31) {
            List<Account> accounts = getAccounts(db);
            for (Account account : accounts) {
                String ownDeviceIdString = account.getKey(SQLiteAxolotlStore.JSONKEY_REGISTRATION_ID);
                if (ownDeviceIdString == null) {
                    continue;
                }
                int ownDeviceId = Integer.valueOf(ownDeviceIdString);
                SignalProtocolAddress ownAddress = new SignalProtocolAddress(account.getJid().asBareJid().toString(), ownDeviceId);
                deleteSession(db, account, ownAddress);
                IdentityKeyPair identityKeyPair = loadOwnIdentityKeyPair(db, account);
                if (identityKeyPair != null) {
                    String[] selectionArgs = {
                            account.getUuid(),
                            CryptoHelper.bytesToHex(identityKeyPair.getPublicKey().serialize())
                    };
                    ContentValues values = new ContentValues();
                    values.put(SQLiteAxolotlStore.TRUSTED, 2);
                    db.update(SQLiteAxolotlStore.IDENTITIES_TABLENAME, values,
                            SQLiteAxolotlStore.ACCOUNT + " = ? AND "
                                    + SQLiteAxolotlStore.FINGERPRINT + " = ? ",
                            selectionArgs);
                } else {
                    Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": could not load own identity key pair");
                }
            }
        }
        if (oldVersion < 18 && newVersion >= 18) {
            db.execSQL("ALTER TABLE " + Message.TABLENAME + " ADD COLUMN " + Message.READ + " NUMBER DEFAULT 1");
        }

        if (oldVersion < 21 && newVersion >= 21) {
            List<Account> accounts = getAccounts(db);
            for (Account account : accounts) {
                account.unsetPgpSignature();
                db.update(Account.TABLENAME, account.getContentValues(), Account.UUID
                        + "=?", new String[]{account.getUuid()});
            }
        }

        if (oldVersion >= 15 && oldVersion < 22 && newVersion >= 22) {
            db.execSQL("ALTER TABLE " + SQLiteAxolotlStore.IDENTITIES_TABLENAME + " ADD COLUMN " + SQLiteAxolotlStore.CERTIFICATE);
        }

        if (oldVersion < 23 && newVersion >= 23) {
            db.execSQL(CREATE_DISCOVERY_RESULTS_STATEMENT);
        }

        if (oldVersion < 24 && newVersion >= 24) {
            db.execSQL("ALTER TABLE " + Message.TABLENAME + " ADD COLUMN " + Message.EDITED + " TEXT");
        }

        if (oldVersion < 25 && newVersion >= 25) {
            db.execSQL("ALTER TABLE " + Message.TABLENAME + " ADD COLUMN " + Message.OOB + " INTEGER");
        }

        if (oldVersion < 26 && newVersion >= 26) {
            db.execSQL(CREATE_PRESENCE_TEMPLATES_STATEMENT);
        }

        if (oldVersion < 27 && newVersion >= 27) {
            db.execSQL("DELETE FROM " + ServiceDiscoveryResult.TABLENAME);
        }

        if (oldVersion < 28 && newVersion >= 28) {
            canonicalizeJids(db);
        }

        if (oldVersion < 29 && newVersion >= 29) {
            db.execSQL("ALTER TABLE " + Message.TABLENAME + " ADD COLUMN " + Message.ERROR_MESSAGE + " TEXT");
        }
        if (oldVersion >= 15 && oldVersion < 31 && newVersion >= 31) {
            db.execSQL("ALTER TABLE " + SQLiteAxolotlStore.IDENTITIES_TABLENAME + " ADD COLUMN " + SQLiteAxolotlStore.TRUST + " TEXT");
            db.execSQL("ALTER TABLE " + SQLiteAxolotlStore.IDENTITIES_TABLENAME + " ADD COLUMN " + SQLiteAxolotlStore.ACTIVE + " NUMBER");
            HashMap<Integer, ContentValues> migration = new HashMap<>();
            migration.put(0, createFingerprintStatusContentValues(FingerprintStatus.Trust.TRUSTED, true));
            migration.put(1, createFingerprintStatusContentValues(FingerprintStatus.Trust.TRUSTED, true));
            migration.put(2, createFingerprintStatusContentValues(FingerprintStatus.Trust.UNTRUSTED, true));
            migration.put(3, createFingerprintStatusContentValues(FingerprintStatus.Trust.COMPROMISED, false));
            migration.put(4, createFingerprintStatusContentValues(FingerprintStatus.Trust.TRUSTED, false));
            migration.put(5, createFingerprintStatusContentValues(FingerprintStatus.Trust.TRUSTED, false));
            migration.put(6, createFingerprintStatusContentValues(FingerprintStatus.Trust.UNTRUSTED, false));
            migration.put(7, createFingerprintStatusContentValues(FingerprintStatus.Trust.VERIFIED_X509, true));
            migration.put(8, createFingerprintStatusContentValues(FingerprintStatus.Trust.VERIFIED_X509, false));
            for (Map.Entry<Integer, ContentValues> entry : migration.entrySet()) {
                String whereClause = SQLiteAxolotlStore.TRUSTED + "=?";
                String[] where = {String.valueOf(entry.getKey())};
                db.update(SQLiteAxolotlStore.IDENTITIES_TABLENAME, entry.getValue(), whereClause, where);
            }

        }
        if (oldVersion >= 15 && oldVersion < 32 && newVersion >= 32) {
            db.execSQL("ALTER TABLE " + SQLiteAxolotlStore.IDENTITIES_TABLENAME + " ADD COLUMN " + SQLiteAxolotlStore.LAST_ACTIVATION + " NUMBER");
            ContentValues defaults = new ContentValues();
            defaults.put(SQLiteAxolotlStore.LAST_ACTIVATION, System.currentTimeMillis());
            db.update(SQLiteAxolotlStore.IDENTITIES_TABLENAME, defaults, null, null);
        }
        if (oldVersion >= 15 && oldVersion < 33 && newVersion >= 33) {
            String whereClause = SQLiteAxolotlStore.OWN + "=1";
            db.update(SQLiteAxolotlStore.IDENTITIES_TABLENAME, createFingerprintStatusContentValues(FingerprintStatus.Trust.VERIFIED, true), whereClause, null);
        }

        if (oldVersion < 34 && newVersion >= 34) {
            db.execSQL(CREATE_MESSAGE_TIME_INDEX);

            final File oldPicturesDirectory = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES) + "/Conversations/");
            final File oldFilesDirectory = new File(Environment.getExternalStorageDirectory() + "/Conversations/");
            final File newFilesDirectory = new File(Environment.getExternalStorageDirectory() + "/Conversations/Media/Conversations Files/");
            final File newVideosDirectory = new File(Environment.getExternalStorageDirectory() + "/Conversations/Media/Conversations Videos/");
            if (oldPicturesDirectory.exists() && oldPicturesDirectory.isDirectory()) {
                final File newPicturesDirectory = new File(Environment.getExternalStorageDirectory() + "/Conversations/Media/Conversations Images/");
                newPicturesDirectory.getParentFile().mkdirs();
                if (oldPicturesDirectory.renameTo(newPicturesDirectory)) {
                    Log.d(Config.LOGTAG, "moved " + oldPicturesDirectory.getAbsolutePath() + " to " + newPicturesDirectory.getAbsolutePath());
                }
            }
            if (oldFilesDirectory.exists() && oldFilesDirectory.isDirectory()) {
                newFilesDirectory.mkdirs();
                newVideosDirectory.mkdirs();
                final File[] files = oldFilesDirectory.listFiles();
                if (files == null) {
                    return;
                }
                for (File file : files) {
                    if (file.getName().equals(".nomedia")) {
                        if (file.delete()) {
                            Log.d(Config.LOGTAG, "deleted nomedia file in " + oldFilesDirectory.getAbsolutePath());
                        }
                    } else if (file.isFile()) {
                        final String name = file.getName();
                        boolean isVideo = false;
                        int start = name.lastIndexOf('.') + 1;
                        if (start < name.length()) {
                            String mime = MimeUtils.guessMimeTypeFromExtension(name.substring(start));
                            isVideo = mime != null && mime.startsWith("video/");
                        }
                        File dst = new File((isVideo ? newVideosDirectory : newFilesDirectory).getAbsolutePath() + "/" + file.getName());
                        if (file.renameTo(dst)) {
                            Log.d(Config.LOGTAG, "moved " + file + " to " + dst);
                        }
                    }
                }
            }
        }
        if (oldVersion < 35 && newVersion >= 35) {
            db.execSQL(CREATE_MESSAGE_CONVERSATION_INDEX);
        }
        if (oldVersion < 36 && newVersion >= 36) {
            List<Account> accounts = getAccounts(db);
            for (Account account : accounts) {
                account.setOption(Account.OPTION_REQUIRES_ACCESS_MODE_CHANGE, true);
                account.setOption(Account.OPTION_LOGGED_IN_SUCCESSFULLY, false);
                db.update(Account.TABLENAME, account.getContentValues(), Account.UUID
                        + "=?", new String[]{account.getUuid()});
            }
        }

        if (oldVersion < 37 && newVersion >= 37) {
            db.execSQL("ALTER TABLE " + Message.TABLENAME + " ADD COLUMN " + Message.READ_BY_MARKERS + " TEXT");
        }

