qBittorrent/src/base/bittorrent/torrentimpl.cpp

/*
 * Bittorrent Client using Qt and libtorrent.
 * Copyright (C) 2015  Vladimir Golovnev <glassez@yandex.ru>
 * Copyright (C) 2006  Christophe Dumez <chris@qbittorrent.org>
 *
 * 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.
 *
 * In addition, as a special exception, the copyright holders give permission to
 * link this program with the OpenSSL project's "OpenSSL" library (or with
 * modified versions of it that use the same license as the "OpenSSL" library),
 * and distribute the linked executables. You must obey the GNU General Public
 * License in all respects for all of the code used other than "OpenSSL".  If you
 * modify file(s), you may extend this exception to your version of the file(s),
 * but you are not obligated to do so. If you do not wish to do so, delete this
 * exception statement from your version.
 */

#include "torrentimpl.h"

#include <algorithm>
#include <memory>
#include <type_traits>

#ifdef Q_OS_WIN
#include <Windows.h>
#endif

#include <libtorrent/address.hpp>
#include <libtorrent/alert_types.hpp>
#include <libtorrent/magnet_uri.hpp>
#include <libtorrent/session.hpp>
#include <libtorrent/storage_defs.hpp>
#include <libtorrent/time.hpp>

#ifdef QBT_USES_LIBTORRENT2
#include <libtorrent/info_hash.hpp>
#endif

#include <QBitArray>
#include <QDebug>
#include <QDir>
#include <QFile>
#include <QStringList>
#include <QUrl>

#include "base/global.h"
#include "base/logger.h"
#include "base/preferences.h"
#include "base/utils/fs.h"
#include "base/utils/string.h"
#include "common.h"
#include "downloadpriority.h"
#include "loadtorrentparams.h"
#include "ltqhash.h"
#include "lttypecast.h"
#include "peeraddress.h"
#include "peerinfo.h"
#include "session.h"
#include "trackerentry.h"

using namespace BitTorrent;

namespace
{
    lt::announce_entry makeNativeAnnouncerEntry(const QString &url, const int tier)
    {
        lt::announce_entry entry {url.toStdString()};
        entry.tier = tier;
        return entry;
    }

#ifdef QBT_USES_LIBTORRENT2
    TrackerEntry fromNativeAnnouncerEntry(const lt::announce_entry &nativeEntry
        , const lt::info_hash_t &hashes, const QMap<lt::tcp::endpoint, int> &trackerPeerCounts)
#else
    TrackerEntry fromNativeAnnouncerEntry(const lt::announce_entry &nativeEntry
        , const QMap<lt::tcp::endpoint, int> &trackerPeerCounts)
#endif
    {
        TrackerEntry trackerEntry {QString::fromStdString(nativeEntry.url), nativeEntry.tier};

        int numUpdating = 0;
        int numWorking = 0;
        int numNotWorking = 0;
        QString firstTrackerMessage;
        QString firstErrorMessage;
#ifdef QBT_USES_LIBTORRENT2
        const auto numEndpoints = static_cast<qsizetype>(nativeEntry.endpoints.size() * ((hashes.has_v1() && hashes.has_v2()) ? 2 : 1));
        trackerEntry.endpoints.reserve(static_cast<decltype(trackerEntry.endpoints)::size_type>(numEndpoints));
        for (const lt::announce_endpoint &endpoint : nativeEntry.endpoints)
        {
            for (const auto protocolVersion : {lt::protocol_version::V1, lt::protocol_version::V2})
            {
                if (hashes.has(protocolVersion))
                {
                    const lt::announce_infohash &infoHash = endpoint.info_hashes[protocolVersion];

                    TrackerEntry::EndpointStats trackerEndpoint;
                    trackerEndpoint.protocolVersion = (protocolVersion == lt::protocol_version::V1) ? 1 : 2;
                    trackerEndpoint.numPeers = trackerPeerCounts.value(endpoint.local_endpoint, -1);
                    trackerEndpoint.numSeeds = infoHash.scrape_complete;
                    trackerEndpoint.numLeeches = infoHash.scrape_incomplete;
                    trackerEndpoint.numDownloaded = infoHash.scrape_downloaded;

                    if (infoHash.updating)
                    {
                        trackerEndpoint.status = TrackerEntry::Updating;
                        ++numUpdating;
                    }
                    else if (infoHash.fails > 0)
                    {
                        trackerEndpoint.status = TrackerEntry::NotWorking;
                        ++numNotWorking;
                    }
                    else if (nativeEntry.verified)
                    {
                        trackerEndpoint.status = TrackerEntry::Working;
                        ++numWorking;
                    }
                    else
                    {
                        trackerEndpoint.status = TrackerEntry::NotContacted;
                    }

                    const QString trackerMessage = QString::fromStdString(infoHash.message);
                    const QString errorMessage = QString::fromLocal8Bit(infoHash.last_error.message().c_str());
                    trackerEndpoint.message = (!trackerMessage.isEmpty() ? trackerMessage : errorMessage);

                    trackerEntry.endpoints.append(trackerEndpoint);
                    trackerEntry.numPeers = std::max(trackerEntry.numPeers, trackerEndpoint.numPeers);
                    trackerEntry.numSeeds = std::max(trackerEntry.numSeeds, trackerEndpoint.numSeeds);
                    trackerEntry.numLeeches = std::max(trackerEntry.numLeeches, trackerEndpoint.numLeeches);
                    trackerEntry.numDownloaded = std::max(trackerEntry.numDownloaded, trackerEndpoint.numDownloaded);

                    if (firstTrackerMessage.isEmpty())
                        firstTrackerMessage = trackerMessage;
                    if (firstErrorMessage.isEmpty())
                        firstErrorMessage = errorMessage;
                }
            }
        }
#else
        const auto numEndpoints = static_cast<qsizetype>(nativeEntry.endpoints.size());
        trackerEntry.endpoints.reserve(static_cast<decltype(trackerEntry.endpoints)::size_type>(numEndpoints));
        for (const lt::announce_endpoint &endpoint : nativeEntry.endpoints)
        {
            TrackerEntry::EndpointStats trackerEndpoint;
            trackerEndpoint.numPeers = trackerPeerCounts.value(endpoint.local_endpoint, -1);
            trackerEndpoint.numSeeds = endpoint.scrape_complete;
            trackerEndpoint.numLeeches = endpoint.scrape_incomplete;
            trackerEndpoint.numDownloaded = endpoint.scrape_downloaded;

            if (endpoint.updating)
            {
                trackerEndpoint.status = TrackerEntry::Updating;
                ++numUpdating;
            }
            else if (endpoint.fails > 0)
            {
                trackerEndpoint.status = TrackerEntry::NotWorking;
                ++numNotWorking;
            }
            else if (nativeEntry.verified)
            {
                trackerEndpoint.status = TrackerEntry::Working;
                ++numWorking;
            }
            else
            {
                trackerEndpoint.status = TrackerEntry::NotContacted;
            }

            const QString trackerMessage = QString::fromStdString(endpoint.message);
            const QString errorMessage = QString::fromLocal8Bit(endpoint.last_error.message().c_str());
            trackerEndpoint.message = (!trackerMessage.isEmpty() ? trackerMessage : errorMessage);

            trackerEntry.endpoints.append(trackerEndpoint);
            trackerEntry.numPeers = std::max(trackerEntry.numPeers, trackerEndpoint.numPeers);
            trackerEntry.numSeeds = std::max(trackerEntry.numSeeds, trackerEndpoint.numSeeds);
            trackerEntry.numLeeches = std::max(trackerEntry.numLeeches, trackerEndpoint.numLeeches);
            trackerEntry.numDownloaded = std::max(trackerEntry.numDownloaded, trackerEndpoint.numDownloaded);

            if (firstTrackerMessage.isEmpty())
                firstTrackerMessage = trackerMessage;
            if (firstErrorMessage.isEmpty())
                firstErrorMessage = errorMessage;
        }
#endif

        if (numEndpoints > 0)
        {
            if (numUpdating > 0)
            {
                trackerEntry.status = TrackerEntry::Updating;
            }
            else if (numWorking > 0)
            {
                trackerEntry.status = TrackerEntry::Working;
                trackerEntry.message = firstTrackerMessage;
            }
            else if (numNotWorking == numEndpoints)
            {
                trackerEntry.status = TrackerEntry::NotWorking;
                trackerEntry.message = (!firstTrackerMessage.isEmpty() ? firstTrackerMessage : firstErrorMessage);
            }
        }

        return trackerEntry;
    }

    void initializeStatus(lt::torrent_status &status, const lt::add_torrent_params &params)
    {
        status.flags = params.flags;
        status.active_duration = lt::seconds {params.active_time};
        status.finished_duration = lt::seconds {params.finished_time};
        status.seeding_duration = lt::seconds {params.seeding_time};
        status.num_complete = params.num_complete;
        status.num_incomplete = params.num_incomplete;
        status.all_time_download = params.total_downloaded;
        status.all_time_upload = params.total_uploaded;
        status.added_time = params.added_time;
        status.last_seen_complete = params.last_seen_complete;
        status.last_download = lt::time_point {lt::seconds {params.last_download}};
        status.last_upload = lt::time_point {lt::seconds {params.last_upload}};
        status.completed_time = params.completed_time;
        status.save_path = params.save_path;
        status.connections_limit = params.max_connections;
        status.pieces = params.have_pieces;
        status.verified_pieces = params.verified_pieces;
    }
}

