[Client] Sync conflict dialog, onboarding and conflict default

cockatrice/CMakeLists.txt

@@ -29,6 +29,7 @@ set(cockatrice_SOURCES
     src/interface/deck_loader/loaded_deck.cpp
     src/interface/deck_sync/deck_sync_profile.cpp
     src/interface/deck_sync/deck_sync_sidecar.cpp
+    src/interface/deck_sync/deck_sync_manager.cpp
     src/interface/widgets/dialogs/dlg_connect.cpp
     src/interface/widgets/dialogs/dlg_convert_deck_to_cod_format.cpp
     src/interface/widgets/dialogs/dlg_create_game.cpp
@@ -57,6 +58,8 @@ set(cockatrice_SOURCES
     src/interface/widgets/dialogs/dlg_shared_decks_preview.cpp
     src/interface/widgets/dialogs/dlg_settings.cpp
     src/interface/widgets/dialogs/dlg_startup_card_check.cpp
+    src/interface/widgets/dialogs/dlg_sync_conflict.cpp
+    src/interface/widgets/dialogs/dlg_sync_onboarding.cpp
     src/interface/widgets/dialogs/dlg_tip_of_the_day.cpp
     src/interface/widgets/dialogs/dlg_update.cpp
     src/interface/widgets/dialogs/dlg_view_log.cpp

cockatrice/src/client/settings/cache_settings.cpp

@@ -25,6 +25,7 @@
 #include <libcockatrice/settings/commander_bracket_settings.h>
 #include <libcockatrice/settings/debug_settings.h>
 #include <libcockatrice/settings/deck_editor_settings.h>
+#include <libcockatrice/settings/deck_sync_settings.h>
 #include <libcockatrice/settings/download_settings.h>
 #include <libcockatrice/settings/game_filters_settings.h>
 #include <libcockatrice/settings/game_settings.h>
@@ -155,6 +156,7 @@ SettingsCache::SettingsCache()
     cardsDisplaySettings = new CardsDisplaySettings(settingsPath, this);
     interfaceSettings = new InterfaceSettings(settingsPath, this);
     deckEditorSettings = new DeckEditorSettings(settingsPath, this);
+    deckSyncSettings = new DeckSyncSettings(settingsPath, this);
     pathsSettings = new PathsSettings(settingsPath, this);
     visualDeckStorageSettings = new VisualDeckStorageSettings(settingsPath, this);
     appearanceSettings = new AppearanceSettings(settingsPath, this);
@@ -456,6 +458,11 @@ DeckEditorSettings &SettingsCache::deckEditor() const
     return *deckEditorSettings;
 }
 
+DeckSyncSettings &SettingsCache::deckSync() const
+{
+    return *deckSyncSettings;
+}
+
 VisualDeckStorageSettings &SettingsCache::visualDeckStorage() const
 {
     return *visualDeckStorageSettings;

cockatrice/src/client/settings/cache_settings.h

@@ -33,6 +33,7 @@ class ChatSettings;
 class CommanderBracketSettings;
 class DebugSettings;
 class DeckEditorSettings;
+class DeckSyncSettings;
 class DownloadSettings;
 class GameFiltersSettings;
 class GameSettings;
@@ -82,6 +83,7 @@ private:
     CardsDisplaySettings *cardsDisplaySettings = nullptr;
     InterfaceSettings *interfaceSettings = nullptr;
     DeckEditorSettings *deckEditorSettings = nullptr;
+    DeckSyncSettings *deckSyncSettings = nullptr;
     PathsSettings *pathsSettings = nullptr;
     VisualDeckStorageSettings *visualDeckStorageSettings = nullptr;
     AppearanceSettings *appearanceSettings = nullptr;
@@ -150,6 +152,7 @@ public:
     [[nodiscard]] CardsDisplaySettings &cardsDisplay() const;
     [[nodiscard]] InterfaceSettings &userInterface() const;
     [[nodiscard]] DeckEditorSettings &deckEditor() const;
+    [[nodiscard]] DeckSyncSettings &deckSync() const;
     [[nodiscard]] PathsSettings &paths() const;
     [[nodiscard]] VisualDeckStorageSettings &visualDeckStorage() const;
     [[nodiscard]] AppearanceSettings &appearance() const;

cockatrice/src/interface/deck_sync/deck_sync_conflict.h

@@ -0,0 +1,50 @@
+/**
+ * @file deck_sync_conflict.h
+ * @brief Conflict payload between the sync engine and the conflict dialog.
+ */
+
+#ifndef DECK_SYNC_CONFLICT_H
+#define DECK_SYNC_CONFLICT_H
+
+#include <QString>
+
+/** @brief How a both-sides-changed deck is resolved. */
+enum DeckSyncResolutionAction
+{
+    DeckSyncKeepMine,     ///< Upload the local deck, discarding the server version.
+    DeckSyncKeepServer,   ///< Download the server deck, discarding local changes.
+    DeckSyncKeepBoth,     ///< Keep the local deck and store the server version aside.
+    DeckSyncUseMerge,     ///< Upload the auto-merged deck (only when mergeable).
+    DeckSyncSkipConflict, ///< Leave both sides untouched for this run.
+};
+
+/** @brief Sync direction for one run. */
+enum class DeckSyncMode
+{
+    TwoWay,       ///< Mirror both sides (default).
+    UploadOnly,   ///< Push local content; never download or propagate deletes.
+    DownloadOnly, ///< Take server content; never upload or push deletes.
+    Separate,     ///< First-sync verdict only: keep this profile out of sync.
+};
+
+/** @brief One deck that changed both locally and on the server. */
+struct DeckSyncConflict
+{
+    QString relativePath;      ///< Local deck path relative to the deck folder.
+    QString localAbsolutePath; ///< Absolute local file path.
+    QString serverDeckString;  ///< Server deck content in native format.
+    QString baseDeckString;    ///< Last-synced content, empty when no snapshot exists.
+    bool hasBase = false;      ///< False when the base snapshot is missing.
+    qint64 localSecs = 0;      ///< Local modification time, seconds since epoch.
+    qint64 serverSecs = 0;     ///< Server modification time, seconds since epoch.
+};
+
+/** @brief The dialog verdict for one DeckSyncConflict. */
+struct DeckSyncResolution
+{
+    DeckSyncResolutionAction action = DeckSyncKeepMine;
+    bool rememberSession = false; ///< Reuse this verdict for later conflicts this run.
+    bool rememberAlways = false;  ///< Store this verdict as the conflict default setting.
+};
+
+#endif // DECK_SYNC_CONFLICT_H

