/*
Copyright (C) 2005-2014 Sergey A. Tachenov

This file is part of QuaZip.

QuaZip is free software: you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation, either version 2.1 of the License, or
(at your option) any later version.

QuaZip is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License
along with QuaZip.  If not, see <http://www.gnu.org/licenses/>.

See COPYING file for the full LGPL text.

Original ZIP package is copyrighted by Gilles Vollant and contributors,
see quazip/(un)zip.h files for details. Basically it's the zlib license.
*/

#include <QtCore/QFile>

#include "quagzipfile.h"

/// \cond internal
class QuaGzipFilePrivate {
    friend class QuaGzipFile;
    QString fileName;
    gzFile gzd;
    inline QuaGzipFilePrivate(): gzd(nullptr) {}
    inline QuaGzipFilePrivate(const QString &fileName): 
        fileName(fileName), gzd(nullptr) {}
    template<typename FileId> bool open(FileId id, 
        QIODevice::OpenMode mode, QString &error);
    gzFile open(int fd, const char *modeString);
    gzFile open(const QString &name, const char *modeString);
};

gzFile QuaGzipFilePrivate::open(const QString &name, const char *modeString)
{
    return gzopen(QFile::encodeName(name).constData(), modeString);
}

gzFile QuaGzipFilePrivate::open(int fd, const char *modeString)
{
    return gzdopen(fd, modeString);
}

template<typename FileId>
bool QuaGzipFilePrivate::open(FileId id, QIODevice::OpenMode mode, 
                              QString &error)
{
    char modeString[2];
    modeString[0] = modeString[1] = '\0';
    if ((mode & QIODevice::Append) != 0) {
        error = QuaGzipFile::tr("QIODevice::Append is not "
                "supported for GZIP");
        return false;
    }
    if ((mode & QIODevice::ReadOnly) != 0
            && (mode & QIODevice::WriteOnly) != 0) {
        error = QuaGzipFile::tr("Opening gzip for both reading"
            " and writing is not supported");
        return false;
    } else if ((mode & QIODevice::ReadOnly) != 0) {
        modeString[0] = 'r';
    } else if ((mode & QIODevice::WriteOnly) != 0) {
        modeString[0] = 'w';
    } else {
        error = QuaGzipFile::tr("You can open a gzip either for reading"
            " or for writing. Which is it?");
        return false;
    }
    gzd = open(id, modeString);
    if (gzd == nullptr) {
        error = QuaGzipFile::tr("Could not gzopen() file");
        return false;
    }
    return true;
}
/// \endcond

QuaGzipFile::QuaGzipFile():
d(new QuaGzipFilePrivate())
{
}

QuaGzipFile::QuaGzipFile(QObject *parent):
QIODevice(parent),
d(new QuaGzipFilePrivate())
{
}

QuaGzipFile::QuaGzipFile(const QString &fileName, QObject *parent):
  QIODevice(parent),
d(new QuaGzipFilePrivate(fileName))
{
}

QuaGzipFile::~QuaGzipFile()
{
  if (isOpen()) {
    close();
  }
  delete d;
}

void QuaGzipFile::setFileName(const QString& fileName)
{
    d->fileName = fileName;
}

QString QuaGzipFile::getFileName() const
{
    return d->fileName;
}

bool QuaGzipFile::isSequential() const
{
  return true;
}

bool QuaGzipFile::open(QIODevice::OpenMode mode)
{
    QString error;
    if (!d->open(d->fileName, mode, error)) {
        setErrorString(error);
        return false;
    }
    return QIODevice::open(mode);
}

bool QuaGzipFile::open(int fd, QIODevice::OpenMode mode)
{
    QString error;
    if (!d->open(fd, mode, error)) {
        setErrorString(error);
        return false;
    }
    return QIODevice::open(mode);
}

bool QuaGzipFile::flush()
{
    return gzflush(d->gzd, Z_SYNC_FLUSH) == Z_OK;
}

void QuaGzipFile::close()
{
  QIODevice::close();
  gzclose(d->gzd);
}

qint64 QuaGzipFile::readData(char *data, qint64 maxSize)
{
    return gzread(d->gzd, (voidp)data, (unsigned)maxSize);
}

qint64 QuaGzipFile::writeData(const char *data, qint64 maxSize)
{
    if (maxSize == 0)
        return 0;
    int written = gzwrite(d->gzd, (voidp)data, (unsigned)maxSize);
    if (written == 0)
        return -1;
    else
        return written;
}