// TorrentImpl

TorrentImpl::TorrentImpl(Session *session, lt::session *nativeSession
                                     , const lt::torrent_handle &nativeHandle, const LoadTorrentParams &params)
    : QObject(session)
    , m_session(session)
    , m_nativeSession(nativeSession)
    , m_nativeHandle(nativeHandle)
#ifdef QBT_USES_LIBTORRENT2
    , m_infoHash(m_nativeHandle.info_hashes())
#else
    , m_infoHash(m_nativeHandle.info_hash())
#endif
    , m_name(params.name)
    , m_savePath(Utils::Fs::toNativePath(params.savePath))
    , m_category(params.category)
    , m_tags(params.tags)
    , m_ratioLimit(params.ratioLimit)
    , m_seedingTimeLimit(params.seedingTimeLimit)
    , m_operatingMode(params.operatingMode)
    , m_contentLayout(params.contentLayout)
    , m_hasSeedStatus(params.hasSeedStatus)
    , m_hasFirstLastPiecePriority(params.firstLastPiecePriority)
    , m_useAutoTMM(params.savePath.isEmpty())
    , m_isStopped(params.stopped)
    , m_ltAddTorrentParams(params.ltAddTorrentParams)
{
    if (m_useAutoTMM)
        m_savePath = Utils::Fs::toNativePath(m_session->categorySavePath(m_category));

    if (m_ltAddTorrentParams.ti)
    {
        // Initialize it only if torrent is added with metadata.
        // Otherwise it should be initialized in "Metadata received" handler.
        m_torrentInfo = TorrentInfo {m_nativeHandle.torrent_file()};
    }

    initializeStatus(m_nativeStatus, m_ltAddTorrentParams);
    updateState();

    if (hasMetadata())
        applyFirstLastPiecePriority(m_hasFirstLastPiecePriority);

    // TODO: Remove the following upgrade code in v.4.4
    // == BEGIN UPGRADE CODE ==
    const QString spath = actualStorageLocation();
    for (int i = 0; i < filesCount(); ++i)
    {
        const QString filepath = filePath(i);
        // Move "unwanted" files back to their original folder
        const QString parentRelPath = Utils::Fs::branchPath(filepath);
        if (QDir(parentRelPath).dirName() == ".unwanted")
        {
            const QString oldName = Utils::Fs::fileName(filepath);
            const QString newRelPath = Utils::Fs::branchPath(parentRelPath);
            if (newRelPath.isEmpty())
                renameFile(i, oldName);
            else
                renameFile(i, QDir(newRelPath).filePath(oldName));

            // Remove .unwanted directory if empty
            qDebug() << "Attempting to remove \".unwanted\" folder at " << QDir(spath + '/' + newRelPath).absoluteFilePath(".unwanted");
            QDir(spath + '/' + newRelPath).rmdir(".unwanted");
        }
    }
    // == END UPGRADE CODE ==
}

TorrentImpl::~TorrentImpl() {}

bool TorrentImpl::isValid() const
{
    return m_nativeHandle.is_valid();
}

InfoHash TorrentImpl::infoHash() const
{
    return m_infoHash;
}

QString TorrentImpl::name() const
{
    if (!m_name.isEmpty())
        return m_name;

    if (hasMetadata())
        return m_torrentInfo.name();

    const QString name = QString::fromStdString(m_nativeStatus.name);
    if (!name.isEmpty())
        return name;

    return id().toString();
}

QDateTime TorrentImpl::creationDate() const
{
    return m_torrentInfo.creationDate();
}

QString TorrentImpl::creator() const
{
    return m_torrentInfo.creator();
}

QString TorrentImpl::comment() const
{
    return m_torrentInfo.comment();
}

bool TorrentImpl::isPrivate() const
{
    return m_torrentInfo.isPrivate();
}

qlonglong TorrentImpl::totalSize() const
{
    return m_torrentInfo.totalSize();
}

// size without the "don't download" files
qlonglong TorrentImpl::wantedSize() const
{
    return m_nativeStatus.total_wanted;
}

qlonglong TorrentImpl::completedSize() const
{
    return m_nativeStatus.total_wanted_done;
}

qlonglong TorrentImpl::pieceLength() const
{
    return m_torrentInfo.pieceLength();
}

qlonglong TorrentImpl::wastedSize() const
{
    return (m_nativeStatus.total_failed_bytes + m_nativeStatus.total_redundant_bytes);
}

QString TorrentImpl::currentTracker() const
{
    return QString::fromStdString(m_nativeStatus.current_tracker);
}

QString TorrentImpl::savePath(bool actual) const
{
    if (actual)
        return Utils::Fs::toUniformPath(actualStorageLocation());
    else
        return Utils::Fs::toUniformPath(m_savePath);
}

QString TorrentImpl::rootPath(bool actual) const
{
    if (!hasMetadata())
        return {};

    const QString firstFilePath = filePath(0);
    const int slashIndex = firstFilePath.indexOf('/');
    if (slashIndex >= 0)
        return QDir(savePath(actual)).absoluteFilePath(firstFilePath.left(slashIndex));
    else
        return QDir(savePath(actual)).absoluteFilePath(firstFilePath);
}

QString TorrentImpl::contentPath(const bool actual) const
{
    if (!hasMetadata())
        return {};

    if (filesCount() == 1)
        return QDir(savePath(actual)).absoluteFilePath(filePath(0));

    if (m_torrentInfo.hasRootFolder())
        return rootPath(actual);

    return savePath(actual);
}

bool TorrentImpl::isAutoTMMEnabled() const
{
    return m_useAutoTMM;
}

void TorrentImpl::setAutoTMMEnabled(bool enabled)
{
    if (m_useAutoTMM == enabled) return;

    m_useAutoTMM = enabled;
    m_session->handleTorrentNeedSaveResumeData(this);
    m_session->handleTorrentSavingModeChanged(this);

    if (m_useAutoTMM)
        move_impl(m_session->categorySavePath(m_category), MoveStorageMode::Overwrite);
}

QString TorrentImpl::actualStorageLocation() const
{
    return QString::fromStdString(m_nativeStatus.save_path);
}

void TorrentImpl::setAutoManaged(const bool enable)
{
    if (enable)
        m_nativeHandle.set_flags(lt::torrent_flags::auto_managed);
    else
        m_nativeHandle.unset_flags(lt::torrent_flags::auto_managed);
}

QVector<TrackerEntry> TorrentImpl::trackers() const
{
    const std::vector<lt::announce_entry> nativeTrackers = m_nativeHandle.trackers();

    QVector<TrackerEntry> entries;
    entries.reserve(static_cast<decltype(entries)::size_type>(nativeTrackers.size()));

    for (const lt::announce_entry &tracker : nativeTrackers)
    {
        const QString trackerURL = QString::fromStdString(tracker.url);
#ifdef QBT_USES_LIBTORRENT2
        entries << fromNativeAnnouncerEntry(tracker, m_nativeHandle.info_hashes(), m_trackerPeerCounts[trackerURL]);
#else
        entries << fromNativeAnnouncerEntry(tracker, m_trackerPeerCounts[trackerURL]);
#endif
    }

    return entries;
}

void TorrentImpl::addTrackers(const QVector<TrackerEntry> &trackers)
{
    QSet<TrackerEntry> currentTrackers;
    for (const lt::announce_entry &entry : m_nativeHandle.trackers())
        currentTrackers.insert({QString::fromStdString(entry.url), entry.tier});

    QVector<TrackerEntry> newTrackers;
    newTrackers.reserve(trackers.size());

    for (const TrackerEntry &tracker : trackers)
    {
        if (!currentTrackers.contains(tracker))
        {
            m_nativeHandle.add_tracker(makeNativeAnnouncerEntry(tracker.url, tracker.tier));
            newTrackers << tracker;
        }
    }

    if (!newTrackers.isEmpty())
    {
        m_session->handleTorrentNeedSaveResumeData(this);
        m_session->handleTorrentTrackersAdded(this, newTrackers);
    }
}

void TorrentImpl::replaceTrackers(const QVector<TrackerEntry> &trackers)
{
    QVector<TrackerEntry> currentTrackers = this->trackers();

    QVector<TrackerEntry> newTrackers;
    newTrackers.reserve(trackers.size());

    std::vector<lt::announce_entry> nativeTrackers;
    nativeTrackers.reserve(trackers.size());

    for (const TrackerEntry &tracker : trackers)
    {
        nativeTrackers.emplace_back(makeNativeAnnouncerEntry(tracker.url, tracker.tier));

        if (!currentTrackers.removeOne(tracker))
            newTrackers << tracker;
    }

    m_nativeHandle.replace_trackers(nativeTrackers);

    m_session->handleTorrentNeedSaveResumeData(this);

    if (newTrackers.isEmpty() && currentTrackers.isEmpty())
    {
        // when existing tracker reorders
        m_session->handleTorrentTrackersChanged(this);
    }
    else
    {
        if (!currentTrackers.isEmpty())
            m_session->handleTorrentTrackersRemoved(this, currentTrackers);

        if (!newTrackers.isEmpty())
            m_session->handleTorrentTrackersAdded(this, newTrackers);

        // Clear the peer list if it's a private torrent since
        // we do not want to keep connecting with peers from old tracker.
        if (isPrivate())
            clearPeers();
    }
}

QVector<QUrl> TorrentImpl::urlSeeds() const
{
    const std::set<std::string> currentSeeds = m_nativeHandle.url_seeds();

    QVector<QUrl> urlSeeds;
    urlSeeds.reserve(static_cast<decltype(urlSeeds)::size_type>(currentSeeds.size()));

    for (const std::string &urlSeed : currentSeeds)
        urlSeeds.append(QString::fromStdString(urlSeed));

    return urlSeeds;
}

void TorrentImpl::addUrlSeeds(const QVector<QUrl> &urlSeeds)
{
    const std::set<std::string> currentSeeds = m_nativeHandle.url_seeds();