cockatrice/src/interface/deck_sync/deck_sync_manager.cpp

@@ -0,0 +1,928 @@
+#include "deck_sync_manager.h"
+
+#include "../deck_loader/deck_file_format.h"
+#include "../deck_loader/deck_loader.h"
+#include "deck_sync_sidecar.h"
+
+#include <QDir>
+#include <QDirIterator>
+#include <QFile>
+#include <QFileInfo>
+#include <QUuid>
+#include <libcockatrice/deck_list/deck_diff.h>
+#include <libcockatrice/deck_list/deck_list.h>
+#include <libcockatrice/network/client/abstract/abstract_client.h>
+#include <libcockatrice/protocol/pb/command_deck_del.pb.h>
+#include <libcockatrice/protocol/pb/command_deck_download.pb.h>
+#include <libcockatrice/protocol/pb/command_deck_list.pb.h>
+#include <libcockatrice/protocol/pb/command_deck_new_dir.pb.h>
+#include <libcockatrice/protocol/pb/command_deck_upload.pb.h>
+#include <libcockatrice/protocol/pb/response.pb.h>
+#include <libcockatrice/protocol/pb/response_deck_download.pb.h>
+#include <libcockatrice/protocol/pb/response_deck_list.pb.h>
+#include <libcockatrice/protocol/pb/response_deck_upload.pb.h>
+#include <libcockatrice/protocol/pb/serverinfo_deckstorage.pb.h>
+#include <libcockatrice/protocol/pending_command.h>
+#include <libcockatrice/utility/string_limits.h>
+
+namespace
+{
+constexpr const char *SYNC_META_DIR = ".sync";
+constexpr const char *BACKUP_SUFFIX = ".sync-backup-";
+
+QString serverPathFor(const QString &relativePath)
+{
+    QString path = relativePath;
+    if (path.endsWith(".cod", Qt::CaseInsensitive)) {
+        path.chop(4);
+    }
+    return path;
+}
+} // namespace
+
+DeckSyncManager::DeckSyncManager(QObject *parent) : QObject(parent)
+{
+}
+
+void DeckSyncManager::setClient(AbstractClient *_client)
+{
+    client = _client;
+}
+
+void DeckSyncManager::setProfile(const DeckSyncProfile &_profile)
+{
+    profile = _profile;
+}
+
+void DeckSyncManager::setDeckPath(const QString &path)
+{
+    deckPath = path;
+}
+
+void DeckSyncManager::setColorIdentityProvider(ColorIdentityProvider provider)
+{
+    colorIdentityProvider = std::move(provider);
+}
+
+void DeckSyncManager::setConflictDefault(int _conflictDefault)
+{
+    conflictDefault = _conflictDefault;
+}
+
+void DeckSyncManager::setSyncMode(DeckSyncMode mode)
+{
+    syncMode = mode;
+}
+
+bool DeckSyncManager::isSyncing() const
+{
+    return syncing;
+}
+
+void DeckSyncManager::syncNow()
+{
+    if (syncing) {
+        return;
+    }
+    if (client == nullptr || !profile.isValid() || deckPath.isEmpty()) {
+        emit syncFinished(0, 0, 0, 0, tr("Not connected to a server."));
+        return;
+    }
+    QDir deckDir(deckPath);
+    if (!deckDir.exists()) {
+        emit syncFinished(0, 0, 0, 0, tr("Deck folder not found."));
+        return;
+    }
+
+    syncing = true;
+    uploadedCount = 0;
+    downloadedCount = 0;
+    unchangedCount = 0;
+    skippedCount = 0;
+    pendingUploads.clear();
+    pendingDownloads.clear();
+    pendingDeletes.clear();
+    conflictPaths.clear();
+    stashedServerFiles.clear();
+    activeConflict = ActiveConflict();
+    ensuredDirs.clear();
+    ensuredDirs.insert(QString());
+    localFiles.clear();
+    sessionDefault = -1;
+    syncMode = DeckSyncMode::TwoWay;
+    firstSyncRun = false;
+    emit syncStarted();
+    emit statusMessage(tr("Scanning local decks..."));
+
+    sidecarPath = DeckSyncSidecar::pathForDeckPath(deckPath, profile.key());
+    DeckSyncSidecar sidecar(sidecarPath);
+    if (!sidecar.load()) {
+        failSync(tr("Could not read sync state."));
+        return;
+    }
+    if (sidecar.mode == DeckSyncSidecar::MODE_SEPARATE) {
+        failSync(tr("Sync is disabled for this server."));
+        return;
+    }
+    firstSyncRun = !QFileInfo(sidecarPath).exists();
+
+    QDirIterator it(deckPath, QDir::Files | QDir::NoDotAndDotDot, QDirIterator::Subdirectories);
+    while (it.hasNext()) {
+        const QString absolutePath = it.next();
+        const QString relativePath = deckDir.relativeFilePath(absolutePath);
+        if (relativePath.startsWith(SYNC_META_DIR + QString("/")) ||
+            !absolutePath.endsWith(".cod", Qt::CaseInsensitive)) {
+            continue;
+        }
+        std::optional<LoadedDeck> loaded = DeckLoader::loadFromFile(absolutePath, DeckFileFormat::Cockatrice);
+        if (!loaded) {
+            ++skippedCount;
+            continue;
+        }
+        LocalFile file;
+        file.absolutePath = absolutePath;
+        file.hash = loaded->deckList.getDeckHash();
+        file.modified = QFileInfo(absolutePath).lastModified();
+        localFiles.insert(relativePath, file);
+    }
+
+    Command_DeckList cmd;
+    PendingCommand *pend = AbstractClient::prepareSessionCommand(cmd);
+    connect(pend, &PendingCommand::finished, this, &DeckSyncManager::onListFinished);
+    client->sendCommand(pend);
+}
+
+void DeckSyncManager::collectServerFiles(const ServerInfo_DeckStorage_Folder &folder,
+                                         const QString &prefix,
+                                         QMap<QString, ServerFile> &files,
+                                         QSet<QString> &dirs)
+{
+    for (const auto &item : folder.items()) {
+        const QString name = QString::fromStdString(item.name());
+        if (item.has_folder()) {
+            const QString path = prefix.isEmpty() ? name : prefix + "/" + name;
+            dirs.insert(path);
+            collectServerFiles(item.folder(), path, files, dirs);
+        } else if (item.has_file()) {
+            const QString path = prefix.isEmpty() ? name : prefix + "/" + name;
+            const ServerInfo_DeckStorage_File &file = item.file();
+            ServerFile entry;
+            entry.id = item.id();
+            entry.guid = QString::fromStdString(file.guid());
+            entry.hash = QString::fromStdString(file.hash());
+            entry.lastModifiedSecs = file.has_last_modified() ? static_cast<qint64>(file.last_modified()) : 0;
+            files.insert(path, entry);
+        }
+    }
+}
+
+void DeckSyncManager::onListFinished(const Response &response, const CommandContainer & /*commandContainer*/)
+{
+    if (!syncing) {
+        return;
+    }
+    if (response.response_code() != Response::RespOk) {
+        failSync(tr("Could not read server decks."));
+        return;
+    }
+
+    QMap<QString, ServerFile> serverFiles;
+    QSet<QString> serverDirs;
+    const Response_DeckList &list = response.GetExtension(Response_DeckList::ext);
+    collectServerFiles(list.root(), QString(), serverFiles, serverDirs);
+    ensuredDirs.unite(serverDirs);
+
+    if (firstSyncRun && !localFiles.isEmpty() && !serverFiles.isEmpty()) {
+        stashedServerFiles = serverFiles;
+        emit firstSyncDetected(localFiles.size(), serverFiles.size());
+        return;
+    }
+    classify(serverFiles);
+}
+
+void DeckSyncManager::continueFirstSync(DeckSyncMode mode)
+{
+    if (!syncing || !firstSyncRun) {
+        return;
+    }
+    firstSyncRun = false;
+    if (mode == DeckSyncMode::Separate) {
+        DeckSyncSidecar sidecar(sidecarPath);
+        sidecar.load();
+        sidecar.mode = DeckSyncSidecar::MODE_SEPARATE;
+        sidecar.save();
+        stashedServerFiles.clear();
+        failSync(tr("Sync is disabled for this server."));
+        return;
+    }
+    syncMode = mode;
+    classify(stashedServerFiles);
+    stashedServerFiles.clear();
+}
+
+void DeckSyncManager::cancelFirstSync()
+{
+    if (!syncing || !firstSyncRun) {
+        return;
+    }
+    firstSyncRun = false;
+    stashedServerFiles.clear();
+    failSync(tr("Sync cancelled."));
+}
+
+void DeckSyncManager::classify(const QMap<QString, ServerFile> &serverFiles)
+{
+    emit statusMessage(tr("Comparing %1 local and %2 server decks...").arg(localFiles.size()).arg(serverFiles.size()));
+
+    DeckSyncSidecar sidecar(sidecarPath);
+    sidecar.load();
+    const qint64 nowSecs = QDateTime::currentDateTime().toSecsSinceEpoch();
+
+    for (auto it = localFiles.begin(); it != localFiles.end(); ++it) {
+        const QString serverPath = serverPathFor(it.key());
+        auto serverIt = serverFiles.find(serverPath);
+        if (serverIt == serverFiles.end()) {
+            const DeckSyncRecord known = sidecar.get(it.key());
+            if (known.remoteId != -1) {
+                if (syncMode == DeckSyncMode::UploadOnly) {
+                    continue;
+                }
+                // The server no longer lists this deck: it was deleted elsewhere.
+                // Apply the delete locally, keeping a backup of the file.
+                const QString absolutePath = deckPath + "/" + it.key();
+                const QString backupPath =
+                    absolutePath + BACKUP_SUFFIX + QString::number(QDateTime::currentDateTime().toSecsSinceEpoch());
+                if (!QFile::copy(absolutePath, backupPath) || !QFile::remove(absolutePath)) {
+                    ++skippedCount;
+                    continue;
+                }
+                sidecar.remove(it.key());
+                ++downloadedCount;
+                continue;
+            }
+            if (syncMode == DeckSyncMode::DownloadOnly) {
+                continue;
+            }
+            UploadOp op;
+            op.relativePath = it.key();
+            op.serverPath = serverPath;
+            op.deckId = -1;
+            op.guid = !known.guid.isEmpty() ? known.guid : QUuid::createUuid().toString(QUuid::WithoutBraces);
+            pendingUploads.append(op);
+            continue;
+        }
+        if (it.value().hash == serverIt.value().hash) {
+            DeckSyncRecord record = sidecar.get(it.key());
+            if (record.guid.isEmpty()) {
+                record.guid = serverIt.value().guid;
+            }
+            record.remoteId = serverIt.value().id;
+            record.baseHash = it.value().hash;
+            record.lastSyncSecs = nowSecs;
+            record.deleted = false;
+            sidecar.set(it.key(), record);
+            snapshotLocalFile(it.key(), record.guid);
+            ++unchangedCount;
+            continue;
+        }
+        const qint64 localSecs = it.value().modified.toSecsSinceEpoch();
+        const int effective = sessionDefault >= 0 ? sessionDefault : conflictDefault;
+        // A server row without last_modified predates sync: the local file wins.
+        // Otherwise strictly newer wins; ties go to the server.
+        if (syncMode == DeckSyncMode::UploadOnly || effective == DeckSyncConflictKeepMine) {
+            applyUpload(it.key(), serverPath, serverIt.value().id, serverIt.value().guid);
+        } else if (syncMode == DeckSyncMode::DownloadOnly || effective == DeckSyncConflictKeepServer) {
+            applyDownload(it.key(), serverIt.value().id, serverIt.value().guid, serverIt.value().hash,
+                          serverIt.value().lastModifiedSecs);
+        } else if (effective == DeckSyncConflictKeepNewer &&
+                   (serverIt.value().lastModifiedSecs == 0 || localSecs > serverIt.value().lastModifiedSecs)) {
+            applyUpload(it.key(), serverPath, serverIt.value().id, serverIt.value().guid);
+        } else if (effective == DeckSyncConflictKeepNewer) {
+            applyDownload(it.key(), serverIt.value().id, serverIt.value().guid, serverIt.value().hash,
+                          serverIt.value().lastModifiedSecs);
+        } else {
+            queueConflict(it.key(), serverPath, serverIt.value().id, serverIt.value().guid, serverIt.value().hash,
+                          serverIt.value().lastModifiedSecs);
+        }
+    }
+
+    if (syncMode != DeckSyncMode::UploadOnly) {
+        for (auto it = serverFiles.begin(); it != serverFiles.end(); ++it) {
+            const QString wantedPath = it.key().endsWith(".cod", Qt::CaseInsensitive) ? it.key() : it.key() + ".cod";
+            if (localFiles.contains(wantedPath) || QFileInfo(deckPath + "/" + wantedPath).exists()) {
+                continue;
+            }
+            const QString relativePath = uniqueLocalPath(wantedPath);
+            if (relativePath.isEmpty()) {
+                ++skippedCount;
+                continue;
+            }
+            DownloadOp op;
+            op.relativePath = relativePath;
+            op.deckId = it.value().id;
+            op.guid = it.value().guid;
+            op.hash = it.value().hash;
+            op.lastModifiedSecs = it.value().lastModifiedSecs;
+            pendingDownloads.append(op);
+        }
+    }
+
+    if (syncMode != DeckSyncMode::DownloadOnly) {
+        const QMap<QString, DeckSyncRecord> knownRecords = sidecar.records();
+        for (auto it = knownRecords.begin(); it != knownRecords.end(); ++it) {
+            if (localFiles.contains(it.key())) {
+                continue;
+            }
+            if (it.value().remoteId == -1) {
+                sidecar.remove(it.key());
+                continue;
+            }
+            pendingDeletes.append(it.key());
+        }
+    }
+
+    sidecar.save();
+    processNext();
+}
+
+QString DeckSyncManager::parentDir(const QString &path)
+{
+    const int slash = path.lastIndexOf('/');
+    return slash == -1 ? QString() : path.left(slash);
+}
+
+void DeckSyncManager::processNext()
+{
+    if (!syncing || activeConflict.active) {
+        return;
+    }
+    if (!pendingDeletes.isEmpty()) {
+        const QString relativePath = pendingDeletes.first();
+        DeckSyncSidecar sidecar(sidecarPath);
+        sidecar.load();
+        sendDelete(relativePath, sidecar.get(relativePath).remoteId);
+    } else if (!pendingUploads.isEmpty()) {
+        processNextUpload();
+    } else if (!pendingDownloads.isEmpty()) {
+        sendDownload(pendingDownloads.first());
+    } else {
+        finishSync();
+    }
+}
+
+void DeckSyncManager::applyUpload(const QString &relativePath,
+                                  const QString &serverPath,
+                                  int deckId,
+                                  const QString &guid)
+{
+    UploadOp op;
+    op.relativePath = relativePath;
+    op.serverPath = serverPath;
+    op.deckId = deckId;
+    op.guid = guid;
+    pendingUploads.append(op);
+}
+
+void DeckSyncManager::applyDownload(const QString &relativePath,
+                                    int deckId,
+                                    const QString &guid,
+                                    const QString &hash,
+                                    qint64 lastModifiedSecs)
+{
+    DownloadOp op;
+    op.relativePath = relativePath;
+    op.deckId = deckId;
+    op.guid = guid;
+    op.hash = hash;
+    op.lastModifiedSecs = lastModifiedSecs;
+    pendingDownloads.append(op);
+}
+
+QString DeckSyncManager::readBaseSnapshot(const QString &guid) const
+{
+    if (guid.isEmpty()) {
+        return {};
+    }
+    QFile snapshot(deckPath + "/" + SYNC_META_DIR + "/bases/" + guid + ".cod");
+    if (!snapshot.open(QIODevice::ReadOnly)) {
+        return {};
+    }
+    return QString::fromUtf8(snapshot.readAll());
+}
+
+void DeckSyncManager::queueConflict(const QString &relativePath,
+                                    const QString &serverPath,
+                                    int deckId,
+                                    const QString &serverGuid,
+                                    const QString &serverHash,
+                                    qint64 serverLastModifiedSecs)
+{
+    DeckSyncSidecar sidecar(sidecarPath);
+    sidecar.load();
+    const QString guid = !serverGuid.isEmpty() ? serverGuid : sidecar.get(relativePath).guid;
+    if (readBaseSnapshot(guid).isEmpty()) {
+        emit statusMessage(tr("No base snapshot for %1, keeping the newer version.").arg(relativePath));
+        const qint64 localSecs = localFiles.value(relativePath).modified.toSecsSinceEpoch();
+        if (serverLastModifiedSecs == 0 || localSecs > serverLastModifiedSecs) {
+            applyUpload(relativePath, serverPath, deckId, serverGuid);
+        } else {
+            applyDownload(relativePath, deckId, serverGuid, serverHash, serverLastModifiedSecs);
+        }
+        return;
+    }
+    ConflictDownload ctx;
+    ctx.serverPath = serverPath;
+    ctx.deckId = deckId;
+    ctx.guid = serverGuid;
+    ctx.hash = serverHash;
+    ctx.lastModifiedSecs = serverLastModifiedSecs;
+    pendingConflicts.insert(relativePath, ctx);
+    conflictPaths.insert(relativePath);
+    applyDownload(relativePath, deckId, serverGuid, serverHash, serverLastModifiedSecs);
+}
+
+void DeckSyncManager::handleConflictDownload(const QString &relativePath, const QString &serverDeckString)
+{
+    const ConflictDownload ctx = pendingConflicts.take(relativePath);
+    if (sessionDefault == DeckSyncConflictKeepMine) {
+        applyUpload(relativePath, ctx.serverPath, ctx.deckId, ctx.guid);
+        processNext();
+        return;
+    }
+    if (sessionDefault == DeckSyncConflictKeepServer) {
+        applyDownloadedDeck(relativePath, ctx.deckId, serverDeckString, ctx.guid, ctx.hash, ctx.lastModifiedSecs,
+                            ctx.lastModifiedSecs != 0);
+        return;
+    }
+    std::optional<LoadedDeck> loaded =
+        DeckLoader::loadFromFile(localFiles.value(relativePath).absolutePath, DeckFileFormat::Cockatrice);
+    DeckList serverDeck;
+    if (!loaded || !serverDeck.loadFromString_Native(serverDeckString)) {
+        ++skippedCount;
+        processNext();
+        return;
+    }
+
+    DeckSyncSidecar sidecar(sidecarPath);
+    sidecar.load();
+    const QString guid = !ctx.guid.isEmpty() ? ctx.guid : sidecar.get(relativePath).guid;
+    activeConflict.active = true;
+    activeConflict.relativePath = relativePath;
+    activeConflict.serverPath = ctx.serverPath;
+    activeConflict.deckId = ctx.deckId;
+    activeConflict.serverGuid = ctx.guid;
+    activeConflict.serverHash = ctx.hash;
+    activeConflict.serverLastModifiedSecs = ctx.lastModifiedSecs;
+    activeConflict.serverDeckString = serverDeckString;
+
+    DeckSyncConflict conflict;
+    conflict.relativePath = relativePath;
+    conflict.localAbsolutePath = localFiles.value(relativePath).absolutePath;