        if (oldVersion < 38 && newVersion >= 38) {
            db.execSQL("ALTER TABLE " + Message.TABLENAME + " ADD COLUMN " + Message.MARKABLE + " NUMBER DEFAULT 0");
        }

        if (oldVersion < 39 && newVersion >= 39) {
            db.execSQL(CREATE_RESOLVER_RESULTS_TABLE);
        }

        if (QuickConversationsService.isQuicksy() && oldVersion < 43 && newVersion >= 43) {
            List<Account> accounts = getAccounts(db);
            for (Account account : accounts) {
                account.setOption(Account.OPTION_MAGIC_CREATE, true);
                db.update(Account.TABLENAME, account.getContentValues(), Account.UUID
                        + "=?", new String[]{account.getUuid()});
            }
        }

        if (oldVersion < 44 && newVersion >= 44) {
            db.execSQL("ALTER TABLE " + Message.TABLENAME + " ADD COLUMN " + Message.DELETED + " NUMBER DEFAULT 0");
            db.execSQL(CREATE_MESSAGE_DELETED_INDEX);
            db.execSQL(CREATE_MESSAGE_RELATIVE_FILE_PATH_INDEX);
            db.execSQL(CREATE_MESSAGE_TYPE_INDEX);
        }

        if (oldVersion < 45 && newVersion >= 45) {
            db.execSQL("ALTER TABLE " + Message.TABLENAME + " ADD COLUMN " + Message.BODY_LANGUAGE);
        }

        if (oldVersion < 46 && newVersion >= 46) {
            final long start = SystemClock.elapsedRealtime();
            db.rawQuery("PRAGMA secure_delete = FALSE", null).close();
            db.execSQL("update " + Message.TABLENAME + " set " + Message.EDITED + "=NULL");
            db.rawQuery("PRAGMA secure_delete=ON", null).close();
            final long diff = SystemClock.elapsedRealtime() - start;
            Log.d(Config.LOGTAG, "deleted old edit information in " + diff + "ms");
        }
        if (oldVersion < 47 && newVersion >= 47) {
            db.execSQL("ALTER TABLE " + Contact.TABLENAME + " ADD COLUMN " + Contact.PRESENCE_NAME + " TEXT");
        }
        if (oldVersion < 48 && newVersion >= 48) {
            db.execSQL("ALTER TABLE " + Contact.TABLENAME + " ADD COLUMN " + Contact.RTP_CAPABILITY + " TEXT");
        }
        if (oldVersion < 49 && newVersion >= 49) {
            db.beginTransaction();
            db.execSQL("DROP TRIGGER IF EXISTS after_message_insert;");
            db.execSQL("DROP TRIGGER IF EXISTS after_message_update;");
            db.execSQL("DROP TRIGGER IF EXISTS after_message_delete;");
            db.execSQL("DROP TABLE IF EXISTS messages_index;");
            // a hack that should not be necessary, but
            // there was at least one occurence when SQLite failed at this
            db.execSQL("DROP TABLE IF EXISTS messages_index_docsize;");
            db.execSQL("DROP TABLE IF EXISTS messages_index_segdir;");
            db.execSQL("DROP TABLE IF EXISTS messages_index_segments;");
            db.execSQL("DROP TABLE IF EXISTS messages_index_stat;");
            db.execSQL(CREATE_MESSAGE_INDEX_TABLE);
            db.execSQL(CREATE_MESSAGE_INSERT_TRIGGER);
            db.execSQL(CREATE_MESSAGE_UPDATE_TRIGGER);
            db.execSQL(CREATE_MESSAGE_DELETE_TRIGGER);
            db.setTransactionSuccessful();
            db.endTransaction();
            requiresMessageIndexRebuild = true;
        }
        if (oldVersion < 50 && newVersion >= 50) {
            db.execSQL("ALTER TABLE " + Account.TABLENAME + " ADD COLUMN " + Account.PINNED_MECHANISM + " TEXT");
            db.execSQL("ALTER TABLE " + Account.TABLENAME + " ADD COLUMN " + Account.PINNED_CHANNEL_BINDING + " TEXT");
        }
        if (oldVersion < 51 && newVersion >= 51) {
            db.execSQL("ALTER TABLE " + Account.TABLENAME + " ADD COLUMN " + Account.FAST_MECHANISM + " TEXT");
            db.execSQL("ALTER TABLE " + Account.TABLENAME + " ADD COLUMN " + Account.FAST_TOKEN + " TEXT");
        }
        if (oldVersion < 52 && newVersion >= 52) {
            db.execSQL("ALTER TABLE " + Message.TABLENAME + " ADD COLUMN " + Message.OCCUPANT_ID + " TEXT");
            db.execSQL("ALTER TABLE " + Message.TABLENAME + " ADD COLUMN " + Message.REACTIONS + " TEXT");
        }
    }

    private void canonicalizeJids(SQLiteDatabase db) {
        // migrate db to new, canonicalized JID domainpart representation

        // Conversation table
        Cursor cursor = db.rawQuery("select * from " + Conversation.TABLENAME, new String[0]);
        while (cursor.moveToNext()) {
            String newJid;
            try {
                newJid = Jid.of(cursor.getString(cursor.getColumnIndex(Conversation.CONTACTJID))).toString();
            } catch (IllegalArgumentException ignored) {
                Log.e(Config.LOGTAG, "Failed to migrate Conversation CONTACTJID "
                        + cursor.getString(cursor.getColumnIndex(Conversation.CONTACTJID))
                        + ": " + ignored + ". Skipping...");
                continue;
            }

            final String[] updateArgs = {
                    newJid,
                    cursor.getString(cursor.getColumnIndex(Conversation.UUID)),
            };
            db.execSQL("update " + Conversation.TABLENAME
                    + " set " + Conversation.CONTACTJID + " = ? "
                    + " where " + Conversation.UUID + " = ?", updateArgs);
        }
        cursor.close();

        // Contact table
        cursor = db.rawQuery("select * from " + Contact.TABLENAME, new String[0]);
        while (cursor.moveToNext()) {
            String newJid;
            try {
                newJid = Jid.of(cursor.getString(cursor.getColumnIndex(Contact.JID))).toString();
            } catch (final IllegalArgumentException e) {
                Log.e(Config.LOGTAG, "Failed to migrate Contact JID "
                        + cursor.getString(cursor.getColumnIndex(Contact.JID))
                        + ":  Skipping...", e);
                continue;
            }

            final String[] updateArgs = {
                    newJid,
                    cursor.getString(cursor.getColumnIndex(Contact.ACCOUNT)),
                    cursor.getString(cursor.getColumnIndex(Contact.JID)),
            };
            db.execSQL("update " + Contact.TABLENAME
                    + " set " + Contact.JID + " = ? "
                    + " where " + Contact.ACCOUNT + " = ? "
                    + " AND " + Contact.JID + " = ?", updateArgs);
        }
        cursor.close();

        // Account table
        cursor = db.rawQuery("select * from " + Account.TABLENAME, new String[0]);
        while (cursor.moveToNext()) {
            String newServer;
            try {
                newServer = Jid.of(
                        cursor.getString(cursor.getColumnIndex(Account.USERNAME)),
                        cursor.getString(cursor.getColumnIndex(Account.SERVER)),
                        null
                ).getDomain().toEscapedString();
            } catch (IllegalArgumentException ignored) {
                Log.e(Config.LOGTAG, "Failed to migrate Account SERVER "
                        + cursor.getString(cursor.getColumnIndex(Account.SERVER))
                        + ": " + ignored + ". Skipping...");
                continue;
            }

            String[] updateArgs = {
                    newServer,
                    cursor.getString(cursor.getColumnIndex(Account.UUID)),
            };
            db.execSQL("update " + Account.TABLENAME
                    + " set " + Account.SERVER + " = ? "
                    + " where " + Account.UUID + " = ?", updateArgs);
        }
        cursor.close();
    }

    public DownloadableFile getFileForCid(Cid cid) {
        if (cid == null) return null;

        SQLiteDatabase db = this.getReadableDatabase();
        Cursor cursor = db.query("cheogram.cids", new String[]{"path"}, "cid=?", new String[]{cid.toString()}, null, null, null);
        DownloadableFile f = null;
        if (cursor.moveToNext()) {
            f = new DownloadableFile(cursor.getString(0));
        }
        cursor.close();
        return f;
    }

    public String getUrlForCid(Cid cid) {
        SQLiteDatabase db = this.getReadableDatabase();
        Cursor cursor = db.query("cheogram.cids", new String[]{"url"}, "cid=?", new String[]{cid.toString()}, null, null, null);
        String url = null;
        if (cursor.moveToNext()) {
            url = cursor.getString(0);
        }
        cursor.close();
        return url;
    }

    public void saveCid(Cid cid, File file) {
        saveCid(cid, file, null);
    }

    public void saveCid(Cid cid, File file, String url) {
        SQLiteDatabase db = this.getWritableDatabase();
        ContentValues cv = new ContentValues();
        cv.put("cid", cid.toString());
        if (file != null) cv.put("path", file.getAbsolutePath());
        if (url != null) cv.put("url", url);
        if (db.update("cheogram.cids", cv, "cid=?", new String[]{cid.toString()}) < 1) {
            db.insertWithOnConflict("cheogram.cids", null, cv, SQLiteDatabase.CONFLICT_REPLACE);
        }
    }

