CollectionBackend/CollectionWatcher: add `HasSongsWithMissingLoudnessCharacteristics` logic

Exactly identical to the "missing fingerprint" logic,
just for the two new fields being added.

src/collection/collectionbackend.cpp

@@ -434,6 +434,29 @@ SongList CollectionBackend::SongsWithMissingFingerprint(const int id) {
 
 }
 
+SongList CollectionBackend::SongsWithMissingLoudnessCharacteristics(const int id) {
+
+  QMutexLocker l(db_->Mutex());
+  QSqlDatabase db(db_->Connect());
+
+  SqlQuery q(db);
+  q.prepare(QString("SELECT ROWID, " + Song::kColumnSpec + " FROM %1 WHERE directory_id = :directory_id AND unavailable = 0 AND (ebur128_integrated_loudness_lufs IS NULL OR ebur128_loudness_range_lu IS NULL)").arg(songs_table_));
+  q.BindValue(":directory_id", id);
+  if (!q.Exec()) {
+    db_->ReportErrors(q);
+    return SongList();
+  }
+
+  SongList ret;
+  while (q.next()) {
+    Song song(source_);
+    song.InitFromQuery(q, true);
+    ret << song;
+  }
+  return ret;
+
+}
+
 void CollectionBackend::SongPathChanged(const Song &song, const QFileInfo &new_file, const std::optional<int> new_collection_directory_id) {
 
   // Take a song and update its path

src/collection/collectionbackend.h

@@ -95,6 +95,7 @@ class CollectionBackendInterface : public QObject {
 
   virtual SongList FindSongsInDirectory(const int id) = 0;
   virtual SongList SongsWithMissingFingerprint(const int id) = 0;
+  virtual SongList SongsWithMissingLoudnessCharacteristics(const int id) = 0;
   virtual CollectionSubdirectoryList SubdirsInDirectory(const int id) = 0;
   virtual CollectionDirectoryList GetAllDirectories() = 0;
   virtual void ChangeDirPath(const int id, const QString &old_path, const QString &new_path) = 0;
@@ -166,6 +167,7 @@ class CollectionBackend : public CollectionBackendInterface {
 
   SongList FindSongsInDirectory(const int id) override;
   SongList SongsWithMissingFingerprint(const int id) override;
+  SongList SongsWithMissingLoudnessCharacteristics(const int id) override;
   CollectionSubdirectoryList SubdirsInDirectory(const int id) override;
   CollectionDirectoryList GetAllDirectories() override;
   void ChangeDirPath(const int id, const QString &old_path, const QString &new_path) override;

src/collection/collectionwatcher.cpp

@@ -195,6 +195,7 @@ CollectionWatcher::ScanTransaction::ScanTransaction(CollectionWatcher *watcher,
       watcher_(watcher),
       cached_songs_dirty_(true),
       cached_songs_missing_fingerprint_dirty_(true),
+      cached_songs_missing_loudness_characteristics_dirty_(true),
       known_subdirs_dirty_(true) {
 
   QString description;
@@ -329,6 +330,21 @@ bool CollectionWatcher::ScanTransaction::HasSongsWithMissingFingerprint(const QS
 
 }
 
+bool CollectionWatcher::ScanTransaction::HasSongsWithMissingLoudnessCharacteristics(const QString &path) {
+
+  if (cached_songs_missing_loudness_characteristics_dirty_) {
+    const SongList songs = watcher_->backend_->SongsWithMissingLoudnessCharacteristics(dir_);
+    for (const Song &song : songs) {
+      const QString p = song.url().toLocalFile().section('/', 0, -2);
+      cached_songs_missing_loudness_characteristics_.insert(p, song);
+    }
+    cached_songs_missing_loudness_characteristics_dirty_ = false;
+  }
+
+  return cached_songs_missing_loudness_characteristics_.contains(path);
+
+}
+
 void CollectionWatcher::ScanTransaction::SetKnownSubdirs(const CollectionSubdirectoryList &subdirs) {
 
   known_subdirs_ = subdirs;

src/collection/collectionwatcher.h

@@ -102,6 +102,7 @@ class CollectionWatcher : public QObject {
 
     SongList FindSongsInSubdirectory(const QString &path);
     bool HasSongsWithMissingFingerprint(const QString &path);
+    bool HasSongsWithMissingLoudnessCharacteristics(const QString &path);
     bool HasSeenSubdir(const QString &path);
     void SetKnownSubdirs(const CollectionSubdirectoryList &subdirs);
     CollectionSubdirectoryList GetImmediateSubdirs(const QString &path);
@@ -156,6 +157,9 @@ class CollectionWatcher : public QObject {
     QMultiMap<QString, Song> cached_songs_missing_fingerprint_;
     bool cached_songs_missing_fingerprint_dirty_;
 
+    QMultiMap<QString, Song> cached_songs_missing_loudness_characteristics_;
+    bool cached_songs_missing_loudness_characteristics_dirty_;
+
     CollectionSubdirectoryList known_subdirs_;
     bool known_subdirs_dirty_;
   };