Add "Export .torrent" action

src/base/bittorrent/torrent.h

@@ -34,6 +34,7 @@
 #include <QMetaType>
 #include <QString>
 
+#include "base/3rdparty/expected.hpp"
 #include "base/pathfwd.h"
 #include "base/tagset.h"
 #include "abstractfilestorage.h"
@@ -300,6 +301,7 @@ namespace BitTorrent
         virtual void clearPeers() = 0;
 
         virtual QString createMagnetURI() const = 0;
+        virtual nonstd::expected<void, QString> exportToFile(const Path &path) const = 0;
 
         TorrentID id() const;
         bool isResumed() const;

src/base/bittorrent/torrentimpl.cpp

@@ -35,6 +35,7 @@
 
 #include <libtorrent/address.hpp>
 #include <libtorrent/alert_types.hpp>
+#include <libtorrent/create_torrent.hpp>
 #include <libtorrent/magnet_uri.hpp>
 #include <libtorrent/session.hpp>
 #include <libtorrent/storage_defs.hpp>
@@ -53,6 +54,7 @@
 #include "base/logger.h"
 #include "base/preferences.h"
 #include "base/utils/fs.h"
+#include "base/utils/io.h"
 #include "base/utils/string.h"
 #include "common.h"
 #include "downloadpriority.h"
@@ -2232,6 +2234,37 @@ QString TorrentImpl::createMagnetURI() const
     return QString::fromStdString(lt::make_magnet_uri(m_nativeHandle));
 }
 
+nonstd::expected<void, QString> TorrentImpl::exportToFile(const Path &path) const
+{
+    if (!hasMetadata())
+        return nonstd::make_unexpected(tr("Missing metadata"));
+
+    try
+    {
+#ifdef QBT_USES_LIBTORRENT2
+        const std::shared_ptr<lt::torrent_info> completeTorrentInfo = m_nativeHandle.torrent_file_with_hashes();
+        const std::shared_ptr<lt::torrent_info> torrentInfo = {completeTorrentInfo ? completeTorrentInfo : info().nativeInfo()};
+#else
+        const std::shared_ptr<lt::torrent_info> torrentInfo = info().nativeInfo();
+#endif
+        auto creator = lt::create_torrent(*torrentInfo);
+
+        for (const TrackerEntry &entry : asConst(trackers()))
+            creator.add_tracker(entry.url.toStdString(), entry.tier);
+
+        const lt::entry torrentEntry = creator.generate();
+        const nonstd::expected<void, QString> result = Utils::IO::saveToFile(path, torrentEntry);
+        if (!result)
+            return result.get_unexpected();
+    }
+    catch (const lt::system_error &err)
+    {
+        return nonstd::make_unexpected(QString::fromLocal8Bit(err.what()));
+    }
+
+    return {};
+}
+
 void TorrentImpl::prioritizeFiles(const QVector<DownloadPriority> &priorities)
 {
     if (!hasMetadata()) return;

src/base/bittorrent/torrentimpl.h

@@ -227,6 +227,7 @@ namespace BitTorrent
         void clearPeers() override;
 
         QString createMagnetURI() const override;
+        nonstd::expected<void, QString> exportToFile(const Path &path) const;
 
         bool needSaveResumeData() const;
 

src/base/bittorrent/torrentinfo.cpp

@@ -38,7 +38,6 @@
 #include <QString>
 #include <QStringList>
 #include <QUrl>
-#include <QVector>
 
 #include "base/global.h"
 #include "base/path.h"

src/base/bittorrent/torrentinfo.h

@@ -32,6 +32,7 @@
 
 #include <QCoreApplication>
 #include <QtContainerFwd>
+#include <QVector>
 
 #include "base/3rdparty/expected.hpp"
 #include "base/indexrange.h"

src/gui/transferlistwidget.cpp

@@ -47,6 +47,7 @@
 #include "base/bittorrent/trackerentry.h"
 #include "base/global.h"
 #include "base/logger.h"
+#include "base/path.h"
 #include "base/preferences.h"
 #include "base/torrentfilter.h"
 #include "base/utils/compare.h"
@@ -757,6 +758,57 @@ void TransferListWidget::editTorrentTrackers()
     trackerDialog->open();
 }
 