    QVector<QUrl> addedUrlSeeds;
    addedUrlSeeds.reserve(urlSeeds.size());

    for (const QUrl &url : urlSeeds)
    {
        const std::string nativeUrl = url.toString().toStdString();
        if (currentSeeds.find(nativeUrl) == currentSeeds.end())
        {
            m_nativeHandle.add_url_seed(nativeUrl);
            addedUrlSeeds << url;
        }
    }

    if (!addedUrlSeeds.isEmpty())
    {
        m_session->handleTorrentNeedSaveResumeData(this);
        m_session->handleTorrentUrlSeedsAdded(this, addedUrlSeeds);
    }
}

void TorrentImpl::removeUrlSeeds(const QVector<QUrl> &urlSeeds)
{
    const std::set<std::string> currentSeeds = m_nativeHandle.url_seeds();

    QVector<QUrl> removedUrlSeeds;
    removedUrlSeeds.reserve(urlSeeds.size());

    for (const QUrl &url : urlSeeds)
    {
        const std::string nativeUrl = url.toString().toStdString();
        if (currentSeeds.find(nativeUrl) != currentSeeds.end())
        {
            m_nativeHandle.remove_url_seed(nativeUrl);
            removedUrlSeeds << url;
        }
    }

    if (!removedUrlSeeds.isEmpty())
    {
        m_session->handleTorrentNeedSaveResumeData(this);
        m_session->handleTorrentUrlSeedsRemoved(this, removedUrlSeeds);
    }
}

void TorrentImpl::clearPeers()
{
    m_nativeHandle.clear_peers();
}

bool TorrentImpl::connectPeer(const PeerAddress &peerAddress)
{
    lt::error_code ec;
    const lt::address addr = lt::make_address(peerAddress.ip.toString().toStdString(), ec);
    if (ec) return false;

    const lt::tcp::endpoint endpoint(addr, peerAddress.port);
    try
    {
        m_nativeHandle.connect_peer(endpoint);
    }
    catch (const lt::system_error &err)
    {
        LogMsg(tr("Failed to add peer \"%1\" to torrent \"%2\". Reason: %3")
            .arg(peerAddress.toString(), name(), QString::fromLocal8Bit(err.what())), Log::WARNING);
        return false;
    }

    LogMsg(tr("Peer \"%1\" is added to torrent \"%2\"").arg(peerAddress.toString(), name()));
    return true;
}

bool TorrentImpl::needSaveResumeData() const
{
    return m_nativeHandle.need_save_resume_data();
}

void TorrentImpl::saveResumeData()
{
    m_nativeHandle.save_resume_data();
    m_session->handleTorrentSaveResumeDataRequested(this);
}

int TorrentImpl::filesCount() const
{
    return m_torrentInfo.filesCount();
}

int TorrentImpl::piecesCount() const
{
    return m_torrentInfo.piecesCount();
}

int TorrentImpl::piecesHave() const
{
    return m_nativeStatus.num_pieces;
}

qreal TorrentImpl::progress() const
{
    if (isChecking())
        return m_nativeStatus.progress;

    if (m_nativeStatus.total_wanted == 0)
        return 0.;

    if (m_nativeStatus.total_wanted_done == m_nativeStatus.total_wanted)
        return 1.;

    const qreal progress = static_cast<qreal>(m_nativeStatus.total_wanted_done) / m_nativeStatus.total_wanted;
    Q_ASSERT((progress >= 0.f) && (progress <= 1.f));
    return progress;
}

QString TorrentImpl::category() const
{
    return m_category;
}

bool TorrentImpl::belongsToCategory(const QString &category) const
{
    if (m_category.isEmpty()) return category.isEmpty();
    if (!Session::isValidCategoryName(category)) return false;

    if (m_category == category) return true;

    if (m_session->isSubcategoriesEnabled() && m_category.startsWith(category + '/'))
        return true;

    return false;
}

TagSet TorrentImpl::tags() const
{
    return m_tags;
}

bool TorrentImpl::hasTag(const QString &tag) const
{
    return m_tags.contains(tag);
}

bool TorrentImpl::addTag(const QString &tag)
{
    if (!Session::isValidTag(tag))
        return false;
    if (hasTag(tag))
        return false;

    if (!m_session->hasTag(tag))
    {
        if (!m_session->addTag(tag))
            return false;
    }
    m_tags.insert(tag);
    m_session->handleTorrentNeedSaveResumeData(this);
    m_session->handleTorrentTagAdded(this, tag);
    return true;
}

bool TorrentImpl::removeTag(const QString &tag)
{
    if (m_tags.remove(tag))
    {
        m_session->handleTorrentNeedSaveResumeData(this);
        m_session->handleTorrentTagRemoved(this, tag);
        return true;
    }
    return false;
}

void TorrentImpl::removeAllTags()
{
    for (const QString &tag : asConst(tags()))
        removeTag(tag);
}

QDateTime TorrentImpl::addedTime() const
{
    return QDateTime::fromSecsSinceEpoch(m_nativeStatus.added_time);
}

qreal TorrentImpl::ratioLimit() const
{
    return m_ratioLimit;
}

int TorrentImpl::seedingTimeLimit() const
{
    return m_seedingTimeLimit;
}

QString TorrentImpl::filePath(const int index) const
{
    return m_torrentInfo.filePath(index);
}

qlonglong TorrentImpl::fileSize(const int index) const
{
    return m_torrentInfo.fileSize(index);
}

QStringList TorrentImpl::filePaths() const
{
    return m_torrentInfo.filePaths();
}

// Return a list of absolute paths corresponding
// to all files in a torrent
QStringList TorrentImpl::absoluteFilePaths() const
{
    if (!hasMetadata()) return {};

    const QDir saveDir {savePath(true)};
    QStringList res;
    res.reserve(filesCount());
    for (int i = 0; i < filesCount(); ++i)
        res << Utils::Fs::expandPathAbs(saveDir.absoluteFilePath(filePath(i)));
    return res;
}

QVector<DownloadPriority> TorrentImpl::filePriorities() const
{
    if (!hasMetadata())
        return {};

    const std::vector<lt::download_priority_t> fp = m_nativeHandle.get_file_priorities();

    QVector<DownloadPriority> ret;
    ret.reserve(filesCount());
    for (const lt::file_index_t nativeIndex : asConst(m_torrentInfo.nativeIndexes()))
    {
        const auto priority = LT::fromNative(fp[LT::toUnderlyingType(nativeIndex)]);
        ret.append(priority);
    }

    return ret;
}

TorrentInfo TorrentImpl::info() const
{
    return m_torrentInfo;
}

bool TorrentImpl::isPaused() const
{
    return m_isStopped;
}

bool TorrentImpl::isQueued() const
{
    // Torrent is Queued if it isn't in Paused state but paused internally
    return (!isPaused()
            && (m_nativeStatus.flags & lt::torrent_flags::auto_managed)
            && (m_nativeStatus.flags & lt::torrent_flags::paused));
}

bool TorrentImpl::isChecking() const
{
    return ((m_nativeStatus.state == lt::torrent_status::checking_files)
            || (m_nativeStatus.state == lt::torrent_status::checking_resume_data));
}

bool TorrentImpl::isDownloading() const
{
    return m_state == TorrentState::Downloading
            || m_state == TorrentState::DownloadingMetadata
            || m_state == TorrentState::ForcedDownloadingMetadata
            || m_state == TorrentState::StalledDownloading
            || m_state == TorrentState::CheckingDownloading
            || m_state == TorrentState::PausedDownloading
            || m_state == TorrentState::QueuedDownloading
            || m_state == TorrentState::ForcedDownloading;
}

bool TorrentImpl::isUploading() const
{
    return m_state == TorrentState::Uploading
            || m_state == TorrentState::StalledUploading
            || m_state == TorrentState::CheckingUploading
            || m_state == TorrentState::QueuedUploading
            || m_state == TorrentState::ForcedUploading;
}

bool TorrentImpl::isCompleted() const
{
    return m_state == TorrentState::Uploading
            || m_state == TorrentState::StalledUploading
            || m_state == TorrentState::CheckingUploading
            || m_state == TorrentState::PausedUploading
            || m_state == TorrentState::QueuedUploading
            || m_state == TorrentState::ForcedUploading;
}

bool TorrentImpl::isActive() const
{
    if (m_state == TorrentState::StalledDownloading)
        return (uploadPayloadRate() > 0);

    return m_state == TorrentState::DownloadingMetadata
            || m_state == TorrentState::ForcedDownloadingMetadata
            || m_state == TorrentState::Downloading
            || m_state == TorrentState::ForcedDownloading
            || m_state == TorrentState::Uploading
            || m_state == TorrentState::ForcedUploading
            || m_state == TorrentState::Moving;
}

bool TorrentImpl::isInactive() const
{
    return !isActive();
}

bool TorrentImpl::isErrored() const
{
    return m_state == TorrentState::MissingFiles
            || m_state == TorrentState::Error;
}

bool TorrentImpl::isSeed() const
{
    return ((m_nativeStatus.state == lt::torrent_status::finished)
            || (m_nativeStatus.state == lt::torrent_status::seeding));
}

bool TorrentImpl::isForced() const
{
    return (!isPaused() && (m_operatingMode == TorrentOperatingMode::Forced));
}

bool TorrentImpl::isSequentialDownload() const
{
    return static_cast<bool>(m_nativeStatus.flags & lt::torrent_flags::sequential_download);
}

bool TorrentImpl::hasFirstLastPiecePriority() const
{
    return m_hasFirstLastPiecePriority;
}

