/*
 * Copyright 2008-2009 Benjamin C. Meyer <ben@meyerhome.net>
 * Copyright 2008 Jason A. Donenfeld <Jason@zx2c4.com>
 *
 * 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 2 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, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA  02110-1301  USA
 */

/****************************************************************************
**
** Copyright (C) 2008-2008 Trolltech ASA. All rights reserved.
**
** This file is part of the demonstration applications of the Qt Toolkit.
**
** This file may be used under the terms of the GNU General Public
** License versions 2.0 or 3.0 as published by the Free Software
** Foundation and appearing in the files LICENSE.GPL2 and LICENSE.GPL3
** included in the packaging of this file.  Alternatively you may (at
** your option) use any later version of the GNU General Public
** License if such license has been publicly approved by Trolltech ASA
** (or its successors, if any) and the KDE Free Qt Foundation. In
** addition, as a special exception, Trolltech gives you certain
** additional rights. These rights are described in the Trolltech GPL
** Exception version 1.2, which can be found at
** http://www.trolltech.com/products/qt/gplexception/ and in the file
** GPL_EXCEPTION.txt in this package.
**
** Please review the following information to ensure GNU General
** Public Licensing requirements will be met:
** http://trolltech.com/products/qt/licenses/licensing/opensource/. If
** you are unsure which license is appropriate for your use, please
** review the following information:
** http://trolltech.com/products/qt/licenses/licensing/licensingoverview
** or contact the sales department at sales@trolltech.com.
**
** In addition, as a special exception, Trolltech, as the sole
** copyright holder for Qt Designer, grants users of the Qt/Eclipse
** Integration plug-in the right for the Qt/Eclipse Integration to
** link to functionality provided by Qt Designer and its related
** libraries.
**
** This file is provided "AS IS" with NO WARRANTY OF ANY KIND,
** INCLUDING THE WARRANTIES OF DESIGN, MERCHANTABILITY AND FITNESS FOR
** A PARTICULAR PURPOSE. Trolltech reserves all rights not expressly
** granted herein.
**
** 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 "downloadmanager.h"

#include "autosaver.h"
#include "browserapplication.h"
#include "networkaccessmanager.h"

#include <math.h>

#include <qdesktopservices.h>
#include <qfiledialog.h>
#include <qfileiconprovider.h>
#include <qheaderview.h>
#include <qmessagebox.h>
#include <qmetaobject.h>
#include <qmimedata.h>
#include <qprocess.h>
#include <qsettings.h>

#include <qdebug.h>

#include <qwebsettings.h>

//#define DOWNLOADMANAGER_DEBUG

/*!
    DownloadItem is a widget that is displayed in the download manager list.
    It moves the data from the QNetworkReply into the QFile as well
    as update the information/progressbar and report errors.
 */
DownloadItem::DownloadItem(QNetworkReply *reply, bool requestFileName, QWidget *parent)
    : QWidget(parent)
    , m_reply(reply)
    , m_requestFileName(requestFileName)
    , m_bytesReceived(0)
    , m_startedSaving(false)
    , m_finishedDownloading(false)
    , m_gettingFileName(false)
    , m_canceledFileSelect(false)
{
    setupUi(this);
    QPalette p = downloadInfoLabel->palette();
    p.setColor(QPalette::Text, Qt::darkGray);
    downloadInfoLabel->setPalette(p);
    progressBar->setMaximum(0);
    tryAgainButton->hide();
    connect(stopButton, SIGNAL(clicked()), this, SLOT(stop()));
    connect(openButton, SIGNAL(clicked()), this, SLOT(open()));
    connect(tryAgainButton, SIGNAL(clicked()), this, SLOT(tryAgain()));

    if (!requestFileName) {
        QSettings settings;
        settings.beginGroup(QLatin1String("downloadmanager"));
        m_requestFileName = settings.value(QLatin1String("alwaysPromptForFileName"), false).toBool();
    }

    init();
}

void DownloadItem::init()
{
    if (!m_reply)
        return;

    m_startedSaving = false;
    m_finishedDownloading = false;

    openButton->setEnabled(false);

