imagemanager.cpp

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#include "imagemanager.h"
 
#include <QImageReader>
#include <QRunnable>
#include <utility>
 
#include "dbaccess.h"  // for FileAssociations
#include "mthreadpool.h"
#include "mythdate.h"
#include "mythmediamonitor.h"
 
 
#define LOC QString("ImageManager: ")
#define DBLOC QString("ImageDb(%1): ").arg(m_table)
 
// Must be empty as it's prepended to path
#define STORAGE_GROUP_MOUNT  ""
 
#define DB_TABLE "gallery_files"
 
#define RESULT_ERR(ERR, MESG) \
{   LOG(VB_GENERAL, LOG_ERR, LOC + (MESG)); \
    return QStringList("ERROR") << (ERR); }
 
#define RESULT_OK(MESG) \
{   LOG(VB_FILE, LOG_DEBUG, LOC + (MESG)); \
    return QStringList("OK"); }
 
#define IMPORTDIR "Import"
 
 
class Device
{
public:
    Device(QString name, QString mount,
           MythMediaDevice *media = nullptr, QTemporaryDir *import = nullptr)
        : m_present(true), m_name(std::move(name)), m_mount(std::move(mount)),
          m_media(media), m_dir(import)
    {
        // Path relative to TEMP storage group
        m_thumbs = QString("%1/%2").arg(THUMBNAIL_SUBDIR, m_name);
    }
 
 
    ~Device()
    {
        Close();
 
        // Remove imported images
        delete m_dir;
 
        // Clean up non-SG thumbnails
        if (m_mount != STORAGE_GROUP_MOUNT)
            RemoveThumbs();
    }
 
 
    void Close(bool eject = false)
    {
        // Imports remain present; others do not
        m_present = isImport();
 
        // Release device
        if (m_media)
        {
            if (eject)
            {
                LOG(VB_GENERAL, LOG_INFO, LOC + QString("Ejecting '%1' at '%2'")
                    .arg(m_name, m_mount));
                MediaMonitor::GetMediaMonitor()->EjectMedia(m_media->getDevicePath());
            }
            else
                LOG(VB_MEDIA, LOG_DEBUG, LOC + QString("Unlocked '%1'").arg(m_name));
 
            MediaMonitor::GetMediaMonitor()->Unlock(m_media);
            m_media = nullptr;
        }
    }
 
 
    static void RemoveDirContents(const QString& path)
    {
        QDir(path).removeRecursively();
    }
 
 
    void RemoveThumbs(void) const
    {
        // Remove thumbnails
        QString dir = QString("%1/" TEMP_SUBDIR "/%2").arg(GetConfDir(), m_thumbs);
        LOG(VB_FILE, LOG_INFO, LOC + QString("Removing thumbnails in %1").arg(dir));
        RemoveDirContents(dir);
        QDir::root().rmpath(dir);
    }
 
 
    bool isImport() const                    { return m_dir; }
    bool isPresent() const                   { return m_present; }
    void setPresent(MythMediaDevice *media)  { m_present = true; m_media = media; }
 
    bool             m_present;
    QString          m_name;   
    QString          m_mount;  
    QString          m_thumbs; 
    MythMediaDevice *m_media;  
    QTemporaryDir   *m_dir;    
};
 
 
static Device kNullDevice = Device("Unknown Device", "<Invalid Path>");
 
 
DeviceManager::~DeviceManager()
{
    qDeleteAll(m_devices);
}
 
 
QString DeviceManager::DeviceMount(int devId) const
{
    return m_devices.value(devId, &kNullDevice)->m_mount;
}
 
 
QString DeviceManager::DeviceName(int devId) const
{
    return m_devices.value(devId, &kNullDevice)->m_name;
}
 
 
QString DeviceManager::ThumbDir(int fs) const
{
    return m_devices.value(fs, &kNullDevice)->m_thumbs;
}
 
 
int DeviceManager::OpenDevice(const QString &name, const QString &mount,
                              MythMediaDevice *media, QTemporaryDir *dir)
{
    // Handle devices reappearing at same mountpoint.
    // If a USB is unplugged whilst in use (without unmounting) we get no event
    // but we do when it's re-inserted
    QString state("Known");
    int id = LocateMount(mount);
 
    if (id == DEVICE_INVALID)
    {
        state = "New";
        id = m_devices.isEmpty() ? 0 : m_devices.lastKey() + 1;
        m_devices.insert(id, new Device(name, mount, media, dir));
    }
    else if (m_devices.value(id))
        m_devices.value(id)->setPresent(media);
 
    LOG(VB_GENERAL, LOG_INFO, LOC +
        QString("%1 device %2 mounted at '%3' [Id %4]")
        .arg(state, name, mount).arg(id));
 
    return id;
}
 
 
QStringList DeviceManager::CloseDevices(int devId, const QString &action)
{
    QStringList clear;
 
    if (action == "DEVICE CLOSE ALL")
    {
        // Close all devices but retain their thumbnails
        for (auto *dev : qAsConst(m_devices))
            if (dev)
                dev->Close();
    }
    else if (action == "DEVICE CLEAR ALL")
    {
        // Remove all thumbnails but retain devices
        for (const auto *dev : qAsConst(m_devices)) {
            if (dev)
            {
                clear << dev->m_mount;
                dev->RemoveThumbs();
            }
        }
    }
    else
    {
        // Remove single device & its thumbnails, optionally ejecting it
        Device *dev = m_devices.take(devId);
        if (dev)
        {
            if (action == "DEVICE EJECT")
                dev->Close(true);
            clear << dev->m_mount;
            delete dev;
        }
    }
    return clear;
}
 
 
int DeviceManager::LocateMount(const QString &mount) const
{
    DeviceMap::const_iterator it = m_devices.constBegin();
    while (it != m_devices.constEnd())
    {
        if (it.value()->m_mount == mount)
            return it.key();
        ++it;
    }
    return DEVICE_INVALID;
}
 
 
StringMap DeviceManager::GetDeviceDirs() const
{
    StringMap paths;
#if QT_VERSION < QT_VERSION_CHECK(5,10,0)
    for (int id : m_devices.keys())
    {
        Device *dev = m_devices.value(id);
        if (dev)
            paths.insert(id, dev->m_mount);
    }
#elif QT_VERSION < QT_VERSION_CHECK(5,15,0)
    for (auto it = m_devices.constKeyValueBegin();
         it != m_devices.constKeyValueEnd(); ++it)
    {
        if ((*it).second)
            paths.insert((*it).first, (*it).second->m_mount);
    }
#else
    for (auto it = m_devices.constKeyValueBegin();
         it != m_devices.constKeyValueEnd(); ++it)
    {
        if (it->second)
            paths.insert(it->first, it->second->m_mount);
    }
#endif
    return paths;
}
 
 
QList<int> DeviceManager::GetAbsentees()
{
    QList<int> absent;
#if QT_VERSION < QT_VERSION_CHECK(5,10,0)
    for (int id : m_devices.keys())
    {
        Device *dev = m_devices.value(id);
        if (dev && !dev->isPresent())
            absent << id;
    }
#elif QT_VERSION < QT_VERSION_CHECK(5,15,0)
    for (auto it = m_devices.constKeyValueBegin();
         it != m_devices.constKeyValueEnd(); it++)
    {
        Device *dev = (*it).second;
        if (dev && !dev->isPresent())
            absent << (*it).first;
    }
#else
    for (auto it = m_devices.constKeyValueBegin();
         it != m_devices.constKeyValueEnd(); it++)
    {
        Device *dev = it->second;
        if (dev && !dev->isPresent())
            absent << it->first;
    }
#endif
    return absent;
}
 
 
ImageAdapterBase::ImageAdapterBase() :
    m_imageFileExt(SupportedImages()),
    m_videoFileExt(SupportedVideos())
{
    // Generate glob list from supported extensions
    QStringList glob;
    QStringList allExt = m_imageFileExt + m_videoFileExt;
    for (const auto& ext : qAsConst(allExt))
        glob << "*." + ext;
 
    // Apply filters to only detect image files
    m_dirFilter.setNameFilters(glob);
    m_dirFilter.setFilter(QDir::AllDirs | QDir::Files | QDir::Readable |
                          QDir::NoDotAndDotDot | QDir::NoSymLinks);
 