+void TransferListWidget::exportTorrent()
+{
+    if (getSelectedTorrents().isEmpty())
+        return;
+
+    auto fileDialog = new QFileDialog(this, tr("Choose folder to save exported .torrent files"));
+    fileDialog->setAttribute(Qt::WA_DeleteOnClose);
+    fileDialog->setFileMode(QFileDialog::Directory);
+    fileDialog->setOptions(QFileDialog::ShowDirsOnly);
+    connect(fileDialog, &QFileDialog::fileSelected, this, [this](const QString &dir)
+    {
+        const QVector<BitTorrent::Torrent *> torrents = getSelectedTorrents();
+        if (torrents.isEmpty())
+            return;
+
+        const Path savePath {dir};
+        if (!savePath.exists())
+            return;
+
+        const QString errorMsg = tr("Export .torrent file failed. Torrent: \"%1\". Save path: \"%2\". Reason: \"%3\"");
+
+        bool hasError = false;
+        for (const BitTorrent::Torrent *torrent : torrents)
+        {
+            const Path filePath = savePath / Path(torrent->name() + u".torrent");
+            if (filePath.exists())
+            {
+                LogMsg(errorMsg.arg(torrent->name(), filePath.toString(), tr("A file with the same name already exists")) , Log::WARNING);
+                hasError = true;
+                continue;
+            }
+
+            const nonstd::expected<void, QString> result = torrent->exportToFile(filePath);
+            if (!result)
+            {
+                LogMsg(errorMsg.arg(torrent->name(), filePath.toString(), result.error()) , Log::WARNING);
+                hasError = true;
+                continue;
+            }
+        }
+
+        if (hasError)
+        {
+            QMessageBox::warning(this, tr("Export .torrent file error")
+                , tr("Errors occured when exporting .torrent files. Check execution log for details."));
+        }
+    });
+
+    fileDialog->open();
+}
+
 void TransferListWidget::confirmRemoveAllTagsForSelection()
 {
     QMessageBox::StandardButton response = QMessageBox::question(
@@ -906,6 +958,8 @@ void TransferListWidget::displayListMenu()
     connect(actionAutoTMM, &QAction::triggered, this, &TransferListWidget::setSelectedAutoTMMEnabled);
     auto *actionEditTracker = new QAction(UIThemeManager::instance()->getIcon(u"edit-rename"_qs), tr("Edit trackers..."), listMenu);
     connect(actionEditTracker, &QAction::triggered, this, &TransferListWidget::editTorrentTrackers);
+    auto *actionExportTorrent = new QAction(UIThemeManager::instance()->getIcon(u"edit-copy"_qs), tr("Export .torrent..."), listMenu);
+    connect(actionExportTorrent, &QAction::triggered, this, &TransferListWidget::exportTorrent);
     // End of actions
 
     // Enable/disable pause/start action given the DL state
@@ -1161,8 +1215,7 @@ void TransferListWidget::displayListMenu()
         queueMenu->addAction(actionBottomQueuePos);
     }
 
-    QMenu *copySubMenu = listMenu->addMenu(
-        UIThemeManager::instance()->getIcon(u"edit-copy"_qs), tr("Copy"));
+    QMenu *copySubMenu = listMenu->addMenu(UIThemeManager::instance()->getIcon(u"edit-copy"_qs), tr("Copy"));
     copySubMenu->addAction(actionCopyName);
     copySubMenu->addAction(actionCopyHash1);
     actionCopyHash1->setEnabled(hasInfohashV1);
@@ -1171,6 +1224,9 @@ void TransferListWidget::displayListMenu()
     copySubMenu->addAction(actionCopyMagnetLink);
     copySubMenu->addAction(actionCopyID);
 
+    actionExportTorrent->setToolTip(u"Exported torrent is not necessarily the same as the imported"_qs);
+    listMenu->addAction(actionExportTorrent);
+
     listMenu->popup(QCursor::pos());
 }
 

src/gui/transferlistwidget.h

@@ -34,9 +34,9 @@
 #include <QTreeView>
 
 #include "base/bittorrent/infohash.h"
-#include "base/path.h"
 
 class MainWindow;
+class Path;
 class TransferListModel;
 class TransferListSortModel;
 
@@ -124,6 +124,7 @@ private:
     QVector<BitTorrent::Torrent *> getSelectedTorrents() const;
     void askAddTagsForSelection();
     void editTorrentTrackers();
+    void exportTorrent();
     void confirmRemoveAllTagsForSelection();
     QStringList askTagsForSelection(const QString &dialogTitle);
     void applyToSelectedTorrents(const std::function<void (BitTorrent::Torrent *const)> &fn);