Genre: Add functions for looking up or creating Genre tags

The genre_db should really be controlled from within the Genre tag,
so this patch adds functions to find or create Genre tags to the tags
namespace.

Signed-off-by: Anna Schumaker <Anna@OcarinaProject.net>

core/tags.cpp

@@ -12,7 +12,6 @@
 #include <taglib/tag.h>
 #include <taglib/fileref.h>
 
-Database<Genre>   genre_db("genre.db", true);
 Database<Library> library_db("library.db", true);
 Database<Track>   track_db("track.db", false);
 
@@ -58,7 +57,7 @@ void Track :: read(File &f)
 	library = library_db.at(library_id);
 	artist  = tags :: get_artist(artist_id);
 	album   = tags :: get_album(album_id);
-	genre   = genre_db.at(genre_id);
+	genre   = tags :: get_genre(genre_id);
 
 	title_lower = filter :: add(title, index());
 	filter :: add(artist->name(), index());
@@ -120,7 +119,7 @@ bool Track :: tag()
 
 	artist = tags :: get_artist(format_tag(tag->artist()));
 	album  = tags :: get_album(format_tag(tag->album()), tag->year());
-	genre  = find_or_insert(Genre(format_tag(tag->genre())), genre_db);
+	genre  = tags :: get_genre(format_tag(tag->genre()));
 	track  = tag->track();
 	length = audio->length();
 	title  = format_tag(tag->title());
@@ -219,7 +218,6 @@ int Track :: less_than(Track *rhs, sort_t field)
 void tagdb :: init()
 {
 	tags :: init();
-	genre_db.load();
 	library_db.load();
 	track_db.load();
 }

core/tags/genre.cpp

@@ -4,9 +4,32 @@
  */
 #include <core/tags/genre.h>
 
+
+static Database<Genre> genre_db("genre.db", true);
+
+
 Genre :: Genre() : GenericTag() {}
 
 Genre :: Genre(const std::string &name)
        : GenericTag(name)
 {
 }
+
+
+void tags :: init_genre_db()
+{
+	genre_db.load();
+}
+
+Genre *tags :: get_genre(const std::string &name)
+{
+	Genre *ret = genre_db.find(name);
+	if (ret)
+		return ret;
+	return genre_db.insert(Genre(name));
+}
+
+Genre *tags :: get_genre(const unsigned int index)
+{
+	return genre_db.at(index);
+}

core/tags/tags.cpp

@@ -4,10 +4,12 @@
  */
 #include <core/tags/album.h>
 #include <core/tags/artist.h>
+#include <core/tags/genre.h>
 #include <core/tags/tags.h>
 
 void tags :: init()
 {
 	tags :: init_album_db();
 	tags :: init_artist_db();
+	tags :: init_genre_db();
 }

include/core/tags/genre.h

@@ -23,4 +23,30 @@ public:
 	Genre(const std::string &);
 };
 
+namespace tags
+{
+
+	/** Called to read the genre_db from disk. */
+	void init_genre_db();
+
+	/**
+	 * Called to look up a Genre tag by name.  If no existing
+	 * tag is found a new one will be created and returned to
+	 * the caller.
+	 *
+	 * @param  name  The name of the genre.
+	 * @return A matching Genre tag.
+	 */
+	Genre *get_genre(const std::string &);
+
+	/**
+	 * Called to look up a Genre tag by tag index.
+	 *
+	 * @param  index  The index of the Genre tag.
+	 * @return A matching Genre tag or NULL.
+	 */
+	Genre *get_genre(const unsigned int);
+
+}
+
 #endif /* OCARINA_CORE_TAGS_GENRE_H */

tests/core/tags/genre.cpp

@@ -18,8 +18,26 @@ static void test_artist_tag()
 	test_equal(genre.primary_key(), (std::string)"Video Game Music");
 }
 
+static void test_genere_tag_lookup()
+{
+	Database<Genre> genre_db("genre.db", false);
+	Genre *genre = tags :: get_genre("Video Game Music");
+
+	test_equal(genre->name(),        (std::string)"Video Game Music");
+	test_equal(genre->lowercase(),   (std::string)"video game music");
+	test_equal(genre->primary_key(), (std::string)"Video Game Music");
+
+	test_equal(tags :: get_genre("Video Game Music"), genre);
+	test_equal(tags :: get_genre(0), genre);
+	test_equal(tags :: get_genre(1), (Genre *)NULL);
+
+	genre_db.load();
+	test_equal(genre_db.size(), (unsigned)1);
+}
+
 int main(int argc, char **argv)
 {
 	run_test("Genre Tag Test", test_artist_tag);
+	run_test("Genre Tag Lookup Test", test_genere_tag_lookup);
 	return 0;
 }