Adds audiobook index to available indexes

src/tangara/database/database.cpp

@@ -293,7 +293,7 @@ auto Database::getIndexes() -> std::vector<IndexInfo> {
   // TODO(jacqueline): This probably needs to be async? When we have runtime
   // configurable indexes, they will need to come from somewhere.
   return {
-      kAllTracks, kAllAlbums, kAlbumsByArtist, kTracksByGenre, kPodcasts,
+      kAllTracks, kAllAlbums, kAlbumsByArtist, kTracksByGenre, kPodcasts, kAudiobooks
   };
 }
 

src/tangara/database/index.cpp

@@ -63,6 +63,13 @@ const IndexInfo kPodcasts{
     .components = {Tag::kTitle},
 };
 
+const IndexInfo kAudiobooks{
+    .id = 6,
+    .type = MediaType::kAudiobook,
+    .name = "Audiobooks",
+    .components = {Tag::kAlbum, Tag::kAlbumOrder},
+};
+
 static auto titleOrFilename(const TrackData& data, const TrackTags& tags)
     -> std::pmr::string {
   auto title = tags.title();

src/tangara/database/index.hpp

@@ -79,5 +79,6 @@ extern const IndexInfo kTracksByGenre;
 extern const IndexInfo kAllTracks;
 extern const IndexInfo kAllAlbums;
 extern const IndexInfo kPodcasts;
+extern const IndexInfo kAudiobooks;
 
 }  // namespace database