    public void blockMedia(Cid cid) {
        SQLiteDatabase db = this.getWritableDatabase();
        ContentValues cv = new ContentValues();
        cv.put("cid", cid.toString());
        db.insertWithOnConflict("cheogram.blocked_media", null, cv, SQLiteDatabase.CONFLICT_REPLACE);
    }

    public boolean isBlockedMedia(Cid cid) {
        SQLiteDatabase db = this.getReadableDatabase();
        Cursor cursor = db.query("cheogram.blocked_media", new String[]{"count(*)"}, "cid=?", new String[]{cid.toString()}, null, null, null);
        boolean is = false;
        if (cursor.moveToNext()) {
            is = cursor.getInt(0) > 0;
        }
        cursor.close();
        return is;
    }

    public void clearBlockedMedia() {
        SQLiteDatabase db = this.getWritableDatabase();
        db.execSQL("DELETE FROM cheogram.blocked_media");
    }

    public Multimap<String, String> loadMutedMucUsers() {
        Multimap<String, String> result = HashMultimap.create();
        SQLiteDatabase db = this.getReadableDatabase();
        Cursor cursor = db.query("cheogram.muted_participants", new String[]{"muc_jid", "occupant_id"}, null, null, null, null, null);
        while (cursor.moveToNext()) {
            result.put(cursor.getString(0), cursor.getString(1));
        }
        cursor.close();
        return result;
    }

    public boolean muteMucUser(MucOptions.User user) {
        if (user.getMuc() == null || user.getOccupantId() == null) return false;

        SQLiteDatabase db = this.getWritableDatabase();
        ContentValues cv = new ContentValues();
        cv.put("muc_jid", user.getMuc().toString());
        cv.put("occupant_id", user.getOccupantId());
        db.insertWithOnConflict("cheogram.muted_participants", null, cv, SQLiteDatabase.CONFLICT_REPLACE);

        return true;
    }

    public boolean unmuteMucUser(MucOptions.User user) {
        if (user.getMuc() == null || user.getOccupantId() == null) return false;

        SQLiteDatabase db = this.getWritableDatabase();
        String where = "muc_jid=? AND occupant_id=?";
        String[] whereArgs = {user.getMuc().toString(), user.getOccupantId()};
        db.delete("cheogram.muted_participants", where, whereArgs);

        return true;
    }

    public void insertWebxdcUpdate(final WebxdcUpdate update) {
        SQLiteDatabase db = this.getWritableDatabase();
        db.insertWithOnConflict("cheogram.webxdc_updates", null, update.getContentValues(), SQLiteDatabase.CONFLICT_IGNORE);
    }

    public WebxdcUpdate findLastWebxdcUpdate(Message message) {
        if (message.getThread() == null) {
            Log.w(Config.LOGTAG, "WebXDC message with no thread!");
            return null;
        }

        SQLiteDatabase db = this.getReadableDatabase();
        String[] selectionArgs = {message.getConversation().getUuid(), message.getThread().getContent()};
        Cursor cursor = db.query("cheogram.webxdc_updates", null,
                Message.CONVERSATION + "=? AND thread=?",
                selectionArgs, null, null, "serial ASC");
        WebxdcUpdate update = null;
        if (cursor.moveToLast()) {
            update = new WebxdcUpdate(cursor, cursor.getLong(cursor.getColumnIndex("serial")));
        }
        cursor.close();
        return update;
    }

    public List<WebxdcUpdate> findWebxdcUpdates(Message message, long serial) {
        SQLiteDatabase db = this.getReadableDatabase();
        String[] selectionArgs = {message.getConversation().getUuid(), message.getThread().getContent(), String.valueOf(serial)};
        Cursor cursor = db.query("cheogram.webxdc_updates", null,
                Message.CONVERSATION + "=? AND thread=? AND serial>?",
                selectionArgs, null, null, "serial ASC");
        long maxSerial = 0;
        if (cursor.moveToLast()) {
            maxSerial = cursor.getLong(cursor.getColumnIndex("serial"));
        }
        cursor.moveToFirst();
        cursor.moveToPrevious();

        List<WebxdcUpdate> updates = new ArrayList<>();
        while (cursor.moveToNext()) {
            updates.add(new WebxdcUpdate(cursor, maxSerial));
        }
        cursor.close();
        return updates;
    }

    public void createConversation(Conversation conversation) {
        SQLiteDatabase db = this.getWritableDatabase();
        db.insert(Conversation.TABLENAME, null, conversation.getContentValues());
    }

    public void createMessage(Message message) {
        SQLiteDatabase db = this.getWritableDatabase();
        db.insert(Message.TABLENAME, null, message.getContentValues());
        db.insert("cheogram." + Message.TABLENAME, null, message.getCheogramContentValues());
    }

    public void createAccount(Account account) {
        SQLiteDatabase db = this.getWritableDatabase();
        db.insert(Account.TABLENAME, null, account.getContentValues());
    }

    public void insertDiscoveryResult(ServiceDiscoveryResult result) {
        SQLiteDatabase db = this.getWritableDatabase();
        db.insert(ServiceDiscoveryResult.TABLENAME, null, result.getContentValues());
    }

    public ServiceDiscoveryResult findDiscoveryResult(final String hash, final String ver) {
        SQLiteDatabase db = this.getReadableDatabase();
        String[] selectionArgs = {hash, ver};
        Cursor cursor = db.query(ServiceDiscoveryResult.TABLENAME, null,
                ServiceDiscoveryResult.HASH + "=? AND " + ServiceDiscoveryResult.VER + "=?",
                selectionArgs, null, null, null);
        if (cursor.getCount() == 0) {
            cursor.close();
            return null;
        }
        cursor.moveToFirst();

        ServiceDiscoveryResult result = null;
        try {
            result = new ServiceDiscoveryResult(cursor);
        } catch (JSONException e) { /* result is still null */ }

        cursor.close();
        return result;
    }

    public void saveResolverResult(String domain, Resolver.Result result) {
        SQLiteDatabase db = this.getWritableDatabase();
        ContentValues contentValues = result.toContentValues();
        contentValues.put(Resolver.Result.DOMAIN, domain);
        db.insert(RESOLVER_RESULTS_TABLENAME, null, contentValues);
    }

    public synchronized Resolver.Result findResolverResult(String domain) {
        SQLiteDatabase db = this.getReadableDatabase();
        String where = Resolver.Result.DOMAIN + "=?";
        String[] whereArgs = {domain};
        final Cursor cursor = db.query(RESOLVER_RESULTS_TABLENAME, null, where, whereArgs, null, null, null);
        Resolver.Result result = null;
        if (cursor != null) {
            try {
                if (cursor.moveToFirst()) {
                    result = Resolver.Result.fromCursor(cursor);
                }
            } catch (Exception e) {
                Log.d(Config.LOGTAG, "unable to find cached resolver result in database " + e.getMessage());
                return null;
            } finally {
                cursor.close();
            }
        }
        return result;
    }

    public void insertPresenceTemplate(PresenceTemplate template) {
        SQLiteDatabase db = this.getWritableDatabase();
        String whereToDelete = PresenceTemplate.MESSAGE + "=?";
        String[] whereToDeleteArgs = {template.getStatusMessage()};
        db.delete(PresenceTemplate.TABELNAME, whereToDelete, whereToDeleteArgs);
        db.delete(PresenceTemplate.TABELNAME, PresenceTemplate.UUID + " not in (select " + PresenceTemplate.UUID + " from " + PresenceTemplate.TABELNAME + " order by " + PresenceTemplate.LAST_USED + " desc limit 9)", null);
        db.insert(PresenceTemplate.TABELNAME, null, template.getContentValues());
    }

    public List<PresenceTemplate> getPresenceTemplates() {
        ArrayList<PresenceTemplate> templates = new ArrayList<>();
        SQLiteDatabase db = this.getReadableDatabase();
        Cursor cursor = db.query(PresenceTemplate.TABELNAME, null, null, null, null, null, PresenceTemplate.LAST_USED + " desc");
        while (cursor.moveToNext()) {
            templates.add(PresenceTemplate.fromCursor(cursor));
        }
        cursor.close();
        return templates;
    }

    public CopyOnWriteArrayList<Conversation> getConversations(int status) {
        CopyOnWriteArrayList<Conversation> list = new CopyOnWriteArrayList<>();
        SQLiteDatabase db = this.getReadableDatabase();
        String[] selectionArgs = {Integer.toString(status)};
        Cursor cursor = db.rawQuery("select * from " + Conversation.TABLENAME
                + " where " + Conversation.STATUS + " = ? and " + Conversation.CONTACTJID + " is not null order by "
                + Conversation.CREATED + " desc", selectionArgs);
        while (cursor.moveToNext()) {
            final Conversation conversation = Conversation.fromCursor(cursor);
            if (conversation.getJid() instanceof InvalidJid) {
                continue;
            }
            list.add(conversation);
        }
        cursor.close();
        return list;
    }

    public Message getMessage(Conversation conversation, String uuid) {
        ArrayList<Message> list = new ArrayList<>();
        SQLiteDatabase db = this.getReadableDatabase();
        Cursor cursor;
        cursor = db.rawQuery(
            "SELECT * FROM " + Message.TABLENAME + " " +
            "LEFT JOIN cheogram." + Message.TABLENAME +
            "  USING (" + Message.UUID + ")" +
            "WHERE " + Message.UUID + "=?",
            new String[]{uuid}
        );
        while (cursor.moveToNext()) {
            try {
                return Message.fromCursor(cursor, conversation);
            } catch (Exception e) {
                Log.e(Config.LOGTAG, "unable to restore message");
            }
        }
        cursor.close();
        return null;
    }

