Album: Add functions for looking up or creating Album tags

The album_db should really be controlled from within the Album tag, so
this patch adds functions to find or create Album 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<Album>   album_db("album.db", true);
 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   = album_db.at(album_id);
+	album   = tags :: get_album(album_id);
 	genre   = genre_db.at(genre_id);
 
 	title_lower = filter :: add(title, index());
@@ -120,7 +119,7 @@ bool Track :: tag()
 	audio = ref.audioProperties();
 
 	artist = tags :: get_artist(format_tag(tag->artist()));
-	album  = find_or_insert(Album(format_tag(tag->album()), tag->year()), album_db);
+	album  = tags :: get_album(format_tag(tag->album()), tag->year());
 	genre  = find_or_insert(Genre(format_tag(tag->genre())), genre_db);
 	track  = tag->track();
 	length = audio->length();
@@ -220,7 +219,6 @@ int Track :: less_than(Track *rhs, sort_t field)
 void tagdb :: init()
 {
 	tags :: init();
-	album_db.load();
 	genre_db.load();
 	library_db.load();
 	track_db.load();

core/tags/album.cpp

@@ -5,6 +5,17 @@
 #include <core/tags/album.h>
 #include <sstream>
 
+
+static Database<Album> album_db("album.db", true);
+
+static const std::string make_key(const std::string &name, unsigned int year)
+{
+	std::stringstream ss;
+	ss << year << "/" << name;
+	return ss.str();
+}
+
+
 Album :: Album() : GenericTag(), _year(0) {}
 
 Album :: Album(const std::string &name, unsigned int year)
@@ -14,9 +25,7 @@ Album :: Album(const std::string &name, unsigned int year)
 
 const std::string Album :: primary_key() const
 {
-	std::stringstream ss;
-	ss << _year << "/" << GenericTag :: primary_key();
-	return ss.str();
+	return make_key(GenericTag :: primary_key(), _year);
 }
 
 void Album :: read(File &file)
@@ -35,3 +44,22 @@ unsigned int Album :: year()
 {
 	return _year;
 }
+
+
+void tags :: init_album_db()
+{
+	album_db.load();
+}
+
+Album *tags :: get_album(const std::string &name, unsigned int year)
+{
+	Album *ret = album_db.find(make_key(name, year));
+	if (ret)
+		return ret;
+	return album_db.insert(Album(name, year));
+}
+
+Album *tags ::get_album(const unsigned int index)
+{
+	return album_db.at(index);
+}

core/tags/tags.cpp

@@ -2,10 +2,12 @@
  * @file
  * Copyright 2014 (c) Anna Schumaker.
  */
+#include <core/tags/album.h>
 #include <core/tags/artist.h>
 #include <core/tags/tags.h>
 
 void tags :: init()
 {
+	tags :: init_album_db();
 	tags :: init_artist_db();
 }

include/core/tags/album.h

@@ -64,4 +64,31 @@ public:
 	unsigned int year();
 };
 
+namespace tags
+{
+
+	/** Called to read the album_db from disk. */
+	void init_album_db();
+
+	/**
+	 * Called to look up an Album tag by name and year.  If no
+	 * existing tag is found a new one will be created and
+	 * returned to the caller.
+	 *
+	 * @param  name  The name of the album.
+	 * @param  year  The year of the album.
+	 * @return A matching Album tag.
+	 */
+	Album *get_album(const std::string &, unsigned int);
+
+	/**
+	 * Called to look up an Album tag by tag index.
+	 *
+	 * @param  index  The index of the Album tag.
+	 * @return A matching Album tag or NULL.
+	 */
+	Album *get_album(const unsigned int);
+
+} /* Namespace: tags */
+
 #endif /* OCARINA_CORE_TAGS_ALBUM_H */

tests/core/tags/album.cpp

@@ -35,8 +35,27 @@ static void test_album_tag()
 	test_equal(album.primary_key(), (std::string)"1998/Hyrule Symphony");
 }
 
+static void test_album_tag_lookup()
+{
+	Database<Album> album_db("album.db", false);
+	Album *album = tags :: get_album("Hyrule Symphony", 1998);
+
+	test_equal(album->name(),        (std::string)"Hyrule Symphony");
+	test_equal(album->lowercase(),   (std::string)"hyrule symphony");
+	test_equal(album->year(),        (unsigned int)1998);
+	test_equal(album->primary_key(), (std::string)"1998/Hyrule Symphony");
+
+	test_equal(tags :: get_album("Hyrule Symphony", 1998), album);
+	test_equal(tags :: get_album(0), album);
+	test_equal(tags :: get_album(1), (Album *)NULL);
+
+	album_db.load();
+	test_equal(album_db.size(), (unsigned)1);
+}
+
 int main(int argc, char **argv)
 {
 	run_test("Album Tag Test", test_album_tag);
+	run_test("Album Tag Lookup Test", test_album_tag_lookup);
 	return 0;
 }