TorrentState TorrentImpl::state() const
{
    return m_state;
}

void TorrentImpl::updateState()
{
    if (m_nativeStatus.state == lt::torrent_status::checking_resume_data)
    {
        m_state = TorrentState::CheckingResumeData;
    }
    else if (isMoveInProgress())
    {
        m_state = TorrentState::Moving;
    }
    else if (hasMissingFiles())
    {
        m_state = TorrentState::MissingFiles;
    }
    else if (hasError())
    {
        m_state = TorrentState::Error;
    }
    else if (!hasMetadata())
    {
        if (isPaused())
            m_state = TorrentState::PausedDownloading;
        else if (m_session->isQueueingSystemEnabled() && isQueued())
            m_state = TorrentState::QueuedDownloading;
        else
            m_state = isForced() ? TorrentState::ForcedDownloadingMetadata : TorrentState::DownloadingMetadata;
    }
    else if ((m_nativeStatus.state == lt::torrent_status::checking_files)
             && (!isPaused() || (m_nativeStatus.flags & lt::torrent_flags::auto_managed)
                 || !(m_nativeStatus.flags & lt::torrent_flags::paused)))
    {
        // If the torrent is not just in the "checking" state, but is being actually checked
        m_state = m_hasSeedStatus ? TorrentState::CheckingUploading : TorrentState::CheckingDownloading;
    }
    else if (isSeed())
    {
        if (isPaused())
            m_state = TorrentState::PausedUploading;
        else if (m_session->isQueueingSystemEnabled() && isQueued())
            m_state = TorrentState::QueuedUploading;
        else if (isForced())
            m_state = TorrentState::ForcedUploading;
        else if (m_nativeStatus.upload_payload_rate > 0)
            m_state = TorrentState::Uploading;
        else
            m_state = TorrentState::StalledUploading;
    }
    else
    {
        if (isPaused())
            m_state = TorrentState::PausedDownloading;
        else if (m_session->isQueueingSystemEnabled() && isQueued())
            m_state = TorrentState::QueuedDownloading;
        else if (isForced())
            m_state = TorrentState::ForcedDownloading;
        else if (m_nativeStatus.download_payload_rate > 0)
            m_state = TorrentState::Downloading;
        else
            m_state = TorrentState::StalledDownloading;
    }
}

bool TorrentImpl::hasMetadata() const
{
    return m_torrentInfo.isValid();
}

bool TorrentImpl::hasMissingFiles() const
{
    return m_hasMissingFiles;
}

bool TorrentImpl::hasError() const
{
    return (m_nativeStatus.errc || (m_nativeStatus.flags & lt::torrent_flags::upload_mode));
}

int TorrentImpl::queuePosition() const
{
    return static_cast<int>(m_nativeStatus.queue_position);
}

QString TorrentImpl::error() const
{
    if (m_nativeStatus.errc)
        return QString::fromStdString(m_nativeStatus.errc.message());

    if (m_nativeStatus.flags & lt::torrent_flags::upload_mode)
    {
        const QString writeErrorStr = tr("Couldn't write to file.");
        const QString uploadModeStr = tr("Torrent is currently in \"upload only\" mode.");
        const QString errorMessage = QString::fromLocal8Bit(m_lastFileError.error.message().c_str());

        return writeErrorStr + QLatin1Char(' ') + errorMessage + QLatin1String(". ") + uploadModeStr;
    }

    return {};
}

qlonglong TorrentImpl::totalDownload() const
{
    return m_nativeStatus.all_time_download;
}

qlonglong TorrentImpl::totalUpload() const
{
    return m_nativeStatus.all_time_upload;
}

qlonglong TorrentImpl::activeTime() const
{
    return lt::total_seconds(m_nativeStatus.active_duration);
}

qlonglong TorrentImpl::finishedTime() const
{
    return lt::total_seconds(m_nativeStatus.finished_duration);
}

qlonglong TorrentImpl::seedingTime() const
{
    return lt::total_seconds(m_nativeStatus.seeding_duration);
}

qlonglong TorrentImpl::eta() const
{
    if (isPaused()) return MAX_ETA;

    const SpeedSampleAvg speedAverage = m_speedMonitor.average();

    if (isSeed())
    {
        const qreal maxRatioValue = maxRatio();
        const int maxSeedingTimeValue = maxSeedingTime();
        if ((maxRatioValue < 0) && (maxSeedingTimeValue < 0)) return MAX_ETA;

        qlonglong ratioEta = MAX_ETA;

        if ((speedAverage.upload > 0) && (maxRatioValue >= 0))
        {

            qlonglong realDL = totalDownload();
            if (realDL <= 0)
                realDL = wantedSize();

            ratioEta = ((realDL * maxRatioValue) - totalUpload()) / speedAverage.upload;
        }

        qlonglong seedingTimeEta = MAX_ETA;

        if (maxSeedingTimeValue >= 0)
        {
            seedingTimeEta = (maxSeedingTimeValue * 60) - seedingTime();
            if (seedingTimeEta < 0)
                seedingTimeEta = 0;
        }

        return qMin(ratioEta, seedingTimeEta);
    }

    if (!speedAverage.download) return MAX_ETA;

    return (wantedSize() - completedSize()) / speedAverage.download;
}

QVector<qreal> TorrentImpl::filesProgress() const
{
    if (!hasMetadata())
        return {};

    std::vector<int64_t> fp;
    m_nativeHandle.file_progress(fp, lt::torrent_handle::piece_granularity);

    const int count = filesCount();
    const auto nativeIndexes = m_torrentInfo.nativeIndexes();
    QVector<qreal> result;
    result.reserve(count);
    for (int i = 0; i < count; ++i)
    {
        const int64_t progress = fp[LT::toUnderlyingType(nativeIndexes[i])];
        const qlonglong size = fileSize(i);
        if ((size <= 0) || (progress == size))
            result << 1;
        else
            result << (progress / static_cast<qreal>(size));
    }

    return result;
}

int TorrentImpl::seedsCount() const
{
    return m_nativeStatus.num_seeds;
}

int TorrentImpl::peersCount() const
{
    return m_nativeStatus.num_peers;
}

int TorrentImpl::leechsCount() const
{
    return (m_nativeStatus.num_peers - m_nativeStatus.num_seeds);
}

int TorrentImpl::totalSeedsCount() const
{
    return (m_nativeStatus.num_complete > 0) ? m_nativeStatus.num_complete : m_nativeStatus.list_seeds;
}

int TorrentImpl::totalPeersCount() const
{
    const int peers = m_nativeStatus.num_complete + m_nativeStatus.num_incomplete;
    return (peers > 0) ? peers : m_nativeStatus.list_peers;
}

int TorrentImpl::totalLeechersCount() const
{
    return (m_nativeStatus.num_incomplete > 0) ? m_nativeStatus.num_incomplete : (m_nativeStatus.list_peers - m_nativeStatus.list_seeds);
}

int TorrentImpl::completeCount() const
{
    // additional info: https://github.com/qbittorrent/qBittorrent/pull/5300#issuecomment-267783646
    return m_nativeStatus.num_complete;
}

int TorrentImpl::incompleteCount() const
{
    // additional info: https://github.com/qbittorrent/qBittorrent/pull/5300#issuecomment-267783646
    return m_nativeStatus.num_incomplete;
}

QDateTime TorrentImpl::lastSeenComplete() const
{
    if (m_nativeStatus.last_seen_complete > 0)
        return QDateTime::fromSecsSinceEpoch(m_nativeStatus.last_seen_complete);
    else
        return {};
}

QDateTime TorrentImpl::completedTime() const
{
    if (m_nativeStatus.completed_time > 0)
        return QDateTime::fromSecsSinceEpoch(m_nativeStatus.completed_time);
    else
        return {};
}

qlonglong TorrentImpl::timeSinceUpload() const
{
    if (m_nativeStatus.last_upload.time_since_epoch().count() == 0)
        return -1;
    return lt::total_seconds(lt::clock_type::now() - m_nativeStatus.last_upload);
}

qlonglong TorrentImpl::timeSinceDownload() const
{
    if (m_nativeStatus.last_download.time_since_epoch().count() == 0)
        return -1;
    return lt::total_seconds(lt::clock_type::now() - m_nativeStatus.last_download);
}

qlonglong TorrentImpl::timeSinceActivity() const
{
    const qlonglong upTime = timeSinceUpload();
    const qlonglong downTime = timeSinceDownload();
    return ((upTime < 0) != (downTime < 0))
        ? std::max(upTime, downTime)
        : std::min(upTime, downTime);
}

int TorrentImpl::downloadLimit() const
{
    return m_nativeHandle.download_limit();
}

int TorrentImpl::uploadLimit() const
{
    return m_nativeHandle.upload_limit();
}

bool TorrentImpl::superSeeding() const
{
    return static_cast<bool>(m_nativeStatus.flags & lt::torrent_flags::super_seeding);
}

bool TorrentImpl::isDHTDisabled() const
{
    return static_cast<bool>(m_nativeStatus.flags & lt::torrent_flags::disable_dht);
}

bool TorrentImpl::isPEXDisabled() const
{
    return static_cast<bool>(m_nativeStatus.flags & lt::torrent_flags::disable_pex);
}

bool TorrentImpl::isLSDDisabled() const
{
    return static_cast<bool>(m_nativeStatus.flags & lt::torrent_flags::disable_lsd);
}

