/****************************************************************************
**
** Copyright (C) 2013 Klaralvdalens Datakonsult AB (KDAB)
** Contact: http://www.qt-project.org/legal
**
** This file is part of the Qt Installer Framework.
**
** $QT_BEGIN_LICENSE:LGPL$
** 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 Digia.  For licensing terms and
** conditions see http://qt.digia.com/licensing.  For further information
** use the contact form at http://qt.digia.com/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 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, Digia gives you certain additional
** rights.  These rights are described in the Digia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 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 the GNU General Public License version 3.0 requirements will be
** met: http://www.gnu.org/copyleft/gpl.html.
**
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** $QT_END_LICENSE$
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****************************************************************************/

#include "kdupdaterfiledownloader_p.h"
#include "kdupdaterfiledownloaderfactory.h"
#include "ui_authenticationdialog.h"

#include <fileutils.h>

#include <QDialog>
#include <QFile>
#include <QtNetwork/QNetworkAccessManager>
#include <QtNetwork/QNetworkProxyFactory>
#include <QPointer>
#include <QUrl>
#include <QTemporaryFile>
#include <QFileInfo>
#include <QThreadPool>
#include <QDebug>
#include <QSslError>
#include <QBasicTimer>
#include <QTimerEvent>

using namespace KDUpdater;
using namespace QInstaller;

static double calcProgress(qint32 done, qint32 total)
{
    return total ? (double(done) / double(total)) : 0;
}


// -- KDUpdater::FileDownloader

/*!
    \internal
    \ingroup kdupdater
    \class KDUpdater::FileDownloader kdupdaterfiledownloader.h

    Base class for file downloaders used in KDUpdater. File downloaders are used by
    the KDUpdater::Update class to download update files. Each subclass of FileDownloader
    can download file from a specific category of sources (e.g. local, ftp, http etc).

    This is an internal class, not a part of the public API. Currently we have three
    subclasses of FileDownloader
    \li LocalFileDownloader - downloads from the local file system
    \li FtpDownloader - downloads from a FTP site
    \li HttpDownloader - downloads from a HTTP site

    Usage

    \code
    KDUpdater::FileDownloader* downloader = new KDUpdater::(some subclass name)

    downloader->setUrl(url);
    downloader->download();

    // wait for downloadCompleted() signal

    QString downloadedFile = downloader->downloadedFileName();
    \endcode
*/

struct KDUpdater::FileDownloader::Private
{
    Private()
        : m_hash(QCryptographicHash::Sha1)
        , m_assumedSha1Sum("")
        , autoRemove(true)
        , m_speedTimerInterval(100)
        , m_bytesReceived(0)
        , m_bytesToReceive(0)
        , m_currentSpeedBin(0)
        , m_sampleIndex(0)
        , m_downloadSpeed(0)
        , m_factory(0)
        , m_ignoreSslErrors(false)
    {
        memset(m_samples, 0, sizeof(m_samples));
    }

    ~Private()
    {
        delete m_factory;
    }

    QUrl url;
    QString scheme;

    QCryptographicHash m_hash;
    QByteArray m_assumedSha1Sum;

    QString errorString;
    bool autoRemove;
    bool followRedirect;

    QBasicTimer m_timer;
    int m_speedTimerInterval;

    qint64 m_bytesReceived;
    qint64 m_bytesToReceive;

    mutable qint64 m_samples[50];
    mutable qint64 m_currentSpeedBin;
    mutable quint32 m_sampleIndex;
    mutable qint64 m_downloadSpeed;

    QAuthenticator m_authenticator;
    FileDownloaderProxyFactory *m_factory;
    bool m_ignoreSslErrors;
};

KDUpdater::FileDownloader::FileDownloader(const QString &scheme, QObject *parent)
    : QObject(parent)
    , d(new Private)
{
    d->scheme = scheme;
    d->followRedirect = false;
}

KDUpdater::FileDownloader::~FileDownloader()
{
    delete d;
}

void KDUpdater::FileDownloader::setUrl(const QUrl &url)
{
    d->url = url;
}

QUrl KDUpdater::FileDownloader::url() const
{
    return d->url;
}

QByteArray KDUpdater::FileDownloader::sha1Sum() const
{
    return d->m_hash.result();
}