    // attach to the m_reply
    m_url = m_reply->url();
    m_reply->setParent(this);
    connect(m_reply, SIGNAL(readyRead()), this, SLOT(downloadReadyRead()));
    connect(m_reply, SIGNAL(error(QNetworkReply::NetworkError)),
            this, SLOT(error(QNetworkReply::NetworkError)));
    connect(m_reply, SIGNAL(downloadProgress(qint64, qint64)),
            this, SLOT(downloadProgress(qint64, qint64)));
    connect(m_reply, SIGNAL(metaDataChanged()),
            this, SLOT(metaDataChanged()));
    connect(m_reply, SIGNAL(finished()),
            this, SLOT(finished()));

    // reset info
    downloadInfoLabel->clear();
    progressBar->setValue(0);
    getFileName();

    // start timer for the download estimation
    m_downloadTime.start();

    if (m_reply->error() != QNetworkReply::NoError) {
        error(m_reply->error());
        finished();
    }
}

void DownloadItem::getFileName()
{
    if (m_gettingFileName)
        return;

    QString downloadDirectory = BrowserApplication::downloadManager()->downloadDirectory();

    QString defaultFileName = saveFileName(downloadDirectory);
    QString fileName = defaultFileName;
    if (m_requestFileName) {
        m_gettingFileName = true;
        fileName = QFileDialog::getSaveFileName(this, tr("Save File"), defaultFileName);
        m_gettingFileName = false;
        if (fileName.isEmpty()) {
            progressBar->setVisible(false);
            stop();
            fileNameLabel->setText(tr("Download canceled: %1").arg(QFileInfo(defaultFileName).fileName()));
            m_canceledFileSelect = true;
            return;
        }
        QFileInfo fileInfo = QFileInfo(fileName);
        BrowserApplication::downloadManager()->setDownloadDirectory(fileInfo.absoluteDir().absolutePath());
        fileNameLabel->setText(fileInfo.fileName());
    }
    m_output.setFileName(fileName);

    // Check file path for saving.
    QDir saveDirPath = QFileInfo(m_output.fileName()).dir();
    if (!saveDirPath.exists()) {
        if (!saveDirPath.mkpath(saveDirPath.absolutePath())) {
            progressBar->setVisible(false);
            stop();
            downloadInfoLabel->setText(tr("Download directory (%1) couldn't be created.").arg(saveDirPath.absolutePath()));
            return;
        }
    }

    fileNameLabel->setText(QFileInfo(m_output.fileName()).fileName());
    if (m_requestFileName)
        downloadReadyRead();
}

QString DownloadItem::saveFileName(const QString &directory) const
{
    // Move this function into QNetworkReply to also get file name sent from the server
    QString path;
    if (m_reply->hasRawHeader("Content-Disposition")) {
        QString value = QLatin1String(m_reply->rawHeader("Content-Disposition"));
        int pos = value.indexOf(QLatin1String("filename="));
        if (pos != -1) {
            QString name = value.mid(pos + 9);
            if (name.startsWith(QLatin1Char('"')) && name.endsWith(QLatin1Char('"')))
                name = name.mid(1, name.size() - 2);
            path = name;
        }
    }
    if (path.isEmpty())
        path = m_url.path();

    QFileInfo info(path);
    QString baseName = info.completeBaseName();
    QString endName = info.suffix();

    if (baseName.isEmpty()) {
        baseName = QLatin1String("unnamed_download");

#ifdef DOWNLOADMANAGER_DEBUG
        qDebug() << "DownloadItem::" << __FUNCTION__ << "downloading unknown file:" << m_url;
#endif
    }

    if (!endName.isEmpty())
        endName = QLatin1Char('.') + endName;