    public ArrayList<Message> getMessages(Conversation conversations, int limit) {
        return getMessages(conversations, limit, -1);
    }

    public Map<String, Message> getMessageFuzzyIds(Conversation conversation, Collection<String> ids) {
        final var result = new Hashtable<String, Message>();
        if (ids.size() < 1) return result;
        final ArrayList<String> params = new ArrayList<>();
        final ArrayList<String> template = new ArrayList<>();
        for (final var id : ids) {
            template.add("?");
        }
        params.addAll(ids);
        params.addAll(ids);
        params.addAll(ids);
        ArrayList<Message> list = new ArrayList<>();
        SQLiteDatabase db = this.getReadableDatabase();
        Cursor cursor;
        cursor = db.rawQuery(
            "SELECT * FROM " + Message.TABLENAME + " " +
            "LEFT JOIN cheogram." + Message.TABLENAME +
            "  USING (" + Message.UUID + ")" +
            "WHERE " + Message.UUID + " IN (" + TextUtils.join(",", template) + ") OR " + Message.SERVER_MSG_ID + " IN (" + TextUtils.join(",", template) + ") OR " + Message.REMOTE_MSG_ID + " IN (" + TextUtils.join(",", template) + ")",
            params.toArray(new String[0])
        );

        while (cursor.moveToNext()) {
            try {
                final var m = Message.fromCursor(cursor, conversation);
                if (ids.contains(m.getUuid())) result.put(m.getUuid(), m);
                if (ids.contains(m.getServerMsgId())) result.put(m.getServerMsgId(), m);
                if (ids.contains(m.getRemoteMsgId())) result.put(m.getRemoteMsgId(), m);
            } catch (Exception e) {
                Log.e(Config.LOGTAG, "unable to restore message");
            }
        }
        cursor.close();
        return result;
    }

    public ArrayList<Message> getMessages(Conversation conversation, int limit, long timestamp) {
        ArrayList<Message> list = new ArrayList<>();
        SQLiteDatabase db = this.getReadableDatabase();
        Cursor cursor;
        if (timestamp == -1) {
            String[] selectionArgs = {conversation.getUuid()};
            cursor = db.rawQuery(
                "SELECT * FROM " + Message.TABLENAME + " " +
                "LEFT JOIN cheogram." + Message.TABLENAME +
                "  USING (" + Message.UUID + ")" +
                " WHERE " + Message.UUID + " IN (" +
                "SELECT " + Message.UUID + " FROM " + Message.TABLENAME +
                " WHERE " + Message.CONVERSATION + "=? " +
                "ORDER BY " + Message.TIME_SENT + " DESC " +
                "LIMIT " + String.valueOf(limit) + ") " +
                "ORDER BY " + Message.TIME_SENT + " DESC ",
                selectionArgs
            );
        } else {
            String[] selectionArgs = {conversation.getUuid(),
                    Long.toString(timestamp)};
            cursor = db.rawQuery(
                "SELECT * FROM " + Message.TABLENAME + " " +
                "LEFT JOIN cheogram." + Message.TABLENAME +
                "  USING (" + Message.UUID + ")" +
                " WHERE " + Message.UUID + " IN (" +
                "SELECT " + Message.UUID + " FROM " + Message.TABLENAME +
                " WHERE " + Message.CONVERSATION + "=? AND " +
                Message.TIME_SENT + "<? " +
                "ORDER BY " + Message.TIME_SENT + " DESC " +
                "LIMIT " + String.valueOf(limit) + ") " +
                "ORDER BY " + Message.TIME_SENT + " DESC ",
                selectionArgs
            );
        }
        CursorUtils.upgradeCursorWindowSize(cursor);
        final Multimap<String, Message> waitingForReplies = HashMultimap.create();
        final var replyIds = new HashSet<String>();
        while (cursor.moveToNext()) {
            try {
                final var m = Message.fromCursor(cursor, conversation);
                final var reply = m.getReply();
                if (reply != null && reply.getAttribute("id") != null) { // Guard against busted replies
                    replyIds.add(reply.getAttribute("id"));
                    waitingForReplies.put(reply.getAttribute("id"), m);
                }
                list.add(0, m);
            } catch (Exception e) {
                Log.e(Config.LOGTAG, "unable to restore message", e);
            }
        }
        for (final var parent : getMessageFuzzyIds(conversation, replyIds).entrySet()) {
            for (final var m : waitingForReplies.get(parent.getKey())) {
                m.setInReplyTo(parent.getValue());
            }
        }
        cursor.close();
        return list;
    }

    public Cursor getMessageSearchCursor(final List<String> term, final String uuid) {
        final SQLiteDatabase db = this.getReadableDatabase();
        final StringBuilder SQL = new StringBuilder();
        final String[] selectionArgs;
        SQL.append("SELECT " + Message.TABLENAME + ".*," + Conversation.TABLENAME + "." + Conversation.CONTACTJID + "," + Conversation.TABLENAME + "." + Conversation.ACCOUNT + "," + Conversation.TABLENAME + "." + Conversation.MODE + " FROM " + Message.TABLENAME + " JOIN " + Conversation.TABLENAME + " ON " + Message.TABLENAME + "." + Message.CONVERSATION + "=" + Conversation.TABLENAME + "." + Conversation.UUID + " JOIN messages_index ON messages_index.rowid=messages.rowid WHERE " + Message.ENCRYPTION + " NOT IN(" + Message.ENCRYPTION_AXOLOTL_NOT_FOR_THIS_DEVICE + "," + Message.ENCRYPTION_PGP + "," + Message.ENCRYPTION_DECRYPTION_FAILED + "," + Message.ENCRYPTION_AXOLOTL_FAILED + ") AND " + Message.TYPE + " IN(" + Message.TYPE_TEXT + "," + Message.TYPE_PRIVATE + ") AND messages_index.body MATCH ?");
        if (uuid == null) {
            selectionArgs = new String[]{FtsUtils.toMatchString(term)};
        } else {
            selectionArgs = new String[]{FtsUtils.toMatchString(term), uuid};
            SQL.append(" AND " + Conversation.TABLENAME + '.' + Conversation.UUID + "=?");
        }
        SQL.append(" ORDER BY " + Message.TIME_SENT + " DESC limit " + Config.MAX_SEARCH_RESULTS);
        Log.d(Config.LOGTAG, "search term: " + FtsUtils.toMatchString(term));
        return db.rawQuery(SQL.toString(), selectionArgs);
    }

    public List<String> markFileAsDeleted(final File file, final boolean internal) {
        SQLiteDatabase db = this.getReadableDatabase();
        String selection;
        String[] selectionArgs;
        if (internal) {
            final String name = file.getName();
            if (name.endsWith(".pgp")) {
                selection = "(" + Message.RELATIVE_FILE_PATH + " IN(?,?) OR (" + Message.RELATIVE_FILE_PATH + "=? and encryption in(1,4))) and type in (1,2,5)";
                selectionArgs = new String[]{file.getAbsolutePath(), name, name.substring(0, name.length() - 4)};
            } else {
                selection = Message.RELATIVE_FILE_PATH + " IN(?,?) and type in (1,2,5)";
                selectionArgs = new String[]{file.getAbsolutePath(), name};
            }
        } else {
            selection = Message.RELATIVE_FILE_PATH + "=? and type in (1,2,5)";
            selectionArgs = new String[]{file.getAbsolutePath()};
        }
        final List<String> uuids = new ArrayList<>();
        Cursor cursor = db.query(Message.TABLENAME, new String[]{Message.UUID}, selection, selectionArgs, null, null, null);
        while (cursor != null && cursor.moveToNext()) {
            uuids.add(cursor.getString(0));
        }
        if (cursor != null) {
            cursor.close();
        }
        markFileAsDeleted(uuids);
        return uuids;
    }

    public void markFileAsDeleted(List<String> uuids) {
        SQLiteDatabase db = this.getReadableDatabase();
        final ContentValues contentValues = new ContentValues();
        final String where = Message.UUID + "=?";
        contentValues.put(Message.DELETED, 1);
        db.beginTransaction();
        for (String uuid : uuids) {
            db.update(Message.TABLENAME, contentValues, where, new String[]{uuid});
        }
        db.setTransactionSuccessful();
        db.endTransaction();
    }

    public void markFilesAsChanged(List<FilePathInfo> files) {
        SQLiteDatabase db = this.getReadableDatabase();
        final String where = Message.UUID + "=?";
        db.beginTransaction();
        for (FilePathInfo info : files) {
            final ContentValues contentValues = new ContentValues();
            contentValues.put(Message.DELETED, info.deleted ? 1 : 0);
            db.update(Message.TABLENAME, contentValues, where, new String[]{info.uuid.toString()});
        }
        db.setTransactionSuccessful();
        db.endTransaction();
    }

    public List<FilePathInfo> getFilePathInfo() {
        final SQLiteDatabase db = this.getReadableDatabase();
        final Cursor cursor = db.query(Message.TABLENAME, new String[]{Message.UUID, Message.RELATIVE_FILE_PATH, Message.DELETED}, "type in (1,2,5) and " + Message.RELATIVE_FILE_PATH + " is not null", null, null, null, null);
        final List<FilePathInfo> list = new ArrayList<>();
        while (cursor != null && cursor.moveToNext()) {
            list.add(new FilePathInfo(cursor.getString(0), cursor.getString(1), cursor.getInt(2) > 0));
        }
        if (cursor != null) {
            cursor.close();
        }
        return list;
    }