QByteArray KDUpdater::FileDownloader::assumedSha1Sum() const
{
    return d->m_assumedSha1Sum;
}

void KDUpdater::FileDownloader::setAssumedSha1Sum(const QByteArray &sum)
{
    d->m_assumedSha1Sum = sum;
}

QString FileDownloader::errorString() const
{
    return d->errorString;
}

void FileDownloader::setDownloadAborted(const QString &error)
{
    d->errorString = error;
    emit downloadStatus(error);
    emit downloadAborted(error);
}

void KDUpdater::FileDownloader::setDownloadCompleted()
{
    if (d->m_assumedSha1Sum.isEmpty() || (d->m_assumedSha1Sum == sha1Sum())) {
        onSuccess();
        emit downloadCompleted();
        emit downloadStatus(tr("Download finished."));
    } else {
        onError();
        setDownloadAborted(tr("Cryptographic hashes do not match."));
    }
}

void KDUpdater::FileDownloader::setDownloadCanceled()
{
    emit downloadCanceled();
    emit downloadStatus(tr("Download canceled."));
}

QString KDUpdater::FileDownloader::scheme() const
{
    return d->scheme;
}

void KDUpdater::FileDownloader::setScheme(const QString &scheme)
{
    d->scheme = scheme;
}

void KDUpdater::FileDownloader::setAutoRemoveDownloadedFile(bool val)
{
    d->autoRemove = val;
}

void KDUpdater::FileDownloader::setFollowRedirects(bool val)
{
    d->followRedirect = val;
}

bool KDUpdater::FileDownloader::followRedirects() const
{
    return d->followRedirect;
}

bool KDUpdater::FileDownloader::isAutoRemoveDownloadedFile() const
{
    return d->autoRemove;
}

void KDUpdater::FileDownloader::download()
{
    QMetaObject::invokeMethod(this, "doDownload", Qt::QueuedConnection);
}

void KDUpdater::FileDownloader::cancelDownload()
{
    // Do nothing
}

void KDUpdater::FileDownloader::runDownloadSpeedTimer()
{
    if (!d->m_timer.isActive())
        d->m_timer.start(d->m_speedTimerInterval, this);
}

void KDUpdater::FileDownloader::stopDownloadSpeedTimer()
{
    d->m_timer.stop();
}

void KDUpdater::FileDownloader::addSample(qint64 sample)
{
    d->m_currentSpeedBin += sample;
}

int KDUpdater::FileDownloader::downloadSpeedTimerId() const
{
    return d->m_timer.timerId();
}

void KDUpdater::FileDownloader::setProgress(qint64 bytesReceived, qint64 bytesToReceive)
{
    d->m_bytesReceived = bytesReceived;
    d->m_bytesToReceive = bytesToReceive;
}

void KDUpdater::FileDownloader::emitDownloadSpeed()
{
    unsigned int windowSize = sizeof(d->m_samples) / sizeof(qint64);

    // add speed of last time bin to the window
    d->m_samples[d->m_sampleIndex % windowSize] = d->m_currentSpeedBin;
    d->m_currentSpeedBin = 0;   // reset bin for next time interval

    // advance the sample index
    d->m_sampleIndex++;
    d->m_downloadSpeed = 0;

    // dynamic window size until the window is completely filled
    if (d->m_sampleIndex < windowSize)
        windowSize = d->m_sampleIndex;

    for (unsigned int i = 0; i < windowSize; ++i)
        d->m_downloadSpeed += d->m_samples[i];

    d->m_downloadSpeed /= windowSize; // computer average
    d->m_downloadSpeed *= 1000.0 / d->m_speedTimerInterval; // rescale to bytes/second

    emit downloadSpeed(d->m_downloadSpeed);
}

void KDUpdater::FileDownloader::emitDownloadStatus()
{
    QString status;
    if (d->m_bytesToReceive > 0) {
        QString bytesReceived = humanReadableSize(d->m_bytesReceived);
        const QString bytesToReceive = humanReadableSize(d->m_bytesToReceive);