    QString name = directory + baseName + endName;
    if (!m_requestFileName && QFile::exists(name)) {
        // already exists, don't overwrite
        int i = 1;
        do {
            name = directory + baseName + QLatin1Char('-') + QString::number(i++) + endName;
        } while (QFile::exists(name));
    }
    return name;
}

void DownloadItem::stop()
{
    setUpdatesEnabled(false);
    stopButton->setEnabled(false);
    stopButton->hide();
    tryAgainButton->setEnabled(true);
    tryAgainButton->show();
    setUpdatesEnabled(true);
    m_reply->abort();
}

void DownloadItem::open()
{
    QFileInfo info(m_output);
    QUrl url = QUrl::fromLocalFile(info.absoluteFilePath());
    QDesktopServices::openUrl(url);
}

void DownloadItem::tryAgain()
{
    if (!tryAgainButton->isEnabled())
        return;

    tryAgainButton->setEnabled(false);
    tryAgainButton->setVisible(false);
    stopButton->setEnabled(true);
    stopButton->setVisible(true);
    progressBar->setVisible(true);

    QNetworkReply *r = BrowserApplication::networkAccessManager()->get(QNetworkRequest(m_url));
    if (m_reply)
        m_reply->deleteLater();
    if (m_output.exists())
        m_output.remove();
    m_reply = r;
    init();
    emit statusChanged();
}

void DownloadItem::downloadReadyRead()
{
    if (m_requestFileName && m_output.fileName().isEmpty())
        return;
    if (!m_output.isOpen()) {
        // in case someone else has already put a file there
        if (!m_requestFileName)
            getFileName();
        if (!m_output.open(QIODevice::WriteOnly)) {
            downloadInfoLabel->setText(tr("Error opening output file: %1")
                    .arg(m_output.errorString()));
            stop();
            emit statusChanged();
            return;
        }
        emit statusChanged();
    }
    if (-1 == m_output.write(m_reply->readAll())) {
        downloadInfoLabel->setText(tr("Error saving: %1")
                .arg(m_output.errorString()));
        stopButton->click();
    } else {
        m_startedSaving = true;
        if (m_finishedDownloading)
            finished();
    }
}

void DownloadItem::error(QNetworkReply::NetworkError)
{
#ifdef DOWNLOADMANAGER_DEBUG
    qDebug() << "DownloadItem::" << __FUNCTION__ << m_reply->errorString() << m_url;
#endif

    downloadInfoLabel->setText(tr("Network Error: %1").arg(m_reply->errorString()));
    tryAgainButton->setEnabled(true);
    tryAgainButton->setVisible(true);
}

void DownloadItem::metaDataChanged()
{
    QVariant locationHeader = m_reply->header(QNetworkRequest::LocationHeader);
    if (locationHeader.isValid()) {
        m_url = locationHeader.toUrl();
        m_reply->deleteLater();
        m_reply = BrowserApplication::networkAccessManager()->get(QNetworkRequest(m_url));
        init();
        return;
    }

#ifdef DOWNLOADMANAGER_DEBUG
    qDebug() << "DownloadItem::" << __FUNCTION__ << "not handled.";
#endif
}

void DownloadItem::downloadProgress(qint64 bytesReceived, qint64 bytesTotal)
{
    QTime now = QTime::currentTime();
    if (m_lastProgressTime.msecsTo(now) < 200)
        return;

    m_lastProgressTime = now;

    m_bytesReceived = bytesReceived;
    qint64 currentValue = 0;
    qint64 totalValue = 0;
    if (bytesTotal > 0) {
        currentValue = bytesReceived * 100 / bytesTotal;
        totalValue = 100;
    }
    progressBar->setValue(currentValue);
    progressBar->setMaximum(totalValue);

    emit progress(currentValue, totalValue);
    updateInfoLabel();
}

qint64 DownloadItem::bytesTotal() const
{
    return m_reply->header(QNetworkRequest::ContentLengthHeader).toULongLong();
}

qint64 DownloadItem::bytesReceived() const
{
    return m_bytesReceived;
}

double DownloadItem::remainingTime() const
{
    if (!downloading())
        return -1.0;

    double timeRemaining = ((double)(bytesTotal() - bytesReceived())) / currentSpeed();