    public List<FilePath> getRelativeFilePaths(String account, Jid jid, int limit) {
        SQLiteDatabase db = this.getReadableDatabase();
        final String SQL = "select uuid,relativeFilePath from messages where type in (1,2,5) and deleted=0 and " + Message.RELATIVE_FILE_PATH + " is not null and conversationUuid=(select uuid from conversations where accountUuid=? and (contactJid=? or contactJid like ?)) order by timeSent desc";
        final String[] args = {account, jid.toString(), jid.toString() + "/%"};
        Cursor cursor = db.rawQuery(SQL + (limit > 0 ? " limit " + limit : ""), args);
        List<FilePath> filesPaths = new ArrayList<>();
        while (cursor.moveToNext()) {
            filesPaths.add(new FilePath(cursor.getString(0), cursor.getString(1)));
        }
        cursor.close();
        return filesPaths;
    }

    public Message getMessageWithServerMsgId(
            final Conversation conversation, final String messageId) {
        final var db = this.getReadableDatabase();
        final String sql =
                "select * from messages LEFT JOIN cheogram.messages USING (uuid) where conversationUuid=? and serverMsgId=? LIMIT 1";
        final String[] args = {conversation.getUuid(), messageId};
        final Cursor cursor = db.rawQuery(sql, args);
        if (cursor == null) {
            return null;
        }
        Message message = null;
        try {
            if (cursor.moveToFirst()) {
                message = Message.fromCursor(cursor, conversation);
            }
        } catch (final IOException e) { }
        cursor.close();
        return message;
    }

    public Message getMessageWithUuidOrRemoteId(
            final Conversation conversation, final String messageId) {
        final var db = this.getReadableDatabase();
        final String sql =
                "select * from messages LEFT JOING cheogram.messages USING (uuid) where conversationUuid=? and (uuid=? OR remoteMsgId=?) LIMIT 1";
        final String[] args = {conversation.getUuid(), messageId, messageId};
        final Cursor cursor = db.rawQuery(sql, args);
        if (cursor == null) {
            return null;
        }
        Message message = null;
        try {
            if (cursor.moveToFirst()) {
                message = Message.fromCursor(cursor, conversation);
            }
        } catch (final IOException e) { }
        cursor.close();
        return message;
    }

    public static class FilePath {
        public final UUID uuid;
        public final String path;

        private FilePath(String uuid, String path) {
            this.uuid = UUID.fromString(uuid);
            this.path = path;
        }
    }

    public static class FilePathInfo extends FilePath {
        public boolean deleted;

        private FilePathInfo(String uuid, String path, boolean deleted) {
            super(uuid, path);
            this.deleted = deleted;
        }

        public boolean setDeleted(boolean deleted) {
            final boolean changed = deleted != this.deleted;
            this.deleted = deleted;
            return changed;
        }
    }

    public Conversation findConversation(final Account account, final Jid contactJid) {
        SQLiteDatabase db = this.getReadableDatabase();
        String[] selectionArgs = {account.getUuid(),
                contactJid.asBareJid().toString() + "/%",
                contactJid.asBareJid().toString()
        };
        try(final Cursor cursor = db.query(Conversation.TABLENAME, null,
                Conversation.ACCOUNT + "=? AND (" + Conversation.CONTACTJID
                        + " like ? OR " + Conversation.CONTACTJID + "=?)", selectionArgs, null, null, null)) {
            if (cursor.getCount() == 0) {
                return null;
            }
            cursor.moveToFirst();
            final Conversation conversation = Conversation.fromCursor(cursor);
            if (conversation.getJid() instanceof InvalidJid) {
                return null;
            }
            return conversation;
        }
    }

    public void updateConversation(final Conversation conversation) {
        final SQLiteDatabase db = this.getWritableDatabase();
        final String[] args = {conversation.getUuid()};
        db.update(Conversation.TABLENAME, conversation.getContentValues(),
                Conversation.UUID + "=?", args);
    }

    public List<Account> getAccounts() {
        SQLiteDatabase db = this.getReadableDatabase();
        return getAccounts(db);
    }

    public List<Jid> getAccountJids(final boolean enabledOnly) {
        final SQLiteDatabase db = this.getReadableDatabase();
        final List<Jid> jids = new ArrayList<>();
        final String[] columns = new String[]{Account.USERNAME, Account.SERVER};
        final String where = enabledOnly ? "not options & (1 <<1)" : null;
        try (final Cursor cursor = db.query(Account.TABLENAME, columns, where, null, null, null, null)) {
            while (cursor != null && cursor.moveToNext()) {
                jids.add(Jid.of(cursor.getString(0), cursor.getString(1), null));
            }
        } catch (final Exception e) {
            return jids;
        }
        return jids;
    }

    private List<Account> getAccounts(SQLiteDatabase db) {
        final List<Account> list = new ArrayList<>();
        try (final Cursor cursor =
                db.query(Account.TABLENAME, null, null, null, null, null, null)) {
            while (cursor != null && cursor.moveToNext()) {
                list.add(Account.fromCursor(cursor));
            }
        }
        return list;
    }

    public boolean updateAccount(Account account) {
        final var db = this.getWritableDatabase();
        final String[] args = {account.getUuid()};
        final int rows =
                db.update(Account.TABLENAME, account.getContentValues(), Account.UUID + "=?", args);
        return rows == 1;
    }

    public boolean deleteAccount(final Account account) {
        final var db = this.getWritableDatabase();
        final String[] args = {account.getUuid()};
        final int rows = db.delete(Account.TABLENAME, Account.UUID + "=?", args);
        return rows == 1;
    }

    public boolean updateMessage(final Message message, final boolean includeBody) {
        final var db = this.getWritableDatabase();
        final String[] args = {message.getUuid()};
        final var contentValues = message.getContentValues();
        contentValues.remove(Message.UUID);
        if (!includeBody) {
            contentValues.remove(Message.BODY);
        }
        return db.update(Message.TABLENAME, contentValues, Message.UUID + "=?", args) == 1 &&
               db.update("cheogram." + Message.TABLENAME, message.getCheogramContentValues(), Message.UUID + "=?", args) == 1;
    }

    public boolean updateMessage(Message message, String uuid) {
        SQLiteDatabase db = this.getWritableDatabase();
        String[] args = {uuid};
        return db.update(Message.TABLENAME, message.getContentValues(), Message.UUID + "=?", args) == 1 &&
               db.update("cheogram." + Message.TABLENAME, message.getCheogramContentValues(), Message.UUID + "=?", args) == 1;
    }


    public boolean deleteMessage(String uuid) {
        SQLiteDatabase db = this.getWritableDatabase();
        String[] args = {uuid};
        return db.delete(Message.TABLENAME, Message.UUID + "=?", args) == 1 &&
               db.delete("cheogram." + Message.TABLENAME, Message.UUID + "=?", args) == 1;
    }

    public void readRoster(Roster roster) {
        final SQLiteDatabase db = this.getReadableDatabase();
        final String[] args = {roster.getAccount().getUuid()};
        try (final Cursor cursor =
                db.query(Contact.TABLENAME, null, Contact.ACCOUNT + "=?", args, null, null, null)) {
            while (cursor.moveToNext()) {
                roster.initContact(Contact.fromCursor(cursor));
            }
        }
    }

    public void writeRoster(final Roster roster) {
        long start = SystemClock.elapsedRealtime();
        final Account account = roster.getAccount();
        final SQLiteDatabase db = this.getWritableDatabase();
        db.beginTransaction();
        for (Contact contact : roster.getContacts()) {
            if (contact.getOption(Contact.Options.IN_ROSTER) || contact.hasAvatarOrPresenceName() || contact.getOption(Contact.Options.SYNCED_VIA_OTHER)) {
                db.insert(Contact.TABLENAME, null, contact.getContentValues());
            } else {
                String where = Contact.ACCOUNT + "=? AND " + Contact.JID + "=?";
                String[] whereArgs = {account.getUuid(), contact.getJid().toString()};
                db.delete(Contact.TABLENAME, where, whereArgs);
            }
        }
        db.setTransactionSuccessful();
        db.endTransaction();
        account.setRosterVersion(roster.getVersion());
        updateAccount(account);
        long duration = SystemClock.elapsedRealtime() - start;
        Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": persisted roster in " + duration + "ms");
    }

    public void deleteMessagesInConversation(Conversation conversation) {
        long start = SystemClock.elapsedRealtime();
        final SQLiteDatabase db = this.getWritableDatabase();
        db.beginTransaction();
        final String[] args = {conversation.getUuid()};
        int num = db.delete(Message.TABLENAME, Message.CONVERSATION + "=?", args);
        db.delete("cheogram.webxdc_updates", Message.CONVERSATION + "=?", args);
        db.setTransactionSuccessful();
        db.endTransaction();
        Log.d(Config.LOGTAG, "deleted " + num + " messages for " + conversation.getJid().asBareJid() + " in " + (SystemClock.elapsedRealtime() - start) + "ms");
    }