        // remove the unit from the bytesReceived value if bytesToReceive has the same
        const QString tmp = bytesToReceive.mid(bytesToReceive.indexOf(QLatin1Char(' ')));
        if (bytesReceived.endsWith(tmp))
            bytesReceived.chop(tmp.length());

        status = tr("%1 of %2").arg(bytesReceived).arg(bytesToReceive);
    } else {
        if (d->m_bytesReceived > 0)
            status = tr("%1 downloaded.").arg(humanReadableSize(d->m_bytesReceived));
    }

    status += QLatin1Char(' ') + tr("(%1/sec)").arg(humanReadableSize(d->m_downloadSpeed));
    if (d->m_bytesToReceive > 0 && d->m_downloadSpeed > 0) {
        const qint64 time = (d->m_bytesToReceive - d->m_bytesReceived) / d->m_downloadSpeed;

        int s = time % 60;
        const int d = time / 86400;
        const int h = (time / 3600) - (d * 24);
        const int m = (time / 60) - (d * 1440) - (h * 60);

        QString days;
        if (d > 0)
            days = tr("%n day(s), ", "", d);

        QString hours;
        if (h > 0)
            hours = tr("%n hour(s), ", "", h);

        QString minutes;
        if (m > 0)
            minutes = tr("%n minute(s)", "", m);

        QString seconds;
        if (s >= 0 && minutes.isEmpty()) {
            s = (s <= 0 ? 1 : s);
            seconds = tr("%n second(s)", "", s);
        }
        status += tr(" - %1%2%3%4 remaining.").arg(days).arg(hours).arg(minutes).arg(seconds);
    } else {
        status += tr(" - unknown time remaining.");
    }

    emit downloadStatus(status);
}

void KDUpdater::FileDownloader::emitDownloadProgress()
{
    emit downloadProgress(d->m_bytesReceived, d->m_bytesToReceive);
}

void KDUpdater::FileDownloader::emitEstimatedDownloadTime()
{
    if (d->m_bytesToReceive <= 0 || d->m_downloadSpeed <= 0) {
        emit estimatedDownloadTime(-1);
        return;
    }
    emit estimatedDownloadTime((d->m_bytesToReceive - d->m_bytesReceived) / d->m_downloadSpeed);
}

void KDUpdater::FileDownloader::addCheckSumData(const QByteArray &data)
{
    d->m_hash.addData(data);
}

void KDUpdater::FileDownloader::addCheckSumData(const char *data, int length)
{
    d->m_hash.addData(data, length);
}

void KDUpdater::FileDownloader::resetCheckSumData()
{
    d->m_hash.reset();
}


/*!
    Returns a copy of the proxy factory that this FileDownloader object is using to determine the proxies to
    be used for requests.
*/
FileDownloaderProxyFactory *KDUpdater::FileDownloader::proxyFactory() const
{
    if (d->m_factory)
        return d->m_factory->clone();
    return 0;
}

/*!
    Sets the proxy factory for this class to be \a factory. A proxy factory is used to determine a more
    specific list of proxies to be used for a given request, instead of trying to use the same proxy value
    for all requests. This might only be of use for http or ftp requests.
*/
void KDUpdater::FileDownloader::setProxyFactory(FileDownloaderProxyFactory *factory)
{
    delete d->m_factory;
    d->m_factory = factory;
}

/*!
    Returns a copy of the authenticator that this FileDownloader object is using to set the username and
    password for download request.
*/
QAuthenticator KDUpdater::FileDownloader::authenticator() const
{
    return d->m_authenticator;
}

/*!
    Sets the authenticator object for this class to be \a authenticator. A authenticator is used to
    pass on the required authentication information. This might only be of use for http or ftp requests.
    Emits the authenticator changed signal with the new authenticator in use.
*/
void KDUpdater::FileDownloader::setAuthenticator(const QAuthenticator &authenticator)
{
    if (d->m_authenticator.isNull() || (d->m_authenticator != authenticator)) {
        d->m_authenticator = authenticator;
        emit authenticatorChanged(authenticator);
    }
}

bool KDUpdater::FileDownloader::ignoreSslErrors()
{
    return d->m_ignoreSslErrors;
}

void KDUpdater::FileDownloader::setIgnoreSslErrors(bool ignore)
{
    d->m_ignoreSslErrors = ignore;
}

// -- KDUpdater::LocalFileDownloader

/*
      Even though QFile::copy() does the task of copying local files from one place
      to another, I prefer to use the timer and copy one block of data per unit time.