    // Sync files before dirs to improve thumb generation response
    // Order by time (oldest first) - this determines the order thumbs appear
    m_dirFilter.setSorting(QDir::DirsLast | QDir::Time | QDir::Reversed);
}
 
QStringList ImageAdapterBase::SupportedImages()
{
    // Determine supported picture formats from Qt
    QStringList formats;
    QList<QByteArray> supported = QImageReader::supportedImageFormats();
    for (const auto& ext : qAsConst(supported))
        formats << QString(ext);
    return formats;
}
 
 
QStringList ImageAdapterBase::SupportedVideos()
{
    // Determine supported video formats from MythVideo
    QStringList formats;
    const FileAssociations::association_list faList =
        FileAssociations::getFileAssociation().getList();
    for (const auto & fa : faList)
    {
        if (!fa.use_default && fa.playcommand == "Internal")
            formats << QString(fa.extension);
    }
    return formats;
}
 
 
ImageItem *ImageAdapterLocal::CreateItem(const QFileInfo &fi, int parentId,
                                         int devId, const QString & /*base*/) const
{
    auto *im = new ImageItem();
 
    im->m_parentId  = parentId;
    im->m_device    = devId;
    im->m_filePath  = fi.absoluteFilePath();
 
    if (parentId == GALLERY_DB_ID)
    {
        // Import devices show time of import, other devices show 'last scan time'
        auto secs     = im->m_filePath.contains(IMPORTDIR)
                ? fi.lastModified().toSecsSinceEpoch()
                : QDateTime::currentSecsSinceEpoch();
        im->m_date    = std::chrono::seconds(secs);
        im->m_modTime = im->m_date;
        im->m_type    = kDevice;
        return im;
    }
 
    im->m_modTime = std::chrono::seconds(fi.lastModified().toSecsSinceEpoch());
 
    if (fi.isDir())
    {
        im->m_type = kDirectory;
        return im;
    }
 
    im->m_extension = fi.suffix().toLower();
    im->m_type      = GetImageType(im->m_extension);
 
    if (im->m_type == kUnknown)
    {
        delete im;
        return nullptr;
    }
 
    im->m_thumbPath = GetAbsThumbPath(ThumbDir(im->m_device), ThumbPath(*im));
    im->m_size      = fi.size();
 
    return im;
}
 
 
void ImageAdapterLocal::Notify(const QString &mesg,
                               const QStringList &extra)
{
    QString host(gCoreContext->GetHostName());
    gCoreContext->SendEvent(MythEvent(QString("%1 %2").arg(mesg, host), extra));
}
 
 
ImageItem *ImageAdapterSg::CreateItem(const QFileInfo &fi, int parentId,
                                      int /*devId*/, const QString &base) const
{
    auto *im = new ImageItem();
 
    im->m_device    = 0;
    im->m_parentId  = parentId;
 
    if (parentId == GALLERY_DB_ID)
    {
        // All SG dirs map to a single Db dir
        im->m_filePath = "";
        im->m_type     = kDevice;
        im->m_date     = std::chrono::seconds(QDateTime::currentSecsSinceEpoch());
        im->m_modTime  = im->m_date;
        return im;
    }
 
    // Strip SG path & leading / to leave a relative path
    im->m_filePath = fi.absoluteFilePath().mid(base.size() + 1);
    im->m_modTime  = std::chrono::seconds(fi.lastModified().toSecsSinceEpoch());
 
    if (fi.isDir())
    {
        im->m_type = kDirectory;
        return im;
    }
 
    im->m_extension = fi.suffix().toLower();
    im->m_type      = GetImageType(im->m_extension);
 
    if (im->m_type == kUnknown)
    {
        delete im;
        return nullptr;
    }
 
    im->m_thumbPath = GetAbsThumbPath(ThumbDir(im->m_device), ThumbPath(*im));
    im->m_size      = fi.size();
 
    return im;
}
 
 
void ImageAdapterSg::Notify(const QString &mesg,
                            const QStringList &extra)
{
    gCoreContext->SendEvent(MythEvent(mesg, extra));
}
 
 
StringMap ImageAdapterSg::GetScanDirs() const
{
    StringMap map;
    int i = 0;
    QStringList paths = m_sg.GetDirList();
    for (const auto& path : qAsConst(paths))
        map.insert(i++, path);
    return map;
}
 
 
QString ImageAdapterSg::GetAbsFilePath(const ImagePtrK &im) const
{
    if (im->IsDevice())
        return m_sg.FindNextDirMostFree();
    return im->m_filePath.startsWith("/") ? im->m_filePath
                                          : m_sg.FindFile(im->m_filePath);
}
 
 
// Database fields used by several image queries
#define DB_COLUMNS \
"file_id, filename, name, dir_id, type, modtime, size, " \
"extension, date, hidden, orientation, angle, path, zoom"
// Id, filepath, basename, parentId, type, modtime, size,
// extension, image date, hidden, orientation, cover id, comment, device id
 
 
template <class FS>
ImageItem *ImageDb<FS>::CreateImage(const MSqlQuery &query) const
{
    auto *im = new ImageItem(FS::ImageId(query.value(0).toInt()));
 
    // Ordered as per DB_COLUMNS
    im->m_filePath      = query.value(1).toString();
    im->m_baseName      = query.value(2).toString();
    im->m_parentId      = FS::ImageId(query.value(3).toInt());
    im->m_type          = query.value(4).toInt();
    im->m_modTime       = std::chrono::seconds(query.value(5).toInt());
    im->m_size          = query.value(6).toInt();
    im->m_extension     = query.value(7).toString();
    im->m_date          = std::chrono::seconds(query.value(8).toUInt());
    im->m_isHidden      = query.value(9).toBool();
    im->m_orientation   = query.value(10).toInt();
    im->m_userThumbnail = FS::ImageId(query.value(11).toInt());
    im->m_comment       = query.value(12).toString();
    im->m_device        = query.value(13).toInt();
    im->m_url           = FS::MakeFileUrl(im->m_filePath);
 
    if (im->IsFile())
    {
        // Only pics/vids have thumbs
        QString thumbPath(FS::ThumbPath(*im));
        QString devPath(FS::ThumbDir(im->m_device));
        QString url(FS::MakeThumbUrl(devPath, thumbPath));
 
        im->m_thumbPath = FS::GetAbsThumbPath(devPath, thumbPath);
        im->m_thumbNails.append(qMakePair(im->m_id, url));
    }
    return im;
}
 
 
template <class FS>
int ImageDb<FS>::GetImages(const QString &ids, ImageList &files, ImageList &dirs,
                           const QString &refine) const
{
    if (ids.isEmpty())
        return 0;
 
    QString select = QString("file_id IN (%1) %2").arg(FS::DbIds(ids), refine);
    return ReadImages(dirs, files, select);
}
 
 
template <class FS>
int ImageDb<FS>::GetChildren(const QString &ids, ImageList &files, ImageList &dirs,
                const QString &refine) const
{
    QString select = QString("dir_id IN (%1) %2").arg(FS::DbIds(ids), refine);
    return ReadImages(dirs, files, select);
}
 
 
template <class FS>
int ImageDb<FS>::GetDirectory(int id, ImagePtr &parent,
                              ImageList &files, ImageList &dirs,
                              const QString &refine) const
{
    MSqlQuery query(MSqlQuery::InitCon());
    query.prepare(QString("SELECT " DB_COLUMNS " FROM %1 "
                          "WHERE (dir_id = :ID1 OR file_id = :ID2) "
                          "%2;").arg(m_table, refine));
 
    // Qt < 5.4 won't bind multiple occurrences
    int dbId = FS::DbId(id);
    query.bindValue(":ID1", dbId);
    query.bindValue(":ID2", dbId);
 
    if (!query.exec())
    {
        MythDB::DBError(DBLOC, query);
        return -1;
    }
    while (query.next())
    {
        ImagePtr im(CreateImage(query));
 
        if (im->IsFile())
            files.append(im);
        else if (im->m_id == id)
            parent = im;
        else
            dirs.append(im);
    }
    return query.size();
}
 
 
template <class FS>
bool ImageDb<FS>::GetDescendants(const QString &ids,
                                 ImageList &files, ImageList &dirs) const
{
    if (ids.isEmpty())
        return false;
 
    if (ReadImages(dirs, files, QString("file_id IN (%1)").arg(FS::DbIds(ids))) < 0)
        return false;
 
