//krazy:skip
// clazy:skip
/****************************************************************************
**
** Copyright (C) 2016 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the QtSql module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
** and conditions see https://www.qt.io/terms-conditions. For further
** information use the contact form at https://www.qt.io/contact-us.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 3 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL3 included in the
** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 3 requirements
** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 2.0 or (at your option) the GNU General
** Public license version 3 or any later version approved by the KDE Free
** Qt Foundation. The licenses are as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
** included in the packaging of this file. Please review the following
** information to ensure the GNU General Public License requirements will
** be met: https://www.gnu.org/licenses/gpl-2.0.html and
** https://www.gnu.org/licenses/gpl-3.0.html.
**
** $QT_END_LICENSE$
**
****************************************************************************/

#include "qsql_sqlite_p.h"

#include <QtSql/private/qsqlcachedresult_p.h>
#include <QtSql/private/qsqldriver_p.h>
#include <qcoreapplication.h>
#include <qdatetime.h>
#include <qdebug.h>
#include <qsqlerror.h>
#include <qsqlfield.h>
#include <qsqlindex.h>
#include <qsqlquery.h>
#include <qstringlist.h>
#include <qvariant.h>
#include <qvector.h>

#if defined Q_OS_WIN
# include <qt_windows.h>
#else
# include <unistd.h>
#endif

#include <sqlite3.h>

Q_DECLARE_OPAQUE_POINTER(sqlite3*)
Q_DECLARE_METATYPE(sqlite3*)

Q_DECLARE_OPAQUE_POINTER(sqlite3_stmt*)
Q_DECLARE_METATYPE(sqlite3_stmt*)

QT_BEGIN_NAMESPACE

static QString _q_escapeIdentifier(const QString& identifier)
{
    QString res = identifier;
    if (!identifier.isEmpty() && identifier.at(0) != QLatin1Char('"') && identifier.right(1) != QString(QLatin1Char('"'))) {
        res.replace(QLatin1Char('"'), QLatin1String("\"\""));
        res.prepend(QLatin1Char('"')).append(QLatin1Char('"'));
        res.replace(QLatin1Char('.'), QLatin1String("\".\""));
    }
    return res;
}

static QVariant::Type qGetColumnType(const QString& tpName)
{
    const QString typeName = tpName.toLower();

    if (typeName == QLatin1String("integer")
        || typeName == QLatin1String("int")) {
        return QVariant::Int;
    }
    if (typeName == QLatin1String("double")
        || typeName == QLatin1String("float")
        || typeName == QLatin1String("real")
        || typeName.startsWith(QLatin1String("numeric"))) {
        return QVariant::Double;
    }
    if (typeName == QLatin1String("blob")) {
        return QVariant::ByteArray;
    }
    if (typeName == QLatin1String("boolean")
        || typeName == QLatin1String("bool")) {
        return QVariant::Bool;
    }
    return QVariant::String;
}

static QSqlError qMakeError(sqlite3* access, const QString& descr, QSqlError::ErrorType type,
                            int errorCode = -1)
{
    return QSqlError(descr,
                     QString(reinterpret_cast<const QChar*>(sqlite3_errmsg16(access))),
                     type, QString::number(errorCode));
}

class QSQLiteResultPrivate;

class QSQLiteResult : public QSqlCachedResult
{
    Q_DECLARE_PRIVATE(QSQLiteResult)
    friend class QSQLiteDriver;

public:
    explicit QSQLiteResult(const QSQLiteDriver* db);
    ~QSQLiteResult() override;
    QVariant handle() const Q_DECL_OVERRIDE;

protected:
    bool gotoNext(QSqlCachedResult::ValueCache& row, int idx) Q_DECL_OVERRIDE;
    bool reset(const QString& query) Q_DECL_OVERRIDE;
    bool prepare(const QString& query) Q_DECL_OVERRIDE;
    bool exec() Q_DECL_OVERRIDE;
    int size() Q_DECL_OVERRIDE;
    int numRowsAffected() Q_DECL_OVERRIDE;
    QVariant lastInsertId() const Q_DECL_OVERRIDE;
    QSqlRecord record() const Q_DECL_OVERRIDE;
    void detachFromResultSet() Q_DECL_OVERRIDE;
    void virtual_hook(int id, void* data) Q_DECL_OVERRIDE;
};