      This is because, it is possible that the user of KDUpdater is simultaneously
      downloading several files. Sometimes in tandem with other file downloaders.
      If the local file that is being downloaded takes a long time; then that will
      hang the other downloads.

      On the other hand, local downloads need not actually download the file. It can
      simply pass on the source file as destination file. At this moment however,
      I think the user of LocalFileDownloader will assume that the downloaded file
      can be fiddled around with without worrying about whether it would mess up
      the original source or not.
*/

struct KDUpdater::LocalFileDownloader::Private
{
    Private()
        : source(0)
        , destination(0)
        , downloaded(false)
        , timerId(-1)
    {}

    QFile *source;
    QFile *destination;
    QString destFileName;
    bool downloaded;
    int timerId;
};

KDUpdater::LocalFileDownloader::LocalFileDownloader(QObject *parent)
    : KDUpdater::FileDownloader(QLatin1String("file"), parent)
    , d (new Private)
{
}

KDUpdater::LocalFileDownloader::~LocalFileDownloader()
{
    if (this->isAutoRemoveDownloadedFile() && !d->destFileName.isEmpty())
        QFile::remove(d->destFileName);

    delete d;
}

bool KDUpdater::LocalFileDownloader::canDownload() const
{
    QFileInfo fi(url().toLocalFile());
    return fi.exists() && fi.isReadable();
}

bool KDUpdater::LocalFileDownloader::isDownloaded() const
{
    return d->downloaded;
}

void KDUpdater::LocalFileDownloader::doDownload()
{
    // Already downloaded
    if (d->downloaded)
        return;

    // Already started downloading
    if (d->timerId >= 0)
        return;

    // Open source and destination files
    QString localFile = this->url().toLocalFile();
    d->source = new QFile(localFile, this);
    if (!d->source->open(QFile::ReadOnly)) {
        onError();
        setDownloadAborted(tr("Cannot open source file '%1' for reading.").arg(QFileInfo(localFile)
            .fileName()));
        return;
    }

    if (d->destFileName.isEmpty()) {
        QTemporaryFile *file = new QTemporaryFile(this);
        file->open();
        d->destination = file;
    } else {
        d->destination = new QFile(d->destFileName, this);
        d->destination->open(QIODevice::ReadWrite | QIODevice::Truncate);
    }

    if (!d->destination->isOpen()) {
        onError();
        setDownloadAborted(tr("Cannot open destination file '%1' for writing.")
            .arg(QFileInfo(d->destination->fileName()).fileName()));
        return;
    }

    runDownloadSpeedTimer();
    // Start a timer and kickoff the copy process
    d->timerId = startTimer(0); // as fast as possible

    emit downloadStarted();
    emit downloadProgress(0);
}

QString KDUpdater::LocalFileDownloader::downloadedFileName() const
{
    return d->destFileName;
}

void KDUpdater::LocalFileDownloader::setDownloadedFileName(const QString &name)
{
    d->destFileName = name;
}

KDUpdater::LocalFileDownloader *KDUpdater::LocalFileDownloader::clone(QObject *parent) const
{
    return new LocalFileDownloader(parent);
}

void KDUpdater::LocalFileDownloader::cancelDownload()
{
    if (d->timerId < 0)
        return;

    killTimer(d->timerId);
    d->timerId = -1;

    onError();
    setDownloadCanceled();
}

void KDUpdater::LocalFileDownloader::timerEvent(QTimerEvent *event)
{
    if (event->timerId() == d->timerId) {
        if (!d->source || !d->destination)
            return;