    MSqlQuery query(MSqlQuery::InitCon());
    QString sql =
            QString("SELECT " DB_COLUMNS
                    ", LENGTH(filename) - LENGTH(REPLACE(filename, '/', ''))"
                    " AS depth "
                    "FROM %1 WHERE filename LIKE :PREFIX "
                    "ORDER BY depth;").arg(m_table);
 
    for (const auto& im1 : qAsConst(dirs))
    {
        query.prepare(sql);
        query.bindValue(":PREFIX", im1->m_filePath + "/%");
 
        if (!query.exec())
        {
            MythDB::DBError(DBLOC, query);
            return false;
        }
 
        while (query.next())
        {
            ImagePtr im2(CreateImage(query));
            if (im2->IsDirectory())
                dirs.append(im2);
            else
                files.append(im2);
        }
    }
    return true;
}
 
 
template <class FS>
bool ImageDb<FS>::GetImageTree(int id, ImageList &files, const QString &refine) const
{
    // Load starting children
    ImageList dirs;
    if (GetChildren(QString::number(id), files, dirs, refine) < 0)
        return false;
 
    for (const auto& im : qAsConst(dirs))
        if (!GetImageTree(im->m_id, files, refine))
            return false;
    return true;
}
 
 
template <class FS>
bool ImageDb<FS>::ReadAllImages(ImageHash &files, ImageHash &dirs) const
{
    MSqlQuery query(MSqlQuery::InitCon());
    query.prepare(QString("SELECT " DB_COLUMNS " FROM %1").arg(m_table));
 
    if (!query.exec())
    {
        MythDB::DBError(DBLOC, query);
        return false;
    }
 
    while (query.next())
    {
        ImagePtr im(CreateImage(query));
        if (im->IsDirectory())
            dirs.insert(im->m_filePath, im);
        else
            files.insert(im->m_filePath, im);
    }
    return true;
}
 
 
template <class FS>
void ImageDb<FS>::ClearDb(int devId, const QString &action)
{
    if (action == "DEVICE CLOSE ALL")
        // Retain Db images when closing UI
        return;
 
    MSqlQuery query(MSqlQuery::InitCon());
 
    if (action == "DEVICE CLEAR ALL")
    {
        // Clear images from all devices. Reset auto-increment
        query.prepare(QString("TRUNCATE TABLE %1;").arg(m_table));
 
        if (!query.exec())
            MythDB::DBError(DBLOC, query);
    }
    else // Actions DEVICE REMOVE & DEVICE EJECT
    {
        // Delete all images of the device
        query.prepare(QString("DELETE IGNORE FROM %1 WHERE zoom = :FS;").arg(m_table));
        query.bindValue(":FS", devId);
 
        if (!query.exec())
            MythDB::DBError(DBLOC, query);
    }
}
 
 
template <class FS>
int ImageDb<FS>::InsertDbImage(ImageItemK &im, bool checkForDuplicate) const
{
    MSqlQuery query(MSqlQuery::InitCon());
 
    if (checkForDuplicate)
    {
        query.prepare(QString("SELECT file_id FROM %1 WHERE filename = :NAME;")
                      .arg(m_table));
 
        query.bindValue(":NAME", im.m_filePath);
 
        if (!query.exec())
        {
            MythDB::DBError(DBLOC, query);
            return -1;
        }
 
        if (query.size() > 0)
        {
            LOG(VB_FILE, LOG_DEBUG, QString("Image: %1 already exists in Db")
                .arg(im.m_filePath));
            return query.value(0).toInt();
        }
    }
 
    query.prepare(QString("INSERT INTO %1 (" DB_COLUMNS ") VALUES (0, "
                          ":FILEPATH, :NAME,      :PARENT, :TYPE,   :MODTIME, "
                          ":SIZE,     :EXTENSION, :DATE,   :HIDDEN, :ORIENT, "
                          ":COVER,    :COMMENT,   :FS);").arg(m_table));
 
    query.bindValue(":FILEPATH",  im.m_filePath);
    query.bindValue(":NAME",      FS::BaseNameOf(im.m_filePath));
    query.bindValue(":FS",        im.m_device);
    query.bindValue(":PARENT",    FS::DbId(im.m_parentId));
    query.bindValue(":TYPE",      im.m_type);
    query.bindValue(":MODTIME",   static_cast<qint64>(im.m_modTime.count()));
    query.bindValue(":SIZE",      im.m_size);
    query.bindValue(":EXTENSION", im.m_extension);
    query.bindValue(":DATE",      static_cast<qint64>(im.m_date.count()));
    query.bindValue(":ORIENT",    im.m_orientation);
    query.bindValue(":COMMENT",   im.m_comment.isNull() ? "" : im.m_comment);
    query.bindValue(":HIDDEN",    im.m_isHidden);
    query.bindValue(":COVER",     FS::DbId(im.m_userThumbnail));
 
    if (query.exec())
        return FS::ImageId(query.lastInsertId().toInt());
 
    MythDB::DBError(DBLOC, query);
    return -1;
}
 
 
template <class FS>
bool ImageDb<FS>::UpdateDbImage(ImageItemK &im) const
{
    MSqlQuery query(MSqlQuery::InitCon());
    query.prepare(QString
                  ("UPDATE %1 SET "
                   "filename = :FILEPATH,  name = :NAME, "
                   "dir_id = :PARENT,    type = :TYPE, "
                   "modtime = :MODTIME,   size = :SIZE, "
                   "extension = :EXTENSION, date = :DATE,   zoom = :FS, "
                   "hidden = :HIDDEN,    orientation = :ORIENT, "
                   "angle = :COVER,     path = :COMMENT "
                   "WHERE file_id = :ID;").arg(m_table));
 
    query.bindValue(":ID",        FS::DbId(im.m_id));
    query.bindValue(":FILEPATH",  im.m_filePath);
    query.bindValue(":NAME",      FS::BaseNameOf(im.m_filePath));
    query.bindValue(":PARENT",    FS::DbId(im.m_parentId));
    query.bindValue(":TYPE",      im.m_type);
    query.bindValue(":MODTIME",   static_cast<qint64>(im.m_modTime.count()));
    query.bindValue(":SIZE",      im.m_size);
    query.bindValue(":EXTENSION", im.m_extension);
    query.bindValue(":DATE",      static_cast<qint64>(im.m_date.count()));
    query.bindValue(":FS",        im.m_device);
    query.bindValue(":HIDDEN",    im.m_isHidden);
    query.bindValue(":ORIENT",    im.m_orientation);
    query.bindValue(":COVER",     FS::DbId(im.m_userThumbnail));
    query.bindValue(":COMMENT",   im.m_comment.isNull() ? "" : im.m_comment);
 
    if (query.exec())
        return true;
 
    MythDB::DBError(DBLOC, query);
    return false;
}
 
 
template <class FS>
QStringList ImageDb<FS>::RemoveFromDB(const ImageList &imList) const
{
    QStringList ids;
    if (!imList.isEmpty())
    {
        for (const auto& im : qAsConst(imList))
            ids << QString::number(FS::DbId(im->m_id));
 
        QString idents = ids.join(",");
        MSqlQuery query(MSqlQuery::InitCon());
        query.prepare(QString("DELETE IGNORE FROM %1 WHERE file_id IN (%2);")
                      .arg(m_table, idents));
 
        if (!query.exec())
        {
            MythDB::DBError(DBLOC, query);
            return QStringList();
        }
    }
    return ids;
}
 
 
template <class FS>
bool ImageDb<FS>::SetHidden(bool hide, const QString &ids) const
{
    if (ids.isEmpty())
        return false;
 
    MSqlQuery query(MSqlQuery::InitCon());
 
    query.prepare(QString("UPDATE %1 SET "
                          "hidden = :HIDDEN "
                          "WHERE file_id IN (%2);").arg(m_table, FS::DbIds(ids)));
    query.bindValue(":HIDDEN", hide ? 1 : 0);
 
    if (query.exec())
        return true;
 
