/****************************************************************************

**

** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).

** All rights reserved.

** Contact: Nokia Corporation (qt-info@nokia.com)

**

** This file is part of the QtSql module of the Qt Toolkit.

**

** $QT_BEGIN_LICENSE:LGPL$

** No Commercial Usage

** This file contains pre-release code and may not be distributed.

** You may use this file in accordance with the terms and conditions

** contained in the Technology Preview License Agreement accompanying

** this package.

**

** GNU Lesser General Public License Usage

** Alternatively, this file may be used under the terms of the GNU Lesser

** General Public License version 2.1 as published by the Free Software

** Foundation and appearing in the file LICENSE.LGPL included in the

** packaging of this file.  Please review the following information to

** ensure the GNU Lesser General Public License version 2.1 requirements

** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.

**

** In addition, as a special exception, Nokia gives you certain additional

** rights.  These rights are described in the Nokia Qt LGPL Exception

** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.

**

** If you have questions regarding the use of this file, please contact

** Nokia at qt-info@nokia.com.

**

**

**

**

**

**

**

**

** $QT_END_LICENSE$

**

****************************************************************************/

#include "qsql_sqlite2.h"

#include <qcoreapplication.h>

#include <qvariant.h>

#include <qdatetime.h>

#include <qfile.h>

#include <qregexp.h>

#include <qsqlerror.h>

#include <qsqlfield.h>

#include <qsqlindex.h>

#include <qsqlquery.h>

#include <qstringlist.h>

#include <qvector.h>

#if !defined Q_WS_WIN32

# include <unistd.h>

#endif

#include <sqlite.h>

typedef struct sqlite_vm sqlite_vm;

Q_DECLARE_METATYPE(sqlite_vm*)

Q_DECLARE_METATYPE(sqlite*)

QT_BEGIN_NAMESPACE

static QVariant::Type nameToType(const QString& typeName)

{

    QString tName = typeName.toUpper();

    if (tName.startsWith(QLatin1String("INT")))

        return QVariant::Int;

    if (tName.startsWith(QLatin1String("FLOAT")) || tName.startsWith(QLatin1String("NUMERIC")))

        return QVariant::Double;

    if (tName.startsWith(QLatin1String("BOOL")))

        return QVariant::Bool;

    // SQLite is typeless - consider everything else as string

    return QVariant::String;

}

class QSQLite2DriverPrivate

{

public:

    QSQLite2DriverPrivate();

    sqlite *access;

    bool utf8;

};

QSQLite2DriverPrivate::QSQLite2DriverPrivate() : access(0)

{

    utf8 = (qstrcmp(sqlite_encoding, "UTF-8") == 0);

}

class QSQLite2ResultPrivate

{

public:

    QSQLite2ResultPrivate(QSQLite2Result *res);

    void cleanup();

    bool fetchNext(QSqlCachedResult::ValueCache &values, int idx, bool initialFetch);

    bool isSelect();

    // initializes the recordInfo and the cache

    void init(const char **cnames, int numCols);

    void finalize();

    QSQLite2Result* q;

    sqlite *access;

    // and we have too keep our own struct for the data (sqlite works via

    // callback.

    const char *currentTail;

    sqlite_vm *currentMachine;

    uint skippedStatus: 1; // the status of the fetchNext() that's skipped

    uint skipRow: 1; // skip the next fetchNext()?

    uint utf8: 1;

    QSqlRecord rInf;

};

static const uint initial_cache_size = 128;

QSQLite2ResultPrivate::QSQLite2ResultPrivate(QSQLite2Result* res) : q(res), access(0), currentTail(0),

    currentMachine(0), skippedStatus(false), skipRow(false), utf8(false)

{

}

void QSQLite2ResultPrivate::cleanup()

{

    finalize();

    rInf.clear();

    currentTail = 0;

    currentMachine = 0;

    skippedStatus = false;

    skipRow = false;

    q->setAt(QSql::BeforeFirstRow);

    q->setActive(false);

    q->cleanup();

}

void QSQLite2ResultPrivate::finalize()

{

    if (!currentMachine)

        return;

    char* err = 0;

    int res = sqlite_finalize(currentMachine, &err);

    if (err) {

        q->setLastError(QSqlError(QCoreApplication::translate("QSQLite2Result",

                                  "Unable to fetch results"), QString::fromAscii(err),

                                  QSqlError::StatementError, res));

        sqlite_freemem(err);

    }

    currentMachine = 0;

}

// called on first fetch

void QSQLite2ResultPrivate::init(const char **cnames, int numCols)

{

    if (!cnames)

        return;

    rInf.clear();

    if (numCols <= 0)

        return;

    q->init(numCols);

    for (int i = 0; i < numCols; ++i) {

        const char* lastDot = strrchr(cnames[i], '.');

        const char* fieldName = lastDot ? lastDot + 1 : cnames[i];