+    conflict.serverDeckString = serverDeckString;
+    conflict.baseDeckString = readBaseSnapshot(guid);
+    conflict.hasBase = !conflict.baseDeckString.isEmpty();
+    conflict.localSecs = localFiles.value(relativePath).modified.toSecsSinceEpoch();
+    conflict.serverSecs = ctx.lastModifiedSecs;
+    emit conflictRequest(conflict);
+}
+
+void DeckSyncManager::resolveConflict(const DeckSyncResolution &resolution)
+{
+    if (!syncing || !activeConflict.active) {
+        return;
+    }
+    if (resolution.rememberSession &&
+        (resolution.action == DeckSyncKeepMine || resolution.action == DeckSyncKeepServer)) {
+        sessionDefault = resolution.action == DeckSyncKeepMine ? DeckSyncConflictKeepMine : DeckSyncConflictKeepServer;
+    }
+    const ActiveConflict conflict = activeConflict;
+    activeConflict.active = false;
+
+    switch (resolution.action) {
+        case DeckSyncKeepMine:
+            applyUpload(conflict.relativePath, conflict.serverPath, conflict.deckId, conflict.serverGuid);
+            break;
+        case DeckSyncKeepServer:
+            applyDownload(conflict.relativePath, conflict.deckId, conflict.serverGuid, conflict.serverHash,
+                          conflict.serverLastModifiedSecs);
+            break;
+        case DeckSyncKeepBoth: {
+            // Persist the already-fetched server bytes synchronously: queuing a
+            // download here would race the upload below and fetch back Mine.
+            // The aside copy is a new local file, so it gets a fresh guid and
+            // uploads as its own deck on the next run.
+            QString asideBase = conflict.relativePath;
+            if (asideBase.endsWith(".cod", Qt::CaseInsensitive)) {
+                asideBase.chop(4);
+            }
+            const QString aside = uniqueLocalPath(asideBase + " (server).cod");
+            DeckList serverDeck;
+            if (aside.isEmpty() || !serverDeck.loadFromString_Native(conflict.serverDeckString)) {
+                emit statusMessage(tr("Could not store the server version of %1 aside, keeping the local deck.")
+                                       .arg(conflict.relativePath));
+                ++skippedCount;
+            } else {
+                const QString asideAbsolute = deckPath + "/" + aside;
+                QDir().mkpath(QFileInfo(asideAbsolute).absolutePath());
+                if (!DeckLoader::saveToFile(serverDeck, asideAbsolute, DeckFileFormat::Cockatrice)) {
+                    ++skippedCount;
+                } else {
+                    DeckSyncSidecar sidecar(sidecarPath);
+                    sidecar.load();
+                    DeckSyncRecord asideRecord;
+                    asideRecord.guid = QUuid::createUuid().toString(QUuid::WithoutBraces);
+                    asideRecord.baseHash = serverDeck.getDeckHash();
+                    sidecar.set(aside, asideRecord);
+                    sidecar.save();
+                    snapshotLocalFile(aside, asideRecord.guid);
+                }
+            }
+            applyUpload(conflict.relativePath, conflict.serverPath, conflict.deckId, conflict.serverGuid);
+            break;
+        }
+        case DeckSyncUseMerge: {
+            DeckSyncSidecar sidecar(sidecarPath);
+            sidecar.load();
+            const QString guid =
+                !conflict.serverGuid.isEmpty() ? conflict.serverGuid : sidecar.get(conflict.relativePath).guid;
+            DeckList localDeck;
+            DeckList serverDeck;
+            DeckList baseDeck;
+            std::optional<LoadedDeck> loaded = DeckLoader::loadFromFile(
+                localFiles.value(conflict.relativePath).absolutePath, DeckFileFormat::Cockatrice);
+            if (!loaded || !serverDeck.loadFromString_Native(conflict.serverDeckString) ||
+                !baseDeck.loadFromString_Native(readBaseSnapshot(guid))) {
+                emit statusMessage(
+                    tr("Could not build the merge for %1, keeping the local deck.").arg(conflict.relativePath));
+                applyUpload(conflict.relativePath, conflict.serverPath, conflict.deckId, conflict.serverGuid);
+                break;
+            }
+            localDeck = loaded->deckList;
+            const DeckDiffResult localChanges = DeckDiff::diff(baseDeck, localDeck);
+            const DeckDiffResult remoteChanges = DeckDiff::diff(baseDeck, serverDeck);
+            const DeckList merged = DeckDiff::merge(baseDeck, localChanges, remoteChanges);
+            const QString absolutePath = deckPath + "/" + conflict.relativePath;
+            const QString backupPath =
+                absolutePath + BACKUP_SUFFIX + QString::number(QDateTime::currentDateTime().toSecsSinceEpoch());
+            if (!QFile::copy(absolutePath, backupPath) ||
+                !DeckLoader::saveToFile(merged, absolutePath, DeckFileFormat::Cockatrice)) {
+                ++skippedCount;
+                break;
+            }
+            std::optional<LoadedDeck> reloaded = DeckLoader::loadFromFile(absolutePath, DeckFileFormat::Cockatrice);
+            if (reloaded) {
+                localFiles[conflict.relativePath].hash = reloaded->deckList.getDeckHash();
+                localFiles[conflict.relativePath].modified = QFileInfo(absolutePath).lastModified();
+            }
+            applyUpload(conflict.relativePath, conflict.serverPath, conflict.deckId, conflict.serverGuid);
+            break;
+        }
+        case DeckSyncSkipConflict:
+            ++skippedCount;
+            break;
+    }
+    processNext();
+}
+
+void DeckSyncManager::processNextUpload()
+{
+    const UploadOp op = pendingUploads.first();
+    const QString dir = parentDir(op.serverPath);
+    if (!ensuredDirs.contains(dir)) {
+        sendMkDirFor(dir);
+        return;
+    }
+    pendingUploads.removeFirst();
+    sendUpload(op);
+}
+
+void DeckSyncManager::sendMkDirFor(const QString &dir)
+{
+    QStringList parts = dir.split('/');
+    QString made;
+    for (const QString &part : parts) {
+        const QString candidate = made.isEmpty() ? part : made + "/" + part;
+        if (!ensuredDirs.contains(candidate)) {
+            Command_DeckNewDir cmd;
+            cmd.set_path(made.toStdString());
+            cmd.set_dir_name(part.toStdString());
+            PendingCommand *pend = AbstractClient::prepareSessionCommand(cmd);
+            pend->setExtraData(dir);
+            connect(pend, &PendingCommand::finished, this, &DeckSyncManager::onEnsureDirFinished);
+            client->sendCommand(pend);
+            return;
+        }
+        made = candidate;
+    }
+    processNextUpload();
+}
+
+void DeckSyncManager::onEnsureDirFinished(const Response &response,
+                                          const CommandContainer & /*commandContainer*/,
+                                          const QVariant &extraData)
+{
+    if (!syncing) {
+        return;
+    }
+    if (response.response_code() != Response::RespOk) {
+        failSync(tr("Could not create server folder."));
+        return;
+    }
+    const QString dir = extraData.toString();
+    QStringList parts = dir.split('/');
+    QString made;
+    for (const QString &part : parts) {
+        made = made.isEmpty() ? part : made + "/" + part;
+        if (!ensuredDirs.contains(made)) {
+            ensuredDirs.insert(made);
+            break;
+        }
+    }
+    processNextUpload();
+}
+
+void DeckSyncManager::sendUpload(const UploadOp &op)
+{
+    emit statusMessage(tr("Uploading %1...").arg(op.relativePath));
+    std::optional<LoadedDeck> loaded =
+        DeckLoader::loadFromFile(localFiles.value(op.relativePath).absolutePath, DeckFileFormat::Cockatrice);
+    if (!loaded) {
+        ++skippedCount;
+        processNext();
+        return;
+    }
+    const QString deckString = loaded->deckList.writeToString_Native();
+    if (deckString.length() > MAX_FILE_LENGTH) {
+        ++skippedCount;
+        processNext();
+        return;
+    }
+
+    Command_DeckUpload cmd;
+    if (op.deckId == -1) {
+        cmd.set_path(parentDir(op.serverPath).toStdString());
+    } else {
+        cmd.set_deck_id(op.deckId);
+    }
+    cmd.set_deck_list(deckString.toStdString());
+    cmd.set_guid(op.guid.toStdString());
+    if (colorIdentityProvider) {
+        cmd.set_color_identity(colorIdentityProvider(loaded->deckList).toStdString());
+    }
+    PendingCommand *pend = AbstractClient::prepareSessionCommand(cmd);
+    QVariantMap context;
+    context.insert("path", op.relativePath);
+    context.insert("serverPath", op.serverPath);
+    context.insert("deckId", op.deckId);
+    context.insert("guid", op.guid);
+    pend->setExtraData(context);
+    connect(pend, &PendingCommand::finished, this, &DeckSyncManager::onUploadFinished);
+    client->sendCommand(pend);
+}
+
+void DeckSyncManager::onUploadFinished(const Response &response,
+                                       const CommandContainer & /*commandContainer*/,
+                                       const QVariant &extraData)
+{
+    if (!syncing) {
+        return;
+    }
+    const QVariantMap context = extraData.toMap();
+    const QString relativePath = context.value("path").toString();
+    const int deckId = context.value("deckId", -1).toInt();
+    if (response.response_code() != Response::RespOk) {
+        if (response.response_code() == Response::RespNameNotFound && deckId != -1) {
+            // The server row is gone (purged tombstone or removed elsewhere):
+            // upload the deck as new instead of updating a dead id.
+            UploadOp retry;
+            retry.relativePath = relativePath;
+            retry.serverPath = context.value("serverPath").toString();
+            retry.deckId = -1;
+            retry.guid = context.value("guid").toString();
+            pendingUploads.prepend(retry);
+            processNext();
+            return;
+        }
+        ++skippedCount;
+        processNext();
+        return;
+    }
+
+    const Response_DeckUpload &upload = response.GetExtension(Response_DeckUpload::ext);
+    DeckSyncSidecar sidecar(sidecarPath);
+    sidecar.load();
+    DeckSyncRecord record = sidecar.get(relativePath);
+    if (upload.has_new_file()) {
+        const auto &file = upload.new_file();
+        if (!file.file().guid().empty()) {
+            record.guid = QString::fromStdString(file.file().guid());
+        }
+        if (!file.file().hash().empty()) {
+            record.baseHash = QString::fromStdString(file.file().hash());
+        }
+        if (file.file().has_last_modified()) {
+            record.lastSyncSecs = static_cast<qint64>(file.file().last_modified());
+        } else {
+            record.lastSyncSecs = QDateTime::currentDateTime().toSecsSinceEpoch();
+        }
+        record.remoteId = file.id();
+    } else if (localFiles.contains(relativePath)) {
+        record.baseHash = localFiles.value(relativePath).hash;
+        record.lastSyncSecs = QDateTime::currentDateTime().toSecsSinceEpoch();
+    }
+    record.deleted = false;
+    sidecar.set(relativePath, record);
+    sidecar.save();
+    snapshotLocalFile(relativePath, record.guid);
+    ++uploadedCount;
+    processNext();
+}
+
+QString DeckSyncManager::uniqueLocalPath(const QString &relativePath) const
+{
+    if (!QFileInfo(deckPath + "/" + relativePath).exists()) {
+        return relativePath;
+    }
+    QString base = relativePath;
+    if (base.endsWith(".cod", Qt::CaseInsensitive)) {
+        base.chop(4);
+    }
+    for (int i = 2; i < 1000; ++i) {
+        const QString candidate = base + " (" + QString::number(i) + ").cod";
+        if (!QFileInfo(deckPath + "/" + candidate).exists()) {
+            return candidate;
+        }
+    }
+    return QString();
+}
+
+void DeckSyncManager::sendDownload(const DownloadOp &op)
+{
+    emit statusMessage(tr("Downloading %1...").arg(op.relativePath));
+    Command_DeckDownload cmd;
+    cmd.set_deck_id(op.deckId);
+    PendingCommand *pend = AbstractClient::prepareSessionCommand(cmd);
+    pend->setExtraData(op.relativePath);
+    connect(pend, &PendingCommand::finished, this, &DeckSyncManager::onDownloadFinished);
+    client->sendCommand(pend);
+}
+
+void DeckSyncManager::onDownloadFinished(const Response &response,
+                                         const CommandContainer & /*commandContainer*/,
+                                         const QVariant &extraData)
+{
+    if (!syncing) {
+        return;
+    }
+    const QString relativePath = extraData.toString();
+    int finishedDeckId = -1;
+    for (int i = 0; i < pendingDownloads.size(); ++i) {
+        if (pendingDownloads.at(i).relativePath == relativePath) {
+            finishedDeckId = pendingDownloads.at(i).deckId;
+            pendingDownloads.removeAt(i);
+            break;
+        }
+    }
+    if (response.response_code() != Response::RespOk) {
+        ++skippedCount;
+        processNext();
+        return;
+    }
+
+    const Response_DeckDownload &download = response.GetExtension(Response_DeckDownload::ext);
+    if (conflictPaths.contains(relativePath)) {
+        conflictPaths.remove(relativePath);
+        handleConflictDownload(relativePath, QString::fromStdString(download.deck()));
+        return;
+    }
+    applyDownloadedDeck(relativePath, finishedDeckId, QString::fromStdString(download.deck()),
+                        QString::fromStdString(download.guid()), QString::fromStdString(download.hash()),
+                        static_cast<qint64>(download.last_modified()), download.has_last_modified());
+}
+
+void DeckSyncManager::applyDownloadedDeck(const QString &relativePath,
+                                          int deckId,
+                                          const QString &deckString,
+                                          const QString &guid,
+                                          const QString &hash,
+                                          qint64 lastModifiedSecs,
+                                          bool hasLastModified)
+{
+    DeckList deck;
+    if (!deck.loadFromString_Native(deckString)) {
+        ++skippedCount;
+        processNext();
+        return;
+    }
+
+    const QString absolutePath = deckPath + "/" + relativePath;
+    if (localFiles.contains(relativePath)) {
+        const QString backupPath =
+            absolutePath + BACKUP_SUFFIX + QString::number(QDateTime::currentDateTime().toSecsSinceEpoch());
+        if (!QFile::copy(absolutePath, backupPath)) {
+            ++skippedCount;
+            processNext();
+            return;
+        }
+    }
+    QDir().mkpath(QFileInfo(absolutePath).absolutePath());
+    if (!DeckLoader::saveToFile(deck, absolutePath, DeckFileFormat::Cockatrice)) {
+        ++skippedCount;
+        processNext();
+        return;
+    }
+
+    DeckSyncSidecar sidecar(sidecarPath);
+    sidecar.load();
+    DeckSyncRecord record = sidecar.get(relativePath);
+    if (deckId != -1) {
+        record.remoteId = deckId;
+    }
+    if (!guid.isEmpty()) {
+        record.guid = guid;
+    }
+    if (!hash.isEmpty()) {
+        record.baseHash = hash;
+    } else {
+        record.baseHash = deck.getDeckHash();
+    }
+    record.lastSyncSecs = hasLastModified ? lastModifiedSecs : QDateTime::currentDateTime().toSecsSinceEpoch();
+    record.deleted = false;
+    sidecar.set(relativePath, record);
+    sidecar.save();
+    snapshotLocalFile(relativePath, record.guid);
+    ++downloadedCount;
+    processNext();
+}
+
+void DeckSyncManager::sendDelete(const QString &relativePath, int deckId)
+{
+    emit statusMessage(tr("Deleting %1 from server...").arg(relativePath));
+    Command_DeckDel cmd;
+    cmd.set_deck_id(deckId);
+    PendingCommand *pend = AbstractClient::prepareSessionCommand(cmd);
+    pend->setExtraData(relativePath);
+    connect(pend, &PendingCommand::finished, this, &DeckSyncManager::onDeleteFinished);
+    client->sendCommand(pend);
+}
+
+void DeckSyncManager::onDeleteFinished(const Response &response,
+                                       const CommandContainer & /*commandContainer*/,
+                                       const QVariant &extraData)
+{
+    if (!syncing) {
+        return;
+    }
+    const QString relativePath = extraData.toString();
+    for (int i = 0; i < pendingDeletes.size(); ++i) {
+        if (pendingDeletes.at(i) == relativePath) {
+            pendingDeletes.removeAt(i);
+            break;
+        }
+    }
+    // Both outcomes converge the record: pushed deletes and server-side
+    // deletes (already tombstoned, answering NameNotFound) are done.
+    if (response.response_code() == Response::RespOk || response.response_code() == Response::RespNameNotFound) {
+        DeckSyncSidecar sidecar(sidecarPath);
+        sidecar.load();
+        sidecar.remove(relativePath);
+        sidecar.save();
+    } else {
+        ++skippedCount;
+    }
+    processNext();
+}
+
+void DeckSyncManager::snapshotLocalFile(const QString &relativePath, const QString &guid)
+{
+    if (guid.isEmpty()) {
+        return;
+    }
+    QFile source(deckPath + "/" + relativePath);
+    if (!source.open(QIODevice::ReadOnly)) {
+        return;
+    }
+    QDir().mkpath(deckPath + "/" + SYNC_META_DIR + "/bases");
+    QFile snapshot(deckPath + "/" + SYNC_META_DIR + "/bases/" + guid + ".cod");
+    if (!snapshot.open(QIODevice::WriteOnly | QIODevice::Truncate)) {
+        return;
+    }
+    snapshot.write(source.readAll());
+}
+
+void DeckSyncManager::failSync(const QString &error)
+{
+    syncing = false;
+    emit syncFinished(uploadedCount, downloadedCount, unchangedCount, skippedCount, error);
+}
+
+void DeckSyncManager::finishSync()
+{
+    syncing = false;
+    emit statusMessage(tr("Sync complete: %1 uploaded, %2 downloaded, %3 unchanged, %4 skipped.")
+                           .arg(uploadedCount)
+                           .arg(downloadedCount)
+                           .arg(unchangedCount)
+                           .arg(skippedCount));
+    emit syncFinished(uploadedCount, downloadedCount, unchangedCount, skippedCount, QString());
+}