    public void expireOldMessages(long timestamp) {
        final String[] args = {String.valueOf(timestamp)};
        SQLiteDatabase db = this.getReadableDatabase();
        db.beginTransaction();
        db.delete(Message.TABLENAME, "timeSent<?", args);
        db.delete("cheogram.messages", "timeReceived<?", args);
        db.setTransactionSuccessful();
        db.endTransaction();
    }

    public MamReference getLastMessageReceived(Account account) {
        Cursor cursor = null;
        try {
            SQLiteDatabase db = this.getReadableDatabase();
            String sql = "select messages.timeSent,messages.serverMsgId from accounts join conversations on accounts.uuid=conversations.accountUuid join messages on conversations.uuid=messages.conversationUuid where accounts.uuid=? and (messages.status=0 or messages.carbon=1 or messages.serverMsgId not null) and (conversations.mode=0 or (messages.serverMsgId not null and messages.type=4)) order by messages.timesent desc limit 1";
            String[] args = {account.getUuid()};
            cursor = db.rawQuery(sql, args);
            if (cursor.getCount() == 0) {
                return null;
            } else {
                cursor.moveToFirst();
                return new MamReference(cursor.getLong(0), cursor.getString(1));
            }
        } catch (Exception e) {
            return null;
        } finally {
            if (cursor != null) {
                cursor.close();
            }
        }
    }

    public long getLastTimeFingerprintUsed(Account account, String fingerprint) {
        String SQL = "select messages.timeSent from accounts join conversations on accounts.uuid=conversations.accountUuid join messages on conversations.uuid=messages.conversationUuid where accounts.uuid=? and messages.axolotl_fingerprint=? order by messages.timesent desc limit 1";
        String[] args = {account.getUuid(), fingerprint};
        Cursor cursor = getReadableDatabase().rawQuery(SQL, args);
        long time;
        if (cursor.moveToFirst()) {
            time = cursor.getLong(0);
        } else {
            time = 0;
        }
        cursor.close();
        return time;
    }

    public MamReference getLastClearDate(Account account) {
        SQLiteDatabase db = this.getReadableDatabase();
        String[] columns = {Conversation.ATTRIBUTES};
        String selection = Conversation.ACCOUNT + "=?";
        String[] args = {account.getUuid()};
        Cursor cursor = db.query(Conversation.TABLENAME, columns, selection, args, null, null, null);
        MamReference maxClearDate = new MamReference(0);
        while (cursor.moveToNext()) {
            try {
                final JSONObject o = new JSONObject(cursor.getString(0));
                maxClearDate = MamReference.max(maxClearDate, MamReference.fromAttribute(o.getString(Conversation.ATTRIBUTE_LAST_CLEAR_HISTORY)));
            } catch (Exception e) {
                //ignored
            }
        }
        cursor.close();
        return maxClearDate;
    }

    private Cursor getCursorForSession(Account account, SignalProtocolAddress contact) {
        final SQLiteDatabase db = this.getReadableDatabase();
        String[] selectionArgs = {account.getUuid(),
                contact.getName(),
                Integer.toString(contact.getDeviceId())};
        return db.query(SQLiteAxolotlStore.SESSION_TABLENAME,
                null,
                SQLiteAxolotlStore.ACCOUNT + " = ? AND "
                        + SQLiteAxolotlStore.NAME + " = ? AND "
                        + SQLiteAxolotlStore.DEVICE_ID + " = ? ",
                selectionArgs,
                null, null, null);
    }

    public SessionRecord loadSession(Account account, SignalProtocolAddress contact) {
        SessionRecord session = null;
        Cursor cursor = getCursorForSession(account, contact);
        if (cursor.getCount() != 0) {
            cursor.moveToFirst();
            try {
                session = new SessionRecord(Base64.decode(cursor.getString(cursor.getColumnIndex(SQLiteAxolotlStore.KEY)), Base64.DEFAULT));
            } catch (IOException e) {
                cursor.close();
                throw new AssertionError(e);
            }
        }
        cursor.close();
        return session;
    }

    public List<Integer> getSubDeviceSessions(Account account, SignalProtocolAddress contact) {
        final SQLiteDatabase db = this.getReadableDatabase();
        return getSubDeviceSessions(db, account, contact);
    }

    private List<Integer> getSubDeviceSessions(SQLiteDatabase db, Account account, SignalProtocolAddress contact) {
        List<Integer> devices = new ArrayList<>();
        String[] columns = {SQLiteAxolotlStore.DEVICE_ID};
        String[] selectionArgs = {account.getUuid(),
                contact.getName()};
        Cursor cursor = db.query(SQLiteAxolotlStore.SESSION_TABLENAME,
                columns,
                SQLiteAxolotlStore.ACCOUNT + " = ? AND "
                        + SQLiteAxolotlStore.NAME + " = ?",
                selectionArgs,
                null, null, null);

        while (cursor.moveToNext()) {
            devices.add(cursor.getInt(
                    cursor.getColumnIndex(SQLiteAxolotlStore.DEVICE_ID)));
        }

        cursor.close();
        return devices;
    }

    public List<String> getKnownSignalAddresses(Account account) {
        List<String> addresses = new ArrayList<>();
        String[] colums = {"DISTINCT " + SQLiteAxolotlStore.NAME};
        String[] selectionArgs = {account.getUuid()};
        Cursor cursor = getReadableDatabase().query(SQLiteAxolotlStore.SESSION_TABLENAME,
                colums,
                SQLiteAxolotlStore.ACCOUNT + " = ?",
                selectionArgs,
                null, null, null
        );
        while (cursor.moveToNext()) {
            addresses.add(cursor.getString(0));
        }
        cursor.close();
        return addresses;
    }

    public boolean containsSession(Account account, SignalProtocolAddress contact) {
        Cursor cursor = getCursorForSession(account, contact);
        int count = cursor.getCount();
        cursor.close();
        return count != 0;
    }

    public void storeSession(Account account, SignalProtocolAddress contact, SessionRecord session) {
        SQLiteDatabase db = this.getWritableDatabase();
        ContentValues values = new ContentValues();
        values.put(SQLiteAxolotlStore.NAME, contact.getName());
        values.put(SQLiteAxolotlStore.DEVICE_ID, contact.getDeviceId());
        values.put(SQLiteAxolotlStore.KEY, Base64.encodeToString(session.serialize(), Base64.DEFAULT));
        values.put(SQLiteAxolotlStore.ACCOUNT, account.getUuid());
        db.insert(SQLiteAxolotlStore.SESSION_TABLENAME, null, values);
    }

    public void deleteSession(Account account, SignalProtocolAddress contact) {
        SQLiteDatabase db = this.getWritableDatabase();
        deleteSession(db, account, contact);
    }

    private void deleteSession(SQLiteDatabase db, Account account, SignalProtocolAddress contact) {
        String[] args = {account.getUuid(),
                contact.getName(),
                Integer.toString(contact.getDeviceId())};
        db.delete(SQLiteAxolotlStore.SESSION_TABLENAME,
                SQLiteAxolotlStore.ACCOUNT + " = ? AND "
                        + SQLiteAxolotlStore.NAME + " = ? AND "
                        + SQLiteAxolotlStore.DEVICE_ID + " = ? ",
                args);
    }

    public void deleteAllSessions(Account account, SignalProtocolAddress contact) {
        SQLiteDatabase db = this.getWritableDatabase();
        String[] args = {account.getUuid(), contact.getName()};
        db.delete(SQLiteAxolotlStore.SESSION_TABLENAME,
                SQLiteAxolotlStore.ACCOUNT + "=? AND "
                        + SQLiteAxolotlStore.NAME + " = ?",
                args);
    }

    private Cursor getCursorForPreKey(Account account, int preKeyId) {
        SQLiteDatabase db = this.getReadableDatabase();
        String[] columns = {SQLiteAxolotlStore.KEY};
        String[] selectionArgs = {account.getUuid(), Integer.toString(preKeyId)};
        Cursor cursor = db.query(SQLiteAxolotlStore.PREKEY_TABLENAME,
                columns,
                SQLiteAxolotlStore.ACCOUNT + "=? AND "
                        + SQLiteAxolotlStore.ID + "=?",
                selectionArgs,
                null, null, null);

        return cursor;
    }

    public PreKeyRecord loadPreKey(Account account, int preKeyId) {
        PreKeyRecord record = null;
        Cursor cursor = getCursorForPreKey(account, preKeyId);
        if (cursor.getCount() != 0) {
            cursor.moveToFirst();
            try {
                record = new PreKeyRecord(Base64.decode(cursor.getString(cursor.getColumnIndex(SQLiteAxolotlStore.KEY)), Base64.DEFAULT));
            } catch (IOException e) {
                throw new AssertionError(e);
            }
        }
        cursor.close();
        return record;
    }

    public boolean containsPreKey(Account account, int preKeyId) {
        Cursor cursor = getCursorForPreKey(account, preKeyId);
        int count = cursor.getCount();
        cursor.close();
        return count != 0;
    }

    public void storePreKey(Account account, PreKeyRecord record) {
        SQLiteDatabase db = this.getWritableDatabase();
        ContentValues values = new ContentValues();
        values.put(SQLiteAxolotlStore.ID, record.getId());
        values.put(SQLiteAxolotlStore.KEY, Base64.encodeToString(record.serialize(), Base64.DEFAULT));
        values.put(SQLiteAxolotlStore.ACCOUNT, account.getUuid());
        db.insert(SQLiteAxolotlStore.PREKEY_TABLENAME, null, values);
    }