class QSQLiteDriverPrivate : public QSqlDriverPrivate
{
    Q_DECLARE_PUBLIC(QSQLiteDriver)

public:
    inline QSQLiteDriverPrivate()
    {
        dbmsType = QSqlDriver::SQLite;
    }
    sqlite3* access{nullptr};
    QList <QSQLiteResult*> results;
};


class QSQLiteResultPrivate: public QSqlCachedResultPrivate
{
    Q_DECLARE_PUBLIC(QSQLiteResult)

public:
    Q_DECLARE_SQLDRIVER_PRIVATE(QSQLiteDriver)
    explicit QSQLiteResultPrivate(QSQLiteResult* q, const QSQLiteDriver* drv);
    void cleanup();
    bool fetchNext(QSqlCachedResult::ValueCache& values, int idx, bool initialFetch);
    // initializes the recordInfo and the cache
    void initColumns(bool emptyResultset);
    void finalize();

    sqlite3_stmt* stmt;

    bool skippedStatus; // the status of the fetchNext() that's skipped
    bool skipRow; // skip the next fetchNext()?
    QSqlRecord rInf;
    QVector<QVariant> firstRow;
};

QSQLiteResultPrivate::QSQLiteResultPrivate(QSQLiteResult* q, const QSQLiteDriver* drv)
    : QSqlCachedResultPrivate(q, drv),
      stmt(nullptr),
      skippedStatus(false),
      skipRow(false)
{
}

void QSQLiteResultPrivate::cleanup()
{
    Q_Q(QSQLiteResult);
    finalize();
    rInf.clear();
    skippedStatus = false;
    skipRow = false;
    q->setAt(QSql::BeforeFirstRow);
    q->setActive(false);
    q->cleanup();
}

void QSQLiteResultPrivate::finalize()
{
    if (stmt == nullptr) {
        return;
    }

    sqlite3_finalize(stmt);
    stmt = nullptr;
}

void QSQLiteResultPrivate::initColumns(bool emptyResultset)
{
    Q_Q(QSQLiteResult);
    int nCols = sqlite3_column_count(stmt);
    if (nCols <= 0) {
        return;
    }

    q->init(nCols);

    for (int i = 0; i < nCols; ++i) {
        QString colName = QString(reinterpret_cast<const QChar*>(
                                      sqlite3_column_name16(stmt, i))
                                 ).remove(QLatin1Char('"'));

        // must use typeName for resolving the type to match QSqliteDriver::record
        QString typeName = QString(reinterpret_cast<const QChar*>(
                                       sqlite3_column_decltype16(stmt, i)));
        // sqlite3_column_type is documented to have undefined behavior if the result set is empty
        int stp = emptyResultset ? -1 : sqlite3_column_type(stmt, i);

        QVariant::Type fieldType;

        if (!typeName.isEmpty()) {
            fieldType = qGetColumnType(typeName);
        } else {
            // Get the proper type for the field based on stp value
            switch (stp) {
            case SQLITE_INTEGER:
                fieldType = QVariant::Int;
                break;
            case SQLITE_FLOAT:
                fieldType = QVariant::Double;
                break;
            case SQLITE_BLOB:
                fieldType = QVariant::ByteArray;
                break;
            case SQLITE_TEXT:
                fieldType = QVariant::String;
                break;
            case SQLITE_NULL:
            default:
                fieldType = QVariant::Invalid;
                break;
            }
        }