    // When downloading the eta should never be 0
    if (timeRemaining == 0)
        timeRemaining = 1;

    return timeRemaining;
}

double DownloadItem::currentSpeed() const
{
    if (!downloading())
        return -1.0;

    return m_bytesReceived * 1000.0 / m_downloadTime.elapsed();
}

void DownloadItem::updateInfoLabel()
{
    if (m_reply->error() != QNetworkReply::NoError)
        return;

    qint64 bytesTotal = m_reply->header(QNetworkRequest::ContentLengthHeader).toULongLong();
    bool running = !downloadedSuccessfully();

    // update info label
    double speed = currentSpeed();
    double timeRemaining = remainingTime();

    QString info;
    if (running) {
        QString remaining;

        if (bytesTotal != 0) {
            remaining = DownloadManager::timeString(timeRemaining);
        }

        info = QString(tr("%1 of %2 (%3/sec) - %4"))
            .arg(DownloadManager::dataString(m_bytesReceived))
            .arg(bytesTotal == 0 ? tr("?") : DownloadManager::dataString(bytesTotal))
            .arg(DownloadManager::dataString((int)speed))
            .arg(remaining);
    } else {
        if (m_bytesReceived == bytesTotal)
            info = DownloadManager::dataString(m_output.size());
        else
            info = tr("%1 of %2 - Download Complete")
                .arg(DownloadManager::dataString(m_bytesReceived))
                .arg(DownloadManager::dataString(bytesTotal));
    }
    downloadInfoLabel->setText(info);
}

bool DownloadItem::downloading() const
{
    return (progressBar->isVisible());
}

bool DownloadItem::downloadedSuccessfully() const
{
    return (stopButton->isHidden() && tryAgainButton->isHidden());
}

void DownloadItem::finished()
{
    m_finishedDownloading = true;
    if (!m_startedSaving) {
        return;
    }
    progressBar->hide();
    stopButton->setEnabled(false);
    stopButton->hide();
    openButton->setEnabled(true);
    m_output.close();
    updateInfoLabel();
    emit statusChanged();
}

/*!
    DownloadManager is a Dialog that contains a list of DownloadItems

    It is a basic download manager.  It only downloads the file, doesn't do BitTorrent,
    extract zipped files or anything fancy.
  */
DownloadManager::DownloadManager(QWidget *parent)
    : QDialog(parent)
    , m_autoSaver(new AutoSaver(this))
    , m_model(new DownloadModel(this))
    , m_manager(BrowserApplication::networkAccessManager())
    , m_iconProvider(0)
    , m_removePolicy(Never)
{
    setupUi(this);

    QSettings settings;
    settings.beginGroup(QLatin1String("downloadmanager"));
    QString defaultLocation = QDesktopServices::storageLocation(QDesktopServices::DesktopLocation);
    setDownloadDirectory(settings.value(QLatin1String("downloadDirectory"), defaultLocation).toString());

    downloadsView->setShowGrid(false);
    downloadsView->verticalHeader()->hide();
    downloadsView->horizontalHeader()->hide();
    downloadsView->setAlternatingRowColors(true);
    downloadsView->horizontalHeader()->setStretchLastSection(true);
    downloadsView->setModel(m_model);
    connect(cleanupButton, SIGNAL(clicked()), this, SLOT(cleanup()));
    connect(buttonBox, SIGNAL(rejected()), this, SLOT(close()));
    load();
}

