Move album flattening algorithm to Sone.

[Sone.git] / src / main / java / net / pterodactylus / sone / data / Sone.java

diff --git a/src/main/java/net/pterodactylus/sone/data/Sone.java b/src/main/java/net/pterodactylus/sone/data/Sone.java
index aa4a155..4467eba 100644 (file)
--- a/src/main/java/net/pterodactylus/sone/data/Sone.java
+++ b/src/main/java/net/pterodactylus/sone/data/Sone.java
@@ -706,6 +706,33 @@ public class Sone implements Fingerprintable, Comparable<Sone> {
        }
 
        //
+       // STATIC METHODS
+       //
+
+       /**
+        * Flattens the given top-level albums so that the resulting list contains
+        * parent albums before child albums and the resulting list can be parsed in
+        * a single pass.
+        *
+        * @param albums
+        *            The albums to flatten
+        * @return The flattened albums
+        */
+       public static List<Album> flattenAlbums(Collection<? extends Album> albums) {
+               List<Album> flatAlbums = new ArrayList<Album>();
+               flatAlbums.addAll(albums);
+               int lastAlbumIndex = 0;
+               while (lastAlbumIndex < flatAlbums.size()) {
+                       int previousAlbumCount = flatAlbums.size();
+                       for (Album album : new ArrayList<Album>(flatAlbums.subList(lastAlbumIndex, flatAlbums.size()))) {
+                               flatAlbums.addAll(album.getAlbums());
+                       }
+                       lastAlbumIndex = previousAlbumCount;
+               }
+               return flatAlbums;
+       }
+
+       //
        // INTERFACE Comparable<Sone>
        //