        QSqlField fld(colName, fieldType);
        fld.setSqlType(stp);
        rInf.append(fld);
    }
}

bool QSQLiteResultPrivate::fetchNext(QSqlCachedResult::ValueCache& values, int idx, bool initialFetch)
{
    Q_Q(QSQLiteResult);
    int res;
    int i;

    if (skipRow) {
        // already fetched
        Q_ASSERT(!initialFetch);
        skipRow = false;
        for (int i = 0; i < firstRow.count(); i++) {
            values[i] = firstRow[i];
        }
        return skippedStatus;
    }
    skipRow = initialFetch;

    if (initialFetch) {
        firstRow.clear();
        firstRow.resize(sqlite3_column_count(stmt));
    }

    if (stmt == nullptr) {
        q->setLastError(QSqlError(QCoreApplication::translate("QSQLiteResult", "Unable to fetch row"),
                                  QCoreApplication::translate("QSQLiteResult", "No query"), QSqlError::ConnectionError));
        q->setAt(QSql::AfterLastRow);
        return false;
    }
    res = sqlite3_step(stmt);

    switch (res) {
    case SQLITE_ROW:
        // check to see if should fill out columns
        if (rInf.isEmpty())
            // must be first call.
        {
            initColumns(false);
        }
        if (idx < 0 && !initialFetch) {
            return true;
        }
        for (i = 0; i < rInf.count(); ++i) {
            switch (sqlite3_column_type(stmt, i)) {
            case SQLITE_BLOB:
                values[i + idx] = QByteArray(static_cast<const char*>(
                                                 sqlite3_column_blob(stmt, i)),
                                             sqlite3_column_bytes(stmt, i));
                break;
            case SQLITE_INTEGER:
                values[i + idx] = sqlite3_column_int64(stmt, i);
                break;
            case SQLITE_FLOAT:
                switch (q->numericalPrecisionPolicy()) {
                case QSql::LowPrecisionInt32:
                    values[i + idx] = sqlite3_column_int(stmt, i);
                    break;
                case QSql::LowPrecisionInt64:
                    values[i + idx] = sqlite3_column_int64(stmt, i);
                    break;
                case QSql::LowPrecisionDouble:
                case QSql::HighPrecision:
                default:
                    values[i + idx] = sqlite3_column_double(stmt, i);
                    break;
                };
                break;
            case SQLITE_NULL:
                values[i + idx] = QVariant(QVariant::String);
                break;
            default:
                values[i + idx] = QString(reinterpret_cast<const QChar*>(
                                              sqlite3_column_text16(stmt, i)),
                                          sqlite3_column_bytes16(stmt, i) / sizeof(QChar));
                break;
            }
        }
        return true;
    case SQLITE_DONE:
        if (rInf.isEmpty())
            // must be first call.
        {
            initColumns(true);
        }
        q->setAt(QSql::AfterLastRow);
        sqlite3_reset(stmt);
        return false;
    case SQLITE_CONSTRAINT:
    case SQLITE_ERROR:
        // SQLITE_ERROR is a generic error code and we must call sqlite3_reset()
        // to get the specific error message.
        res = sqlite3_reset(stmt);
        q->setLastError(qMakeError(drv_d_func()->access, QCoreApplication::translate("QSQLiteResult",
                                   "Unable to fetch row"), QSqlError::ConnectionError, res));
        q->setAt(QSql::AfterLastRow);
        return false;
    case SQLITE_MISUSE:
    case SQLITE_BUSY:
    default:
        // something wrong, don't get col info, but still return false
        q->setLastError(qMakeError(drv_d_func()->access, QCoreApplication::translate("QSQLiteResult",
                                   "Unable to fetch row"), QSqlError::ConnectionError, res));
        sqlite3_reset(stmt);
        q->setAt(QSql::AfterLastRow);
        return false;
    }
    return false;
}

QSQLiteResult::QSQLiteResult(const QSQLiteDriver* db)
    : QSqlCachedResult(*new QSQLiteResultPrivate(this, db))
{
    Q_D(QSQLiteResult);
    const_cast<QSQLiteDriverPrivate*>(d->drv_d_func())->results.append(this);
}