    public int deletePreKey(Account account, int preKeyId) {
        SQLiteDatabase db = this.getWritableDatabase();
        String[] args = {account.getUuid(), Integer.toString(preKeyId)};
        return db.delete(SQLiteAxolotlStore.PREKEY_TABLENAME,
                SQLiteAxolotlStore.ACCOUNT + "=? AND "
                        + SQLiteAxolotlStore.ID + "=?",
                args);
    }

    private Cursor getCursorForSignedPreKey(Account account, int signedPreKeyId) {
        SQLiteDatabase db = this.getReadableDatabase();
        String[] columns = {SQLiteAxolotlStore.KEY};
        String[] selectionArgs = {account.getUuid(), Integer.toString(signedPreKeyId)};
        Cursor cursor = db.query(SQLiteAxolotlStore.SIGNED_PREKEY_TABLENAME,
                columns,
                SQLiteAxolotlStore.ACCOUNT + "=? AND " + SQLiteAxolotlStore.ID + "=?",
                selectionArgs,
                null, null, null);

        return cursor;
    }

    public SignedPreKeyRecord loadSignedPreKey(Account account, int signedPreKeyId) {
        SignedPreKeyRecord record = null;
        Cursor cursor = getCursorForSignedPreKey(account, signedPreKeyId);
        if (cursor.getCount() != 0) {
            cursor.moveToFirst();
            try {
                record = new SignedPreKeyRecord(Base64.decode(cursor.getString(cursor.getColumnIndex(SQLiteAxolotlStore.KEY)), Base64.DEFAULT));
            } catch (IOException e) {
                throw new AssertionError(e);
            }
        }
        cursor.close();
        return record;
    }

    public List<SignedPreKeyRecord> loadSignedPreKeys(Account account) {
        List<SignedPreKeyRecord> prekeys = new ArrayList<>();
        SQLiteDatabase db = this.getReadableDatabase();
        String[] columns = {SQLiteAxolotlStore.KEY};
        String[] selectionArgs = {account.getUuid()};
        Cursor cursor = db.query(SQLiteAxolotlStore.SIGNED_PREKEY_TABLENAME,
                columns,
                SQLiteAxolotlStore.ACCOUNT + "=?",
                selectionArgs,
                null, null, null);

        while (cursor.moveToNext()) {
            try {
                prekeys.add(new SignedPreKeyRecord(Base64.decode(cursor.getString(cursor.getColumnIndex(SQLiteAxolotlStore.KEY)), Base64.DEFAULT)));
            } catch (IOException ignored) {
            }
        }
        cursor.close();
        return prekeys;
    }

    public int getSignedPreKeysCount(Account account) {
        String[] columns = {"count(" + SQLiteAxolotlStore.KEY + ")"};
        String[] selectionArgs = {account.getUuid()};
        SQLiteDatabase db = this.getReadableDatabase();
        Cursor cursor = db.query(SQLiteAxolotlStore.SIGNED_PREKEY_TABLENAME,
                columns,
                SQLiteAxolotlStore.ACCOUNT + "=?",
                selectionArgs,
                null, null, null);
        final int count;
        if (cursor.moveToFirst()) {
            count = cursor.getInt(0);
        } else {
            count = 0;
        }
        cursor.close();
        return count;
    }

    public boolean containsSignedPreKey(Account account, int signedPreKeyId) {
        Cursor cursor = getCursorForPreKey(account, signedPreKeyId);
        int count = cursor.getCount();
        cursor.close();
        return count != 0;
    }

    public void storeSignedPreKey(Account account, SignedPreKeyRecord record) {
        SQLiteDatabase db = this.getWritableDatabase();
        ContentValues values = new ContentValues();
        values.put(SQLiteAxolotlStore.ID, record.getId());
        values.put(SQLiteAxolotlStore.KEY, Base64.encodeToString(record.serialize(), Base64.DEFAULT));
        values.put(SQLiteAxolotlStore.ACCOUNT, account.getUuid());
        db.insert(SQLiteAxolotlStore.SIGNED_PREKEY_TABLENAME, null, values);
    }

    public void deleteSignedPreKey(Account account, int signedPreKeyId) {
        SQLiteDatabase db = this.getWritableDatabase();
        String[] args = {account.getUuid(), Integer.toString(signedPreKeyId)};
        db.delete(SQLiteAxolotlStore.SIGNED_PREKEY_TABLENAME,
                SQLiteAxolotlStore.ACCOUNT + "=? AND "
                        + SQLiteAxolotlStore.ID + "=?",
                args);
    }

    private Cursor getIdentityKeyCursor(Account account, String name, boolean own) {
        final SQLiteDatabase db = this.getReadableDatabase();
        return getIdentityKeyCursor(db, account, name, own);
    }

    private Cursor getIdentityKeyCursor(SQLiteDatabase db, Account account, String name, boolean own) {
        return getIdentityKeyCursor(db, account, name, own, null);
    }

    private Cursor getIdentityKeyCursor(Account account, String fingerprint) {
        final SQLiteDatabase db = this.getReadableDatabase();
        return getIdentityKeyCursor(db, account, fingerprint);
    }

    private Cursor getIdentityKeyCursor(SQLiteDatabase db, Account account, String fingerprint) {
        return getIdentityKeyCursor(db, account, null, null, fingerprint);
    }

    private Cursor getIdentityKeyCursor(SQLiteDatabase db, Account account, String name, Boolean own, String fingerprint) {
        String[] columns = {SQLiteAxolotlStore.TRUST,
                SQLiteAxolotlStore.ACTIVE,
                SQLiteAxolotlStore.LAST_ACTIVATION,
                SQLiteAxolotlStore.KEY};
        ArrayList<String> selectionArgs = new ArrayList<>(4);
        selectionArgs.add(account.getUuid());
        String selectionString = SQLiteAxolotlStore.ACCOUNT + " = ?";
        if (name != null) {
            selectionArgs.add(name);
            selectionString += " AND " + SQLiteAxolotlStore.NAME + " = ?";
        }
        if (fingerprint != null) {
            selectionArgs.add(fingerprint);
            selectionString += " AND " + SQLiteAxolotlStore.FINGERPRINT + " = ?";
        }
        if (own != null) {
            selectionArgs.add(own ? "1" : "0");
            selectionString += " AND " + SQLiteAxolotlStore.OWN + " = ?";
        }
        Cursor cursor = db.query(SQLiteAxolotlStore.IDENTITIES_TABLENAME,
                columns,
                selectionString,
                selectionArgs.toArray(new String[selectionArgs.size()]),
                null, null, null);

        return cursor;
    }

    public IdentityKeyPair loadOwnIdentityKeyPair(Account account) {
        SQLiteDatabase db = getReadableDatabase();
        return loadOwnIdentityKeyPair(db, account);
    }

    private IdentityKeyPair loadOwnIdentityKeyPair(SQLiteDatabase db, Account account) {
        String name = account.getJid().asBareJid().toString();
        IdentityKeyPair identityKeyPair = null;
        Cursor cursor = getIdentityKeyCursor(db, account, name, true);
        if (cursor.getCount() != 0) {
            cursor.moveToFirst();
            try {
                identityKeyPair = new IdentityKeyPair(Base64.decode(cursor.getString(cursor.getColumnIndex(SQLiteAxolotlStore.KEY)), Base64.DEFAULT));
            } catch (InvalidKeyException e) {
                Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Encountered invalid IdentityKey in database for account" + account.getJid().asBareJid() + ", address: " + name);
            }
        }
        cursor.close();

        return identityKeyPair;
    }

    public Set<IdentityKey> loadIdentityKeys(Account account, String name) {
        return loadIdentityKeys(account, name, null);
    }

    public Set<IdentityKey> loadIdentityKeys(Account account, String name, FingerprintStatus status) {
        Set<IdentityKey> identityKeys = new HashSet<>();
        Cursor cursor = getIdentityKeyCursor(account, name, false);

        while (cursor.moveToNext()) {
            if (status != null && !FingerprintStatus.fromCursor(cursor).equals(status)) {
                continue;
            }
            try {
                String key = cursor.getString(cursor.getColumnIndex(SQLiteAxolotlStore.KEY));
                if (key != null) {
                    identityKeys.add(new IdentityKey(Base64.decode(key, Base64.DEFAULT), 0));
                } else {
                    Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Missing key (possibly preverified) in database for account" + account.getJid().asBareJid() + ", address: " + name);
                }
            } catch (InvalidKeyException e) {
                Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Encountered invalid IdentityKey in database for account" + account.getJid().asBareJid() + ", address: " + name);
            }
        }
        cursor.close();

        return identityKeys;
    }

    public long numTrustedKeys(Account account, String name) {
        SQLiteDatabase db = getReadableDatabase();
        String[] args = {
                account.getUuid(),
                name,
                FingerprintStatus.Trust.TRUSTED.toString(),
                FingerprintStatus.Trust.VERIFIED.toString(),
                FingerprintStatus.Trust.VERIFIED_X509.toString()
        };
        return DatabaseUtils.queryNumEntries(db, SQLiteAxolotlStore.IDENTITIES_TABLENAME,
                SQLiteAxolotlStore.ACCOUNT + " = ?"
                        + " AND " + SQLiteAxolotlStore.NAME + " = ?"
                        + " AND (" + SQLiteAxolotlStore.TRUST + " = ? OR " + SQLiteAxolotlStore.TRUST + " = ? OR " + SQLiteAxolotlStore.TRUST + " = ?)"
                        + " AND " + SQLiteAxolotlStore.ACTIVE + " > 0",
                args
        );
    }

