MediaLibrary: Moved some helpers for working with model classes, names, and files into here.

core/src/main/groovy/com/jdbernard/wdiwtlt/MediaLibrary.groovy

@@ -20,6 +20,8 @@ public class MediaLibrary {
 
     private static Logger logger = LoggerFactory.getLogger(MediaLibrary)
 
+    private static UPPERCASE_PATTERN = Pattern.compile(/(.)(\p{javaUpperCase})/)
+
     @Delegate ORM orm
     private File libraryRoot
 
@@ -135,6 +137,13 @@ public class MediaLibrary {
     public List<Album> getAlbumsByName(String name) {
         return orm.getAlbumsWhere(name: name) ?: orm.getAlbumsLikeName(name) }
 
+    public List<MediaFile> collectMediaFiles(List<Model> models) {
+        if (!models) return []
+
+        return models.collectMany { m ->
+            if (m.class == MediaFile) return [m]
+            return orm.getMediaFilesWhere((idKeyFor(m.class)): m.id) }.findAll() }
+
     public List<Artist> splitArtist(Artist toSplit, Pattern splitPattern) {
         return splitArtist(toSplit, pattern.split(toSplit.name)) }
 
@@ -233,9 +242,21 @@ public class MediaLibrary {
         if (b != parentPath.length) return ""
         return (['.'] + childPath[b..<childPath.length]).join('/') }
 
-
     public static Integer safeToInteger(def val) {
         if (val == null) return null
         try { return val.trim() as Integer }
         catch (NumberFormatException nfe) { return null } }
+
+    public static String uncapitalize(String s) {
+        if (s == null) return null;
+        if (s.length() < 2) return s.toLowerCase();
+        return s[0].toLowerCase() + s[1..-1] }
+
+    public static String toEnglish(Class c) {
+        return UPPERCASE_PATTERN.matcher(c.simpleName).
+            replaceAll(/$1 $2/).toLowerCase() }
+
+    public static String idKeyFor(Class c) {
+        return uncapitalize(c.simpleName) + 'Id'; }
+
 }