/****************************************************************************
**
** Copyright (C) 1992-2005 Trolltech AS. All rights reserved.
**
** This file is part of the QtCore module of the Qt Toolkit.
**
** This file may be used under the terms of the GNU General Public
** License version 2.0 as published by the Free Software Foundation
** and appearing in the file LICENSE.GPL included in the packaging of
** this file.  Please review the following information to ensure GNU
** General Public Licensing requirements will be met:
** http://www.trolltech.com/products/qt/opensource.html
**
** If you are unsure which license is appropriate for your use, please
** review the following information:
** http://www.trolltech.com/products/qt/licensing.html or contact the
** sales department at sales@trolltech.com.
**
** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
**
****************************************************************************/

#include "qplatformdefs.h"

#include "qtemporaryfile.h"
#include <qfileengine.h>
#include <private/qfile_p.h>
#include <private/qfileengine_p.h>
#include <private/qbufferedfsfileengine_p.h>

#include <stdlib.h>
#include <errno.h>

#ifndef Q_OS_WIN
# define HAS_MKSTEMP
#endif

//************* QTemporaryFileEngine
class QTemporaryFileEngine : public QFSFileEngine
{
    Q_DECLARE_PRIVATE(QFSFileEngine)
public:
    QTemporaryFileEngine(const QString &file) : QFSFileEngine(file) { }
    ~QTemporaryFileEngine();

    bool open(int flags);
};

QTemporaryFileEngine::~QTemporaryFileEngine()
{
}

bool QTemporaryFileEngine::open(int)
{
    Q_D(QFSFileEngine);

    QString qfilename = d->file;
    if(!qfilename.endsWith(QLatin1String("XXXXXX")))
        qfilename += QLatin1String(".XXXXXX");
    d->external_file = 0;
    char *filename = qstrdup(qfilename.toLocal8Bit());
    
#ifdef HAS_MKSTEMP
    d->fd = mkstemp(filename);
#else
#if defined(_MSC_VER) && _MSC_VER >= 1400
    int len = int(strlen(filename)) + 1;
    if(_mktemp_s(filename, len) == 0) {
#else
    if(mktemp(filename)) {
#endif
        int oflags = QT_OPEN_RDWR | QT_OPEN_CREAT;
#if defined(Q_OS_MSDOS) || defined(Q_OS_WIN32) || defined(Q_OS_OS2)
        oflags |= QT_OPEN_BINARY; // we handle all text translations our self.
#endif
        d->fd = d->sysOpen(filename, oflags);
    }
#endif
    if(d->fd != -1) {
        d->file = QString::fromLocal8Bit(filename); //changed now!
        free(filename);
        d->sequential = 0;
        return true;
    }
    free(filename);
    d->setError(errno == EMFILE ? QFile::ResourceError : QFile::OpenError, errno);
    return false;
}


//************* QTemporaryFilePrivate
class QTemporaryFilePrivate : public QFilePrivate
{
    Q_DECLARE_PUBLIC(QTemporaryFile)

protected:
    QTemporaryFilePrivate();
    ~QTemporaryFilePrivate();

    bool autoRemove;
    QString templateName;
    mutable QTemporaryFileEngine *fileEngine;
};

QTemporaryFilePrivate::QTemporaryFilePrivate() : autoRemove(true), fileEngine(0)
{
}

QTemporaryFilePrivate::~QTemporaryFilePrivate()
{
    delete fileEngine;
    fileEngine = 0;
}

//************* QTemporaryFile

/*!
    \class QTemporaryFile
    \reentrant
    \brief The QTemporaryFile class is an I/O device that operates on temporary files.

    \ingroup io
    \mainclass

    QTemporaryFile is an I/O device that will get its input/output
    from the local disk. The filename for the temporary file will be
    guaranteed to be unique once the file is opened and will
    subsequently be removed upon destruction of the QTemporaryFile
    object.

    A temporary file will have some static part of the name and some
    part that is calculated to be unique. The default filename qt_temp
    will be placed into the temporary path as returned by
    QDir::tempPath().

    \sa QDir::tempPath(), QFile
*/

#ifdef QT_NO_QOBJECT
QTemporaryFile::QTemporaryFile()
    : QFile(*new QTemporaryFilePrivate)
{
    Q_D(QTemporaryFile);
    d->templateName = QDir::tempPath() + "/" + QLatin1String("qt_temp.XXXXXX");
}

QTemporaryFile::QTemporaryFile(const QString &templateName)
    : QFile(*new QTemporaryFilePrivate)
{
    Q_D(QTemporaryFile);
    d->templateName = templateName;
}

#else
/*!
    Constructs a QTemporaryFile with no name.

    \sa setFileTemplate()
*/
QTemporaryFile::QTemporaryFile()
    : QFile(*new QTemporaryFilePrivate, 0)
{
    Q_D(QTemporaryFile);
    d->templateName = QDir::tempPath() + QLatin1String("/qt_temp.XXXXXX");
}

/*!
    Constructs a QTemporaryFile with a template filename of \a
    templateName. Upon opening the temporary file this will be used to
    create a unique filename. If the \a templateName does end in
    XXXXXX it will automatically be appended and used as the dynamic
    portion of the filename.

    \sa open(), fileTemplate()
*/
QTemporaryFile::QTemporaryFile(const QString &templateName)
    : QFile(*new QTemporaryFilePrivate, 0)
{
    Q_D(QTemporaryFile);
    d->templateName = templateName;
}

/*!
    Constructs a QTemporaryFile with the given \a parent, but with no name.