cockatrice/src/interface/deck_sync/deck_sync_manager.h

@@ -0,0 +1,208 @@
+/**
+ * @file deck_sync_manager.h
+ * @brief One-shot two-way deck collection sync between local files and the server.
+ */
+
+#ifndef DECK_SYNC_MANAGER_H
+#define DECK_SYNC_MANAGER_H
+
+#include "deck_sync_conflict.h"
+#include "deck_sync_profile.h"
+
+#include <QDateTime>
+#include <QList>
+#include <QMap>
+#include <QObject>
+#include <QSet>
+#include <QString>
+#include <QVariant>
+#include <functional>
+#include <libcockatrice/settings/deck_sync_settings.h>
+
+class AbstractClient;
+class CommandContainer;
+class DeckList;
+class Response;
+class ServerInfo_DeckStorage_Folder;
+
+/**
+ * @class DeckSyncManager
+ * @brief Runs a manual whole-collection sync: local *.cod files vs server deck storage.
+ *
+ * Each syncNow() run loads the profile sidecar, scans the deck folder, fetches
+ * the server tree and mirrors both sides: unknown local decks upload, unknown
+ * server decks download, and decks changed on both sides resolve newer-wins
+ * (ties go to the server). Matching is path-based; a rename looks like a
+ * delete plus an add. Before a download overwrites a locally modified file, the
+ * local content is copied to a .sync-backup file next to it.
+ *
+ * Ownership: fire-and-forget per run, driven by PendingCommand round trips.
+ * Both-sides-changed decks pause the queue for a verdict via conflictRequest /
+ * resolveConflict (or the conflict default setting); the first sync of an
+ * unknown profile pauses for an onboarding verdict via firstSyncDetected /
+ * continueFirstSync. No watcher and no auto triggers — those arrive later.
+ *
+ * Deletes are tombstones, never silent: a locally deleted deck is pushed with
+ * Command_DeckDel, a server-side delete is applied locally only after copying
+ * the file to a .sync-backup, and resurrection reuses the stored deck id.
+ */
+class DeckSyncManager : public QObject
+{
+    Q_OBJECT
+public:
+    /** @brief Computes the color identity string uploaded alongside a deck. May be empty. */
+    using ColorIdentityProvider = std::function<QString(const DeckList &)>;
+
+    explicit DeckSyncManager(QObject *parent = nullptr);
+
+    void setClient(AbstractClient *_client);
+    void setProfile(const DeckSyncProfile &_profile);
+    void setDeckPath(const QString &path);
+    void setColorIdentityProvider(ColorIdentityProvider provider);
+    void setConflictDefault(int conflictDefault);
+    void setSyncMode(DeckSyncMode mode);
+    [[nodiscard]] bool isSyncing() const;
+
+public slots:
+    void syncNow();
+    /** @brief Continues a paused first sync after the onboarding verdict. */
+    void continueFirstSync(DeckSyncMode mode);
+    /** @brief Aborts a paused first sync without writing any verdict. */
+    void cancelFirstSync();
+    /** @brief Applies the dialog verdict for the active conflict and resumes. */
+    void resolveConflict(const DeckSyncResolution &resolution);
+
+signals:
+    void syncStarted();
+    void statusMessage(const QString &message);
+    void syncFinished(int uploaded, int downloaded, int unchanged, int skipped, const QString &error);
+    /** @brief First sync with content on both sides: the tab must ask how to proceed. */
+    void firstSyncDetected(int localCount, int serverCount);
+    /** @brief A both-sides-changed deck needs a verdict; the queue pauses until resolveConflict. */
+    void conflictRequest(const DeckSyncConflict &conflict);
+
+private slots:
+    void onListFinished(const Response &response, const CommandContainer &commandContainer);
+    void
+    onEnsureDirFinished(const Response &response, const CommandContainer &commandContainer, const QVariant &extraData);
+    void
+    onUploadFinished(const Response &response, const CommandContainer &commandContainer, const QVariant &extraData);
+    void
+    onDownloadFinished(const Response &response, const CommandContainer &commandContainer, const QVariant &extraData);
+    void
+    onDeleteFinished(const Response &response, const CommandContainer &commandContainer, const QVariant &extraData);
+
+private:
+    struct ServerFile
+    {
+        int id = -1;
+        QString guid;
+        QString hash;
+        qint64 lastModifiedSecs = 0;
+    };
+    struct LocalFile
+    {
+        QString absolutePath;
+        QString hash;
+        QDateTime modified;
+    };
+    struct UploadOp
+    {
+        QString relativePath;
+        QString serverPath;
+        int deckId = -1;
+        QString guid;
+    };
+    struct DownloadOp
+    {
+        QString relativePath;
+        int deckId = -1;
+        QString guid;
+        QString hash;
+        qint64 lastModifiedSecs = 0;
+    };
+    struct ActiveConflict
+    {
+        bool active = false;
+        QString relativePath;
+        QString serverPath;
+        int deckId = -1;
+        QString serverGuid;
+        QString serverHash;
+        qint64 serverLastModifiedSecs = 0;
+        QString serverDeckString;
+    };
+    struct ConflictDownload
+    {
+        QString serverPath;
+        int deckId = -1;
+        QString guid;
+        QString hash;
+        qint64 lastModifiedSecs = 0;
+    };
+
+    void failSync(const QString &error);
+    void finishSync();
+    void collectServerFiles(const ServerInfo_DeckStorage_Folder &folder,
+                            const QString &prefix,
+                            QMap<QString, ServerFile> &files,
+                            QSet<QString> &dirs);
+    void processNext();
+    void processNextUpload();
+    void sendMkDirFor(const QString &dir);
+    void sendUpload(const UploadOp &op);
+    void sendDownload(const DownloadOp &op);
+    void sendDelete(const QString &relativePath, int deckId);
+    void snapshotLocalFile(const QString &relativePath, const QString &guid);
+    QString readBaseSnapshot(const QString &guid) const;
+    void classify(const QMap<QString, ServerFile> &serverFiles);
+    void queueConflict(const QString &relativePath,
+                       const QString &serverPath,
+                       int deckId,
+                       const QString &serverGuid,
+                       const QString &serverHash,
+                       qint64 serverLastModifiedSecs);
+    void handleConflictDownload(const QString &relativePath, const QString &serverDeckString);
+    void applyDownloadedDeck(const QString &relativePath,
+                             int deckId,
+                             const QString &deckString,
+                             const QString &guid,
+                             const QString &hash,
+                             qint64 lastModifiedSecs,
+                             bool hasLastModified);
+    void applyUpload(const QString &relativePath, const QString &serverPath, int deckId, const QString &guid);
+    void applyDownload(const QString &relativePath,
+                       int deckId,
+                       const QString &guid,
+                       const QString &hash,
+                       qint64 lastModifiedSecs);
+    static QString parentDir(const QString &path);
+    QString uniqueLocalPath(const QString &relativePath) const;
+
+    AbstractClient *client = nullptr;
+    DeckSyncProfile profile;
+    QString deckPath;
+    ColorIdentityProvider colorIdentityProvider;
+    bool syncing = false;
+
+    QString sidecarPath;
+    QMap<QString, LocalFile> localFiles;
+    QSet<QString> ensuredDirs;
+    QList<UploadOp> pendingUploads;
+    QList<DownloadOp> pendingDownloads;
+    QList<QString> pendingDeletes;
+    QSet<QString> conflictPaths;
+    QMap<QString, ConflictDownload> pendingConflicts;
+    QMap<QString, ServerFile> stashedServerFiles;
+    ActiveConflict activeConflict;
+    DeckSyncMode syncMode = DeckSyncMode::TwoWay;
+    int conflictDefault = DeckSyncConflictAsk;
+    int sessionDefault = -1;
+    bool firstSyncRun = false;
+    int uploadedCount = 0;
+    int downloadedCount = 0;
+    int unchangedCount = 0;
+    int skippedCount = 0;
+};
+
+#endif // DECK_SYNC_MANAGER_H

cockatrice/src/interface/deck_sync/deck_sync_sidecar.cpp

@@ -15,9 +15,15 @@ DeckSyncSidecar::DeckSyncSidecar(const QString &_filePath) : filePath(_filePath)
 {
 }
 