    MythDB::DBError(DBLOC, query);
    return false;
}
 
 
template <class FS>
bool ImageDb<FS>::SetCover(int dir, int id) const
{
    MSqlQuery query(MSqlQuery::InitCon());
 
    query.prepare(QString("UPDATE %1 SET "
                          "angle = :COVER "
                          "WHERE file_id = :DIR").arg(m_table));
    query.bindValue(":COVER", FS::DbId(id));
    query.bindValue(":DIR", FS::DbId(dir));
    \
    if (query.exec())
        return true;
 
    MythDB::DBError(DBLOC, query);
    return false;
}
 
 
template <class FS>
bool ImageDb<FS>::SetOrientation(int id, int orientation) const
{
    MSqlQuery query(MSqlQuery::InitCon());
 
    query.prepare(QString("UPDATE %1 SET ").arg(m_table) +
                  "orientation = :ORIENTATION "
                  "WHERE file_id = :ID");
    query.bindValue(":ORIENTATION", orientation);
    query.bindValue(":ID", FS::DbId(id));
    \
    if (query.exec())
        return true;
 
    MythDB::DBError(DBLOC, query);
    return false;
}
 
 
template <class FS>
int ImageDb<FS>::ReadImages(ImageList &dirs, ImageList &files,
                            const QString &selector) const
{
    MSqlQuery query(MSqlQuery::InitCon());
    query.prepare(QString("SELECT " DB_COLUMNS " FROM %1 WHERE %2")
                  .arg(m_table, selector));
    if (!query.exec())
    {
        MythDB::DBError(DBLOC, query);
        return -1;
    }
 
    while (query.next())
    {
        ImagePtr im(CreateImage(query));
 
        if (im->IsFile())
            files.append(im);
        else
            dirs.append(im);
    }
    return query.size();
}
 
 
template <class FS>
void ImageDb<FS>::GetDescendantCount(int id, bool all, int &dirs,
                                     int &pics, int &videos, int &sizeKb) const
{
    QString whereClause;
    if (!all)
    {
        whereClause = "WHERE filename LIKE "
                      "( SELECT CONCAT(filename, '/%') "
                      "  FROM %2 WHERE file_id = :ID);";
    }
 
    MSqlQuery query(MSqlQuery::InitCon());
    query.prepare(QString("SELECT SUM(type <= :FLDR) AS Fldr, "
                          "       SUM(type =  :PIC)  AS Pics, "
                          "       SUM(type =  :VID)  AS Vids, "
                          "       SUM(size / 1024) "
                          "FROM %2 %1;").arg(whereClause, m_table));
 
    query.bindValue(":FLDR", kDirectory);
    query.bindValue(":PIC",  kImageFile);
    query.bindValue(":VID",  kVideoFile);
    if (!all)
        query.bindValue(":ID", FS::DbId(id));
 
    if (!query.exec())
    {
        MythDB::DBError(DBLOC, query);
    }
    else if (query.next())
    {
        dirs   += query.value(0).toInt();
        pics   += query.value(1).toInt();
        videos += query.value(2).toInt();
        sizeKb += query.value(3).toInt();
    }
}
 
 
ImageDbSg::ImageDbSg() : ImageDb(DB_TABLE)
{
    // Be has a single SG device
    OpenDevice(IMAGE_STORAGE_GROUP, STORAGE_GROUP_MOUNT);
}
 
 
ImageDbLocal::ImageDbLocal()
    : ImageDb(QString("`%1_%2`").arg(DB_TABLE, gCoreContext->GetHostName()))
{
    // Remove any table leftover from a previous FE crash
    DropTable();
}
 
 
void ImageDbLocal::DropTable()
{
    MSqlQuery query(MSqlQuery::InitCon());
    query.prepare(QString("DROP TABLE IF EXISTS %1;").arg(m_table));
    if (query.exec())
        m_dbExists = false;
    else
        MythDB::DBError(DBLOC, query);
}
 
 
bool ImageDbLocal::CreateTable()
{
    if (m_dbExists)
        return true;
 
    MSqlQuery query(MSqlQuery::InitCon());
 
    // Create temporary table
    query.prepare(QString("CREATE TABLE %1 LIKE " DB_TABLE ";").arg(m_table));
    if (query.exec())
    {
        // Store it in memory only
        query.prepare(QString("ALTER TABLE %1 ENGINE = MEMORY;").arg(m_table));
        if (query.exec())
        {
            m_dbExists = true;
            LOG(VB_FILE, LOG_DEBUG, QString("Created Db table %1").arg(m_table));
            return true;
        }
    }
    MythDB::DBError(DBLOC, query);
 
    // Clean up after failure
    query.prepare(QString("DROP TABLE IF EXISTS %1;").arg(m_table));
    query.exec();
    return false;
}
 
 
class ReadMetaThread : public QRunnable
{
public:
    ReadMetaThread(ImagePtrK im, QString path)
        : m_im(std::move(im)), m_path(std::move(path)) {}
 
    void run() override // QRunnable
    {
        QStringList tags;
        QString     orientation;
        QString     size;
 
        // Read metadata for files only
        if (m_im->IsFile())
        {
            ImageMetaData *metadata = (m_im->m_type == kVideoFile)
                    ? ImageMetaData::FromVideo(m_path)
                    : ImageMetaData::FromPicture(m_path);
            tags        = metadata->GetAllTags();
            orientation = Orientation(m_im->m_orientation).Description();
            size        = ImageAdapterBase::FormatSize(m_im->m_size / 1024);
            delete metadata;
        }
 
        // Add identifier at front
        tags.prepend(QString::number(m_im->m_id));
 
        // Include file info
        tags << ImageMetaData::ToString(EXIF_MYTH_HOST,   "Host",
                                        gCoreContext->GetHostName());
        tags << ImageMetaData::ToString(EXIF_MYTH_PATH,   "Path",
                                        ImageAdapterBase::PathOf(m_path));
        tags << ImageMetaData::ToString(EXIF_MYTH_NAME,   "Name",
                                        ImageAdapterBase::BaseNameOf(m_path));
        tags << ImageMetaData::ToString(EXIF_MYTH_SIZE,   "Size", size);
        tags << ImageMetaData::ToString(EXIF_MYTH_ORIENT, "Orientation",
                                        orientation);
 
        MythEvent me("IMAGE_METADATA", tags);
        gCoreContext->SendEvent(me);
    }
 
private:
    ImagePtrK m_im;
    QString   m_path;
};
 
 
template <class DBFS>
QStringList ImageHandler<DBFS>::HandleGetMetadata(const QString &id) const
{
    // Find image in DB
    ImageList files;
    ImageList dirs;
    if (DBFS::GetImages(id, files, dirs) != 1)
        RESULT_ERR("Image not found", QString("Unknown image %1").arg(id))
 
    ImagePtr im = files.isEmpty() ? dirs[0] : files[0];
 
    QString absPath = DBFS::GetAbsFilePath(im);
    if (absPath.isEmpty())
        RESULT_ERR("Image not found",
                   QString("File %1 not found").arg(im->m_filePath))
 
    auto *worker = new ReadMetaThread(im, absPath);
 
    MThreadPool::globalInstance()->start(worker, "ImageMetaData");
 
    RESULT_OK(QString("Fetching metadata for %1").arg(id))
}
 
 
template <class DBFS>
QStringList ImageHandler<DBFS>::HandleRename(const QString &id,
                                             const QString &newBase) const
{
    // Sanity check new name
    if (newBase.isEmpty() || newBase.contains("/") || newBase.contains("\\"))
        RESULT_ERR("Invalid name", QString("Invalid name %1").arg(newBase))
 
    // Find image in DB
    ImageList files;
    ImageList dirs;
    if (DBFS::GetImages(id, files, dirs) != 1)
        RESULT_ERR("Image not found", QString("Image %1 not in Db").arg(id))
 
    ImagePtr im = files.isEmpty() ? dirs[0] : files[0];
 
    // Find file
    QString oldPath = DBFS::GetAbsFilePath(im);
    if (oldPath.isEmpty())
        RESULT_ERR("Image not found",
                   QString("File %1 not found").arg(im->m_filePath))
 
    // Generate new filename
    QFileInfo oldFi = QFileInfo(oldPath);
    QString newName = im->IsDirectory()
            ? newBase : QString("%1.%2").arg(newBase, oldFi.suffix());
 
    im->m_filePath = DBFS::ConstructPath(DBFS::PathOf(im->m_filePath), newName);
 