        const qint64 blockSize = 32768;
        QByteArray buffer;
        buffer.resize(blockSize);
        const qint64 numRead = d->source->read(buffer.data(), buffer.size());
        qint64 toWrite = numRead;
        while (toWrite > 0) {
            const qint64 numWritten = d->destination->write(buffer.constData() + numRead - toWrite, toWrite);
            if (numWritten < 0) {
                killTimer(d->timerId);
                d->timerId = -1;
                onError();
                setDownloadAborted(tr("Writing to %1 failed: %2").arg(d->destination->fileName(),
                    d->destination->errorString()));
                return;
            }
            toWrite -= numWritten;
        }
        addSample(numRead);
        addCheckSumData(buffer.data(), numRead);

        if (numRead > 0) {
            setProgress(d->source->pos(), d->source->size());
            emit downloadProgress(calcProgress(d->source->pos(), d->source->size()));
            return;
        }

        d->destination->flush();

        killTimer(d->timerId);
        d->timerId = -1;

        setDownloadCompleted();
    } else if (event->timerId() == downloadSpeedTimerId()) {
        emitDownloadSpeed();
        emitDownloadStatus();
        emitDownloadProgress();
        emitEstimatedDownloadTime();
    }
}

void LocalFileDownloader::onSuccess()
{
    d->downloaded = true;
    d->destFileName = d->destination->fileName();
    if (QTemporaryFile *file = dynamic_cast<QTemporaryFile *>(d->destination))
        file->setAutoRemove(false);
    d->destination->close();
    delete d->destination;
    d->destination = 0;
    delete d->source;
    d->source = 0;
    stopDownloadSpeedTimer();
}

void LocalFileDownloader::onError()
{
    d->downloaded = false;
    d->destFileName.clear();
    delete d->destination;
    d->destination = 0;
    delete d->source;
    d->source = 0;
    stopDownloadSpeedTimer();
}


// -- ResourceFileDownloader

struct KDUpdater::ResourceFileDownloader::Private
{
    Private()
        : timerId(-1)
        , downloaded(false)
    {}

    int timerId;
    QFile destFile;
    bool downloaded;
};

KDUpdater::ResourceFileDownloader::ResourceFileDownloader(QObject *parent)
    : KDUpdater::FileDownloader(QLatin1String("resource"), parent)
    , d(new Private)
{
}

KDUpdater::ResourceFileDownloader::~ResourceFileDownloader()
{
    delete d;
}

bool KDUpdater::ResourceFileDownloader::canDownload() const
{
    QUrl url = this->url();
    url.setScheme(QString::fromLatin1("file"));
    QString localFile = QString::fromLatin1(":%1").arg(url.toLocalFile());
    QFileInfo fi(localFile);
    return fi.exists() && fi.isReadable();
}

bool KDUpdater::ResourceFileDownloader::isDownloaded() const
{
    return d->downloaded;
}

void KDUpdater::ResourceFileDownloader::doDownload()
{
    // Already downloaded
    if (d->downloaded)
        return;

    // Already started downloading
    if (d->timerId >= 0)
        return;

    // Open source and destination files
    QUrl url = this->url();
    url.setScheme(QString::fromLatin1("file"));
    d->destFile.setFileName(QString::fromLatin1(":%1").arg(url.toLocalFile()));

    emit downloadStarted();
    emit downloadProgress(0);

    d->destFile.open(QIODevice::ReadOnly);
    d->timerId = startTimer(0); // start as fast as possible
}

QString KDUpdater::ResourceFileDownloader::downloadedFileName() const
{
    return d->destFile.fileName();
}

void KDUpdater::ResourceFileDownloader::setDownloadedFileName(const QString &/*name*/)
{
    Q_ASSERT_X(false, "KDUpdater::ResourceFileDownloader::setDownloadedFileName", "Not supported!");
}

KDUpdater::ResourceFileDownloader *KDUpdater::ResourceFileDownloader::clone(QObject *parent) const
{
    return new ResourceFileDownloader(parent);
}

void KDUpdater::ResourceFileDownloader::cancelDownload()
{
    if (d->timerId < 0)
        return;

    killTimer(d->timerId);
    d->timerId = -1;

    setDownloadCanceled();
}

void KDUpdater::ResourceFileDownloader::timerEvent(QTimerEvent *event)
{
    if (event->timerId() == d->timerId) {
        if (!d->destFile.isOpen()) {
            onError();
            killTimer(d->timerId);
            emit downloadProgress(1);
            setDownloadAborted(tr("Could not read resource file \"%1\". Reason:").arg(downloadedFileName(),
                d->destFile.errorString()));
            return;
        }