QSQLiteResult::~QSQLiteResult()
{
    Q_D(QSQLiteResult);
    if (d->drv_d_func() != nullptr) {
        const_cast<QSQLiteDriverPrivate*>(d->drv_d_func())->results.removeOne(this);
    }
    d->cleanup();
}

void QSQLiteResult::virtual_hook(int id, void* data)
{
    QSqlCachedResult::virtual_hook(id, data);
}

bool QSQLiteResult::reset(const QString& query)
{
    if (!prepare(query)) {
        return false;
    }
    return exec();
}

bool QSQLiteResult::prepare(const QString& query)
{
    Q_D(QSQLiteResult);
    if ((driver() == nullptr) || !driver()->isOpen() || driver()->isOpenError()) {
        return false;
    }

    d->cleanup();

    setSelect(false);

    const void* pzTail = nullptr;

#if (SQLITE_VERSION_NUMBER >= 3003011)
    int res = sqlite3_prepare16_v2(d->drv_d_func()->access, query.constData(), (query.size() + 1) * sizeof(QChar),
                                   &d->stmt, &pzTail);
#else
    int res = sqlite3_prepare16(d->access, query.constData(), (query.size() + 1) * sizeof(QChar),
                                &d->stmt, &pzTail);
#endif

    if (res != SQLITE_OK) {
        setLastError(qMakeError(d->drv_d_func()->access, QCoreApplication::translate("QSQLiteResult",
                                "Unable to execute statement"), QSqlError::StatementError, res));
        d->finalize();
        return false;
    }
    if ((pzTail != nullptr) && !QString(reinterpret_cast<const QChar*>(pzTail)).trimmed().isEmpty()) {
        setLastError(qMakeError(d->drv_d_func()->access, QCoreApplication::translate("QSQLiteResult",
                                "Unable to execute multiple statements at a time"), QSqlError::StatementError, SQLITE_MISUSE));
        d->finalize();
        return false;
    }
    return true;
}

bool QSQLiteResult::exec()
{
    Q_D(QSQLiteResult);
    const QVector<QVariant> values = boundValues();

    d->skippedStatus = false;
    d->skipRow = false;
    d->rInf.clear();
    clearValues();
    setLastError(QSqlError());

    int res = sqlite3_reset(d->stmt);
    if (res != SQLITE_OK) {
        setLastError(qMakeError(d->drv_d_func()->access, QCoreApplication::translate("QSQLiteResult",
                                "Unable to reset statement"), QSqlError::StatementError, res));
        d->finalize();
        return false;
    }
    int paramCount = sqlite3_bind_parameter_count(d->stmt);
    if (paramCount == values.count()) {
        for (int i = 0; i < paramCount; ++i) {
            res = SQLITE_OK;
            const QVariant& value = values.at(i);