QVector<PeerInfo> TorrentImpl::peers() const
{
    std::vector<lt::peer_info> nativePeers;
    m_nativeHandle.get_peer_info(nativePeers);

    QVector<PeerInfo> peers;
    peers.reserve(static_cast<decltype(peers)::size_type>(nativePeers.size()));

    for (const lt::peer_info &peer : nativePeers)
        peers << PeerInfo(this, peer);

    return peers;
}

QBitArray TorrentImpl::pieces() const
{
    QBitArray result(m_nativeStatus.pieces.size());
    for (int i = 0; i < result.size(); ++i)
    {
        if (m_nativeStatus.pieces[lt::piece_index_t {i}])
            result.setBit(i, true);
    }
    return result;
}

QBitArray TorrentImpl::downloadingPieces() const
{
    QBitArray result(piecesCount());

    std::vector<lt::partial_piece_info> queue;
    m_nativeHandle.get_download_queue(queue);

    for (const lt::partial_piece_info &info : queue)
        result.setBit(LT::toUnderlyingType(info.piece_index));

    return result;
}

QVector<int> TorrentImpl::pieceAvailability() const
{
    std::vector<int> avail;
    m_nativeHandle.piece_availability(avail);

    return {avail.cbegin(), avail.cend()};
}

qreal TorrentImpl::distributedCopies() const
{
    return m_nativeStatus.distributed_copies;
}

qreal TorrentImpl::maxRatio() const
{
    if (m_ratioLimit == USE_GLOBAL_RATIO)
        return m_session->globalMaxRatio();

    return m_ratioLimit;
}

int TorrentImpl::maxSeedingTime() const
{
    if (m_seedingTimeLimit == USE_GLOBAL_SEEDING_TIME)
        return m_session->globalMaxSeedingMinutes();

    return m_seedingTimeLimit;
}

qreal TorrentImpl::realRatio() const
{
    const int64_t upload = m_nativeStatus.all_time_upload;
    // special case for a seeder who lost its stats, also assume nobody will import a 99% done torrent
    const int64_t download = (m_nativeStatus.all_time_download < (m_nativeStatus.total_done * 0.01))
        ? m_nativeStatus.total_done
        : m_nativeStatus.all_time_download;

    if (download == 0)
        return (upload == 0) ? 0 : MAX_RATIO;

    const qreal ratio = upload / static_cast<qreal>(download);
    Q_ASSERT(ratio >= 0);
    return (ratio > MAX_RATIO) ? MAX_RATIO : ratio;
}

int TorrentImpl::uploadPayloadRate() const
{
    return m_nativeStatus.upload_payload_rate;
}

int TorrentImpl::downloadPayloadRate() const
{
    return m_nativeStatus.download_payload_rate;
}

qlonglong TorrentImpl::totalPayloadUpload() const
{
    return m_nativeStatus.total_payload_upload;
}

qlonglong TorrentImpl::totalPayloadDownload() const
{
    return m_nativeStatus.total_payload_download;
}

int TorrentImpl::connectionsCount() const
{
    return m_nativeStatus.num_connections;
}

int TorrentImpl::connectionsLimit() const
{
    return m_nativeStatus.connections_limit;
}

qlonglong TorrentImpl::nextAnnounce() const
{
    return lt::total_seconds(m_nativeStatus.next_announce);
}

void TorrentImpl::setName(const QString &name)
{
    if (m_name != name)
    {
        m_name = name;
        m_session->handleTorrentNeedSaveResumeData(this);
        m_session->handleTorrentNameChanged(this);
    }
}

bool TorrentImpl::setCategory(const QString &category)
{
    if (m_category != category)
    {
        if (!category.isEmpty() && !m_session->categories().contains(category))
            return false;

        const QString oldCategory = m_category;
        m_category = category;
        m_session->handleTorrentNeedSaveResumeData(this);
        m_session->handleTorrentCategoryChanged(this, oldCategory);

        if (m_useAutoTMM)
        {
            if (!m_session->isDisableAutoTMMWhenCategoryChanged())
                move_impl(m_session->categorySavePath(m_category), MoveStorageMode::Overwrite);
            else
                setAutoTMMEnabled(false);
        }
    }

    return true;
}

void TorrentImpl::move(QString path)
{
    if (m_useAutoTMM)
    {
        m_useAutoTMM = false;
        m_session->handleTorrentNeedSaveResumeData(this);
        m_session->handleTorrentSavingModeChanged(this);
    }

    path = Utils::Fs::toUniformPath(path.trimmed());
    if (path.isEmpty())
        path = m_session->defaultSavePath();
    if (!path.endsWith('/'))
        path += '/';

    move_impl(path, MoveStorageMode::KeepExistingFiles);
}

void TorrentImpl::move_impl(QString path, const MoveStorageMode mode)
{
    if (path == savePath()) return;

    path = Utils::Fs::toNativePath(path);
    if (!useTempPath())
    {
        moveStorage(path, mode);
    }
    else
    {
        m_savePath = path;
        m_session->handleTorrentNeedSaveResumeData(this);
        m_session->handleTorrentSavePathChanged(this);
    }
}

void TorrentImpl::forceReannounce(const int index)
{
    m_nativeHandle.force_reannounce(0, index);
}

void TorrentImpl::forceDHTAnnounce()
{
    m_nativeHandle.force_dht_announce();
}

void TorrentImpl::forceRecheck()
{
    if (!hasMetadata()) return;

    m_nativeHandle.force_recheck();
    m_hasMissingFiles = false;
    m_unchecked = false;

    if (isPaused())
    {
        // When "force recheck" is applied on paused torrent, we temporarily resume it
        // (really we just allow libtorrent to resume it by enabling auto management for it).
        m_nativeHandle.set_flags(lt::torrent_flags::stop_when_ready | lt::torrent_flags::auto_managed);
    }
}

void TorrentImpl::setSequentialDownload(const bool enable)
{
    if (enable)
    {
        m_nativeHandle.set_flags(lt::torrent_flags::sequential_download);
        m_nativeStatus.flags |= lt::torrent_flags::sequential_download;  // prevent return cached value
    }
    else
    {
        m_nativeHandle.unset_flags(lt::torrent_flags::sequential_download);
        m_nativeStatus.flags &= ~lt::torrent_flags::sequential_download;  // prevent return cached value
    }

    m_session->handleTorrentNeedSaveResumeData(this);
}

void TorrentImpl::setFirstLastPiecePriority(const bool enabled)
{
    if (m_hasFirstLastPiecePriority == enabled)
        return;

    m_hasFirstLastPiecePriority = enabled;
    if (hasMetadata())
        applyFirstLastPiecePriority(enabled);

    LogMsg(tr("Download first and last piece first: %1, torrent: '%2'")
        .arg((enabled ? tr("On") : tr("Off")), name()));

    m_session->handleTorrentNeedSaveResumeData(this);
}

void TorrentImpl::applyFirstLastPiecePriority(const bool enabled, const QVector<DownloadPriority> &updatedFilePrio)
{
    Q_ASSERT(hasMetadata());

    // Download first and last pieces first for every file in the torrent

    const QVector<DownloadPriority> filePriorities =
            !updatedFilePrio.isEmpty() ? updatedFilePrio : this->filePriorities();
    std::vector<lt::download_priority_t> piecePriorities = nativeHandle().get_piece_priorities();

    // Updating file priorities is an async operation in libtorrent, when we just updated it and immediately query it
    // we might get the old/wrong values, so we rely on `updatedFilePrio` in this case.
    for (int index = 0; index < filePriorities.size(); ++index)
    {
        const DownloadPriority filePrio = filePriorities[index];
        if (filePrio <= DownloadPriority::Ignored)
            continue;

        // Determine the priority to set
        const DownloadPriority newPrio = enabled ? DownloadPriority::Maximum : filePrio;
        const auto piecePrio = static_cast<lt::download_priority_t>(static_cast<int>(newPrio));
        const TorrentInfo::PieceRange extremities = info().filePieces(index);

        // worst case: AVI index = 1% of total file size (at the end of the file)
        const int nNumPieces = std::ceil(fileSize(index) * 0.01 / pieceLength());
        for (int i = 0; i < nNumPieces; ++i)
        {
            piecePriorities[extremities.first() + i] = piecePrio;
            piecePriorities[extremities.last() - i] = piecePrio;
        }
    }

    m_nativeHandle.prioritize_pieces(piecePriorities);
}

void TorrentImpl::fileSearchFinished(const QString &savePath, const QStringList &fileNames)
{
    endReceivedMetadataHandling(savePath, fileNames);
}

void TorrentImpl::endReceivedMetadataHandling(const QString &savePath, const QStringList &fileNames)
{
    lt::add_torrent_params &p = m_ltAddTorrentParams;

    const TorrentInfo torrentInfo {m_nativeHandle.torrent_file()};
    const auto nativeIndexes = torrentInfo.nativeIndexes();
    for (int i = 0; i < fileNames.size(); ++i)
        p.renamed_files[nativeIndexes[i]] = fileNames[i].toStdString();
    p.save_path = Utils::Fs::toNativePath(savePath).toStdString();
    p.ti = torrentInfo.nativeInfo();

    const int internalFilesCount = p.ti->files().num_files(); // including .pad files
    // Use qBittorrent default priority rather than libtorrent's (4)
    p.file_priorities = std::vector(internalFilesCount, LT::toNative(DownloadPriority::Normal));

    reload();