+QString DeckSyncSidecar::pathForDeckPath(const QString &deckPath, const QString &profileKey)
+{
+    return QDir(deckPath).filePath(".sync/" + profileKey + ".json");
+}
+
 bool DeckSyncSidecar::load()
 {
     recordMap.clear();
+    mode = MODE_LINKED;
 
     QFile file(filePath);
     if (!file.exists()) {
@@ -30,6 +36,8 @@ bool DeckSyncSidecar::load()
     if (!document.isObject() || !document.object().value("records").isObject()) {
         return false;
     }
+    const QJsonValue modeValue = document.object().value("mode");
+    mode = modeValue.isString() ? modeValue.toString() : MODE_LINKED;
     const QJsonObject records = document.object().value("records").toObject();
     for (auto it = records.begin(); it != records.end(); ++it) {
         if (!it.value().isObject()) {
@@ -61,6 +69,7 @@ bool DeckSyncSidecar::save() const
     }
     QJsonObject root;
     root.insert("version", SIDECAR_FORMAT_VERSION);
+    root.insert("mode", mode);
     root.insert("records", records);
 
     QDir().mkpath(QFileInfo(filePath).absolutePath());

cockatrice/src/interface/deck_sync/deck_sync_sidecar.h

@@ -30,10 +30,17 @@ struct DeckSyncRecord
 class DeckSyncSidecar
 {
 public:
-    QString filePath; ///< Full path of the sidecar JSON file.
+    static constexpr const char *MODE_LINKED = "linked";
+    static constexpr const char *MODE_SEPARATE = "separate";
+
+    QString filePath;           ///< Full path of the sidecar JSON file.
+    QString mode = MODE_LINKED; ///< Linked normally; separate keeps this profile out of sync.
 
     explicit DeckSyncSidecar(const QString &_filePath);
 
+    /** @brief Sidecar file path for a deck folder and profile key. */
+    static QString pathForDeckPath(const QString &deckPath, const QString &profileKey);
+
     /** @brief Loads records; a missing file loads as empty and returns true. */
     bool load();
     /** @brief Stores records, creating parent folders as needed. */

cockatrice/src/interface/widgets/dialogs/dlg_sync_conflict.cpp

@@ -0,0 +1,178 @@
+#include "dlg_sync_conflict.h"
+
+#include <QCheckBox>
+#include <QDateTime>
+#include <QDialogButtonBox>
+#include <QFile>
+#include <QLabel>
+#include <QListWidget>
+#include <QLocale>
+#include <QRadioButton>
+#include <QVBoxLayout>
+#include <libcockatrice/deck_list/deck_diff.h>
+#include <libcockatrice/deck_list/deck_list.h>
+#include <libcockatrice/deck_list/tree/deck_list_card_node.h>
+#include <libcockatrice/deck_list/tree/inner_deck_list_node.h>
+
+namespace
+{
+QString formatTime(qint64 secsSinceEpoch)
+{
+    return QLocale().toString(QDateTime::fromSecsSinceEpoch(secsSinceEpoch), QLocale::ShortFormat);
+}
+
+int zoneCardCount(const DeckList &deck, const QString &zone)
+{
+    int count = 0;
+    deck.forEachCard([&count, &zone](InnerDecklistNode *zoneNode, DecklistCardNode *card) {
+        if (zoneNode->getName() == zone) {
+            count += card->getNumber();
+        }
+    });
+    return count;
+}
+} // namespace
+
+DlgSyncConflict::DlgSyncConflict(const DeckSyncConflict &_conflict, QWidget *parent)
+    : QDialog(parent), conflict(_conflict)
+{
+    auto *layout = new QVBoxLayout(this);
+
+    titleLabel = new QLabel(this);
+    detailLabel = new QLabel(this);
+    detailLabel->setWordWrap(true);
+    keepMineRadio = new QRadioButton(this);
+    keepServerRadio = new QRadioButton(this);
+    keepBothRadio = new QRadioButton(this);
+    mergeRadio = new QRadioButton(this);
+    changesList = new QListWidget(this);
+    mergeSummaryLabel = new QLabel(this);
+    mergeSummaryLabel->setWordWrap(true);
+    rememberSessionBox = new QCheckBox(this);
+    rememberAlwaysBox = new QCheckBox(this);
+
+    layout->addWidget(titleLabel);
+    layout->addWidget(detailLabel);
+    layout->addWidget(keepMineRadio);
+    layout->addWidget(keepServerRadio);
+    layout->addWidget(keepBothRadio);
+    layout->addWidget(mergeRadio);
+    layout->addWidget(changesList);
+    layout->addWidget(mergeSummaryLabel);
+    layout->addWidget(rememberSessionBox);
+    layout->addWidget(rememberAlwaysBox);
+
+    auto *buttons = new QDialogButtonBox(QDialogButtonBox::Ok | QDialogButtonBox::Cancel, this);
+    connect(buttons, &QDialogButtonBox::accepted, this, &QDialog::accept);
+    connect(buttons, &QDialogButtonBox::rejected, this, &QDialog::reject);
+    layout->addWidget(buttons);
+
+    DeckList localDeck;
+    DeckList serverDeck;
+    QFile localFile(conflict.localAbsolutePath);
+    decksParsed = localFile.open(QIODevice::ReadOnly) && localDeck.loadFromFile_Native(&localFile) &&
+                  serverDeck.loadFromString_Native(conflict.serverDeckString);
+    localIsNewer = conflict.localSecs >= conflict.serverSecs;
+
+    if (decksParsed) {
+        shownChanges = DeckDiff::diff(localDeck, serverDeck);
+        if (conflict.hasBase) {
+            DeckList baseDeck;
+            if (baseDeck.loadFromString_Native(conflict.baseDeckString)) {
+                const DeckDiffResult localChanges = DeckDiff::diff(baseDeck, localDeck);
+                const DeckDiffResult remoteChanges = DeckDiff::diff(baseDeck, serverDeck);
+                mergeable = DeckDiff::canAutoMerge(localChanges, remoteChanges);
+                if (mergeable) {
+                    const DeckList merged = DeckDiff::merge(baseDeck, localChanges, remoteChanges);
+                    mergedMainCount = zoneCardCount(merged, "main");
+                    mergedSideCount = zoneCardCount(merged, "side");
+                }
+            }
+        }
+    }
+
+    if (localIsNewer) {
+        keepMineRadio->setChecked(true);
+    } else {
+        keepServerRadio->setChecked(true);
+    }
+    mergeRadio->setEnabled(mergeable);
+
+    connect(keepMineRadio, &QRadioButton::toggled, this, &DlgSyncConflict::updateRememberBoxes);
+    connect(keepServerRadio, &QRadioButton::toggled, this, &DlgSyncConflict::updateRememberBoxes);
+    connect(keepBothRadio, &QRadioButton::toggled, this, &DlgSyncConflict::updateRememberBoxes);
+    connect(mergeRadio, &QRadioButton::toggled, this, &DlgSyncConflict::updateRememberBoxes);
+    updateRememberBoxes();
+    retranslateUi();
+}
+
+void DlgSyncConflict::retranslateUi()
+{
+    setWindowTitle(tr("Sync conflict"));
+    titleLabel->setText(conflict.relativePath);
+    if (!decksParsed) {
+        detailLabel->setText(tr("This deck changed on both sides, but one version could not be read."));
+    } else {
+        detailLabel->setText(tr("This deck changed both on this device and on the server."));
+    }
+
+    keepMineRadio->setText(
+        tr("Keep my deck (%1%2)").arg(formatTime(conflict.localSecs), localIsNewer ? tr(", newest") : QString()));
+    keepServerRadio->setText(tr("Keep the server deck (%1%2)")
+                                 .arg(formatTime(conflict.serverSecs), localIsNewer ? QString() : tr(", newest")));
+    keepBothRadio->setText(tr("Keep both (store the server version aside)"));
+    mergeRadio->setText(mergeable ? tr("Use the auto-merge") : tr("Use the auto-merge (not available)"));
+
+    changesList->clear();
+    for (const DeckCardChange &change : shownChanges.changes) {
+        changesList->addItem(
+            tr("%1: %2 %3 → %4").arg(change.zone).arg(change.cardName).arg(change.oldCount).arg(change.newCount));
+    }
+
+    if (mergeable) {
+        mergeSummaryLabel->setText(tr("Auto-merge proposal: union of both sides (%1 main, %2 side).")
+                                       .arg(mergedMainCount)
+                                       .arg(mergedSideCount));
+    } else if (!conflict.hasBase) {
+        mergeSummaryLabel->setText(tr("No base snapshot exists, so the versions cannot be merged automatically."));
+    } else {
+        mergeSummaryLabel->setText(tr("The changes overlap, so they cannot be merged automatically."));
+    }
+
+    rememberSessionBox->setText(tr("Remember for the rest of this sync"));
+    rememberAlwaysBox->setText(tr("Always use this rule"));
+}
+
+void DlgSyncConflict::updateRememberBoxes()
+{
+    const bool single = keepMineRadio->isChecked() || keepServerRadio->isChecked();
+    rememberSessionBox->setEnabled(single);
+    rememberAlwaysBox->setEnabled(single);
+    if (!single) {
+        rememberSessionBox->setChecked(false);
+        rememberAlwaysBox->setChecked(false);
+    }
+}
+
+DeckSyncResolutionAction DlgSyncConflict::selectedAction() const
+{
+    if (keepServerRadio->isChecked()) {
+        return DeckSyncKeepServer;
+    }
+    if (keepBothRadio->isChecked()) {
+        return DeckSyncKeepBoth;
+    }
+    if (mergeRadio->isChecked()) {
+        return DeckSyncUseMerge;
+    }
+    return DeckSyncKeepMine;
+}
+
+DeckSyncResolution DlgSyncConflict::resolution() const
+{
+    DeckSyncResolution result;
+    result.action = selectedAction();
+    result.rememberSession = rememberSessionBox->isEnabled() && rememberSessionBox->isChecked();
+    result.rememberAlways = rememberAlwaysBox->isEnabled() && rememberAlwaysBox->isChecked();
+    return result;
+}