    // Ensure no SG duplicate files are created. (Creating clone dirs is ok)
    if (im->IsFile())
    {
        QString existPath = DBFS::GetAbsFilePath(im);
        if (!existPath.isEmpty())
            RESULT_ERR("Filename already used",
                       QString("Renaming %1 to %2 will create a duplicate of %3")
                          .arg(oldPath, im->m_filePath, existPath))
    }
 
    // Rename file or directory
    QString newPath = oldFi.dir().absoluteFilePath(newName);
    if (!QFile::rename(oldPath, newPath))
        RESULT_ERR("Rename failed",
                   QString("Rename of %1 -> %2 failed").arg(oldPath, newPath))
 
    if (im->IsDirectory())
    {
        // Dir name change affects path of all sub-dirs & files and their thumbs
        HandleScanRequest("START");
    }
    else // file
    {
        // Update db
        DBFS::UpdateDbImage(*im);
 
        // Image is modified, not deleted
        QStringList mesg("");
        mesg << QString::number(im->m_id);
 
        // Rename thumbnail.
        m_thumbGen->MoveThumbnail(im);
 
        // Notify clients of changed image
        DBFS::Notify("IMAGE_DB_CHANGED", mesg);
    }
    RESULT_OK(QString("Renamed %1 -> %2").arg(oldPath, newPath))
}
 
 
template <class DBFS>
QStringList ImageHandler<DBFS>::HandleDelete(const QString &ids) const
{
    // Get subtree of all files
    ImageList files;
    ImageList dirs;
    // Dirs will be in depth-first order, (subdirs after parent)
    DBFS::GetDescendants(ids, files, dirs);
 
    // Remove files from filesystem first
    RemoveFiles(files);
    // ... then dirs, which should now be empty
    RemoveFiles(dirs);
 
    // Fail if nothing deleted
    if (files.isEmpty() && dirs.isEmpty())
        RESULT_ERR("Delete failed", QString("Delete of %1 failed").arg(ids))
 
    // Update Db
    DBFS::RemoveFromDB(files + dirs);
 
    // Clean up thumbnails
    QStringList mesg(m_thumbGen->DeleteThumbs(files));
 
    // Notify clients of deleted ids
    DBFS::Notify("IMAGE_DB_CHANGED", mesg);
 
    return QStringList("OK");
}
 
 
template <class DBFS>
QStringList ImageHandler<DBFS>::HandleDbCreate(QStringList defs) const
{
    if (defs.isEmpty())
        RESULT_ERR("Copy Failed", "Empty defs")
 
    // First item is the field seperator
    const QString separator = defs.takeFirst();
 
    // Convert cover ids to their new equivalent. Map<source id, new id>
    // Dirs follow their children so new cover ids will be defined before they
    // are used
    QHash<QString, int> idMap;
 
    // Create skeleton Db images using copied settings.
    // Scanner will update other attributes
    ImageItem im;
    for (const auto& def : qAsConst(defs))
    {
        QStringList aDef = def.split(separator);
 
        // Expects id, type, path, hidden, orientation, cover
        if (aDef.size() != 6)
        {
            // Coding error
            LOG(VB_GENERAL, LOG_ERR,
                LOC + QString("Bad definition: (%1)").arg(def));
            continue;
        }
 
        LOG(VB_FILE, LOG_DEBUG, LOC + QString("Creating %1").arg(aDef.join(",")));
 
        im.m_type          = aDef[1].toInt();
        im.m_filePath      = aDef[2];
        im.m_isHidden      = (aDef[3].toInt() != 0);
        im.m_orientation   = aDef[4].toInt();
        im.m_userThumbnail = idMap.value(aDef[5]);
 
        // Don't insert duplicate filepaths
        int newId = DBFS::InsertDbImage(im, true);
 
        // Record old->new id map in case it's being used as a cover
        idMap.insert(aDef[0], newId);
    }
    HandleScanRequest("START");
 
    RESULT_OK("Created Db images")
}
 
 
template <class DBFS>
QStringList ImageHandler<DBFS>::HandleDbMove(const QString &ids,
                                             const QString &srcPath,
                                             QString destPath) const
{
    // Sanity check new path
    if (destPath.contains(".."))
        RESULT_ERR("Invalid path", QString("Invalid path %1").arg(destPath))
 
    // Get subtrees of renamed files
    ImageList images;
    ImageList dirs;
    ImageList files;
    bool ok = DBFS::GetDescendants(ids, files, dirs);
    images << dirs << files;
 
    if (!ok || images.isEmpty())
        RESULT_ERR("Image not found", QString("Images %1 not in Db").arg(ids))
 
    if (!destPath.isEmpty() && !destPath.endsWith(QChar('/')))
        destPath.append("/");
 
    // Update path of images only. Scanner will repair parentId
    for (const auto& im : qAsConst(images))
    {
        QString old = im->m_filePath;
 
        if (srcPath.isEmpty())
        {
            // Image in SG root
            im->m_filePath.prepend(destPath);
        }
        else if (im->m_filePath.startsWith(srcPath))
        {
            // All other images
            im->m_filePath.replace(srcPath, destPath);
        }
        else
        {
            // Coding error
            LOG(VB_GENERAL, LOG_ERR,
                LOC + QString("Bad image: (%1 -> %2)").arg(srcPath, destPath));
            continue;
        }
 
        LOG(VB_FILE, LOG_DEBUG,
            LOC + QString("Db Renaming %1 -> %2").arg(old, im->m_filePath));
 
        DBFS::UpdateDbImage(*im);
 
        // Rename thumbnail
        if (im->IsFile())
            m_thumbGen->MoveThumbnail(im);
    }
    HandleScanRequest("START");
 
    RESULT_OK(QString("Moved %1 from %2 -> %3").arg(ids, srcPath, destPath))
}
 
 
template <class DBFS>
QStringList ImageHandler<DBFS>::HandleHide(bool hide, const QString &ids) const
{
    if (!DBFS::SetHidden(hide, ids))
        RESULT_ERR("Hide failed", QString("Db hide failed for %1").arg(ids))
 
    // Send changed ids only (none deleted)
    QStringList mesg = QStringList("") << ids;
    DBFS::Notify("IMAGE_DB_CHANGED", mesg);
 
    RESULT_OK(QString("Images %1 now %2hidden").arg(ids, hide ? "" : "un"))
}
 
 
template <class DBFS>
QStringList ImageHandler<DBFS>::HandleTransform(int transform,
                                                const QString &ids) const
{
    if (transform < kResetToExif || transform > kFlipVertical)
        RESULT_ERR("Transform failed", QString("Bad transform %1").arg(transform))
 
    ImageList files;
    ImageList dirs;
    if (DBFS::GetImages(ids, files, dirs) < 1 || files.isEmpty())
        RESULT_ERR("Image not found", QString("Images %1 not in Db").arg(ids))
 
    // Update db
    for (const auto& im : qAsConst(files))
    {
        int old           = im->m_orientation;
        im->m_orientation = Orientation(im->m_orientation).Transform(transform);
 
        // Update Db
        if (DBFS::SetOrientation(im->m_id, im->m_orientation))
        {
            LOG(VB_FILE, LOG_DEBUG, LOC + QString("Transformed %1 from %2 to %3")
                .arg(im->m_filePath).arg(old).arg(im->m_orientation));
        }
    }
 
    // Images are changed, not deleted
    QStringList mesg("");
 
    // Clean up thumbnails
    mesg << m_thumbGen->DeleteThumbs(files);
 
    // Notify clients of changed images
    DBFS::Notify("IMAGE_DB_CHANGED", mesg);
 
    return QStringList("OK");
}
 
 
template <class DBFS>
QStringList ImageHandler<DBFS>::HandleDirs(const QString &destId,
                                           bool rescan,
                                           const QStringList &relPaths) const
{
    // Find image in DB
    ImageList files;
    ImageList dirs;
    if (DBFS::GetImages(destId, files, dirs) != 1 || dirs.isEmpty())
        RESULT_ERR("Destination not found",
                   QString("Image %1 not in Db").arg(destId))
 