DownloadManager::~DownloadManager()
{
    m_autoSaver->changeOccurred();
    m_autoSaver->saveIfNeccessary();
    if (m_iconProvider)
        delete m_iconProvider;
}

int DownloadManager::activeDownloads() const
{
    int count = 0;
    for (int i = 0; i < m_downloads.count(); ++i) {
        if (m_downloads.at(i)->stopButton->isEnabled())
            ++count;
    }
    return count;
}

bool DownloadManager::allowQuit()
{
    if (activeDownloads() >= 1) {
        int choice = QMessageBox::warning(this, QString(),
                                        tr("There are %1 downloads in progress\n"
                                           "Do you want to quit anyway?").arg(activeDownloads()),
                                        QMessageBox::Yes | QMessageBox::No,
                                        QMessageBox::No);
        if (choice == QMessageBox::No) {
            show();
            return false;
        }
    }
    return true;
}

bool DownloadManager::externalDownload(const QUrl &url)
{
    QSettings settings;
    settings.beginGroup(QLatin1String("downloadmanager"));
    if (!settings.value(QLatin1String("external"), false).toBool())
        return false;

    QString program = settings.value(QLatin1String("externalPath")).toString();
    if (program.isEmpty())
        return false;

    // Split program at every space not inside double quotes
    QRegExp regex(QLatin1String("\"([^\"]+)\"|([^ ]+)"));
    QStringList args;
    for (int pos = 0; (pos = regex.indexIn(program, pos)) != -1; pos += regex.matchedLength())
        args << regex.cap(1) + regex.cap(2);
    if (args.isEmpty())
        return false;

    return QProcess::startDetached(args.takeFirst(), args << QString::fromUtf8(url.toEncoded()));
}

void DownloadManager::download(const QNetworkRequest &request, bool requestFileName)
{
    if (request.url().isEmpty())
        return;
    if (externalDownload(request.url()))
        return;
    handleUnsupportedContent(m_manager->get(request), requestFileName);
}

void DownloadManager::handleUnsupportedContent(QNetworkReply *reply, bool requestFileName)
{
    if (!reply || reply->url().isEmpty())
        return;
    if (externalDownload(reply->url()))
        return;

    QVariant header = reply->header(QNetworkRequest::ContentLengthHeader);
    bool ok;
    int size = header.toInt(&ok);
    if (ok && size == 0)
        return;

#ifdef DOWNLOADMANAGER_DEBUG
    qDebug() << "DownloadManager::" << __FUNCTION__ << reply->url() << "requestFileName" << requestFileName;
#endif

    DownloadItem *item = new DownloadItem(reply, requestFileName, this);
    addItem(item);

    if (item->m_canceledFileSelect)
        return;

    if (!isVisible())
        show();

    activateWindow();
    raise();
}

void DownloadManager::addItem(DownloadItem *item)
{
    connect(item, SIGNAL(statusChanged()), this, SLOT(updateRow()));
    int row = m_downloads.count();
    m_model->beginInsertRows(QModelIndex(), row, row);
    m_downloads.append(item);
    m_model->endInsertRows();
    updateItemCount();
    downloadsView->setIndexWidget(m_model->index(row, 0), item);
    QIcon icon = style()->standardIcon(QStyle::SP_FileIcon);
    item->fileIcon->setPixmap(icon.pixmap(48, 48));
    downloadsView->setRowHeight(row, item->sizeHint().height());
    updateRow(item); //incase download finishes before the constructor returns
}

void DownloadManager::updateRow()
{
    if (DownloadItem *item = qobject_cast<DownloadItem*>(sender()))
        updateRow(item);
}

void DownloadManager::updateRow(DownloadItem *item)
{
    int row = m_downloads.indexOf(item);
    if (-1 == row)
        return;
    if (!m_iconProvider)
        m_iconProvider = new QFileIconProvider();
    QIcon icon = m_iconProvider->icon(item->m_output.fileName());
    if (icon.isNull())
        icon = style()->standardIcon(QStyle::SP_FileIcon);
    item->fileIcon->setPixmap(icon.pixmap(48, 48));

    int oldHeight = downloadsView->rowHeight(row);
    downloadsView->setRowHeight(row, qMax(oldHeight, item->minimumSizeHint().height()));

    bool remove = false;
    QWebSettings *globalSettings = QWebSettings::globalSettings();
    if (!item->downloading()
        && globalSettings->testAttribute(QWebSettings::PrivateBrowsingEnabled))
        remove = true;