    \sa setFileTemplate()
*/
QTemporaryFile::QTemporaryFile(QObject *parent)
    : QFile(*new QTemporaryFilePrivate, parent)
{
    Q_D(QTemporaryFile);
    d->templateName = QDir::tempPath() + QLatin1String("qt_temp.XXXXXX");
}

/*!
    Constructs a QTemporaryFile with a template filename of \a
    templateName and the specified \a parent.
    Upon opening the temporary file this will be used to
    create a unique filename. If the \a templateName does end in
    XXXXXX it will automatically be appended and used as the dynamic
    portion of the filename.

    \sa open(), fileTemplate()
*/
QTemporaryFile::QTemporaryFile(const QString &templateName, QObject *parent)
    : QFile(*new QTemporaryFilePrivate, parent)
{
    Q_D(QTemporaryFile);
    d->templateName = templateName;
}
#endif

/*!
    Destroys the temporary file object, the file is automatically
    closed if necessary and if in auto remove mode it will
    automatically delete the file.

    \sa autoRemove()
*/
QTemporaryFile::~QTemporaryFile()
{
    Q_D(QTemporaryFile);
    close();
    if (!d->fileName.isEmpty() && d->autoRemove)
        remove();
}

/*!
  \fn bool QTemporaryFile::open()

  A QTemporaryFile will always be opened in QIODevice::ReadWrite mode,
  this allows easy access to the data in the file. This function will
  return true upon success and will set the fileName() to the unique
  filename used.

  \sa fileName()
*/

/*!
   Returns true if the QTemporaryFile is in auto remove
   mode. Auto-remove mode will automatically delete the filename from
   disk upon destruction. This makes it very easy to create your
   QTemporaryFile object on the stack, fill it with data, read from
   it, and finally on function return it will automatically clean up
   after itself.

   Auto-remove is on by default.

   \sa setAutoRemove(), remove()
*/
bool QTemporaryFile::autoRemove() const
{
    Q_D(const QTemporaryFile);
    return d->autoRemove;
}

/*!
    Sets the QTemporaryFile into auto-remove mode if \a b is true.

    Auto-remove is on by default.

    \sa autoRemove(), remove()
*/
void QTemporaryFile::setAutoRemove(bool b)
{
    Q_D(QTemporaryFile);
    d->autoRemove = b;
}

/*!
   Returns the complete unique filename backing the QTemporaryFile
   object. This string is null before the QTemporaryFile is opened,
   afterwards it will contain the fileTemplate() plus
   additional characters to make it unique.

   \sa fileTemplate()
*/

QString QTemporaryFile::fileName() const
{
    if(!isOpen())
        return QString();
    return fileEngine()->fileName(QFileEngine::DefaultName);
}

/*!
  Returns the set file template. The default file template will be
  called qt_temp and be placed in QDir::tempPath().

  \sa setFileTemplate()
*/
QString QTemporaryFile::fileTemplate() const
{
    Q_D(const QTemporaryFile);
    return d->templateName;
}

/*!
   Sets the static portion of the file name to \a name. If the file
   template ends in XXXXXX that will automatically be replaced with
   the unique part of the filename, otherwise a filename will be
   determined automatically based on the static portion specified.

   \sa fileTemplate()
*/
void QTemporaryFile::setFileTemplate(const QString &name)
{
    Q_ASSERT(!isOpen());
    Q_D(QTemporaryFile);
    fileEngine()->setFileName(name);
    d->templateName = name;
}

/*!
    \fn QTemporaryFile *QTemporaryFile::createLocalFile(const QString &fileName)
    \overload

    Works on the given \a fileName rather than an existing QFile
    object.
*/


/*!
    Creates and returns a local temporary file whose contents are a
    copy of the contents of the given \a file.
*/
QTemporaryFile *QTemporaryFile::createLocalFile(QFile &file)
{
    if(QFileEngine *engine = file.fileEngine()) {
        if(engine->fileFlags(QFileEngine::FlagsMask) & QFileEngine::LocalDiskFlag)
            return 0; //local already
        //cache
        bool wasOpen = file.isOpen();
        qint64 old_off = 0;
        if(wasOpen)
            old_off = file.pos();
        else
            file.open(QIODevice::ReadOnly);
        //dump data
        QTemporaryFile *ret = new QTemporaryFile;
        ret->open();
        file.seek(0);
        char buffer[1024];
        while(true) {
            qint64 len = file.read(buffer, 1024);
            if(len < 1)
                break;
            ret->write(buffer, len);
        }
        ret->seek(0);
        //restore
        if(wasOpen)
            file.seek(old_off);
        else
            file.close();
        //done
        return ret;
    }
    return 0;
}

/*!
   \internal
*/

QFileEngine *QTemporaryFile::fileEngine() const
{
    Q_D(const QTemporaryFile);
    if(!d->fileEngine)
        d->fileEngine = new QTemporaryFileEngine(d->templateName);
    return d->fileEngine;
}

/*!
   \reimp
*/

bool QTemporaryFile::open(OpenMode flags)
{
    Q_D(QTemporaryFile);
    if (QFile::open(flags)) {
        d->fileName = d->fileEngine->fileName(QFileEngine::DefaultName);
        return true;
    }
    return false;
}