            if (value.isNull()) {
                res = sqlite3_bind_null(d->stmt, i + 1);
            } else {
                switch (value.type()) {
                case QVariant::ByteArray: {
                    const auto* ba = static_cast<const QByteArray*>(value.constData());
                    res = sqlite3_bind_blob(d->stmt, i + 1, ba->constData(),
                                            ba->size(), SQLITE_STATIC);
                    break;
                }
                case QVariant::Int:
                case QVariant::Bool:
                    res = sqlite3_bind_int(d->stmt, i + 1, value.toInt());
                    break;
                case QVariant::Double:
                    res = sqlite3_bind_double(d->stmt, i + 1, value.toDouble());
                    break;
                case QVariant::UInt:
                case QVariant::LongLong:
                    res = sqlite3_bind_int64(d->stmt, i + 1, value.toLongLong());
                    break;
                case QVariant::DateTime: {
                    const QDateTime dateTime = value.toDateTime();
                    const QString str = dateTime.toString(QStringLiteral("yyyy-MM-ddThh:mm:ss.zzz"));
                    res = sqlite3_bind_text16(d->stmt, i + 1, str.utf16(),
                                              str.size() * sizeof(ushort), SQLITE_TRANSIENT);
                    break;
                }
                case QVariant::Time: {
                    const QTime time = value.toTime();
                    const QString str = time.toString(QStringLiteral("hh:mm:ss.zzz"));
                    res = sqlite3_bind_text16(d->stmt, i + 1, str.utf16(),
                                              str.size() * sizeof(ushort), SQLITE_TRANSIENT);
                    break;
                }
                case QVariant::String: {
                    // lifetime of string == lifetime of its qvariant
                    const auto* str = static_cast<const QString*>(value.constData());
                    res = sqlite3_bind_text16(d->stmt, i + 1, str->utf16(),
                                              (str->size()) * sizeof(QChar), SQLITE_STATIC);
                    break;
                }
                default: {
                    QString str = value.toString();
                    // SQLITE_TRANSIENT makes sure that sqlite buffers the data
                    res = sqlite3_bind_text16(d->stmt, i + 1, str.utf16(),
                                              (str.size()) * sizeof(QChar), SQLITE_TRANSIENT);
                    break;
                }
                }
            }
            if (res != SQLITE_OK) {
                setLastError(qMakeError(d->drv_d_func()->access, QCoreApplication::translate("QSQLiteResult",
                                        "Unable to bind parameters"), QSqlError::StatementError, res));
                d->finalize();
                return false;
            }
        }
    } else {
        setLastError(QSqlError(QCoreApplication::translate("QSQLiteResult",
                               "Parameter count mismatch"), QString(), QSqlError::StatementError));
        return false;
    }
    d->skippedStatus = d->fetchNext(d->firstRow, 0, true);
    if (lastError().isValid()) {
        setSelect(false);
        setActive(false);
        return false;
    }
    setSelect(!d->rInf.isEmpty());
    setActive(true);
    return true;
}

bool QSQLiteResult::gotoNext(QSqlCachedResult::ValueCache& row, int idx)
{
    Q_D(QSQLiteResult);
    return d->fetchNext(row, idx, false);
}

int QSQLiteResult::size()
{
    return -1;
}

int QSQLiteResult::numRowsAffected()
{
    Q_D(const QSQLiteResult);
    return sqlite3_changes(d->drv_d_func()->access);
}

QVariant QSQLiteResult::lastInsertId() const
{
    Q_D(const QSQLiteResult);
    if (isActive()) {
        qint64 id = sqlite3_last_insert_rowid(d->drv_d_func()->access);
        if (id != 0) {
            return id;
        }
    }
    return QVariant();
}

QSqlRecord QSQLiteResult::record() const
{
    Q_D(const QSQLiteResult);
    if (!isActive() || !isSelect()) {
        return QSqlRecord();
    }
    return d->rInf;
}

void QSQLiteResult::detachFromResultSet()
{
    Q_D(QSQLiteResult);
    if (d->stmt != nullptr) {
        sqlite3_reset(d->stmt);
    }
}

QVariant QSQLiteResult::handle() const
{
    Q_D(const QSQLiteResult);
    return QVariant::fromValue(d->stmt);
}

/////////////////////////////////////////////////////////

QSQLiteDriver::QSQLiteDriver(QObject* parent)
    : QSqlDriver(*new QSQLiteDriverPrivate, parent)
{
}

QSQLiteDriver::QSQLiteDriver(sqlite3* connection, QObject* parent)
    : QSqlDriver(*new QSQLiteDriverPrivate, parent)
{
    Q_D(QSQLiteDriver);
    d->access = connection;
    setOpen(true);
    setOpenError(false);
}


QSQLiteDriver::~QSQLiteDriver()
    = default;

bool QSQLiteDriver::hasFeature(DriverFeature f) const
{
    switch (f) {
    case BLOB:
    case Transactions:
    case Unicode:
    case LastInsertId:
    case PreparedQueries:
    case PositionalPlaceholders:
    case SimpleLocking:
    case FinishQuery:
    case LowPrecisionNumbers:
        return true;
    case QuerySize:
    case NamedPlaceholders:
    case BatchOperations:
    case EventNotifications:
    case MultipleResultSets:
    case CancelQuery:
        return false;
    }
    return false;
}