        //remove quotations around the field name if any

        QString fieldStr = QString::fromAscii(fieldName);

        QLatin1Char quote('\"');

        if ( fieldStr.length() > 2 && fieldStr.startsWith(quote) && fieldStr.endsWith(quote)) {

            fieldStr = fieldStr.mid(1);

            fieldStr.chop(1);

        }

        rInf.append(QSqlField(fieldStr,

                              nameToType(QString::fromAscii(cnames[i+numCols]))));

    }

}

bool QSQLite2ResultPrivate::fetchNext(QSqlCachedResult::ValueCache &values, int idx, bool initialFetch)

{

    // may be caching.

    const char **fvals;

    const char **cnames;

    int colNum;

    int res;

    int i;

    if (skipRow) {

        // already fetched

        Q_ASSERT(!initialFetch);

        skipRow = false;

        return skippedStatus;

    }

    skipRow = initialFetch;

    if (!currentMachine)

        return false;

    // keep trying while busy, wish I could implement this better.

    while ((res = sqlite_step(currentMachine, &colNum, &fvals, &cnames)) == SQLITE_BUSY) {

        // sleep instead requesting result again immidiately.

#if defined Q_WS_WIN32

        Sleep(1000);

#else

        sleep(1);

#endif

    }

    switch(res) {

    case SQLITE_ROW:

        // check to see if should fill out columns

        if (rInf.isEmpty())

            // must be first call.

            init(cnames, colNum);

        if (!fvals)

            return false;

        if (idx < 0 && !initialFetch)

            return true;

        for (i = 0; i < colNum; ++i)

            values[i + idx] = utf8 ? QString::fromUtf8(fvals[i]) : QString::fromAscii(fvals[i]);

        return true;

    case SQLITE_DONE:

        if (rInf.isEmpty())

            // must be first call.

            init(cnames, colNum);

        q->setAt(QSql::AfterLastRow);

        return false;

    case SQLITE_ERROR:

    case SQLITE_MISUSE:

    default:

        // something wrong, don't get col info, but still return false

        finalize(); // finalize to get the error message.

        q->setAt(QSql::AfterLastRow);

        return false;

    }

    return false;

}

QSQLite2Result::QSQLite2Result(const QSQLite2Driver* db)

: QSqlCachedResult(db)

{

    d = new QSQLite2ResultPrivate(this);

    d->access = db->d->access;

    d->utf8 = db->d->utf8;

}

QSQLite2Result::~QSQLite2Result()

{

    d->cleanup();

    delete d;

}

void QSQLite2Result::virtual_hook(int id, void *data)

{

    switch (id) {

    case QSqlResult::DetachFromResultSet:

        d->finalize();

        break;

    default:

        QSqlCachedResult::virtual_hook(id, data);

    }

}

/*

   Execute \a query.

*/

bool QSQLite2Result::reset (const QString& query)

{

    // this is where we build a query.

    if (!driver())

        return false;

    if (!driver()-> isOpen() || driver()->isOpenError())

        return false;

    d->cleanup();

    // Um, ok.  callback based so.... pass private static function for this.

    setSelect(false);

    char *err = 0;

    int res = sqlite_compile(d->access,

                                d->utf8 ? query.toUtf8().constData()

                                        : query.toAscii().constData(),

                                &(d->currentTail),

                                &(d->currentMachine),

                                &err);

    if (res != SQLITE_OK || err) {

        setLastError(QSqlError(QCoreApplication::translate("QSQLite2Result",

                     "Unable to execute statement"), QString::fromAscii(err),

                     QSqlError::StatementError, res));

        sqlite_freemem(err);

    }

    //if (*d->currentTail != '\000' then there is more sql to eval

    if (!d->currentMachine) {

        setActive(false);

        return false;

    }

    // we have to fetch one row to find out about

    // the structure of the result set

    d->skippedStatus = d->fetchNext(cache(), 0, true);

    if (lastError().isValid()) {

        setSelect(false);

        setActive(false);

        return false;

    }

    setSelect(!d->rInf.isEmpty());

    setActive(true);

    return true;

}

bool QSQLite2Result::gotoNext(QSqlCachedResult::ValueCache& row, int idx)

{

    return d->fetchNext(row, idx, false);

}

int QSQLite2Result::size()

{

    return -1;

}

int QSQLite2Result::numRowsAffected()

{

    return sqlite_changes(d->access);

}

QSqlRecord QSQLite2Result::record() const

{

    if (!isActive() || !isSelect())

        return QSqlRecord();

    return d->rInf;

}

QVariant QSQLite2Result::handle() const

{

    return qVariantFromValue(d->currentMachine);

}

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

QSQLite2Driver::QSQLite2Driver(QObject * parent)

    : QSqlDriver(parent)

{

    d = new QSQLite2DriverPrivate();

}

QSQLite2Driver::QSQLite2Driver(sqlite *connection, QObject *parent)

    : QSqlDriver(parent)

{

    d = new QSQLite2DriverPrivate();

    d->access = connection;

    setOpen(true);

    setOpenError(false);

}

QSQLite2Driver::~QSQLite2Driver()

{

    delete d;

}

bool QSQLite2Driver::hasFeature(DriverFeature f) const

{

    switch (f) {

    case Transactions:

    case SimpleLocking:

        return true;

    case Unicode:

        return d->utf8;

    default:

        return false;

    }

}

/*

   SQLite dbs have no user name, passwords, hosts or ports.

   just file names.

