Implement Album and Track metadata for duration and genres.

For tracks, we will fetch the duration from the ID3 tag information, alongside genres. These genres will be used for multiple purposes, e.g. search. At the moment however, it is used in koto_album_add_track to collate a list of genres that apply to the album based on the contents of it.

We can have multiple genres, we separate them by semi-column as is the case for TagLib. We will attempt to filter and rename some select genres to enforce consistency.

Changed position and playback position from guint to guint64.

Implemented multiple koto utility functions:

- koto_utils_join_string_list
- koto_utils_string_contains_substring
- koto_utils_string_to_string_list

Drastically simplified koto_utils_replace_string_all.

Implement koto_track_helpers_init to initialize our hashtable.

Fixed a segfault during first load of Koto where we were attempting to get the playback engine last used volume in koto_config_save, when the KotoPlaybackEngine was not yet initialized. Default it to 1.0.

src/indexer/album.c

@@ -39,6 +39,7 @@ enum {
 	PROP_ALBUM_NAME,
 	PROP_ART_PATH,
 	PROP_ARTIST_UUID,
+	PROP_ALBUM_PREPARED_GENRES,
 	N_PROPERTIES
 };
 
@@ -64,6 +65,8 @@ struct _KotoAlbum {
 	gchar * art_path;
 	gchar * artist_uuid;
 
+	GList * genres;
+
 	GList * tracks;
 	GHashTable * paths;
 
@@ -147,6 +150,14 @@ static void koto_album_class_init(KotoAlbumClass * c) {
 		G_PARAM_CONSTRUCT_ONLY | G_PARAM_EXPLICIT_NOTIFY | G_PARAM_READWRITE
 	);
 
+	props[PROP_ALBUM_PREPARED_GENRES] = g_param_spec_string(
+		"preparsed-genres",
+		"Preparsed Genres",
+		"Preparsed Genres",
+		NULL,
+		G_PARAM_CONSTRUCT | G_PARAM_EXPLICIT_NOTIFY | G_PARAM_WRITABLE
+	);
+
 	g_object_class_install_properties(gobject_class, N_PROPERTIES, props);
 
 	album_signals[SIGNAL_TRACK_ADDED] = g_signal_new(
@@ -178,6 +189,7 @@ static void koto_album_class_init(KotoAlbumClass * c) {
 
 static void koto_album_init(KotoAlbum * self) {
 	self->has_album_art = FALSE;
+	self->genres = NULL;
 	self->tracks = NULL;
 	self->paths = g_hash_table_new(g_str_hash, g_str_equal);
 }
@@ -196,17 +208,34 @@ void koto_album_add_track(
 
 	gchar * track_uuid = koto_track_get_uuid(track);
 
-	if (g_list_index(self->tracks, track_uuid) == -1) { // Haven't already added the track
-		koto_cartographer_add_track(koto_maps, track); // Add the track to cartographer if necessary
-		self->tracks = g_list_insert_sorted_with_data(self->tracks, track_uuid, koto_track_helpers_sort_tracks_by_uuid, NULL);
-
-		g_signal_emit(
-			self,
-			album_signals[SIGNAL_TRACK_ADDED],
-			0,
-			track
-		);
+	if (g_list_index(self->tracks, track_uuid) != -1) { // Have added it already
+		return;
 	}
+
+	koto_cartographer_add_track(koto_maps, track); // Add the track to cartographer if necessary
+	self->tracks = g_list_insert_sorted_with_data(self->tracks, track_uuid, koto_track_helpers_sort_tracks_by_uuid, NULL);
+
+	GList * track_genres = koto_track_get_genres(track); // Get the genres for the track
+	GList * current_genre_list;
+
+	gchar * existing_genres_as_string = koto_utils_join_string_list(self->genres, ";");
+
+	for (current_genre_list = track_genres; current_genre_list != NULL; current_genre_list = current_genre_list->next) { // Iterate over each item in the track genres
+		gchar * track_genre = current_genre_list->data; // Get this genre
+
+		if (koto_utils_string_contains_substring(existing_genres_as_string, track_genre)) { // Genres list contains this genre
+			continue;
+		}
+
+		self->genres = g_list_append(self->genres, g_strdup(track_genre)); // Duplicate the genre and add it to our list
+	}
+
+	g_signal_emit(
+		self,
+		album_signals[SIGNAL_TRACK_ADDED],
+		0,
+		track
+	);
 }
 