    // If first/last piece priority was specified when adding this torrent,
    // we should apply it now that we have metadata:
    if (m_hasFirstLastPiecePriority)
        applyFirstLastPiecePriority(true);

    m_maintenanceJob = MaintenanceJob::None;
    updateStatus();
    prepareResumeData(p);

    m_session->handleTorrentMetadataReceived(this);
}

void TorrentImpl::reload()
{
    const auto queuePos = m_nativeHandle.queue_position();

    m_nativeSession->remove_torrent(m_nativeHandle, lt::session::delete_partfile);

    lt::add_torrent_params p = m_ltAddTorrentParams;
    p.flags |= lt::torrent_flags::update_subscribe
            | lt::torrent_flags::override_trackers
            | lt::torrent_flags::override_web_seeds;

    if (m_isStopped)
    {
        p.flags |= lt::torrent_flags::paused;
        p.flags &= ~lt::torrent_flags::auto_managed;
    }
    else if (m_operatingMode == TorrentOperatingMode::AutoManaged)
    {
        p.flags |= (lt::torrent_flags::auto_managed | lt::torrent_flags::paused);
    }
    else
    {
        p.flags &= ~(lt::torrent_flags::auto_managed | lt::torrent_flags::paused);
    }

    m_nativeHandle = m_nativeSession->add_torrent(p);
    m_nativeHandle.queue_position_set(queuePos);

    m_torrentInfo = TorrentInfo {m_nativeHandle.torrent_file()};
}

void TorrentImpl::pause()
{
    if (!m_isStopped)
    {
        m_isStopped = true;
        m_session->handleTorrentNeedSaveResumeData(this);
        m_session->handleTorrentPaused(this);
    }

    if (m_maintenanceJob == MaintenanceJob::None)
    {
        setAutoManaged(false);
        m_nativeHandle.pause();

        m_speedMonitor.reset();
    }
}

void TorrentImpl::resume(const TorrentOperatingMode mode)
{
    if (hasError())
    {
        m_nativeHandle.clear_error();
        m_nativeHandle.unset_flags(lt::torrent_flags::upload_mode);
    }

    m_operatingMode = mode;

    if (m_hasMissingFiles)
    {
        m_hasMissingFiles = false;
        m_isStopped = false;
        m_ltAddTorrentParams.ti = std::const_pointer_cast<lt::torrent_info>(m_nativeHandle.torrent_file());
        reload();
        updateStatus();
        return;
    }

    if (m_isStopped)
    {
        // Torrent may have been temporarily resumed to perform checking files
        // so we have to ensure it will not pause after checking is done.
        m_nativeHandle.unset_flags(lt::torrent_flags::stop_when_ready);

        m_isStopped = false;
        m_session->handleTorrentNeedSaveResumeData(this);
        m_session->handleTorrentResumed(this);
    }

    if (m_maintenanceJob == MaintenanceJob::None)
    {
        setAutoManaged(m_operatingMode == TorrentOperatingMode::AutoManaged);
        if (m_operatingMode == TorrentOperatingMode::Forced)
            m_nativeHandle.resume();
    }
}

void TorrentImpl::moveStorage(const QString &newPath, const MoveStorageMode mode)
{
    if (m_session->addMoveTorrentStorageJob(this, newPath, mode))
    {
        m_storageIsMoving = true;
        updateStatus();
    }
}

void TorrentImpl::renameFile(const int index, const QString &path)
{
#ifndef QBT_USES_LIBTORRENT2
    const QString oldPath = filePath(index);
    m_oldPath[index].push_back(oldPath);
#endif
    ++m_renameCount;
    m_nativeHandle.rename_file(m_torrentInfo.nativeIndexes()[index], Utils::Fs::toNativePath(path).toStdString());
}

void TorrentImpl::handleStateUpdate(const lt::torrent_status &nativeStatus)
{
    updateStatus(nativeStatus);
}

void TorrentImpl::handleMoveStorageJobFinished(const bool hasOutstandingJob)
{
    m_session->handleTorrentNeedSaveResumeData(this);
    m_storageIsMoving = hasOutstandingJob;

    updateStatus();
    const QString newPath = QString::fromStdString(m_nativeStatus.save_path);
    if (!useTempPath() && (newPath != m_savePath))
    {
        m_savePath = newPath;
        m_session->handleTorrentSavePathChanged(this);
    }

    if (!m_storageIsMoving)
    {
        if (m_hasMissingFiles)
        {
            // it can be moved to the proper location
            m_hasMissingFiles = false;
            m_ltAddTorrentParams.save_path = m_nativeStatus.save_path;
            m_ltAddTorrentParams.ti = std::const_pointer_cast<lt::torrent_info>(m_nativeHandle.torrent_file());
            reload();
            updateStatus();
        }

        while ((m_renameCount == 0) && !m_moveFinishedTriggers.isEmpty())
            m_moveFinishedTriggers.takeFirst()();
    }
}

void TorrentImpl::handleTrackerReplyAlert(const lt::tracker_reply_alert *p)
{
    const QString trackerUrl = p->tracker_url();
    m_trackerPeerCounts[trackerUrl][p->local_endpoint] = p->num_peers;

    m_session->handleTorrentTrackerReply(this, trackerUrl);
}

void TorrentImpl::handleTrackerWarningAlert(const lt::tracker_warning_alert *p)
{
    const QString trackerUrl = p->tracker_url();
    m_session->handleTorrentTrackerWarning(this, trackerUrl);
}

void TorrentImpl::handleTrackerErrorAlert(const lt::tracker_error_alert *p)
{
    const QString trackerUrl = p->tracker_url();

    // Starting with libtorrent 1.2.x each tracker has multiple local endpoints from which
    // an announce is attempted. Some endpoints might succeed while others might fail.
    // Emit the signal only if all endpoints have failed.
    const QVector<TrackerEntry> trackerList = trackers();
    const auto iter = std::find_if(trackerList.cbegin(), trackerList.cend(), [&trackerUrl](const TrackerEntry &entry)
    {
        return (entry.url == trackerUrl);
    });
    if ((iter != trackerList.cend()) && (iter->status == TrackerEntry::NotWorking))
        m_session->handleTorrentTrackerError(this, trackerUrl);
}

void TorrentImpl::handleTorrentCheckedAlert(const lt::torrent_checked_alert *p)
{
    Q_UNUSED(p);
    qDebug("\"%s\" have just finished checking.", qUtf8Printable(name()));


    if (!hasMetadata())
    {
        // The torrent is checked due to metadata received, but we should not process
        // this event until the torrent is reloaded using the received metadata.
        return;
    }

    if (m_nativeHandle.need_save_resume_data())
        m_session->handleTorrentNeedSaveResumeData(this);

    if (m_fastresumeDataRejected && !m_hasMissingFiles)
        m_fastresumeDataRejected = false;

    updateStatus();

    if (!m_hasMissingFiles)
    {
        if ((progress() < 1.0) && (wantedSize() > 0))
            m_hasSeedStatus = false;
        else if (progress() == 1.0)
            m_hasSeedStatus = true;

        adjustActualSavePath();
        manageIncompleteFiles();
    }

    m_session->handleTorrentChecked(this);
}

void TorrentImpl::handleTorrentFinishedAlert(const lt::torrent_finished_alert *p)
{
    Q_UNUSED(p);
    qDebug("Got a torrent finished alert for \"%s\"", qUtf8Printable(name()));
    qDebug("Torrent has seed status: %s", m_hasSeedStatus ? "yes" : "no");
    m_hasMissingFiles = false;
    if (m_hasSeedStatus) return;

    updateStatus();
    m_hasSeedStatus = true;

    adjustActualSavePath();
    manageIncompleteFiles();

    m_session->handleTorrentNeedSaveResumeData(this);

    const bool recheckTorrentsOnCompletion = Preferences::instance()->recheckTorrentsOnCompletion();
    if (isMoveInProgress() || (m_renameCount > 0))
    {
        if (recheckTorrentsOnCompletion)
            m_moveFinishedTriggers.append([this]() { forceRecheck(); });
        m_moveFinishedTriggers.append([this]() { m_session->handleTorrentFinished(this); });
    }
    else
    {
        if (recheckTorrentsOnCompletion && m_unchecked)
            forceRecheck();
        m_session->handleTorrentFinished(this);
    }
}

void TorrentImpl::handleTorrentPausedAlert(const lt::torrent_paused_alert *p)
{
    Q_UNUSED(p);
}

void TorrentImpl::handleTorrentResumedAlert(const lt::torrent_resumed_alert *p)
{
    Q_UNUSED(p);
}

void TorrentImpl::handleSaveResumeDataAlert(const lt::save_resume_data_alert *p)
{
    if (m_maintenanceJob == MaintenanceJob::HandleMetadata)
    {
        m_ltAddTorrentParams = p->params;

        m_ltAddTorrentParams.have_pieces.clear();
        m_ltAddTorrentParams.verified_pieces.clear();

        TorrentInfo metadata = TorrentInfo {m_nativeHandle.torrent_file()};
        metadata.setContentLayout(m_contentLayout);

        m_session->findIncompleteFiles(metadata, m_savePath);
    }
    else
    {
        prepareResumeData(p->params);
    }
}

void TorrentImpl::prepareResumeData(const lt::add_torrent_params &params)
{
    if (m_hasMissingFiles)
    {
        const auto havePieces = m_ltAddTorrentParams.have_pieces;
        const auto unfinishedPieces = m_ltAddTorrentParams.unfinished_pieces;
        const auto verifiedPieces = m_ltAddTorrentParams.verified_pieces;