*/

bool QSQLite2Driver::open(const QString & db, const QString &, const QString &, const QString &, int, const QString &)

{

    if (isOpen())

        close();

    if (db.isEmpty())

        return false;

    char* err = 0;

    d->access = sqlite_open(QFile::encodeName(db), 0, &err);

    if (err) {

        setLastError(QSqlError(tr("Error opening database"), QString::fromAscii(err),

                     QSqlError::ConnectionError));

        sqlite_freemem(err);

        err = 0;

    }

    if (d->access) {

        setOpen(true);

        setOpenError(false);

        return true;

    }

    setOpenError(true);

    return false;

}

void QSQLite2Driver::close()

{

    if (isOpen()) {

        sqlite_close(d->access);

        d->access = 0;

        setOpen(false);

        setOpenError(false);

    }

}

QSqlResult *QSQLite2Driver::createResult() const

{

    return new QSQLite2Result(this);

}

bool QSQLite2Driver::beginTransaction()

{

    if (!isOpen() || isOpenError())

        return false;

    char* err;

    int res = sqlite_exec(d->access, "BEGIN", 0, this, &err);

    if (res == SQLITE_OK)

        return true;

    setLastError(QSqlError(tr("Unable to begin transaction"),

                           QString::fromAscii(err), QSqlError::TransactionError, res));

    sqlite_freemem(err);

    return false;

}

bool QSQLite2Driver::commitTransaction()

{

    if (!isOpen() || isOpenError())

        return false;

    char* err;

    int res = sqlite_exec(d->access, "COMMIT", 0, this, &err);

    if (res == SQLITE_OK)

        return true;

    setLastError(QSqlError(tr("Unable to commit transaction"),

                QString::fromAscii(err), QSqlError::TransactionError, res));

    sqlite_freemem(err);

    return false;

}

bool QSQLite2Driver::rollbackTransaction()

{

    if (!isOpen() || isOpenError())

        return false;

    char* err;

    int res = sqlite_exec(d->access, "ROLLBACK", 0, this, &err);

    if (res == SQLITE_OK)

        return true;

    setLastError(QSqlError(tr("Unable to rollback transaction"),

                           QString::fromAscii(err), QSqlError::TransactionError, res));

    sqlite_freemem(err);

    return false;

}

QStringList QSQLite2Driver::tables(QSql::TableType type) const

{

    QStringList res;

    if (!isOpen())

        return res;

    QSqlQuery q(createResult());

    q.setForwardOnly(true);

    if ((type & QSql::Tables) && (type & QSql::Views))

        q.exec(QLatin1String("SELECT name FROM sqlite_master WHERE type='table' OR type='view'"));

    else if (type & QSql::Tables)

        q.exec(QLatin1String("SELECT name FROM sqlite_master WHERE type='table'"));

    else if (type & QSql::Views)

        q.exec(QLatin1String("SELECT name FROM sqlite_master WHERE type='view'"));

    if (q.isActive()) {

        while(q.next())

            res.append(q.value(0).toString());

    }

    if (type & QSql::SystemTables) {

        // there are no internal tables beside this one:

        res.append(QLatin1String("sqlite_master"));

    }

    return res;

}

QSqlIndex QSQLite2Driver::primaryIndex(const QString &tblname) const

{

    QSqlRecord rec(record(tblname)); // expensive :(

    if (!isOpen())

        return QSqlIndex();

    QSqlQuery q(createResult());

    q.setForwardOnly(true);

    QString table = tblname;

    if (isIdentifierEscaped(table, QSqlDriver::TableName))

        table = stripDelimiters(table, QSqlDriver::TableName);

    // finrst find a UNIQUE INDEX

    q.exec(QLatin1String("PRAGMA index_list('") + table + QLatin1String("');"));

    QString indexname;

    while(q.next()) {

        if (q.value(2).toInt()==1) {

            indexname = q.value(1).toString();

            break;

        }

    }

    if (indexname.isEmpty())

        return QSqlIndex();

    q.exec(QLatin1String("PRAGMA index_info('") + indexname + QLatin1String("');"));

    QSqlIndex index(table, indexname);

    while(q.next()) {

        QString name = q.value(2).toString();