/*************************************************************************
 *  Copyright (C) 2008, 2009, 2010 by Volker Lanz <vl@fidra.de>          *
 *  Copyright (C) 2016 by Andrius Štikonas <andrius@stikonas.eu>         *
 *                                                                       *
 *  This program is free software; you can redistribute it and/or        *
 *  modify it under the terms of the GNU General Public License as       *
 *  published by the Free Software Foundation; either version 3 of       *
 *  the License, or (at your option) any later version.                  *
 *                                                                       *
 *  This program 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 General Public License for more details.                         *
 *                                                                       *
 *  You should have received a copy of the GNU General Public License    *
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.*
 *************************************************************************/

#include "jobs/job.h"

#include "core/device.h"
#include "core/copysource.h"
#include "core/copytarget.h"
#include "core/copysourcedevice.h"
#include "core/copytargetdevice.h"

#include "util/report.h"

#include <QDebug>
#include <QIcon>
#include <QTime>

#include <KIconLoader>
#include <KLocalizedString>

Job::Job() :
    m_Status(Pending)
{
}

bool Job::copyBlocks(Report& report, CopyTarget& target, CopySource& source)
{
    /** @todo copyBlocks() assumes that source.sectorSize() == target.sectorSize(). */

    if (source.sectorSize() != target.sectorSize()) {
        report.line() << xi18nc("@info:progress", "The logical sector sizes in the source and target for copying are not the same. This is currently unsupported.");
        return false;
    }

    bool rval = true;
    const qint64 blockSize = 16065 * 8; // number of sectors per block to copy
    const qint64 blocksToCopy = source.length() / blockSize;

    qint64 readOffset = source.firstSector();
    qint64 writeOffset = target.firstSector();
    qint32 copyDir = 1;

    if (target.firstSector() > source.firstSector()) {
        readOffset = source.firstSector() + source.length() - blockSize;
        writeOffset = target.firstSector() + source.length() - blockSize;
        copyDir = -1;
    }

    report.line() << xi18nc("@info:progress", "Copying %1 blocks (%2 sectors) from %3 to %4, direction: %5.", blocksToCopy, source.length(), readOffset, writeOffset, copyDir);

    qint64 blocksCopied = 0;

    void* buffer = malloc(blockSize * source.sectorSize());
    int percent = 0;
    QTime t;
    t.start();

    while (blocksCopied < blocksToCopy) {
        if (!(rval = source.readSectors(buffer, readOffset + blockSize * blocksCopied * copyDir, blockSize)))
            break;

        if (!(rval = target.writeSectors(buffer, writeOffset + blockSize * blocksCopied * copyDir, blockSize)))
            break;

        if (++blocksCopied * 100 / blocksToCopy != percent) {
            percent = blocksCopied * 100 / blocksToCopy;

            if (percent % 5 == 0 && t.elapsed() > 1000) {
                const qint64 mibsPerSec = (blocksCopied * blockSize * source.sectorSize() / 1024 / 1024) / (t.elapsed() / 1000);
                const qint64 estSecsLeft = (100 - percent) * t.elapsed() / percent / 1000;
                report.line() << xi18nc("@info:progress", "Copying %1 MiB/second, estimated time left: %2", mibsPerSec, QTime(0, 0).addSecs(estSecsLeft).toString());
            }
            emit progress(percent);
        }
    }

    const qint64 lastBlock = source.length() % blockSize;

    // copy the remainder
    if (rval && lastBlock > 0) {
        Q_ASSERT(lastBlock < blockSize);

        const qint64 lastBlockReadOffset = copyDir > 0 ? readOffset + blockSize * blocksCopied : source.firstSector();
        const qint64 lastBlockWriteOffset = copyDir > 0 ? writeOffset + blockSize * blocksCopied : target.firstSector();

        report.line() << xi18nc("@info:progress", "Copying remainder of block size %1 from %2 to %3.", lastBlock, lastBlockReadOffset, lastBlockWriteOffset);

        rval = source.readSectors(buffer, lastBlockReadOffset, lastBlock);

        if (rval)
            rval = target.writeSectors(buffer, lastBlockWriteOffset, lastBlock);

        if (rval)
            emit progress(100);
    }

    free(buffer);