    // Find dir. SG device (Photographs) uses most-free filesystem
    QString destPath = DBFS::GetAbsFilePath(dirs[0]);
    if (destPath.isEmpty())
        RESULT_ERR("Destination not found",
                   QString("Dest dir %1 not found").arg(dirs[0]->m_filePath))
 
    QDir destDir(destPath);
    bool succeeded = false;
    for (const auto& relPath : qAsConst(relPaths))
    {
        // Validate dir name
        if (relPath.isEmpty() || relPath.contains("..") || relPath.startsWith(QChar('/')))
            continue;
 
        QString newPath = DBFS::ConstructPath(destDir.absolutePath(), relPath);
        if (!destDir.mkpath(relPath))
        {
            LOG(VB_GENERAL, LOG_ERR,
                LOC + QString("Failed to create dir %1").arg(newPath));
            continue;
        }
        LOG(VB_FILE, LOG_DEBUG, LOC + QString("Dir %1 created").arg(newPath));
        succeeded = true;
    }
 
    if (!succeeded)
        // Failures should only occur due to user input
        RESULT_ERR("Invalid Name", QString("Invalid name %1")
                   .arg(relPaths.join(",")))
 
    if (rescan)
        // Rescan to detect new dir
        HandleScanRequest("START");
 
    return QStringList("OK");
}
 
 
template <class DBFS>
QStringList ImageHandler<DBFS>::HandleCover(int dir, int cover) const
{
    if (!DBFS::SetCover(dir, cover))
        RESULT_ERR("Set Cover failed",
                   QString("Failed to set %1 to cover %2").arg(dir).arg(cover))
 
    // Image has changed, nothing deleted
    QStringList mesg = QStringList("") << QString::number(dir);
    DBFS::Notify("IMAGE_DB_CHANGED", mesg);
 
    RESULT_OK(QString("Cover of %1 is now %2").arg(dir).arg(cover));
}
 
 
template <class DBFS>
QStringList ImageHandler<DBFS>::HandleIgnore(const QString &exclusions) const
{
    // Save new setting. FE will have already saved it but not cleared the cache
    gCoreContext->SaveSettingOnHost("GalleryIgnoreFilter", exclusions, nullptr);
 
    // Rescan
    HandleScanRequest("START");
 
    RESULT_OK(QString("Using exclusions '%1'").arg(exclusions))
}
 
 
template <class DBFS>
QStringList ImageHandler<DBFS>::HandleScanRequest(const QString &command,
                                                  int devId) const
{
    if (!m_scanner)
        RESULT_ERR("Missing Scanner", "Missing Scanner");
 
    if (command == "START")
    {
        // Must be dormant to start a scan
        if (m_scanner->IsScanning())
            RESULT_ERR("", "Scanner is busy");
 
        m_scanner->ChangeState(true);
        RESULT_OK("Scan requested");
    }
    else if (command == "STOP")
    {
        // Must be scanning to interrupt
        if (!m_scanner->IsScanning())
            RESULT_ERR("Scanner not running", "Scanner not running");
 
        m_scanner->ChangeState(false);
        RESULT_OK("Terminate scan requested");
    }
    else if (command == "QUERY")
    {
        return QStringList("OK") << m_scanner->GetProgress();
    }
    else if (command.startsWith(QString("DEVICE")))
    {
        m_scanner->EnqueueClear(devId, command);
        RESULT_OK(QString("Clearing device %1 %2").arg(command).arg(devId))
    }
    RESULT_ERR("Unknown command", QString("Unknown command %1").arg(command));
}
 
 
template <class DBFS>
QStringList ImageHandler<DBFS>::HandleCreateThumbnails
(const QStringList &message) const
{
    if (message.size() != 2)
        RESULT_ERR("Unknown Command",
                   QString("Bad request: %1").arg(message.join("|")))
 
    int priority = message.at(0).toInt()
                ? kDirRequestPriority : kPicRequestPriority;
 
    // get specific image details from db
    ImageList files;
    ImageList dirs;
    DBFS::GetImages(message.at(1), files, dirs);
 
    for (const auto& im : qAsConst(files))
        // notify clients when done; highest priority
        m_thumbGen->CreateThumbnail(im, priority, true);
 
    return QStringList("OK");
}
 
 
template <class DBFS>
void ImageHandler<DBFS>::RemoveFiles(ImageList &images) const
{
#if QT_VERSION < QT_VERSION_CHECK(6,0,0)
    QMutableVectorIterator<ImagePtr> it(images);
#else
    QMutableListIterator<ImagePtr> it(images);
#endif
    it.toBack();
    while (it.hasPrevious())
    {
        ImagePtrK im = it.previous();
 
        // Remove file or directory
        QString absFilename = DBFS::GetAbsFilePath(im);
 
        bool success = !absFilename.isEmpty()
                && (im->IsFile() ? QFile::remove(absFilename)
                                 : QDir::root().rmdir(absFilename));
        if (success)
            LOG(VB_FILE, LOG_DEBUG, LOC + QString("Deleted %1").arg(absFilename));
        else
        {
            LOG(VB_GENERAL, LOG_ERR, LOC +
                QString("Can't delete %1").arg(absFilename));
            // Remove from list
            it.remove();
        }
    }
}
 
 
QString ImageDbReader::TypeSelector(int type)
{
    switch (type)
    {
    case kPicOnly:     return QString("AND type != %1").arg(kVideoFile);
    case kVideoOnly:   return QString("AND type != %1").arg(kImageFile);
    case kPicAndVideo: return "";
    }
    return "";
}
 
 
void ImageDbReader::SetRefinementClause()
{
    m_refineClause = QString("%2 %3 "
                             "ORDER BY "
                             "CASE WHEN type <= %1 THEN %4, "
                             "CASE WHEN type >  %1 THEN %5 ")
            .arg(kDirectory)
            .arg(m_showHidden ? "" : "AND hidden = 0",
                 TypeSelector(m_showType),
                 OrderSelector(m_dirOrder),
                 OrderSelector(m_fileOrder));
}
 
 
QString ImageDbReader::OrderSelector(int order)
{
    // prepare the sorting statement
    switch (order)
    {
    default:
    case kSortByNameAsc:     return "name END ASC";
    case kSortByNameDesc:    return "name END DESC";
    case kSortByModTimeAsc:  return "modtime END ASC";
    case kSortByModTimeDesc: return "modtime END DESC";
    case kSortByExtAsc:      return "extension END ASC,  name ASC";
    case kSortByExtDesc:     return "extension END DESC, name DESC";
    case kSortBySizeAsc:     return "size END ASC,  name ASC";
    case kSortBySizeDesc:    return "size END DESC, name DESC";
    case kSortByDateAsc:     return "IF(date=0, modtime, date) END ASC";
    case kSortByDateDesc:    return "IF(date=0, modtime, date) END DESC";
    }
}
 
 
int ImageDbReader::GetDirectory(int id, ImagePtr &parent,
                                ImageList &files, ImageList &dirs) const
{
    // Only Root node will invoke both Db queries but result set will be small
    // For Root the SG is always ordered before local devices
    // Root node has no Db entry so the 2 queries will not overwrite the parent.
    int count = 0;
    if (!ImageItem::IsLocalId(id))
        count = m_remote->GetDirectory(id, parent, files, dirs, m_refineClause);
    if (m_dbExists && ImageItem::IsLocalParent(id))
        count += ImageHandler::GetDirectory(id, parent, files, dirs, m_refineClause);
 
    if (id == GALLERY_DB_ID)
    {
        // Add a Root node
        parent = ImagePtr(new ImageItem(GALLERY_DB_ID));
        parent->m_parentId = GALLERY_DB_ID;
        parent->m_type     = kDevice;
 