cockatrice/src/interface/widgets/dialogs/dlg_sync_conflict.h

@@ -0,0 +1,63 @@
+/**
+ * @file dlg_sync_conflict.h
+ * @brief Dialog for resolving a deck that changed both locally and on the server.
+ */
+
+#ifndef DLG_SYNC_CONFLICT_H
+#define DLG_SYNC_CONFLICT_H
+
+#include "../../deck_sync/deck_sync_conflict.h"
+
+#include <QDialog>
+#include <QString>
+#include <libcockatrice/deck_list/deck_diff.h>
+
+class QCheckBox;
+class QLabel;
+class QListWidget;
+class QRadioButton;
+
+/**
+ * @class DlgSyncConflict
+ * @brief Shows both versions of a conflicted deck and returns the verdict.
+ *
+ * Radio choice between Keep mine / Keep server (newest preselected), Keep both
+ * and Use merge (enabled only when the changes touch disjoint cards). The
+ * change list shows card-count deltas between the two versions; the merge
+ * summary describes the auto-merge proposal. Rejected dialogs resolve as Skip.
+ */
+class DlgSyncConflict : public QDialog
+{
+    Q_OBJECT
+public:
+    explicit DlgSyncConflict(const DeckSyncConflict &conflict, QWidget *parent = nullptr);
+    [[nodiscard]] DeckSyncResolution resolution() const;
+    void retranslateUi();
+
+private slots:
+    void updateRememberBoxes();
+
+private:
+    DeckSyncResolutionAction selectedAction() const;
+
+    DeckSyncConflict conflict;
+    bool decksParsed = false;
+    bool localIsNewer = true;
+    DeckDiffResult shownChanges;
+    bool mergeable = false;
+    int mergedMainCount = 0;
+    int mergedSideCount = 0;
+
+    QLabel *titleLabel;
+    QLabel *detailLabel;
+    QRadioButton *keepMineRadio;
+    QRadioButton *keepServerRadio;
+    QRadioButton *keepBothRadio;
+    QRadioButton *mergeRadio;
+    QListWidget *changesList;
+    QLabel *mergeSummaryLabel;
+    QCheckBox *rememberSessionBox;
+    QCheckBox *rememberAlwaysBox;
+};
+
+#endif // DLG_SYNC_CONFLICT_H

cockatrice/src/interface/widgets/dialogs/dlg_sync_onboarding.cpp

@@ -0,0 +1,59 @@
+#include "dlg_sync_onboarding.h"
+
+#include <QDialogButtonBox>
+#include <QLabel>
+#include <QRadioButton>
+#include <QVBoxLayout>
+
+DlgSyncOnboarding::DlgSyncOnboarding(int _localCount, int _serverCount, QWidget *parent)
+    : QDialog(parent), localCount(_localCount), serverCount(_serverCount)
+{
+    auto *layout = new QVBoxLayout(this);
+
+    detailLabel = new QLabel(this);
+    detailLabel->setWordWrap(true);
+    mergeRadio = new QRadioButton(this);
+    uploadRadio = new QRadioButton(this);
+    downloadRadio = new QRadioButton(this);
+    separateRadio = new QRadioButton(this);
+    mergeRadio->setChecked(true);
+
+    layout->addWidget(detailLabel);
+    layout->addWidget(mergeRadio);
+    layout->addWidget(uploadRadio);
+    layout->addWidget(downloadRadio);
+    layout->addWidget(separateRadio);
+
+    auto *buttons = new QDialogButtonBox(QDialogButtonBox::Ok | QDialogButtonBox::Cancel, this);
+    connect(buttons, &QDialogButtonBox::accepted, this, &QDialog::accept);
+    connect(buttons, &QDialogButtonBox::rejected, this, &QDialog::reject);
+    layout->addWidget(buttons);
+
+    retranslateUi();
+}
+
+void DlgSyncOnboarding::retranslateUi()
+{
+    setWindowTitle(tr("Sync decks to this server"));
+    detailLabel->setText(tr("You have %1 local decks and %2 decks stored on this server. How should they be combined?")
+                             .arg(localCount)
+                             .arg(serverCount));
+    mergeRadio->setText(tr("Merge: keep everything, sync both ways (recommended)"));
+    uploadRadio->setText(tr("Upload mine: push local decks to the server"));
+    downloadRadio->setText(tr("Download server: take the server decks"));
+    separateRadio->setText(tr("Keep separate: do not sync with this server"));
+}
+
+DeckSyncMode DlgSyncOnboarding::selectedMode() const
+{
+    if (uploadRadio->isChecked()) {
+        return DeckSyncMode::UploadOnly;
+    }
+    if (downloadRadio->isChecked()) {
+        return DeckSyncMode::DownloadOnly;
+    }
+    if (separateRadio->isChecked()) {
+        return DeckSyncMode::Separate;
+    }
+    return DeckSyncMode::TwoWay;
+}

cockatrice/src/interface/widgets/dialogs/dlg_sync_onboarding.h

@@ -0,0 +1,43 @@
+/**
+ * @file dlg_sync_onboarding.h
+ * @brief First-sync choice when local decks and server decks meet.
+ */
+
+#ifndef DLG_SYNC_ONBOARDING_H
+#define DLG_SYNC_ONBOARDING_H
+
+#include "../../deck_sync/deck_sync_conflict.h"
+
+#include <QDialog>
+
+class QLabel;
+class QRadioButton;
+
+/**
+ * @class DlgSyncOnboarding
+ * @brief Asks how to combine a non-empty local collection with a non-empty server collection.
+ *
+ * Merge (two-way) is the default. Upload and download restrict the run to one
+ * direction; keeping separate records the profile as sync-disabled.
+ * Rejected dialogs cancel the sync without recording anything.
+ */
+class DlgSyncOnboarding : public QDialog
+{
+    Q_OBJECT
+public:
+    DlgSyncOnboarding(int _localCount, int _serverCount, QWidget *parent = nullptr);
+    [[nodiscard]] DeckSyncMode selectedMode() const;
+    void retranslateUi();
+
+private:
+    int localCount = 0;
+    int serverCount = 0;
+
+    QLabel *detailLabel;
+    QRadioButton *mergeRadio;
+    QRadioButton *uploadRadio;
+    QRadioButton *downloadRadio;
+    QRadioButton *separateRadio;
+};
+
+#endif // DLG_SYNC_ONBOARDING_H

cockatrice/src/interface/widgets/settings_page/general_settings_page.cpp

@@ -28,6 +28,7 @@
 #include <QtGlobal>
 #include <libcockatrice/card/card_localization.h>
 #include <libcockatrice/settings/cards_display_settings.h>
+#include <libcockatrice/settings/deck_sync_settings.h>
 #include <libcockatrice/settings/download_settings.h>
 #include <libcockatrice/settings/paths_settings.h>
 #include <libcockatrice/settings/personal_settings.h>
@@ -332,12 +333,32 @@ GeneralSettingsPage::GeneralSettingsPage()
     pathsGroupBox = new QGroupBox;
     pathsGroupBox->setLayout(pathsGrid);
 
+    // deck sync settings
+    conflictDefaultSelector.addItem("", DeckSyncConflictAsk);
+    conflictDefaultSelector.addItem("", DeckSyncConflictKeepMine);
+    conflictDefaultSelector.addItem("", DeckSyncConflictKeepServer);
+    conflictDefaultSelector.addItem("", DeckSyncConflictKeepNewer);
+    int conflictIndex = conflictDefaultSelector.findData(settings.deckSync().getConflictDefault());
+    if (conflictIndex >= 0) {
+        conflictDefaultSelector.setCurrentIndex(conflictIndex);
+    }
+    connect(&conflictDefaultSelector, qOverload<int>(&QComboBox::currentIndexChanged), this, [this](int index) {
+        SettingsCache::instance().deckSync().setConflictDefault(conflictDefaultSelector.itemData(index).toInt());
+    });
+
+    auto *deckSyncGrid = new QGridLayout;
+    deckSyncGrid->addWidget(&conflictDefaultLabel, 0, 0);
+    deckSyncGrid->addWidget(&conflictDefaultSelector, 0, 1);
+    deckSyncGroupBox = new QGroupBox;
+    deckSyncGroupBox->setLayout(deckSyncGrid);
+
     auto *mainLayout = new QVBoxLayout;
     mainLayout->addWidget(languageGroupBox);
     mainLayout->addWidget(versionGroupBox);
     mainLayout->addWidget(cardDatabaseGroupBox);
     mainLayout->addWidget(startupGroupBox);
     mainLayout->addWidget(pathsGroupBox);
+    mainLayout->addWidget(deckSyncGroupBox);
     mainLayout->addStretch();
 
     GeneralSettingsPage::retranslateUi();
@@ -607,5 +628,13 @@ void GeneralSettingsPage::retranslateUi()
     cardDatabasePathLabel.setText(tr("Card database:"));
     customCardDatabasePathLabel.setText(tr("Custom database directory:"));
     tokenDatabasePathLabel.setText(tr("Token database:"));
+    deckSyncGroupBox->setTitle(tr("Deck sync"));
+    conflictDefaultLabel.setText(tr("When a deck changed on both sides:"));
+    conflictDefaultSelector.setItemText(conflictDefaultSelector.findData(DeckSyncConflictAsk), tr("Ask me every time"));
+    conflictDefaultSelector.setItemText(conflictDefaultSelector.findData(DeckSyncConflictKeepMine), tr("Keep my deck"));
+    conflictDefaultSelector.setItemText(conflictDefaultSelector.findData(DeckSyncConflictKeepServer),
+                                        tr("Keep the server deck"));
+    conflictDefaultSelector.setItemText(conflictDefaultSelector.findData(DeckSyncConflictKeepNewer),
+                                        tr("Keep the newer deck"));
     resetAllPathsButton->setText(tr("Reset all paths"));
 }

cockatrice/src/interface/widgets/settings_page/general_settings_page.h

@@ -52,6 +52,7 @@ private:
     QGroupBox *cardDatabaseGroupBox;
     QGroupBox *startupGroupBox;
     QGroupBox *pathsGroupBox;
+    QGroupBox *deckSyncGroupBox;
 
     QLabel languageLabel;
     QComboBox languageBox;
@@ -101,6 +102,9 @@ private:
     QLineEdit *tokenDatabasePathEdit;
     QPushButton *resetAllPathsButton;
     QLabel *allPathsResetLabel;
+
+    QLabel conflictDefaultLabel;
+    QComboBox conflictDefaultSelector;
 };
 
 #endif // COCKATRICE_GENERAL_SETTINGS_PAGE_H

cockatrice/src/interface/widgets/tabs/tab_deck_storage.cpp

@@ -4,10 +4,15 @@
 #include "../../deck_loader/deck_file_format.h"
 #include "../../deck_loader/deck_loader.h"
 #include "../../deck_loader/loaded_deck.h"
+#include "../../deck_sync/deck_sync_conflict.h"
+#include "../../deck_sync/deck_sync_manager.h"
+#include "../../deck_sync/deck_sync_profile.h"
 #include "../../pixel_map_generator.h"
 #include "../cards/additional_info/deck_color_identity.h"
 #include "../deck_share/deck_share_utils.h"
 #include "../deck_share/share_bar_widget.h"
+#include "../dialogs/dlg_sync_conflict.h"
+#include "../dialogs/dlg_sync_onboarding.h"
 #include "../interface/widgets/server/remote/remote_decklist_tree_widget.h"
 #include "../interface/widgets/utility/get_text_with_max.h"
 #include "abstract_client.h"
@@ -32,6 +37,7 @@
 #include <QInputDialog>
 #include <QItemSelection>
 #include <QItemSelectionModel>
+#include <QLabel>
 #include <QLineEdit>
 #include <QMessageBox>
 #include <QModelIndex>
@@ -63,6 +69,7 @@
 #include <libcockatrice/protocol/pb/response_deck_download.pb.h>
 #include <libcockatrice/protocol/pb/response_deck_upload.pb.h>
 #include <libcockatrice/protocol/pending_command.h>
+#include <libcockatrice/settings/deck_sync_settings.h>
 #include <libcockatrice/settings/network_settings.h>
 #include <libcockatrice/settings/paths_settings.h>
 #include <libcockatrice/utility/string_limits.h>
@@ -178,6 +185,9 @@ TabDeckStorage::TabDeckStorage(TabSupervisor *_tabSupervisor,
     rightVbox->addWidget(shareBar);
     rightVbox->addWidget(serverDirView);
     rightVbox->addLayout(rightToolBarLayout);
+    syncStatusLabel = new QLabel(this);
+    syncStatusLabel->setWordWrap(true);
+    rightVbox->addWidget(syncStatusLabel);
     rightGroupBox = new QGroupBox;
     rightGroupBox->setLayout(rightVbox);
 
@@ -229,6 +239,10 @@ TabDeckStorage::TabDeckStorage(TabSupervisor *_tabSupervisor,
     aPublishDeck->setIcon(QPixmap("theme:icons/lock"));
     connect(aPublishDeck, &QAction::triggered, this, &TabDeckStorage::actPublishDeck);
 