    private void storeIdentityKey(Account account, String name, boolean own, String fingerprint, String base64Serialized, FingerprintStatus status) {
        SQLiteDatabase db = this.getWritableDatabase();
        ContentValues values = new ContentValues();
        values.put(SQLiteAxolotlStore.ACCOUNT, account.getUuid());
        values.put(SQLiteAxolotlStore.NAME, name);
        values.put(SQLiteAxolotlStore.OWN, own ? 1 : 0);
        values.put(SQLiteAxolotlStore.FINGERPRINT, fingerprint);
        values.put(SQLiteAxolotlStore.KEY, base64Serialized);
        values.putAll(status.toContentValues());
        String where = SQLiteAxolotlStore.ACCOUNT + "=? AND " + SQLiteAxolotlStore.NAME + "=? AND " + SQLiteAxolotlStore.FINGERPRINT + " =?";
        String[] whereArgs = {account.getUuid(), name, fingerprint};
        int rows = db.update(SQLiteAxolotlStore.IDENTITIES_TABLENAME, values, where, whereArgs);
        if (rows == 0) {
            db.insert(SQLiteAxolotlStore.IDENTITIES_TABLENAME, null, values);
        }
    }

    public void storePreVerification(Account account, String name, String fingerprint, FingerprintStatus status) {
        SQLiteDatabase db = this.getWritableDatabase();
        ContentValues values = new ContentValues();
        values.put(SQLiteAxolotlStore.ACCOUNT, account.getUuid());
        values.put(SQLiteAxolotlStore.NAME, name);
        values.put(SQLiteAxolotlStore.OWN, 0);
        values.put(SQLiteAxolotlStore.FINGERPRINT, fingerprint);
        values.putAll(status.toContentValues());
        db.insert(SQLiteAxolotlStore.IDENTITIES_TABLENAME, null, values);
    }

    public FingerprintStatus getFingerprintStatus(Account account, String fingerprint) {
        Cursor cursor = getIdentityKeyCursor(account, fingerprint);
        final FingerprintStatus status;
        if (cursor.getCount() > 0) {
            cursor.moveToFirst();
            status = FingerprintStatus.fromCursor(cursor);
        } else {
            status = null;
        }
        cursor.close();
        return status;
    }

    public boolean setIdentityKeyTrust(Account account, String fingerprint, FingerprintStatus fingerprintStatus) {
        SQLiteDatabase db = this.getWritableDatabase();
        return setIdentityKeyTrust(db, account, fingerprint, fingerprintStatus);
    }

    private boolean setIdentityKeyTrust(SQLiteDatabase db, Account account, String fingerprint, FingerprintStatus status) {
        String[] selectionArgs = {
                account.getUuid(),
                fingerprint
        };
        int rows = db.update(SQLiteAxolotlStore.IDENTITIES_TABLENAME, status.toContentValues(),
                SQLiteAxolotlStore.ACCOUNT + " = ? AND "
                        + SQLiteAxolotlStore.FINGERPRINT + " = ? ",
                selectionArgs);
        return rows == 1;
    }

    public boolean setIdentityKeyCertificate(Account account, String fingerprint, X509Certificate x509Certificate) {
        SQLiteDatabase db = this.getWritableDatabase();
        String[] selectionArgs = {
                account.getUuid(),
                fingerprint
        };
        try {
            ContentValues values = new ContentValues();
            values.put(SQLiteAxolotlStore.CERTIFICATE, x509Certificate.getEncoded());
            return db.update(SQLiteAxolotlStore.IDENTITIES_TABLENAME, values,
                    SQLiteAxolotlStore.ACCOUNT + " = ? AND "
                            + SQLiteAxolotlStore.FINGERPRINT + " = ? ",
                    selectionArgs) == 1;
        } catch (CertificateEncodingException e) {
            Log.d(Config.LOGTAG, "could not encode certificate");
            return false;
        }
    }

    public X509Certificate getIdentityKeyCertifcate(Account account, String fingerprint) {
        SQLiteDatabase db = this.getReadableDatabase();
        String[] selectionArgs = {
                account.getUuid(),
                fingerprint
        };
        String[] colums = {SQLiteAxolotlStore.CERTIFICATE};
        String selection = SQLiteAxolotlStore.ACCOUNT + " = ? AND " + SQLiteAxolotlStore.FINGERPRINT + " = ? ";
        Cursor cursor = db.query(SQLiteAxolotlStore.IDENTITIES_TABLENAME, colums, selection, selectionArgs, null, null, null);
        if (cursor.getCount() < 1) {
            return null;
        } else {
            cursor.moveToFirst();
            byte[] certificate = cursor.getBlob(cursor.getColumnIndex(SQLiteAxolotlStore.CERTIFICATE));
            cursor.close();
            if (certificate == null || certificate.length == 0) {
                return null;
            }
            try {
                CertificateFactory certificateFactory = CertificateFactory.getInstance("X.509");
                return (X509Certificate) certificateFactory.generateCertificate(new ByteArrayInputStream(certificate));
            } catch (CertificateException e) {
                Log.d(Config.LOGTAG, "certificate exception " + e.getMessage());
                return null;
            }
        }
    }

    public void storeIdentityKey(Account account, String name, IdentityKey identityKey, FingerprintStatus status) {
        storeIdentityKey(account, name, false, CryptoHelper.bytesToHex(identityKey.getPublicKey().serialize()), Base64.encodeToString(identityKey.serialize(), Base64.DEFAULT), status);
    }

    public void storeOwnIdentityKeyPair(Account account, IdentityKeyPair identityKeyPair) {
        storeIdentityKey(account, account.getJid().asBareJid().toString(), true, CryptoHelper.bytesToHex(identityKeyPair.getPublicKey().serialize()), Base64.encodeToString(identityKeyPair.serialize(), Base64.DEFAULT), FingerprintStatus.createActiveVerified(false));
    }


    private void recreateAxolotlDb(SQLiteDatabase db) {
        Log.d(Config.LOGTAG, AxolotlService.LOGPREFIX + " : " + ">>> (RE)CREATING AXOLOTL DATABASE <<<");
        db.execSQL("DROP TABLE IF EXISTS " + SQLiteAxolotlStore.SESSION_TABLENAME);
        db.execSQL(CREATE_SESSIONS_STATEMENT);
        db.execSQL("DROP TABLE IF EXISTS " + SQLiteAxolotlStore.PREKEY_TABLENAME);
        db.execSQL(CREATE_PREKEYS_STATEMENT);
        db.execSQL("DROP TABLE IF EXISTS " + SQLiteAxolotlStore.SIGNED_PREKEY_TABLENAME);
        db.execSQL(CREATE_SIGNED_PREKEYS_STATEMENT);
        db.execSQL("DROP TABLE IF EXISTS " + SQLiteAxolotlStore.IDENTITIES_TABLENAME);
        db.execSQL(CREATE_IDENTITIES_STATEMENT);
    }

    public void wipeAxolotlDb(Account account) {
        String accountName = account.getUuid();
        Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + ">>> WIPING AXOLOTL DATABASE FOR ACCOUNT " + accountName + " <<<");
        SQLiteDatabase db = this.getWritableDatabase();
        String[] deleteArgs = {
                accountName
        };
        db.delete(SQLiteAxolotlStore.SESSION_TABLENAME,
                SQLiteAxolotlStore.ACCOUNT + " = ?",
                deleteArgs);
        db.delete(SQLiteAxolotlStore.PREKEY_TABLENAME,
                SQLiteAxolotlStore.ACCOUNT + " = ?",
                deleteArgs);
        db.delete(SQLiteAxolotlStore.SIGNED_PREKEY_TABLENAME,
                SQLiteAxolotlStore.ACCOUNT + " = ?",
                deleteArgs);
        db.delete(SQLiteAxolotlStore.IDENTITIES_TABLENAME,
                SQLiteAxolotlStore.ACCOUNT + " = ?",
                deleteArgs);
    }

    public List<ShortcutService.FrequentContact> getFrequentContacts(int days) {
        SQLiteDatabase db = this.getReadableDatabase();
        final String SQL = "select " + Conversation.TABLENAME + "." + Conversation.ACCOUNT + "," + Conversation.TABLENAME + "." + Conversation.CONTACTJID + " from " + Conversation.TABLENAME + " join " + Message.TABLENAME + " on conversations.uuid=messages.conversationUuid where messages.status!=0 and carbon==0  and conversations.mode=0 and messages.timeSent>=? group by conversations.uuid order by count(body) desc limit 4;";
        String[] whereArgs = new String[]{String.valueOf(System.currentTimeMillis() - (Config.MILLISECONDS_IN_DAY * days))};
        Cursor cursor = db.rawQuery(SQL, whereArgs);
        ArrayList<ShortcutService.FrequentContact> contacts = new ArrayList<>();
        while (cursor.moveToNext()) {
            try {
                contacts.add(new ShortcutService.FrequentContact(cursor.getString(0), Jid.of(cursor.getString(1))));
            } catch (Exception e) {
                Log.d(Config.LOGTAG, e.getMessage());
            }
        }
        cursor.close();
        return contacts;
    }
}