/** \fn MythDownloadManager::GetLastModified(const QString &url)
 *  \brief Gets the Last Modified timestamp for a URI
 *  \param url    URI to test.
 *  \return Timestamp the URI was last modified or now if an error occurred
 */
QDateTime MythDownloadManager::GetLastModified(const QString &url)
{
    static const char dateFormat[] = "ddd, dd MMM yyyy hh:mm:ss 'GMT'";
    VERBOSE(VB_FILE+VB_EXTRA, LOC + QString("GetLastModified('%1')").arg(url));
    QDateTime result;

    QDateTime now = QDateTime::currentDateTime();
    QNetworkCacheMetaData urlData = m_manager->cache()->metaData(QUrl(url));

    if (urlData.isValid())
    {
        if (urlData.lastModified().secsTo(now) <= 60)
        {
            result = urlData.lastModified();
        }
        else
        {
            // If the last modification date is older than 60 seconds, and
            // we loaded the page over 60 seconds ago, then redownload the
            // page to re-verify it's last modified date.
            QNetworkCacheMetaData::RawHeaderList headers =
                urlData.rawHeaders();
            bool found = false;
            QNetworkCacheMetaData::RawHeaderList::iterator it
                = headers.begin();
            for (; !found && it != headers.end(); ++it)
            {
                if ((*it).first == "Date")
                {
                    found = true;
                    QDateTime loadDate =
                       QDateTime::fromString((*it).second, dateFormat);
                    loadDate.setTimeSpec(Qt::UTC);
                    if (loadDate.secsTo(now) <= 60)
                        result = urlData.lastModified();
                }
            }
        }
    }

    if (!result.isValid())
    {
        MythDownloadInfo *dlInfo = new MythDownloadInfo;
        dlInfo->m_url      = url;
        dlInfo->m_syncMode = true;

        if (downloadNow(dlInfo, false) && dlInfo->m_reply)
        {
            QVariant lastMod =
                dlInfo->m_reply->header(QNetworkRequest::LastModifiedHeader);
            if (lastMod.isValid())
                result = lastMod.toDateTime();
        }

        delete dlInfo;
    }

    return result;
}
/** \fn MythDownloadManager::downloadQNetworkRequest(MythDownloadInfo *dlInfo)
 *  \brief Downloads a QNetworkRequest via the QNetworkAccessManager
 *  \param dlInfo   MythDownloadInfo information for download
 */
void MythDownloadManager::downloadQNetworkRequest(MythDownloadInfo *dlInfo)
{
    static const char dateFormat[] = "ddd, dd MMM yyyy hh:mm:ss 'GMT'";
    QUrl qurl(dlInfo->m_url);
    QNetworkRequest request;
    
    if (dlInfo->m_request)
    {
        request = *dlInfo->m_request;
        delete dlInfo->m_request;
        dlInfo->m_request = NULL;
    }
    else
        request.setUrl(qurl);

    if (!dlInfo->m_reload)
    {
        // Prefer the in-cache item if one exists and it is less than 60
        // seconds old and has not expired in the last 10 seconds.
        QDateTime now = QDateTime::currentDateTime();
        QNetworkCacheMetaData urlData = m_manager->cache()->metaData(qurl);
        if ((urlData.isValid()) &&
            ((!urlData.expirationDate().isValid()) ||
             (urlData.expirationDate().secsTo(now) < 10)))
        {
            QNetworkCacheMetaData::RawHeaderList headers =
                urlData.rawHeaders();
            bool found = false;
            QNetworkCacheMetaData::RawHeaderList::iterator it
                = headers.begin();
            for (; !found && it != headers.end(); ++it)
            {
                if ((*it).first == "Date")
                {
                    found = true;
                    QDateTime loadDate =
                       QDateTime::fromString((*it).second, dateFormat);
                    loadDate.setTimeSpec(Qt::UTC);
                    if (loadDate.secsTo(now) < 60)
                        dlInfo->m_preferCache = true;
                }
            }
        }
    }

    if (dlInfo->m_preferCache)
        request.setAttribute(QNetworkRequest::CacheLoadControlAttribute,
                             QNetworkRequest::PreferCache);

    request.setRawHeader("User-Agent",
                         "MythDownloadManager v" MYTH_BINARY_VERSION);

    if (dlInfo->m_post)
        dlInfo->m_reply = m_manager->post(request, *dlInfo->m_data);
    else
        dlInfo->m_reply = m_manager->get(request);

    m_downloadReplies[dlInfo->m_reply] = dlInfo;

    connect(dlInfo->m_reply, SIGNAL(error(QNetworkReply::NetworkError)), this,
            SLOT(downloadError(QNetworkReply::NetworkError)));
    connect(dlInfo->m_reply, SIGNAL(downloadProgress(qint64, qint64)),
            this, SLOT(downloadProgress(qint64, qint64))); 
}