        ++count;
    }
    return count;
}
 
 
int ImageDbReader::GetImages(const ImageIdList& ids,
                             ImageList &files, ImageList &dirs) const
{
    // Ids are either all local or all remote. GALLERY_DB_ID not valid
    StringPair lists = ImageItem::PartitionIds(ids);
 
    if (!lists.second.isEmpty())
        return m_remote->GetImages(lists.second, files, dirs, m_refineClause);
    if (m_dbExists && !lists.first.isEmpty())
        return ImageHandler::GetImages(lists.first, files, dirs, m_refineClause);
    return 0;
}
 
 
int ImageDbReader::GetChildren(int id, ImageList &files, ImageList &dirs) const
{
    int count = 0;
    if (!ImageItem::IsLocalId(id))
        count = m_remote->GetChildren(QString::number(id), files, dirs,
                                      m_refineClause);
    if (m_dbExists && ImageItem::IsLocalParent(id))
        count += ImageHandler::GetChildren(QString::number(id), files, dirs,
                                           m_refineClause);
    return count;
}
 
 
void ImageDbReader::GetDescendants(const ImageIdList &ids,
                                   ImageList &files, ImageList &dirs) const
{
    // Ids are either all local or all remote
    StringPair lists = ImageItem::PartitionIds(ids);
 
    if (!lists.second.isEmpty())
        m_remote->GetDescendants(lists.second, files, dirs);
    if (m_dbExists && !lists.first.isEmpty())
        ImageHandler::GetDescendants(lists.first, files, dirs);
}
 
 
void ImageDbReader::GetImageTree(int id, ImageList &files) const
{
    if (!ImageItem::IsLocalId(id))
        m_remote->GetImageTree(id, files, m_refineClause);
    if (m_dbExists && ImageItem::IsLocalParent(id))
        ImageHandler::GetImageTree(id, files, m_refineClause);
}
 
 
void ImageDbReader::GetDescendantCount(int id, int &dirs, int &pics,
                                       int &videos, int &sizeKb) const
{
    if (id == GALLERY_DB_ID)
    {
        // Sum both unfiltered tables
        m_remote->GetDescendantCount(id, true, dirs, pics, videos, sizeKb);
        if (m_dbExists)
            ImageHandler::GetDescendantCount(id, true, dirs, pics, videos, sizeKb);
    }
    else if (!ImageItem::IsLocalId(id))
    {
        // Don't filter on SG path (it's blank)
        m_remote->GetDescendantCount(id, id == PHOTO_DB_ID,
                                     dirs, pics, videos, sizeKb);
    }
    else if (m_dbExists)
    {
        // Always filter on device/dir
        ImageHandler::GetDescendantCount(id, false, dirs, pics, videos, sizeKb);
    }
}
 
 
ImageManagerBe *ImageManagerBe::s_instance = nullptr;
ImageManagerFe *ImageManagerFe::s_instance = nullptr;
 
 
ImageManagerBe* ImageManagerBe::getInstance()
{
    if (!s_instance)
        s_instance = new ImageManagerBe();
    return s_instance;
}
 
 
ImageManagerFe& ImageManagerFe::getInstance()
{
    if (!s_instance)
    {
        // Use saved settings
        s_instance = new ImageManagerFe
                (gCoreContext->GetNumSetting("GalleryImageOrder"),
                 gCoreContext->GetNumSetting("GalleryDirOrder"),
                 gCoreContext->GetBoolSetting("GalleryShowHidden"),
                 gCoreContext->GetNumSetting("GalleryShowType"),
                 gCoreContext->GetSetting("GalleryDateFormat"));
    }
    return *s_instance;
}
 
 
void ImageManagerFe::CreateThumbnails(const ImageIdList &ids, bool forFolder)
{
    // Split images into <locals, remotes>
    StringPair lists = ImageItem::PartitionIds(ids);
 
    if (!lists.second.isEmpty())
    {
        LOG(VB_FILE, LOG_DEBUG, LOC +
            QString("Sending CREATE_THUMBNAILS %1 (forFolder %2)")
            .arg(lists.second).arg(forFolder));
 
        QStringList message;
        message << QString::number(static_cast<int>(forFolder)) << lists.second;
        gCoreContext->SendEvent(MythEvent("CREATE_THUMBNAILS", message));
    }
 
    if (!lists.first.isEmpty())
    {
        LOG(VB_FILE, LOG_DEBUG, LOC +
            QString("Creating local thumbnails %1 (forFolder %2)")
            .arg(lists.first).arg(forFolder));
 
        QStringList message;
        message << QString::number(static_cast<int>(forFolder)) << lists.first;
        HandleCreateThumbnails(message);
    }
}
 
 
QString ImageManagerFe::ScanImagesAction(bool start, bool local)
{
    QStringList command;
    command << (start ? "START" : "STOP");
 
    if (!local)
    {
        command.push_front("IMAGE_SCAN");
        bool ok = gCoreContext->SendReceiveStringList(command, true);
        return ok ? "" : command[1];
    }
 
    // Create database on first scan
    if (!CreateTable())
        return "Couldn't create database";
 
    QStringList err = HandleScanRequest(command[0]);
    return err[0] == "OK" ? "" : err[1];
}
 
 
QStringList ImageManagerFe::ScanQuery()
{
    QStringList strList;
    strList << "IMAGE_SCAN" << "QUERY";
 
    if (!gCoreContext->SendReceiveStringList(strList))
    {
        LOG(VB_GENERAL, LOG_ERR, LOC + QString("Scan query failed : %1")
            .arg(strList.join(",")));
    }
    return strList;
}
 
 
QString ImageManagerFe::HideFiles(bool hidden, const ImageIdList &ids)
{
    // Split images into <locals, remotes>
    StringPair lists = ImageItem::PartitionIds(ids);
    QString result = "";
 
    if (!lists.second.isEmpty())
    {
        QStringList message;
        message << "IMAGE_HIDE" << QString::number(static_cast<int>(hidden)) << lists.second;
 
        if (!gCoreContext->SendReceiveStringList(message, true))
            result = message[1];
    }
 
    if (!lists.first.isEmpty())
    {
        QStringList err = HandleHide(hidden, lists.first);
        if (err[0] != "OK")
            result = err[1];
    }
    return result;
}
 
 
QString ImageManagerFe::ChangeOrientation(ImageFileTransform transform,
                                          const ImageIdList &ids)
{
    // Split images into <locals, remotes>
    StringPair lists = ImageItem::PartitionIds(ids);
    QString result = "";
 
    if (!lists.second.isEmpty())
    {
        QStringList message;
        message << "IMAGE_TRANSFORM" << QString::number(transform) << lists.second;
 
        if (!gCoreContext->SendReceiveStringList(message, true))
            result = message[1];
    }
 
    if (!lists.first.isEmpty())
    {
        QStringList err = HandleTransform(transform, lists.first);
        if (err[0] != "OK")
            result = err[1];
    }
    return result;
}
 
 
QString ImageManagerFe::SetCover(int parent, int cover)
{
    if (!ImageItem::IsLocalId(parent))
    {
        QStringList message;
        message << "IMAGE_COVER" << QString::number(parent) << QString::number(cover);
 
        bool ok = gCoreContext->SendReceiveStringList(message, true);
        return ok ? "" : message[1];
    }
 
    QStringList err = HandleCover(parent, cover);
    return err[0] == "OK" ? "" : err[1];
}
 
 
void ImageManagerFe::RequestMetaData(int id)
{
    if (ImageItem::IsLocalId(id))
        HandleGetMetadata(QString::number(id));
    else
        gCoreContext->SendEvent(MythEvent("IMAGE_GET_METADATA", QString::number(id)));
}
 
 
void ImageManagerFe::ClearStorageGroup()
{
    QStringList message("IMAGE_SCAN");
    message << "DEVICE CLEAR ALL";
    gCoreContext->SendReceiveStringList(message, true);
}
 
 
QString ImageManagerFe::IgnoreDirs(const QString &excludes)
{
    QStringList message("IMAGE_IGNORE");
    message << excludes;
    bool ok = gCoreContext->SendReceiveStringList(message, true);
    return ok ? "" : message[1];
}
 
 
QString ImageManagerFe::MakeDir(int parent, const QStringList &names, bool rescan)
{
    QString destId = QString::number(parent);
 
    if (!ImageItem::IsLocalId(parent))
    {
        QStringList message("IMAGE_CREATE_DIRS");
        message << destId << QString::number(static_cast<int>(rescan)) << names;
        bool ok = gCoreContext->SendReceiveStringList(message, true);
        return ok ? "" : message[1];
    }
    QStringList err = HandleDirs(destId, rescan, names);
    return (err[0] == "OK") ? "" : err[1];
}
 