    if (item->downloadedSuccessfully()
        && removePolicy() == DownloadManager::SuccessFullDownload) {
        remove = true;
    }
    if (remove)
        m_model->removeRow(row);

    cleanupButton->setEnabled(m_downloads.count() - activeDownloads() > 0);
}

DownloadManager::RemovePolicy DownloadManager::removePolicy() const
{
    return m_removePolicy;
}

void DownloadManager::setRemovePolicy(RemovePolicy policy)
{
    if (policy == m_removePolicy)
        return;
    m_removePolicy = policy;
    m_autoSaver->changeOccurred();
}

void DownloadManager::save() const
{
    QSettings settings;
    settings.beginGroup(QLatin1String("downloadmanager"));
    QMetaEnum removePolicyEnum = staticMetaObject.enumerator(staticMetaObject.indexOfEnumerator("RemovePolicy"));
    settings.setValue(QLatin1String("removeDownloadsPolicy"), QLatin1String(removePolicyEnum.valueToKey(m_removePolicy)));
    settings.setValue(QLatin1String("size"), size());
    if (m_removePolicy == Exit)
        return;

    for (int i = 0; i < m_downloads.count(); ++i) {
        QString key = QString(QLatin1String("download_%1_")).arg(i);
        settings.setValue(key + QLatin1String("url"), m_downloads[i]->m_url);
        settings.setValue(key + QLatin1String("location"), QFileInfo(m_downloads[i]->m_output).filePath());
        settings.setValue(key + QLatin1String("done"), m_downloads[i]->downloadedSuccessfully());
    }
    int i = m_downloads.count();
    QString key = QString(QLatin1String("download_%1_")).arg(i);
    while (settings.contains(key + QLatin1String("url"))) {
        settings.remove(key + QLatin1String("url"));
        settings.remove(key + QLatin1String("location"));
        settings.remove(key + QLatin1String("done"));
        key = QString(QLatin1String("download_%1_")).arg(++i);
    }
}

void DownloadManager::load()
{
    QSettings settings;
    settings.beginGroup(QLatin1String("downloadmanager"));
    QSize size = settings.value(QLatin1String("size")).toSize();
    if (size.isValid())
        resize(size);
    QByteArray value = settings.value(QLatin1String("removeDownloadsPolicy"), QLatin1String("Never")).toByteArray();
    QMetaEnum removePolicyEnum = staticMetaObject.enumerator(staticMetaObject.indexOfEnumerator("RemovePolicy"));
    m_removePolicy = removePolicyEnum.keyToValue(value) == -1 ?
                        Never :
                        static_cast<RemovePolicy>(removePolicyEnum.keyToValue(value));

    int i = 0;
    QString key = QString(QLatin1String("download_%1_")).arg(i);
    while (settings.contains(key + QLatin1String("url"))) {
        QUrl url = settings.value(key + QLatin1String("url")).toUrl();
        QString fileName = settings.value(key + QLatin1String("location")).toString();
        bool done = settings.value(key + QLatin1String("done"), true).toBool();
        if (!url.isEmpty() && !fileName.isEmpty()) {
            DownloadItem *item = new DownloadItem(0, this);
            item->m_output.setFileName(fileName);
            item->fileNameLabel->setText(QFileInfo(item->m_output.fileName()).fileName());
            item->m_url = url;
            addItem(item);
            item->stopButton->setVisible(false);
            item->stopButton->setEnabled(false);
            item->tryAgainButton->setVisible(!done);
            item->tryAgainButton->setEnabled(!done);
            item->progressBar->setVisible(false);
        }
        key = QString(QLatin1String("download_%1_")).arg(++i);
    }
    cleanupButton->setEnabled(m_downloads.count() - activeDownloads() > 0);
}

void DownloadManager::cleanup()
{
    if (m_downloads.isEmpty())
        return;
    m_model->removeRows(0, m_downloads.count());
    updateItemCount();
    if (m_downloads.isEmpty() && m_iconProvider) {
        delete m_iconProvider;
        m_iconProvider = 0;
    }
    m_autoSaver->changeOccurred();
}

void DownloadManager::updateItemCount()
{
    int count = m_downloads.count();
    itemCount->setText(tr("%n Download(s)", "", count));
}

void DownloadManager::setDownloadDirectory(const QString &directory)
{
    m_downloadDirectory = directory;
    if (!m_downloadDirectory.isEmpty())
        m_downloadDirectory += QLatin1Char('/');
}