        QByteArray buffer;
        buffer.resize(32768);
        const qint64 numRead = d->destFile.read(buffer.data(), buffer.size());

        addSample(numRead);
        addCheckSumData(buffer.data(), numRead);

        if (numRead > 0) {
            setProgress(d->destFile.pos(), d->destFile.size());
            emit downloadProgress(calcProgress(d->destFile.pos(), d->destFile.size()));
            return;
        }

        killTimer(d->timerId);
        d->timerId = -1;
        setDownloadCompleted();
    } else if (event->timerId() == downloadSpeedTimerId()) {
        emitDownloadSpeed();
        emitDownloadStatus();
        emitDownloadProgress();
        emitEstimatedDownloadTime();
    }
}

void KDUpdater::ResourceFileDownloader::onSuccess()
{
    d->destFile.close();
    d->downloaded = true;
    stopDownloadSpeedTimer();
}

void KDUpdater::ResourceFileDownloader::onError()
{
    d->destFile.close();
    d->downloaded = false;
    stopDownloadSpeedTimer();
    d->destFile.setFileName(QString());
}


// -- KDUpdater::HttpDownloader

struct KDUpdater::HttpDownloader::Private
{
    explicit Private(HttpDownloader *qq)
        : q(qq)
        , http(0)
        , destination(0)
        , downloaded(false)
        , aborted(false)
        , m_authenticationCount(0)
    {}

    HttpDownloader *const q;
    QNetworkAccessManager manager;
    QNetworkReply *http;
    QFile *destination;
    QString destFileName;
    bool downloaded;
    bool aborted;
    int m_authenticationCount;

    void shutDown()
    {
        disconnect(http, SIGNAL(finished()), q, SLOT(httpReqFinished()));
        http->deleteLater();
        http = 0;
        destination->close();
        destination->deleteLater();
        destination = 0;
        q->resetCheckSumData();
    }
};

KDUpdater::HttpDownloader::HttpDownloader(QObject *parent)
    : KDUpdater::FileDownloader(QLatin1String("http"), parent)
    , d(new Private(this))
{
#ifndef QT_NO_OPENSSL
    // TODO: once we switch to Qt5, use QT_NO_SSL instead of QT_NO_OPENSSL
    connect(&d->manager, SIGNAL(sslErrors(QNetworkReply*, QList<QSslError>)),
        this, SLOT(onSslErrors(QNetworkReply*, QList<QSslError>)));
#endif
    connect(&d->manager, SIGNAL(authenticationRequired(QNetworkReply*, QAuthenticator*)), this,
        SLOT(onAuthenticationRequired(QNetworkReply*, QAuthenticator*)));
}

KDUpdater::HttpDownloader::~HttpDownloader()
{
    if (this->isAutoRemoveDownloadedFile() && !d->destFileName.isEmpty())
        QFile::remove(d->destFileName);
    delete d;
}

bool KDUpdater::HttpDownloader::canDownload() const
{
    // TODO: Check whether the http file actually exists or not.
    return true;
}

bool KDUpdater::HttpDownloader::isDownloaded() const
{
    return d->downloaded;
}

void KDUpdater::HttpDownloader::doDownload()
{
    if (d->downloaded)
        return;

    if (d->http)
        return;

    startDownload(url());
    runDownloadSpeedTimer();
}

QString KDUpdater::HttpDownloader::downloadedFileName() const
{
    return d->destFileName;
}

void KDUpdater::HttpDownloader::setDownloadedFileName(const QString &name)
{
    d->destFileName = name;
}