+    aSyncNow = new QAction(this);
+    aSyncNow->setIcon(qApp->style()->standardIcon(QStyle::SP_BrowserReload));
+    connect(aSyncNow, &QAction::triggered, this, &TabDeckStorage::actSyncNow);
+
     // Add actions to toolbars
     leftToolBar->addAction(aOpenLocalDeck);
     leftToolBar->addAction(aRenameLocal);
@@ -240,11 +254,27 @@ TabDeckStorage::TabDeckStorage(TabSupervisor *_tabSupervisor,
 
     rightToolBar->addAction(aOpenRemoteDeck);
     rightToolBar->addAction(aDownload);
+    rightToolBar->addAction(aSyncNow);
     rightToolBar->addAction(aShareDecks);
     rightToolBar->addAction(aPublishDeck);
     rightToolBar->addAction(aNewFolder);
     rightToolBar->addAction(aDeleteRemoteDeck);
 
+    syncManager = new DeckSyncManager(this);
+    syncManager->setClient(client);
+    syncManager->setColorIdentityProvider(
+        [](const DeckList &deck) { return getDeckColorIdentity(deck, CardDatabaseManager::query()); });
+    syncManager->setConflictDefault(SettingsCache::instance().deckSync().getConflictDefault());
+    connect(&SettingsCache::instance().deckSync(), &DeckSyncSettings::conflictDefaultChanged, syncManager,
+            &DeckSyncManager::setConflictDefault);
+    connect(syncManager, &DeckSyncManager::statusMessage, this, &TabDeckStorage::onSyncStatusMessage);
+    connect(syncManager, &DeckSyncManager::syncFinished, this, &TabDeckStorage::onSyncFinished);
+    connect(syncManager, &DeckSyncManager::firstSyncDetected, this, &TabDeckStorage::onFirstSyncDetected);
+    connect(syncManager, &DeckSyncManager::conflictRequest, this, &TabDeckStorage::onConflictRequest);
+    if (currentUserInfo != nullptr) {
+        syncUsername = QString::fromStdString(currentUserInfo->name());
+    }
+
     retranslateUi();
 
     QWidget *mainWidget = new QWidget(this);
@@ -273,6 +303,8 @@ void TabDeckStorage::retranslateUi()
     aShareDecks->setText(tr("Share decks"));
     aPublishDeck->setText(tr("Publish/unpublish deck"));
     aOpenDecksFolder->setText(tr("Open decks folder"));
+    aSyncNow->setText(tr("Sync now"));
+    renderSyncStatus();
     shareBar->retranslateUi();
     if (shareBar->isVisible()) {
         onServerSelectionChanged();
@@ -300,6 +332,7 @@ QString TabDeckStorage::getTargetPath() const
 
 void TabDeckStorage::handleConnected(const ServerInfo_User &userInfo)
 {
+    syncUsername = QString::fromStdString(userInfo.name());
     setRemoteEnabled(userInfo.user_level() & ServerInfo_User::IsRegistered);
 }
 
@@ -317,6 +350,7 @@ void TabDeckStorage::handleConnectionChanged(ClientStatus status)
 
 void TabDeckStorage::setRemoteEnabled(bool enabled)
 {
+    remoteEnabled = enabled;
     aUpload->setEnabled(enabled);
     aOpenRemoteDeck->setEnabled(enabled);
     aDownload->setEnabled(enabled);
@@ -324,6 +358,7 @@ void TabDeckStorage::setRemoteEnabled(bool enabled)
     aPublishDeck->setEnabled(enabled);
     aNewFolder->setEnabled(enabled);
     aDeleteRemoteDeck->setEnabled(enabled);
+    aSyncNow->setEnabled(enabled && !syncManager->isSyncing());
 
     if (enabled) {
         serverDirView->refreshTree();
@@ -527,6 +562,89 @@ void TabDeckStorage::actOpenDecksFolder()
     QDesktopServices::openUrl(QUrl::fromLocalFile(dir));
 }
 
+void TabDeckStorage::actSyncNow()
+{
+    DeckSyncProfile profile(client->serverName(), client->serverPort(), syncUsername);
+    syncManager->setProfile(profile);
+    syncManager->setDeckPath(SettingsCache::instance().paths().getDeckPath());
+    aSyncNow->setEnabled(false);
+    syncManager->syncNow();
+}
+
+void TabDeckStorage::onFirstSyncDetected(int localCount, int serverCount)
+{
+    DlgSyncOnboarding dialog(localCount, serverCount, this);
+    if (dialog.exec() == QDialog::Accepted) {
+        syncManager->continueFirstSync(dialog.selectedMode());
+    } else {
+        syncManager->cancelFirstSync();
+    }
+}
+
+void TabDeckStorage::onConflictRequest(const DeckSyncConflict &conflict)
+{
+    DlgSyncConflict dialog(conflict, this);
+    if (dialog.exec() != QDialog::Accepted) {
+        DeckSyncResolution skip;
+        skip.action = DeckSyncSkipConflict;
+        syncManager->resolveConflict(skip);
+        return;
+    }
+    const DeckSyncResolution resolution = dialog.resolution();
+    if (resolution.rememberAlways &&
+        (resolution.action == DeckSyncKeepMine || resolution.action == DeckSyncKeepServer)) {
+        SettingsCache::instance().deckSync().setConflictDefault(
+            resolution.action == DeckSyncKeepMine ? DeckSyncConflictKeepMine : DeckSyncConflictKeepServer);
+    }
+    syncManager->resolveConflict(resolution);
+}
+
+void TabDeckStorage::onSyncStatusMessage(const QString &message)
+{
+    syncStatusType = SyncStatusType::Working;
+    syncStatusDetail = message;
+    renderSyncStatus();
+}
+
+void TabDeckStorage::onSyncFinished(int uploaded, int downloaded, int unchanged, int skipped, const QString &error)
+{
+    aSyncNow->setEnabled(remoteEnabled);
+    if (!error.isEmpty()) {
+        syncStatusType = SyncStatusType::Failed;
+        syncStatusDetail = error;
+    } else {
+        syncStatusType = SyncStatusType::Finished;
+        syncStatusDetail.clear();
+        lastSyncSummary = {uploaded, downloaded, unchanged, skipped};
+    }
+    renderSyncStatus();
+    if (error.isEmpty()) {
+        serverDirView->refreshTree();
+    }
+}
+
+void TabDeckStorage::renderSyncStatus()
+{
+    switch (syncStatusType) {
+        case SyncStatusType::Working:
+            syncStatusLabel->setText(syncStatusDetail);
+            break;
+        case SyncStatusType::Failed:
+            syncStatusLabel->setText(tr("Sync failed: %1").arg(syncStatusDetail));
+            break;
+        case SyncStatusType::Finished:
+            syncStatusLabel->setText(tr("Sync complete: %1 uploaded, %2 downloaded, %3 unchanged, %4 skipped.")
+                                         .arg(lastSyncSummary.uploaded)
+                                         .arg(lastSyncSummary.downloaded)
+                                         .arg(lastSyncSummary.unchanged)
+                                         .arg(lastSyncSummary.skipped));
+            break;
+        case SyncStatusType::Idle:
+            syncStatusLabel->setText(tr("Not synced yet"));
+            break;
+    }
+}
+
 void TabDeckStorage::actRemoteDoubleClick(const QModelIndex &curRight)
 {
     if (dynamic_cast<RemoteDeckList_TreeModel::FileNode *>(serverDirView->getNode(curRight))) {

cockatrice/src/interface/widgets/tabs/tab_deck_storage.h

@@ -19,15 +19,19 @@
 #include <qtmetamacros.h>
 
 struct LoadedDeck;
+struct DeckSyncConflict;
+struct DeckSyncResolution;
 class ServerInfo_User;
 class QTreeView;
 class QFileSystemModel;
 class QToolBar;
 class QGroupBox;
 class QTimer;
+class QLabel;
 class CommandContainer;
 class Response;
 class ShareBarWidget;
+class DeckSyncManager;
 class QAction;
 class QModelIndex;
 class TabSupervisor;
@@ -50,6 +54,29 @@ private:
     QAction *aOpenLocalDeck, *aRenameLocal, *aUpload, *aNewLocalFolder, *aDeleteLocalDeck;
     QAction *aOpenDecksFolder;
     QAction *aOpenRemoteDeck, *aDownload, *aShareDecks, *aPublishDeck, *aNewFolder, *aDeleteRemoteDeck;
+    QAction *aSyncNow;
+    QLabel *syncStatusLabel;
+    DeckSyncManager *syncManager;
+    QString syncUsername;
+    bool remoteEnabled = false;
+    enum class SyncStatusType
+    {
+        Idle,
+        Working,
+        Finished,
+        Failed
+    };
+    struct SyncSummary
+    {
+        int uploaded = 0;
+        int downloaded = 0;
+        int unchanged = 0;
+        int skipped = 0;
+    };
+    SyncStatusType syncStatusType = SyncStatusType::Idle;
+    QString syncStatusDetail;
+    SyncSummary lastSyncSummary;
+    void renderSyncStatus();
     bool visibilityRefreshStarted = false;
     QTimer *visibilityRefreshTimer;
     QStringList visibilityFailures;
@@ -108,6 +135,12 @@ private slots:
     void deleteFolderFinished(const Response &response, const CommandContainer &commandContainer);
     void deleteDeckFinished(const Response &response, const CommandContainer &commandContainer);
 
+    void actSyncNow();
+    void onFirstSyncDetected(int localCount, int serverCount);
+    void onConflictRequest(const DeckSyncConflict &conflict);
+    void onSyncStatusMessage(const QString &message);
+    void onSyncFinished(int uploaded, int downloaded, int unchanged, int skipped, const QString &error);
+
 public:
     TabDeckStorage(TabSupervisor *_tabSupervisor, AbstractClient *_client, const ServerInfo_User *currentUserInfo);
     void retranslateUi() override;

libcockatrice_settings/CMakeLists.txt

@@ -12,6 +12,7 @@ set(HEADERS
     libcockatrice/settings/commander_bracket_settings.h
     libcockatrice/settings/debug_settings.h
     libcockatrice/settings/deck_editor_settings.h
+    libcockatrice/settings/deck_sync_settings.h
     libcockatrice/settings/download_settings.h
     libcockatrice/settings/game_filters_settings.h
     libcockatrice/settings/game_settings.h
@@ -45,6 +46,7 @@ add_library(
   libcockatrice/settings/chat_settings.cpp
   libcockatrice/settings/debug_settings.cpp
   libcockatrice/settings/deck_editor_settings.cpp
+  libcockatrice/settings/deck_sync_settings.cpp
   libcockatrice/settings/download_settings.cpp
   libcockatrice/settings/game_filters_settings.cpp
   libcockatrice/settings/game_settings.cpp

libcockatrice_settings/libcockatrice/settings/deck_sync_settings.cpp

@@ -0,0 +1,21 @@
+#include "deck_sync_settings.h"
+
+#include "libcockatrice/settings/settings_manager.h"
+
+#include <QVariant>
+
+DeckSyncSettings::DeckSyncSettings(const QString &settingPath, QObject *parent)
+    : SettingsManager(settingPath + "deck_sync.ini", "decksync", QString(), parent)
+{
+}
+
+int DeckSyncSettings::getConflictDefault() const
+{
+    return getValue("conflictDefault", QString(), QString(), DeckSyncConflictAsk).toInt();
+}
+
+void DeckSyncSettings::setConflictDefault(int _conflictDefault)
+{
+    setValue(_conflictDefault, "conflictDefault");
+    emit conflictDefaultChanged(_conflictDefault);
+}

libcockatrice_settings/libcockatrice/settings/deck_sync_settings.h

@@ -0,0 +1,38 @@
+#ifndef DECK_SYNC_SETTINGS_H
+#define DECK_SYNC_SETTINGS_H
+
+#include "settings_manager.h"
+
+#include <QString>
+#include <qtmetamacros.h>
+
+class QObject;
+
+enum DeckSyncConflictDefault
+{
+    DeckSyncConflictAsk = 0,    ///< Ask every time a deck changed on both sides.
+    DeckSyncConflictKeepMine,   ///< Silently keep the local deck.
+    DeckSyncConflictKeepServer, ///< Silently keep the server deck.
+    DeckSyncConflictKeepNewer,  ///< Silently keep whichever side changed last.
+};
+
+class DeckSyncSettings : public SettingsManager
+{
+    Q_OBJECT
+    friend class SettingsCache;
+
+public:
+    [[nodiscard]] int getConflictDefault() const;
+    void setConflictDefault(int _conflictDefault);
+
+signals:
+    void conflictDefaultChanged(int conflictDefault);
+
+public:
+    explicit DeckSyncSettings(const QString &settingPath, QObject *parent = nullptr);
+
+private:
+    DeckSyncSettings(const DeckSyncSettings & /*other*/);
+};
+
+#endif // DECK_SYNC_SETTINGS_H

servatrice/servatrice.ini.example

@@ -488,3 +488,10 @@ max_shares_per_day=50
 ; Minimum enforced: 1.
 ; Default: 20
 max_versions=20
+
+; How many days a deleted deck stays restorable as a tombstone before the
+; cleanup clock purges it (with its versions) for good. Re-uploading the
+; same deck within this window resurrects it instead of creating a copy.
+; A value of 0 purges tombstones on the next cleanup run.
+; Default: 30
+tombstone_days=30

servatrice/src/servatrice.cpp

@@ -460,6 +460,7 @@ bool Servatrice::initServer()
 
     deckShareCleanupClock = new QTimer(this);
     connect(deckShareCleanupClock, SIGNAL(timeout()), this, SLOT(cleanupExpiredDeckShares()));
+    connect(deckShareCleanupClock, SIGNAL(timeout()), this, SLOT(purgeDeckTombstones()));
     const int deckShareCleanupInterval = getDeckShareCleanupInterval();
     if (deckShareCleanupInterval > 0) {
         qDebug() << "Starting deck share cleanup clock, interval" << deckShareCleanupInterval << "ms";
@@ -689,6 +690,11 @@ void Servatrice::cleanupExpiredDeckShares()
     servatriceDatabaseInterface->cleanupExpiredDeckShares();
 }
 