        // Update recent resume data but preserve existing progress
        m_ltAddTorrentParams = params;
        m_ltAddTorrentParams.have_pieces = havePieces;
        m_ltAddTorrentParams.unfinished_pieces = unfinishedPieces;
        m_ltAddTorrentParams.verified_pieces = verifiedPieces;
    }
    else
    {
        // Update recent resume data
        m_ltAddTorrentParams = params;
    }

    m_ltAddTorrentParams.added_time = addedTime().toSecsSinceEpoch();

    // We shouldn't save upload_mode flag to allow torrent operate normally on next run
    m_ltAddTorrentParams.flags &= ~lt::torrent_flags::upload_mode;

    LoadTorrentParams resumeData;
    resumeData.name = m_name;
    resumeData.category = m_category;
    resumeData.savePath = m_useAutoTMM ? "" : m_savePath;
    resumeData.tags = m_tags;
    resumeData.contentLayout = m_contentLayout;
    resumeData.ratioLimit = m_ratioLimit;
    resumeData.seedingTimeLimit = m_seedingTimeLimit;
    resumeData.firstLastPiecePriority = m_hasFirstLastPiecePriority;
    resumeData.hasSeedStatus = m_hasSeedStatus;
    resumeData.stopped = m_isStopped;
    resumeData.operatingMode = m_operatingMode;
    resumeData.ltAddTorrentParams = m_ltAddTorrentParams;

    m_session->handleTorrentResumeDataReady(this, resumeData);
}

void TorrentImpl::handleSaveResumeDataFailedAlert(const lt::save_resume_data_failed_alert *p)
{
    Q_UNUSED(p);
    Q_ASSERT_X(false, Q_FUNC_INFO, "This point should be unreachable since libtorrent 1.2.11");
}

void TorrentImpl::handleFastResumeRejectedAlert(const lt::fastresume_rejected_alert *p)
{
    m_fastresumeDataRejected = true;

    if (p->error.value() == lt::errors::mismatching_file_size)
    {
        // Mismatching file size (files were probably moved)
        m_hasMissingFiles = true;
        LogMsg(tr("File sizes mismatch for torrent '%1'. Cannot proceed further.").arg(name()), Log::CRITICAL);
    }
    else
    {
        LogMsg(tr("Fast resume data was rejected for torrent '%1'. Reason: %2. Checking again...")
            .arg(name(), QString::fromStdString(p->message())), Log::WARNING);
    }
}

void TorrentImpl::handleFileRenamedAlert(const lt::file_renamed_alert *p)
{
    const int fileIndex = m_torrentInfo.nativeIndexes().indexOf(p->index);
    Q_ASSERT(fileIndex >= 0);

    // Remove empty leftover folders
    // For example renaming "a/b/c" to "d/b/c", then folders "a/b" and "a" will
    // be removed if they are empty
#ifndef QBT_USES_LIBTORRENT2
    const QString oldFilePath = m_oldPath[fileIndex].takeFirst();
    if (m_oldPath[fileIndex].isEmpty())
        m_oldPath.remove(fileIndex);
#else
    const QString oldFilePath = Utils::Fs::toUniformPath(p->old_name());
#endif
    const QString newFilePath = Utils::Fs::toUniformPath(p->new_name());

    QList<QStringView> oldPathParts = QStringView(oldFilePath).split('/', Qt::SkipEmptyParts);
    oldPathParts.removeLast();  // drop file name part
    QList<QStringView> newPathParts = QStringView(newFilePath).split('/', Qt::SkipEmptyParts);
    newPathParts.removeLast();  // drop file name part

#if defined(Q_OS_WIN)
    const Qt::CaseSensitivity caseSensitivity = Qt::CaseInsensitive;
#else
    const Qt::CaseSensitivity caseSensitivity = Qt::CaseSensitive;
#endif

    int pathIdx = 0;
    while ((pathIdx < oldPathParts.size()) && (pathIdx < newPathParts.size()))
    {
        if (oldPathParts[pathIdx].compare(newPathParts[pathIdx], caseSensitivity) != 0)
            break;
        ++pathIdx;
    }

    for (int i = (oldPathParts.size() - 1); i >= pathIdx; --i)
    {
        QDir().rmdir(savePath() + Utils::String::join(oldPathParts, QString::fromLatin1("/")));
        oldPathParts.removeLast();
    }

    --m_renameCount;
    while (!isMoveInProgress() && (m_renameCount == 0) && !m_moveFinishedTriggers.isEmpty())
        m_moveFinishedTriggers.takeFirst()();

    m_session->handleTorrentNeedSaveResumeData(this);
}

void TorrentImpl::handleFileRenameFailedAlert(const lt::file_rename_failed_alert *p)
{
    const int fileIndex = m_torrentInfo.nativeIndexes().indexOf(p->index);
    Q_ASSERT(fileIndex >= 0);

    LogMsg(tr("File rename failed. Torrent: \"%1\", file: \"%2\", reason: \"%3\"")
        .arg(name(), filePath(fileIndex), QString::fromLocal8Bit(p->error.message().c_str())), Log::WARNING);

#ifndef QBT_USES_LIBTORRENT2
    m_oldPath[fileIndex].removeFirst();
    if (m_oldPath[fileIndex].isEmpty())
        m_oldPath.remove(fileIndex);
#endif

    --m_renameCount;
    while (!isMoveInProgress() && (m_renameCount == 0) && !m_moveFinishedTriggers.isEmpty())
        m_moveFinishedTriggers.takeFirst()();

    m_session->handleTorrentNeedSaveResumeData(this);
}

void TorrentImpl::handleFileCompletedAlert(const lt::file_completed_alert *p)
{
    const int fileIndex = m_torrentInfo.nativeIndexes().indexOf(p->index);
    Q_ASSERT(fileIndex >= 0);

    qDebug("A file completed download in torrent \"%s\"", qUtf8Printable(name()));
    if (m_session->isAppendExtensionEnabled())
    {
        QString name = filePath(fileIndex);
        if (name.endsWith(QB_EXT))
        {
            const QString oldName = name;
            name.chop(QB_EXT.size());
            qDebug("Renaming %s to %s", qUtf8Printable(oldName), qUtf8Printable(name));
            renameFile(fileIndex, name);
        }
    }
}

void TorrentImpl::handleFileErrorAlert(const lt::file_error_alert *p)
{
    m_lastFileError = {p->error, p->op};
}

#ifdef QBT_USES_LIBTORRENT2
void TorrentImpl::handleFilePrioAlert(const lt::file_prio_alert *)
{
    if (m_nativeHandle.need_save_resume_data())
        m_session->handleTorrentNeedSaveResumeData(this);
}
#endif

void TorrentImpl::handleMetadataReceivedAlert(const lt::metadata_received_alert *p)
{
    Q_UNUSED(p);
    qDebug("Metadata received for torrent %s.", qUtf8Printable(name()));

    m_maintenanceJob = MaintenanceJob::HandleMetadata;
    m_session->handleTorrentNeedSaveResumeData(this);
}

void TorrentImpl::handlePerformanceAlert(const lt::performance_alert *p) const
{
    LogMsg((tr("Performance alert: ") + QString::fromStdString(p->message()))
           , Log::INFO);
}

void TorrentImpl::handleTempPathChanged()
{
    adjustActualSavePath();
}

void TorrentImpl::handleCategorySavePathChanged()
{
    if (m_useAutoTMM)
        move_impl(m_session->categorySavePath(m_category), MoveStorageMode::Overwrite);
}

void TorrentImpl::handleAppendExtensionToggled()
{
    if (!hasMetadata()) return;

    manageIncompleteFiles();
}

void TorrentImpl::handleAlert(const lt::alert *a)
{
    switch (a->type())
    {
#ifdef QBT_USES_LIBTORRENT2
    case lt::file_prio_alert::alert_type:
        handleFilePrioAlert(static_cast<const lt::file_prio_alert*>(a));
        break;
#endif
    case lt::file_renamed_alert::alert_type:
        handleFileRenamedAlert(static_cast<const lt::file_renamed_alert*>(a));
        break;
    case lt::file_rename_failed_alert::alert_type:
        handleFileRenameFailedAlert(static_cast<const lt::file_rename_failed_alert*>(a));
        break;
    case lt::file_completed_alert::alert_type:
        handleFileCompletedAlert(static_cast<const lt::file_completed_alert*>(a));
        break;
    case lt::file_error_alert::alert_type:
        handleFileErrorAlert(static_cast<const lt::file_error_alert*>(a));
        break;
    case lt::torrent_finished_alert::alert_type:
        handleTorrentFinishedAlert(static_cast<const lt::torrent_finished_alert*>(a));
        break;
    case lt::save_resume_data_alert::alert_type:
        handleSaveResumeDataAlert(static_cast<const lt::save_resume_data_alert*>(a));
        break;
    case lt::save_resume_data_failed_alert::alert_type:
        handleSaveResumeDataFailedAlert(static_cast<const lt::save_resume_data_failed_alert*>(a));
        break;
    case lt::torrent_paused_alert::alert_type:
        handleTorrentPausedAlert(static_cast<const lt::torrent_paused_alert*>(a));
        break;
    case lt::torrent_resumed_alert::alert_type:
        handleTorrentResumedAlert(static_cast<const lt::torrent_resumed_alert*>(a));
        break;
    case lt::tracker_error_alert::alert_type:
        handleTrackerErrorAlert(static_cast<const lt::tracker_error_alert*>(a));
        break;
    case lt::tracker_reply_alert::alert_type:
        handleTrackerReplyAlert(static_cast<const lt::tracker_reply_alert*>(a));
        break;
    case lt::tracker_warning_alert::alert_type:
        handleTrackerWarningAlert(static_cast<const lt::tracker_warning_alert*>(a));
        break;
    case lt::metadata_received_alert::alert_type:
        handleMetadataReceivedAlert(static_cast<const lt::metadata_received_alert*>(a));
        break;
    case lt::fastresume_rejected_alert::alert_type:
        handleFastResumeRejectedAlert(static_cast<const lt::fastresume_rejected_alert*>(a));
        break;
    case lt::torrent_checked_alert::alert_type:
        handleTorrentCheckedAlert(static_cast<const lt::torrent_checked_alert*>(a));
        break;
    case lt::performance_alert::alert_type:
        handlePerformanceAlert(static_cast<const lt::performance_alert*>(a));
        break;
    }
}