 
QString ImageManagerFe::RenameFile(const ImagePtrK& im, const QString &name)
{
    if (!im->IsLocal())
    {
        QStringList message("IMAGE_RENAME");
        message << QString::number(im->m_id) << name;
        bool ok = gCoreContext->SendReceiveStringList(message, true);
        return ok ? "" : message[1];
    }
    QStringList err = HandleRename(QString::number(im->m_id), name);
    return (err[0] == "OK") ? "" : err[1];
}
 
 
QString ImageManagerFe::CreateImages(int destId, const ImageListK &images)
{
    if (images.isEmpty())
        return "";
 
    // Define field seperator & include it in message
    const QString seperator("...");
    QStringList imageDefs(seperator);
    ImageIdList ids;
    for (const auto& im : qAsConst(images))
    {
        ids << im->m_id;
 
        // Copies preserve hide state, orientation & cover
        QStringList aDef;
        aDef << QString::number(im->m_id)
             << QString::number(im->m_type)
             << im->m_filePath
             << QString::number(static_cast<int>(im->m_isHidden))
             << QString::number(im->m_orientation)
             << QString::number(im->m_userThumbnail);
 
        imageDefs << aDef.join(seperator);
    }
 
    // Images are either all local or all remote
    if (ImageItem::IsLocalId(destId))
    {
        QStringList err = HandleDbCreate(imageDefs);
        return (err[0] == "OK") ? "" : err[1];
    }
    imageDefs.prepend("IMAGE_COPY");
    bool ok = gCoreContext->SendReceiveStringList(imageDefs, true);
    return ok ? "" : imageDefs[1];
}
 
 
QString ImageManagerFe::MoveDbImages(const ImagePtrK& destDir, ImageListK &images,
                                     const QString &srcPath)
{
    QStringList idents;
    for (const auto& im : qAsConst(images))
        idents << QString::number(im->m_id);
 
    // Images are either all local or all remote
    if (destDir->IsLocal())
    {
        QStringList err = HandleDbMove(idents.join(","), srcPath,
                                       destDir->m_filePath);
        return (err[0] == "OK") ? "" : err[1];
    }
 
    QStringList message("IMAGE_MOVE");
    message << idents.join(",") << srcPath << destDir->m_filePath;
    bool ok = gCoreContext->SendReceiveStringList(message, true);
    return ok ? "" : message[1];
}
 
 
QString ImageManagerFe::DeleteFiles(const ImageIdList &ids)
{
    StringPair lists = ImageItem::PartitionIds(ids);
 
    QString result = "";
    if (!lists.second.isEmpty())
    {
        QStringList message("IMAGE_DELETE");
        message << lists.second;
 
        bool ok = gCoreContext->SendReceiveStringList(message, true);
        if (!ok)
            result = message[1];
    }
    if (!lists.first.isEmpty())
    {
        QStringList err = HandleDelete(lists.first);
        if (err[0] != "OK")
            result = err[1];
    }
    return result;
}
 
 
QString ImageManagerFe::LongDateOf(const ImagePtrK& im)
{
    if (im->m_id == GALLERY_DB_ID)
        return "";
 
    std::chrono::seconds secs = 0s;
    uint format = MythDate::kDateFull | MythDate::kAddYear;
 
    if (im->m_date > 0s)
    {
        secs = im->m_date;
        format |= MythDate::kTime;
    }
    else
        secs = im->m_modTime;
 
    return MythDate::toString(QDateTime::fromSecsSinceEpoch(secs.count()), format);
}
 
 
QString ImageManagerFe::ShortDateOf(const ImagePtrK& im) const
{
    if (im->m_id == GALLERY_DB_ID)
        return "";
 
    std::chrono::seconds secs(im->m_date > 0s ? im->m_date : im->m_modTime);
    return QDateTime::fromSecsSinceEpoch(secs.count()).date().toString(m_dateFormat);
}
 
 
QString ImageManagerFe::DeviceCaption(ImageItemK &im) const
{
    if (im.m_id == GALLERY_DB_ID)
        return tr("Gallery");
    if (im.m_id == PHOTO_DB_ID)
        return tr("Photographs");
    return im.IsLocal() ? DeviceName(im.m_device)
                        : m_remote->DeviceName(im.m_device);
}
 
 
QString ImageManagerFe::CrumbName(ImageItemK &im, bool getPath) const
{
    if (im.IsDevice())
        return DeviceCaption(im);
 
    if (!getPath)
        return im.m_baseName;
 
    QString dev;
    QString path(im.m_filePath);
 
    if (im.IsLocal())
    {
        // Replace local mount path with device name
        path.remove(0, DeviceMount(im.m_device).size());
        dev = DeviceName(im.m_device);
    }
    return dev + path.replace("/", " > ");
}
 
 
void ImageManagerFe::CloseDevices(int devId, bool eject)
{
    QString reason = (devId == DEVICE_INVALID)
            ? "DEVICE CLOSE ALL"
            : eject ? "DEVICE EJECT" : "DEVICE REMOVE";
    HandleScanRequest(reason, devId);
}
 
 
bool ImageManagerFe::DetectLocalDevices()
{
    MediaMonitor *monitor = MediaMonitor::GetMediaMonitor();
    if (!monitor)
        return false;
 
    // Detect all local media
    QList<MythMediaDevice*> devices
            = monitor->GetMedias(MEDIATYPE_DATA | MEDIATYPE_MGALLERY);
 
    for (auto *dev : qAsConst(devices))
    {
        if (monitor->ValidateAndLock(dev) && dev->isUsable())
            OpenDevice(dev->getDeviceModel(), dev->getMountPath(), dev);
        else
            monitor->Unlock(dev);
    }
 
    if (DeviceCount() > 0)
    {
        // Close devices that are no longer present
        QList absentees = GetAbsentees();
        for (int devId : qAsConst(absentees))
            CloseDevices(devId);
 
        // Start local scan
        QString err = ScanImagesAction(true, true);
        if (!err.isEmpty())
            LOG(VB_GENERAL, LOG_ERR, LOC + err);
    }
    return DeviceCount() > 0;
}
 
 
void ImageManagerFe::DeviceEvent(MythMediaEvent *event)
{
    MediaMonitor *monitor = MediaMonitor::GetMediaMonitor();
 
    if (!event || !monitor)
        return;
 
    MythMediaDevice *dev = event->getDevice();
    if (!dev)
        return;
 
    MythMediaType   type   = dev->getMediaType();
    MythMediaStatus status = dev->getStatus();
 
    LOG(VB_FILE, LOG_DEBUG, LOC +
        QString("Media event for %1 (%2) at %3, type %4, status %5 (was %6)")
        .arg(dev->getDeviceModel(), dev->getVolumeID(), dev->getMountPath())
        .arg(type).arg(status).arg(event->getOldStatus()));
 
    if (!(type & (MEDIATYPE_DATA | MEDIATYPE_MIXED | MEDIATYPE_MGALLERY)))
    {
        LOG(VB_FILE, LOG_DEBUG, LOC +
            QString("Ignoring event - wrong type %1").arg(type));
        return;
    }
 
    if (status == MEDIASTAT_USEABLE || status == MEDIASTAT_MOUNTED)
    {
        // New device. Lock it & scan
        if (monitor->ValidateAndLock(dev))
        {
            OpenDevice(dev->getDeviceModel(), dev->getMountPath(), dev);
            ScanImagesAction(true, true);
        }
        else
            monitor->Unlock(dev);
        return;
    }
 
    // Device has disappeared
    int devId = LocateMount(dev->getMountPath());
    if (devId != DEVICE_INVALID)
        CloseDevices(devId);
}
 
 
QString ImageManagerFe::CreateImport()
{
    auto *tmp = new QTemporaryDir(QDir::tempPath() % "/" IMPORTDIR "-XXXXXX");
    if (!tmp->isValid())
    {
        delete tmp;
        return "";
    }
 
    QString time(QDateTime::currentDateTime().toString("mm:ss"));
    OpenDevice("Import " + time, tmp->path(), nullptr, tmp);
    return tmp->path();
}
 
 
// Must define the valid template implementations to generate code for the
// instantiations (as they are defined in the cpp rather than header).
// Otherwise the linker will fail with undefined references...
template class ImageDb<ImageAdapterSg>;
template class ImageDb<ImageAdapterLocal>;
template class ImageHandler<ImageDbSg>;
template class ImageHandler<ImageDbLocal>;