/*
   SQLite dbs have no user name, passwords, hosts or ports.
   just file names.
*/
bool QSQLiteDriver::open(const QString& db, const QString& /*user*/, const QString& /*password*/, const QString& /*host*/, int /*port*/, const QString& conOpts)
{
    Q_D(QSQLiteDriver);
    if (isOpen()) {
        close();
    }


    int timeOut = 5000;
    bool sharedCache = false;
    bool openReadOnlyOption = false;
    bool openUriOption = false;

    const auto opts = conOpts.splitRef(QLatin1Char(';'));
    for (auto option : opts) {
        option = option.trimmed();
        if (option.startsWith(QLatin1String("QSQLITE_BUSY_TIMEOUT"))) {
            option = option.mid(20).trimmed();
            if (option.startsWith(QLatin1Char('='))) {
                bool ok;
                const int nt = option.mid(1).trimmed().toInt(&ok);
                if (ok) {
                    timeOut = nt;
                }
            }
        } else if (option == QLatin1String("QSQLITE_OPEN_READONLY")) {
            openReadOnlyOption = true;
        } else if (option == QLatin1String("QSQLITE_OPEN_URI")) {
            openUriOption = true;
        } else if (option == QLatin1String("QSQLITE_ENABLE_SHARED_CACHE")) {
            sharedCache = true;
        }
    }

    int openMode = (openReadOnlyOption ? SQLITE_OPEN_READONLY : (SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE));
    if (openUriOption) {
        openMode |= SQLITE_OPEN_URI;
    }

    sqlite3_enable_shared_cache(static_cast<int>(sharedCache));

    if (sqlite3_open_v2(db.toUtf8().constData(), &d->access, openMode, nullptr) == SQLITE_OK) {
        sqlite3_busy_timeout(d->access, timeOut);
        setOpen(true);
        setOpenError(false);
        return true;
    }
    if (d->access != nullptr) {
        sqlite3_close(d->access);
        d->access = nullptr;
    }

    setLastError(qMakeError(d->access, tr("Error opening database"),
                            QSqlError::ConnectionError));
    setOpenError(true);
    return false;

}

void QSQLiteDriver::close()
{
    Q_D(QSQLiteDriver);
    if (isOpen()) {
        for (QSQLiteResult* result : qAsConst(d->results)) {
            result->d_func()->finalize();
        }

        if (sqlite3_close(d->access) != SQLITE_OK) {
            setLastError(qMakeError(d->access, tr("Error closing database"),
                                    QSqlError::ConnectionError));
        }
        d->access = nullptr;
        setOpen(false);
        setOpenError(false);
    }
}

QSqlResult* QSQLiteDriver::createResult() const
{
    return new QSQLiteResult(this);
}

bool QSQLiteDriver::beginTransaction()
{
    if (!isOpen() || isOpenError()) {
        return false;
    }

    QSqlQuery q(createResult());
    if (!q.exec(QStringLiteral("BEGIN"))) {
        setLastError(QSqlError(tr("Unable to begin transaction"),
                               q.lastError().databaseText(), QSqlError::TransactionError));
        return false;
    }

    return true;
}

bool QSQLiteDriver::commitTransaction()
{
    if (!isOpen() || isOpenError()) {
        return false;
    }

    QSqlQuery q(createResult());
    if (!q.exec(QStringLiteral("COMMIT"))) {
        setLastError(QSqlError(tr("Unable to commit transaction"),
                               q.lastError().databaseText(), QSqlError::TransactionError));
        return false;
    }

    return true;
}

bool QSQLiteDriver::rollbackTransaction()
{
    if (!isOpen() || isOpenError()) {
        return false;
    }