void TorrentImpl::manageIncompleteFiles()
{
    const bool isAppendExtensionEnabled = m_session->isAppendExtensionEnabled();
    const QVector<qreal> fp = filesProgress();
    if (fp.size() != filesCount())
    {
        qDebug() << "skip manageIncompleteFiles because of invalid torrent meta-data or empty file-progress";
        return;
    }

    for (int i = 0; i < filesCount(); ++i)
    {
        QString name = filePath(i);
        if (isAppendExtensionEnabled && (fileSize(i) > 0) && (fp[i] < 1))
        {
            if (!name.endsWith(QB_EXT, Qt::CaseInsensitive))
            {
                const QString newName = name + QB_EXT;
                qDebug() << "Renaming" << name << "to" << newName;
                renameFile(i, newName);
            }
        }
        else
        {
            if (name.endsWith(QB_EXT, Qt::CaseInsensitive))
            {
                const QString oldName = name;
                name.chop(QB_EXT.size());
                qDebug() << "Renaming" << oldName << "to" << name;
                renameFile(i, name);
            }
        }
    }
}

void TorrentImpl::adjustActualSavePath()
{
    if (!isMoveInProgress())
        adjustActualSavePath_impl();
    else
        m_moveFinishedTriggers.append([this]() { adjustActualSavePath_impl(); });
}

void TorrentImpl::adjustActualSavePath_impl()
{
    const bool needUseTempDir = useTempPath();
    const QDir tempDir {m_session->torrentTempPath(info())};
    const QDir currentDir {actualStorageLocation()};
    const QDir targetDir {needUseTempDir ? tempDir : QDir {savePath()}};

    if (targetDir == currentDir) return;

    if (!needUseTempDir)
    {
        if ((currentDir == tempDir) && (currentDir != QDir {m_session->tempPath()}))
        {
            // torrent without root folder still has it in its temporary save path
            // so its temp path isn't equal to temp path root
            const QString currentDirPath = currentDir.absolutePath();
            m_moveFinishedTriggers.append([currentDirPath]
            {
                qDebug() << "Removing torrent temp folder:" << currentDirPath;
                Utils::Fs::smartRemoveEmptyFolderTree(currentDirPath);
            });
        }
    }

    moveStorage(Utils::Fs::toNativePath(targetDir.absolutePath()), MoveStorageMode::Overwrite);
}

lt::torrent_handle TorrentImpl::nativeHandle() const
{
    return m_nativeHandle;
}

bool TorrentImpl::isMoveInProgress() const
{
    return m_storageIsMoving;
}

bool TorrentImpl::useTempPath() const
{
    return m_session->isTempPathEnabled() && !(isSeed() || m_hasSeedStatus);
}

void TorrentImpl::updateStatus()
{
    updateStatus(m_nativeHandle.status());
}

void TorrentImpl::updateStatus(const lt::torrent_status &nativeStatus)
{
    m_nativeStatus = nativeStatus;
    updateState();

    m_speedMonitor.addSample({nativeStatus.download_payload_rate
                              , nativeStatus.upload_payload_rate});

    if (hasMetadata())
    {
        // NOTE: Don't change the order of these conditionals!
        // Otherwise it will not work properly since torrent can be CheckingDownloading.
        if (isChecking())
            m_unchecked = false;
        else if (isDownloading())
            m_unchecked = true;
    }
}

void TorrentImpl::setRatioLimit(qreal limit)
{
    if (limit < USE_GLOBAL_RATIO)
        limit = NO_RATIO_LIMIT;
    else if (limit > MAX_RATIO)
        limit = MAX_RATIO;

    if (m_ratioLimit != limit)
    {
        m_ratioLimit = limit;
        m_session->handleTorrentNeedSaveResumeData(this);
        m_session->handleTorrentShareLimitChanged(this);
    }
}

void TorrentImpl::setSeedingTimeLimit(int limit)
{
    if (limit < USE_GLOBAL_SEEDING_TIME)
        limit = NO_SEEDING_TIME_LIMIT;
    else if (limit > MAX_SEEDING_TIME)
        limit = MAX_SEEDING_TIME;

    if (m_seedingTimeLimit != limit)
    {
        m_seedingTimeLimit = limit;
        m_session->handleTorrentNeedSaveResumeData(this);
        m_session->handleTorrentShareLimitChanged(this);
    }
}

void TorrentImpl::setUploadLimit(const int limit)
{
    if (limit == uploadLimit())
        return;

    m_nativeHandle.set_upload_limit(limit);
    m_session->handleTorrentNeedSaveResumeData(this);
}

void TorrentImpl::setDownloadLimit(const int limit)
{
    if (limit == downloadLimit())
        return;

    m_nativeHandle.set_download_limit(limit);
    m_session->handleTorrentNeedSaveResumeData(this);
}

void TorrentImpl::setSuperSeeding(const bool enable)
{
    if (enable == superSeeding())
        return;

    if (enable)
        m_nativeHandle.set_flags(lt::torrent_flags::super_seeding);
    else
        m_nativeHandle.unset_flags(lt::torrent_flags::super_seeding);

    m_session->handleTorrentNeedSaveResumeData(this);
}

void TorrentImpl::setDHTDisabled(const bool disable)
{
    if (disable == isDHTDisabled())
        return;

    if (disable)
        m_nativeHandle.set_flags(lt::torrent_flags::disable_dht);
    else
        m_nativeHandle.unset_flags(lt::torrent_flags::disable_dht);

    m_session->handleTorrentNeedSaveResumeData(this);
}

void TorrentImpl::setPEXDisabled(const bool disable)
{
    if (disable == isPEXDisabled())
        return;

    if (disable)
        m_nativeHandle.set_flags(lt::torrent_flags::disable_pex);
    else
        m_nativeHandle.unset_flags(lt::torrent_flags::disable_pex);

    m_session->handleTorrentNeedSaveResumeData(this);
}

void TorrentImpl::setLSDDisabled(const bool disable)
{
    if (disable == isLSDDisabled())
        return;

    if (disable)
        m_nativeHandle.set_flags(lt::torrent_flags::disable_lsd);
    else
        m_nativeHandle.unset_flags(lt::torrent_flags::disable_lsd);

    m_session->handleTorrentNeedSaveResumeData(this);
}

void TorrentImpl::flushCache() const
{
    m_nativeHandle.flush_cache();
}

QString TorrentImpl::createMagnetURI() const
{
    return QString::fromStdString(lt::make_magnet_uri(m_nativeHandle));
}

void TorrentImpl::prioritizeFiles(const QVector<DownloadPriority> &priorities)
{
    if (!hasMetadata()) return;

    Q_ASSERT(priorities.size() == filesCount());

    // Reset 'm_hasSeedStatus' if needed in order to react again to
    // 'torrent_finished_alert' and eg show tray notifications
    const QVector<qreal> progress = filesProgress();
    const QVector<DownloadPriority> oldPriorities = filePriorities();
    for (int i = 0; i < oldPriorities.size(); ++i)
    {
        if ((oldPriorities[i] == DownloadPriority::Ignored)
            && (priorities[i] > DownloadPriority::Ignored)
            && (progress[i] < 1.0))
        {
            m_hasSeedStatus = false;
            break;
        }
    }

    const int internalFilesCount = m_torrentInfo.nativeInfo()->files().num_files(); // including .pad files
    auto nativePriorities = std::vector<lt::download_priority_t>(internalFilesCount, LT::toNative(DownloadPriority::Normal));
    const auto nativeIndexes = m_torrentInfo.nativeIndexes();
    for (int i = 0; i < priorities.size(); ++i)
        nativePriorities[LT::toUnderlyingType(nativeIndexes[i])] = LT::toNative(priorities[i]);

    qDebug() << Q_FUNC_INFO << "Changing files priorities...";
    m_nativeHandle.prioritize_files(nativePriorities);

    // Restore first/last piece first option if necessary
    if (m_hasFirstLastPiecePriority)
        applyFirstLastPiecePriority(true, priorities);
}

QVector<qreal> TorrentImpl::availableFileFractions() const
{
    const int filesCount = this->filesCount();
    if (filesCount <= 0) return {};

    const QVector<int> piecesAvailability = pieceAvailability();
    // libtorrent returns empty array for seeding only torrents
    if (piecesAvailability.empty()) return QVector<qreal>(filesCount, -1);

    QVector<qreal> res;
    res.reserve(filesCount);
    const TorrentInfo info = this->info();
    for (int i = 0; i < filesCount; ++i)
    {
        const TorrentInfo::PieceRange filePieces = info.filePieces(i);

        int availablePieces = 0;
        for (const int piece : filePieces)
            availablePieces += (piecesAvailability[piece] > 0) ? 1 : 0;

        const qreal availability = filePieces.isEmpty()
            ? 1  // the file has no pieces, so it is available by default
            : static_cast<qreal>(availablePieces) / filePieces.size();
        res.push_back(availability);
    }
    return res;
}