 void koto_album_commit(KotoAlbum * self) {
@@ -214,18 +243,23 @@ void koto_album_commit(KotoAlbum * self) {
 		koto_album_set_album_art(self, ""); // Set to an empty string
 	}
 
+	gchar * genres_string = koto_utils_join_string_list(self->genres, ";");
+
 	gchar * commit_op = g_strdup_printf(
-		"INSERT INTO albums(id, artist_id, name, art_path)"
-		"VALUES('%s', '%s', quote(\"%s\"), quote(\"%s\"))"
-		"ON CONFLICT(id) DO UPDATE SET artist_id=excluded.artist_id, name=excluded.name, art_path=excluded.art_path;",
+		"INSERT INTO albums(id, artist_id, name, art_path, genres)"
+		"VALUES('%s', '%s', quote(\"%s\"), quote(\"%s\"), '%s')"
+		"ON CONFLICT(id) DO UPDATE SET artist_id=excluded.artist_id, name=excluded.name, art_path=excluded.art_path, genres=excluded.genres;",
 		self->uuid,
 		self->artist_uuid,
 		self->name,
-		self->art_path
+		self->art_path,
+		genres_string
 	);
 
 	new_transaction(commit_op, "Failed to write our album to the database", FALSE);
 
+	g_free(genres_string);
+
 	GHashTableIter paths_iter;
 	g_hash_table_iter_init(&paths_iter, self->paths); // Create an iterator for our paths
 	gpointer lib_uuid_ptr, album_rel_path_ptr;
@@ -302,6 +336,14 @@ void koto_album_find_album_art(KotoAlbum * self) {
 	closedir(dir);
 }
 
+GList * koto_album_get_genres(KotoAlbum * self) {
+	if (!KOTO_IS_ALBUM(self)) { // Not an album
+		return NULL;
+	}
+
+	return self->genres;
+}
+
 static void koto_album_get_property(
 	GObject * obj,
 	guint prop_id,
@@ -357,6 +399,9 @@ static void koto_album_set_property(
 		case PROP_ARTIST_UUID:
 			koto_album_set_artist_uuid(self, g_value_get_string(val));
 			break;
+		case PROP_ALBUM_PREPARED_GENRES:
+			koto_album_set_preparsed_genres(self, g_strdup(g_value_get_string(val)));
+			break;
 		default:
 			G_OBJECT_WARN_INVALID_PROPERTY_ID(obj, prop_id, spec);
 			break;
@@ -573,6 +618,30 @@ void koto_album_set_as_current_playlist(KotoAlbum * self) {
 	koto_current_playlist_set_playlist(current_playlist, new_album_playlist); // Set our new current playlist
 }
 
+void koto_album_set_preparsed_genres(
+	KotoAlbum * self,
+	gchar * genrelist
+) {
+	if (!KOTO_IS_ALBUM(self)) { // Not an album
+		return;
+	}
+
+	if (!koto_utils_is_string_valid(genrelist)) { // If it is an empty string
+		return;
+	}
+
+	GList * preparsed_genres_list = koto_utils_string_to_string_list(genrelist, ";");
+
+	if (g_list_length(preparsed_genres_list) == 0) { // No genres
+		g_list_free(preparsed_genres_list);
+		return;
+	}
+
+	// TODO: Do a pass on in first memory optimization phase to ensure string elements are freed.
+	g_list_free_full(self->genres, NULL); // Free the existing genres list
+	self->genres = preparsed_genres_list;
+};
+
 KotoAlbum * koto_album_new(gchar * artist_uuid) {
 	if (!koto_utils_is_string_valid(artist_uuid)) { // Invalid artist UUID provided
 		return NULL;