QString DownloadManager::downloadDirectory()
{
    return m_downloadDirectory;
}

QString DownloadManager::timeString(double timeRemaining)
{
    QString remaining;

    if (timeRemaining > 60) {
        timeRemaining = timeRemaining / 60;
        timeRemaining = floor(timeRemaining);
        remaining = tr("%n minutes remaining", "", int(timeRemaining));
    }
    else {
        timeRemaining = floor(timeRemaining);
        remaining = tr("%n seconds remaining", "", int(timeRemaining));
    }

    return remaining;
}

QString DownloadManager::dataString(qint64 size)
{
    QString unit;
    double newSize;

    if (size < 1024) {
        newSize = size;
        unit = tr("bytes");
    } else if (size < 1024 * 1024) {
        newSize = (double)size / (double)1024;
        unit = tr("kB");
    } else if (size < 1024 * 1024 * 1024) {
        newSize = (double)size / (double)(1024 * 1024);
        unit = tr("MB");
    } else {
        newSize = (double)size / (double)(1024 * 1024 * 1024);
        unit = tr("GB");
    }

    return QString(QLatin1String("%1 %2")).arg(newSize, 0, 'f', 1).arg(unit);
}

DownloadModel::DownloadModel(DownloadManager *downloadManager, QObject *parent)
    : QAbstractListModel(parent)
    , m_downloadManager(downloadManager)
{
}

QVariant DownloadModel::data(const QModelIndex &index, int role) const
{
    if (index.row() < 0 || index.row() >= rowCount(index.parent()))
        return QVariant();
    if (role == Qt::ToolTipRole)
        if (!m_downloadManager->m_downloads.at(index.row())->downloadedSuccessfully())
            return m_downloadManager->m_downloads.at(index.row())->downloadInfoLabel->text();
    return QVariant();
}

int DownloadModel::rowCount(const QModelIndex &parent) const
{
    return (parent.isValid()) ? 0 : m_downloadManager->m_downloads.count();
}

bool DownloadModel::removeRows(int row, int count, const QModelIndex &parent)
{
    if (parent.isValid())
        return false;

    int lastRow = row + count - 1;
    for (int i = lastRow; i >= row; --i) {
        if (m_downloadManager->m_downloads.at(i)->downloadedSuccessfully()
            || m_downloadManager->m_downloads.at(i)->tryAgainButton->isEnabled()) {
            beginRemoveRows(parent, i, i);
            m_downloadManager->m_downloads.takeAt(i)->deleteLater();
            endRemoveRows();
        }
    }
    m_downloadManager->m_autoSaver->changeOccurred();
    return true;
}

Qt::ItemFlags DownloadModel::flags(const QModelIndex &index) const
{
    if (index.row() < 0 || index.row() >= rowCount(index.parent()))
        return 0;

    Qt::ItemFlags defaultFlags = QAbstractItemModel::flags(index);

    DownloadItem *item = m_downloadManager->m_downloads.at(index.row());
    if (item->downloadedSuccessfully())
        return defaultFlags | Qt::ItemIsDragEnabled;

    return defaultFlags;
}

QMimeData *DownloadModel::mimeData(const QModelIndexList &indexes) const
{
    QMimeData *mimeData = new QMimeData();
    QList<QUrl> urls;
    foreach (const QModelIndex &index, indexes) {
        if (!index.isValid())
            continue;
        DownloadItem *item = m_downloadManager->m_downloads.at(index.row());
        urls.append(QUrl::fromLocalFile(QFileInfo(item->m_output).absoluteFilePath()));
    }
    mimeData->setUrls(urls);
    return mimeData;
}