    report.line() << xi18ncp("@info:progress argument 2 is a string such as 7 sectors (localized accordingly)", "Copying 1 block (%2) finished.", "Copying %1 blocks (%2) finished.", blocksCopied, i18np("1 sector", "%1 sectors", target.sectorsWritten()));

    return rval;
}

bool Job::rollbackCopyBlocks(Report& report, CopyTarget& origTarget, CopySource& origSource)
{
    if (!origSource.overlaps(origTarget)) {
        report.line() << xi18nc("@info:progress", "Source and target for copying do not overlap: Rollback is not required.");
        return true;
    }

    try {
        CopySourceDevice& csd = dynamic_cast<CopySourceDevice&>(origSource);
        CopyTargetDevice& ctd = dynamic_cast<CopyTargetDevice&>(origTarget);

        // default: use values as if we were copying from front to back.
        qint64 undoSourceFirstSector = origTarget.firstSector();
        qint64 undoSourceLastSector = origTarget.firstSector() + origTarget.sectorsWritten() - 1;

        qint64 undoTargetFirstSector = origSource.firstSector();
        qint64 undoTargetLastSector = origSource.firstSector() + origTarget.sectorsWritten() - 1;

        if (origTarget.firstSector() > origSource.firstSector()) {
            // we were copying from back to front
            undoSourceFirstSector = origTarget.firstSector() + origSource.length() - origTarget.sectorsWritten();
            undoSourceLastSector = origTarget.firstSector() + origSource.length() - 1;

            undoTargetFirstSector = origSource.lastSector() - origTarget.sectorsWritten() + 1;
            undoTargetLastSector = origSource.lastSector();
        }

        report.line() << xi18nc("@info:progress", "Rollback from: First sector: %1, last sector: %2.", undoSourceFirstSector, undoSourceLastSector);
        report.line() << xi18nc("@info:progress", "Rollback to: First sector: %1, last sector: %2.", undoTargetFirstSector, undoTargetLastSector);

        CopySourceDevice undoSource(ctd.device(), undoSourceFirstSector, undoSourceLastSector);
        if (!undoSource.open()) {
            report.line() << xi18nc("@info:progress", "Could not open device <filename>%1</filename> to rollback copying.", ctd.device().deviceNode());
            return false;
        }

        CopyTargetDevice undoTarget(csd.device(), undoTargetFirstSector, undoTargetLastSector);
        if (!undoTarget.open()) {
            report.line() << xi18nc("@info:progress", "Could not open device <filename>%1</filename> to rollback copying.", csd.device().deviceNode());
            return false;
        }

        return copyBlocks(report, undoTarget, undoSource);
    } catch (...) {
        report.line() << xi18nc("@info:progress", "Rollback failed: Source or target are not devices.");
    }

    return false;
}

void Job::emitProgress(int i)
{
    emit progress(i);
}

Report* Job::jobStarted(Report& parent)
{
    emit started();

    return parent.newChild(xi18nc("@info:progress", "Job: %1", description()));
}

void Job::jobFinished(Report& report, bool b)
{
    setStatus(b ? Success : Error);
    emit progress(numSteps());
    emit finished();

    report.setStatus(xi18nc("@info:progress job status (error, warning, ...)", "%1: %2", description(), statusText()));
}

/** @return the Job's current status icon */
QIcon Job::statusIcon() const
{
    static const QString icons[] = {
        QStringLiteral("dialog-information"),
        QStringLiteral("dialog-ok"),
        QStringLiteral("dialog-error")
    };

    Q_ASSERT(status() >= 0 && static_cast<quint32>(status()) < sizeof(icons) / sizeof(icons[0]));

    if (status() < 0 || static_cast<quint32>(status()) >= sizeof(icons) / sizeof(icons[0]))
        return QIcon();

    return QIcon::fromTheme(icons[status()]).pixmap(IconSize(KIconLoader::Small));
}

/** @return the Job's current status text */
QString Job::statusText() const
{
    static const QString s[] = {
        xi18nc("@info:progress job", "Pending"),
        xi18nc("@info:progress job", "Success"),
        xi18nc("@info:progress job", "Error")
    };

    Q_ASSERT(status() >= 0 && static_cast<quint32>(status()) < sizeof(s) / sizeof(s[0]));

    if (status() < 0 || static_cast<quint32>(status()) >= sizeof(s) / sizeof(s[0]))
        return QString();

    return s[status()];
}