KDUpdater::HttpDownloader *KDUpdater::HttpDownloader::clone(QObject *parent) const
{
    return new HttpDownloader(parent);
}

void KDUpdater::HttpDownloader::httpReadyRead()
{
    static QByteArray buffer(16384, '\0');
    while (d->http->bytesAvailable()) {
        const qint64 read = d->http->read(buffer.data(), buffer.size());
        qint64 written = 0;
        while (written < read) {
            const qint64 numWritten = d->destination->write(buffer.data() + written, read - written);
            if (numWritten < 0) {
                const QString error = d->destination->errorString();
                const QString fileName = d->destination->fileName();
                d->shutDown();
                setDownloadAborted(tr("Cannot download %1: Writing to file '%2' failed: %3")
                    .arg(url().toString(), fileName, error));
                return;
            }
            written += numWritten;
        }
        addSample(written);
        addCheckSumData(buffer.data(), read);
    }
}

void KDUpdater::HttpDownloader::httpError(QNetworkReply::NetworkError)
{
    if (!d->aborted)
        httpDone(true);
}

void KDUpdater::HttpDownloader::cancelDownload()
{
    d->aborted = true;
    if (d->http) {
        d->http->abort();
        httpDone(true);
    }
}

void KDUpdater::HttpDownloader::httpDone(bool error)
{
    if (error) {
        QString err;
        if (d->http) {
            err = d->http->errorString();
            d->http->deleteLater();
            d->http = 0;
            onError();
        }

        if (d->aborted) {
            d->aborted = false;
            setDownloadCanceled();
        } else {
            setDownloadAborted(err);
        }
    }
    //PENDING: what about the non-error case??
}

void KDUpdater::HttpDownloader::onError()
{
    d->downloaded = false;
    d->destFileName.clear();
    delete d->destination;
    d->destination = 0;
    stopDownloadSpeedTimer();
}

void KDUpdater::HttpDownloader::onSuccess()
{
    d->downloaded = true;
    d->destFileName = d->destination->fileName();
    if (QTemporaryFile *file = dynamic_cast<QTemporaryFile *>(d->destination))
        file->setAutoRemove(false);
    delete d->destination;
    d->destination = 0;
    stopDownloadSpeedTimer();
}

void KDUpdater::HttpDownloader::httpReqFinished()
{
    const QVariant redirect = d->http == 0 ? QVariant()
        : d->http->attribute(QNetworkRequest::RedirectionTargetAttribute);

    const QUrl redirectUrl = redirect.toUrl();
    if (followRedirects() && redirectUrl.isValid()) {
        d->shutDown();  // clean the previous download
        startDownload(redirectUrl);
    } else {
        if (d->http == 0)
            return;

        httpReadyRead();
        d->destination->flush();
        setDownloadCompleted();
        d->http->deleteLater();
        d->http = 0;
    }
}

void KDUpdater::HttpDownloader::httpReadProgress(qint64 done, qint64 total)
{
    if (d->http) {
        const QUrl redirectUrl = d->http->attribute(QNetworkRequest::RedirectionTargetAttribute).toUrl();
        if (followRedirects() && redirectUrl.isValid())
            return; // if we are a redirection, do not emit the progress
    }

    setProgress(done, total);
    emit downloadProgress(calcProgress(done, total));
}

void KDUpdater::HttpDownloader::timerEvent(QTimerEvent *event)
{
    if (event->timerId() == downloadSpeedTimerId()) {
        emitDownloadSpeed();
        emitDownloadStatus();
        emitDownloadProgress();
        emitEstimatedDownloadTime();
    }
}

void KDUpdater::HttpDownloader::startDownload(const QUrl &url)
{
    d->m_authenticationCount = 0;
    d->manager.setProxyFactory(proxyFactory());
    d->http = d->manager.get(QNetworkRequest(url));

    connect(d->http, SIGNAL(readyRead()), this, SLOT(httpReadyRead()));
    connect(d->http, SIGNAL(downloadProgress(qint64, qint64)), this,
        SLOT(httpReadProgress(qint64, qint64)));
    connect(d->http, SIGNAL(finished()), this, SLOT(httpReqFinished()));
    connect(d->http, SIGNAL(error(QNetworkReply::NetworkError)), this,
        SLOT(httpError(QNetworkReply::NetworkError)));