+void Servatrice::purgeDeckTombstones()
+{
+    servatriceDatabaseInterface->purgeDeckTombstones(getDeckSyncTombstoneDays());
+}
+
 void Servatrice::statusUpdate()
 {
     if (!servatriceDatabaseInterface->checkSql()) {
@@ -1127,6 +1133,11 @@ int Servatrice::getDeckSyncMaxVersions() const
     return qMax(1, settingsCache->value("deck_sync/max_versions", 20).toInt());
 }
 
+int Servatrice::getDeckSyncTombstoneDays() const
+{
+    return qMax(0, settingsCache->value("deck_sync/tombstone_days", 30).toInt());
+}
+
 int Servatrice::getNumberOfTCPPools() const
 {
     return settingsCache->value("server/number_pools", 1).toInt();

servatrice/src/servatrice.h

@@ -157,6 +157,7 @@ private slots:
     void statusUpdate();
     void shutdownTimeout();
     void cleanupExpiredDeckShares();
+    void purgeDeckTombstones();
 
 protected:
     void doSendIslMessage(const IslMessage &msg, int _serverId) override;
@@ -293,6 +294,7 @@ public:
     int getDeckShareMaxDecksPerShare() const;
     int getDeckShareMaxSharesPerDay() const;
     int getDeckSyncMaxVersions() const;
+    int getDeckSyncTombstoneDays() const;
     int getMaxUsersPerAddress() const;
     int getMessageCountingInterval() const override;
     int getMaxMessageCountPerInterval() const override;

servatrice/src/servatrice_database_interface.cpp

@@ -1088,8 +1088,8 @@ DeckList *Servatrice_DatabaseInterface::getDeckFromDatabase(int deckId, int user
 {
     checkSql();
 
-    QSqlQuery *query =
-        prepareQuery("select content from {prefix}_decklist_files where id = :id and id_user = :id_user");
+    QSqlQuery *query = prepareQuery(
+        "select content from {prefix}_decklist_files where id = :id and id_user = :id_user and deleted = 0");
     query->bindValue(":id", deckId);
     query->bindValue(":id_user", userId);
     execSqlQuery(query);
@@ -1240,6 +1240,19 @@ void Servatrice_DatabaseInterface::cleanupExpiredDeckShares()
     execSqlQuery(query);
 }
 
+void Servatrice_DatabaseInterface::purgeDeckTombstones(int olderThanDays)
+{
+    checkSql();
+
+    // DB-native clock: tombstones are stamped with NOW() on this same
+    // database, so the grace window is immune to app/db clock skew.
+    // The null arm only catches manually flagged rows.
+    QSqlQuery *query = prepareQuery("delete from {prefix}_decklist_files where deleted = 1 and (last_modified < "
+                                    "DATE_SUB(NOW(), INTERVAL :days DAY) or last_modified is null)");
+    query->bindValue(":days", qMax(0, olderThanDays));
+    execSqlQuery(query);
+}
+
 bool Servatrice_DatabaseInterface::getDeckSharesForUser(int userId, QList<DeckShareSummaryRecord> &shares)
 {
     checkSql();

servatrice/src/servatrice_database_interface.h

@@ -140,6 +140,11 @@ public:
     bool getDeckShareItem(const QString &token, int itemId, QString &content);
     /** @brief Deletes all expired share bundles (cascades to their items). */
     void cleanupExpiredDeckShares();
+    /**
+     * @brief Hard-deletes tombstoned decks older than the grace period (cascades to versions).
+     * @param olderThanDays Tombstones older than this many days are purged; 0 purges all tombstones.
+     */
+    void purgeDeckTombstones(int olderThanDays);
 
     int getNextGameId() override;
     int getNextReplayId() override;

servatrice/src/serversocketinterface.cpp

@@ -683,7 +683,8 @@ bool AbstractServerSocketInterface::deckListHelper(int folderId,
 
     query = sqlInterface->prepareQuery("select id, name, upload_time, is_public, banner_card_name, "
                                        "banner_card_provider, color_identity, tags, guid, hash, last_modified from "
-                                       "{prefix}_decklist_files where id_folder = :id_folder and id_user = :id_user");
+                                       "{prefix}_decklist_files where id_folder = :id_folder and id_user = :id_user "
+                                       "and deleted = 0");
     query->bindValue(":id_folder", folderId);
     query->bindValue(":id_user", userId);
     if (!sqlInterface->execSqlQuery(query)) {
@@ -828,8 +829,8 @@ Response::ResponseCode AbstractServerSocketInterface::cmdDeckSetVisibility(const
     sqlInterface->checkSql();
 
     if (cmd.has_deck_id()) {
-        QSqlQuery *query =
-            sqlInterface->prepareQuery("select 1 from {prefix}_decklist_files where id = :id and id_user = :id_user");
+        QSqlQuery *query = sqlInterface->prepareQuery(
+            "select 1 from {prefix}_decklist_files where id = :id and id_user = :id_user and deleted = 0");
         query->bindValue(":id", cmd.deck_id());
         query->bindValue(":id_user", userInfo->id());
         sqlInterface->execSqlQuery(query);
@@ -939,7 +940,8 @@ void AbstractServerSocketInterface::deckDelDirHelper(int basePathId)
         deckDelDirHelper(query->value(0).toInt());
     }
 
-    query = sqlInterface->prepareQuery("delete from {prefix}_decklist_files where id_folder = :id_folder");
+    query = sqlInterface->prepareQuery("update {prefix}_decklist_files set deleted = 1, last_modified = NOW() "
+                                       "where id_folder = :id_folder and deleted = 0");
     query->bindValue(":id_folder", basePathId);
     sqlInterface->execSqlQuery(query);
 
@@ -990,18 +992,17 @@ Response::ResponseCode AbstractServerSocketInterface::cmdDeckDel(const Command_D
 
     sqlInterface->checkSql();
     QSqlQuery *query =
-        sqlInterface->prepareQuery("select id from {prefix}_decklist_files where id = :id and id_user = :id_user");
+        sqlInterface->prepareQuery("update {prefix}_decklist_files set deleted = 1, last_modified = NOW() where id = "
+                                   ":id and id_user = :id_user and deleted = 0");
     query->bindValue(":id", cmd.deck_id());
     query->bindValue(":id_user", userInfo->id());
-    sqlInterface->execSqlQuery(query);
-    if (!query->next()) {
+    if (!sqlInterface->execSqlQuery(query)) {
+        return Response::RespContextError;
+    }
+    if (query->numRowsAffected() == 0) {
         return Response::RespNameNotFound;
     }
 
-    query = sqlInterface->prepareQuery("delete from {prefix}_decklist_files where id = :id");
-    query->bindValue(":id", cmd.deck_id());
-    sqlInterface->execSqlQuery(query);
-
     return Response::RespOk;
 }
 
@@ -1169,9 +1170,11 @@ Response::ResponseCode AbstractServerSocketInterface::cmdDeckUpload(const Comman
         }
         const QString oldHash = currentQuery->value(1).toString();
 
-        QString updateQuery = "update {prefix}_decklist_files set name=:name, upload_time=NOW(), content=:content, "
-                              "banner_card_name=:banner_card_name, banner_card_provider=:banner_card_provider, "
-                              "color_identity=:color_identity, tags=:tags, guid=:guid, hash=:hash, last_modified=NOW()";
+        QString updateQuery =
+            "update {prefix}_decklist_files set name=:name, upload_time=NOW(), content=:content, "
+            "banner_card_name=:banner_card_name, banner_card_provider=:banner_card_provider, "
+            "color_identity=:color_identity, tags=:tags, guid=:guid, hash=:hash, last_modified=NOW(), "
+            "deleted=0";
         if (cmd.has_is_public()) {
             updateQuery += ", is_public=:is_public";
         }
@@ -1373,7 +1376,7 @@ Response::ResponseCode AbstractServerSocketInterface::cmdDeckShareCreate(const C
         // issues its own query on the same cached statement set.
         QSqlQuery *query =
             sqlInterface->prepareQuery("select id, color_identity from {prefix}_decklist_files where id_folder = "
-                                       ":id_folder and id_user = :id_user");
+                                       ":id_folder and id_user = :id_user and deleted = 0");
         query->bindValue(":id_folder", folderId);
         query->bindValue(":id_user", userInfo->id());
         if (!sqlInterface->execSqlQuery(query)) {

tests/deck_sync_sidecar_test.cpp

@@ -119,6 +119,26 @@ TEST(DeckSyncSidecarTest, RemoveDropsRecord)
     EXPECT_FALSE(reloaded.contains("a.cod"));
 }
 
+TEST(DeckSyncSidecarTest, ModeRoundTripsAndDefaultsToLinked)
+{
+    QTemporaryDir dir;
+    ASSERT_TRUE(dir.isValid());
+    DeckSyncSidecar sidecar(sidecarPath(dir));
+    EXPECT_EQ(sidecar.mode, DeckSyncSidecar::MODE_LINKED);
+    sidecar.mode = DeckSyncSidecar::MODE_SEPARATE;
+    EXPECT_TRUE(sidecar.save());
+
+    DeckSyncSidecar reloaded(sidecarPath(dir));
+    EXPECT_TRUE(reloaded.load());
+    EXPECT_EQ(reloaded.mode, DeckSyncSidecar::MODE_SEPARATE);
+}
+
+TEST(DeckSyncSidecarTest, PathForDeckPathBuildsSidecarPath)
+{
+    QString path = DeckSyncSidecar::pathForDeckPath("/decks", "abc123");
+    EXPECT_EQ(path, QString("/decks/.sync/abc123.json"));
+}
+
 int main(int argc, char **argv)
 {
     ::testing::InitGoogleTest(&argc, argv);

tests/settings/settings_defaults_test.cpp

@@ -11,6 +11,7 @@
 #include <libcockatrice/settings/cards_display_settings.h>
 #include <libcockatrice/settings/chat_settings.h>
 #include <libcockatrice/settings/deck_editor_settings.h>
+#include <libcockatrice/settings/deck_sync_settings.h>
 #include <libcockatrice/settings/download_settings.h>
 #include <libcockatrice/settings/game_settings.h>
 #include <libcockatrice/settings/interface_settings.h>
@@ -531,6 +532,25 @@ TEST_F(SettingsDefaultsTest, DeckEditor_VdeStartupTab_SetAndGet)
     ASSERT_EQ(s.getVdeStartupTab(), VdeStartupTabContext);
 }
 
+// --- DeckSyncSettings ---
+
+TEST_F(SettingsDefaultsTest, DeckSync_ConflictDefault_Default)
+{
+    DeckSyncSettings s(settingsPath, nullptr);
+    ASSERT_EQ(s.getConflictDefault(), DeckSyncConflictAsk);
+}
+
+TEST_F(SettingsDefaultsTest, DeckSync_ConflictDefault_SetAndGet)
+{
+    DeckSyncSettings s(settingsPath, nullptr);
+    s.setConflictDefault(DeckSyncConflictKeepNewer);
+    ASSERT_EQ(s.getConflictDefault(), DeckSyncConflictKeepNewer);
+    s.setConflictDefault(DeckSyncConflictKeepMine);
+    ASSERT_EQ(s.getConflictDefault(), DeckSyncConflictKeepMine);
+    s.setConflictDefault(DeckSyncConflictAsk);
+    ASSERT_EQ(s.getConflictDefault(), DeckSyncConflictAsk);
+}
+
 // --- NetworkSettings ---
 
 TEST_F(SettingsDefaultsTest, Network_ClientID_Default)