    QSqlQuery q(createResult());
    if (!q.exec(QStringLiteral("ROLLBACK"))) {
        setLastError(QSqlError(tr("Unable to rollback transaction"),
                               q.lastError().databaseText(), QSqlError::TransactionError));
        return false;
    }

    return true;
}

QStringList QSQLiteDriver::tables(QSql::TableType type) const
{
    QStringList res;
    if (!isOpen()) {
        return res;
    }

    QSqlQuery q(createResult());
    q.setForwardOnly(true);

    QString sql = QStringLiteral("SELECT name FROM sqlite_master WHERE %1 "
                                 "UNION ALL SELECT name FROM sqlite_temp_master WHERE %1");
    if (((type & QSql::Tables) != 0) && ((type & QSql::Views) != 0)) {
        sql = sql.arg(QStringLiteral("type='table' OR type='view'"));
    } else if ((type & QSql::Tables) != 0) {
        sql = sql.arg(QStringLiteral("type='table'"));
    } else if ((type & QSql::Views) != 0) {
        sql = sql.arg(QStringLiteral("type='view'"));
    } else {
        sql.clear();
    }

    if (!sql.isEmpty() && q.exec(sql)) {
        while (q.next()) {
            res.append(q.value(0).toString());
        }
    }

    if ((type & QSql::SystemTables) != 0) {
        // there are no internal tables beside this one:
        res.append(QStringLiteral("sqlite_master"));
    }

    return res;
}

static QSqlIndex qGetTableInfo(QSqlQuery& q, const QString& tableName, bool onlyPIndex = false)
{
    QString schema;
    QString table(tableName);
    int indexOfSeparator = tableName.indexOf(QLatin1Char('.'));
    if (indexOfSeparator > -1) {
        schema = tableName.left(indexOfSeparator).append(QLatin1Char('.'));
        table = tableName.mid(indexOfSeparator + 1);
    }
    q.exec(QLatin1String("PRAGMA ") + schema + QLatin1String("table_info (") + _q_escapeIdentifier(table) + QLatin1Char(')'));

    QSqlIndex ind;
    while (q.next()) {
        bool isPk = q.value(5).toInt() != 0;
        if (onlyPIndex && !isPk) {
            continue;
        }
        QString typeName = q.value(2).toString().toLower();
        QSqlField fld(q.value(1).toString(), qGetColumnType(typeName));
        if (isPk && (typeName == QLatin1String("integer")))
            // INTEGER PRIMARY KEY fields are auto-generated in sqlite
            // INT PRIMARY KEY is not the same as INTEGER PRIMARY KEY!
        {
            fld.setAutoValue(true);
        }
        fld.setRequired(q.value(3).toInt() != 0);
        fld.setDefaultValue(q.value(4));
        ind.append(fld);
    }
    return ind;
}

QSqlIndex QSQLiteDriver::primaryIndex(const QString& tblname) const
{
    if (!isOpen()) {
        return QSqlIndex();
    }

    QString table = tblname;
    if (isIdentifierEscaped(table, QSqlDriver::TableName)) {
        table = stripDelimiters(table, QSqlDriver::TableName);
    }

    QSqlQuery q(createResult());
    q.setForwardOnly(true);
    return qGetTableInfo(q, table, true);
}

QSqlRecord QSQLiteDriver::record(const QString& tbl) const
{
    if (!isOpen()) {
        return QSqlRecord();
    }

    QString table = tbl;
    if (isIdentifierEscaped(table, QSqlDriver::TableName)) {
        table = stripDelimiters(table, QSqlDriver::TableName);
    }

    QSqlQuery q(createResult());
    q.setForwardOnly(true);
    return qGetTableInfo(q, table);
}

QVariant QSQLiteDriver::handle() const
{
    Q_D(const QSQLiteDriver);
    return QVariant::fromValue(d->access);
}

QString QSQLiteDriver::escapeIdentifier(const QString& identifier, IdentifierType type) const
{
    Q_UNUSED(type)
    return _q_escapeIdentifier(identifier);
}

QT_END_NAMESPACE