    if (d->destFileName.isEmpty()) {
        QTemporaryFile *file = new QTemporaryFile(this);
        file->open();
        d->destination = file;
    } else {
        d->destination = new QFile(d->destFileName, this);
        d->destination->open(QIODevice::ReadWrite | QIODevice::Truncate);
    }

    if (!d->destination->isOpen()) {
        const QString error = d->destination->errorString();
        const QString fileName = d->destination->fileName();
        d->shutDown();
        setDownloadAborted(tr("Cannot download %1: Could not create %2: %3").arg(
            url.toString(), fileName, error));
    }
}

void KDUpdater::HttpDownloader::onAuthenticationRequired(QNetworkReply *reply, QAuthenticator *authenticator)
{
    Q_UNUSED(reply)
    // first try with the information we have already
    if (d->m_authenticationCount == 0) {
        d->m_authenticationCount++;
        authenticator->setUser(this->authenticator().user());
        authenticator->setPassword(this->authenticator().password());
    } else if (d->m_authenticationCount == 1) {
        // we failed to authenticate, ask for new credentials
        QDialog dlg;
        Ui::Dialog ui;
        ui.setupUi(&dlg);
        dlg.adjustSize();
        ui.siteDescription->setText(tr("%1 at %2").arg(authenticator->realm()).arg(url().host()));

        ui.userEdit->setText(this->authenticator().user());
        ui.passwordEdit->setText(this->authenticator().password());

        if (dlg.exec() == QDialog::Accepted) {
            authenticator->setUser(ui.userEdit->text());
            authenticator->setPassword(ui.passwordEdit->text());

            // update the authenticator we used initially
            QAuthenticator auth;
            auth.setUser(ui.userEdit->text());
            auth.setPassword(ui.passwordEdit->text());
            emit authenticatorChanged(auth);
        } else {
            d->shutDown();
            setDownloadAborted(tr("Authentication request canceled."));
            emit downloadCanceled();
        }
        d->m_authenticationCount++;
    }
}

#ifndef QT_NO_OPENSSL

#include "messageboxhandler.h"

// TODO: once we switch to Qt5, use QT_NO_SSL instead of QT_NO_OPENSSL
void KDUpdater::HttpDownloader::onSslErrors(QNetworkReply* reply, const QList<QSslError> &errors)
{
    Q_UNUSED(reply)
    QString errorString;
    foreach (const QSslError &error, errors) {
        if (!errorString.isEmpty())
            errorString += QLatin1String(", ");
        errorString += error.errorString();
    }
    qDebug() << errorString;

    const QStringList arguments = QCoreApplication::arguments();
    if (arguments.contains(QLatin1String("--script")) || arguments.contains(QLatin1String("Script"))
        || ignoreSslErrors()) {
            reply->ignoreSslErrors();
            return;
    }
    // TODO: Remove above code once we have a proper implementation for message box handler supporting
    // methods used in the following code, right now we return here cause the message box is not scriptable.

    QMessageBox msgBox(MessageBoxHandler::currentBestSuitParent());
    msgBox.setDetailedText(errorString);
    msgBox.setIcon(QMessageBox::Warning);
    msgBox.setWindowModality(Qt::WindowModal);
    msgBox.setWindowTitle(tr("Secure Connection Failed"));
    msgBox.setText(tr("There was an error during connection to: %1.").arg(url().toString()));
    msgBox.setInformativeText(QString::fromLatin1("<ul><li>%1</li><li>%2</li></ul>").arg(tr("This could be "
        "a problem with the server's configuration, or it could be someone trying to impersonate the "
        "server."), tr("If you have connected to this server successfully in the past or trust this server, "
        "the error may be temporary and you can try again.")));

    msgBox.setStandardButtons(QMessageBox::Yes | QMessageBox::Cancel);
    msgBox.setButtonText(QMessageBox::Yes, tr("Try again"));
    msgBox.setDefaultButton(QMessageBox::Cancel);

    if (msgBox.exec() == QMessageBox::Cancel) {
        if (!d->aborted)
            httpDone(true);
    } else {
        reply->ignoreSslErrors();
        KDUpdater::FileDownloaderFactory::instance().setIgnoreSslErrors(true);
    }
}
#endif
