1 files changed, 27 insertions, 0 deletions
diff --git a/src/main/java/org/zwobble/mammoth/internal/documents/Notes.java b/src/main/java/org/zwobble/mammoth/internal/documents/Notes.java
new file mode 100644
index 0000000..d8ca28d
--- /dev/null
+++ b/src/main/java/org/zwobble/mammoth/internal/documents/Notes.java
@@ -0,0 +1,27 @@
+package org.zwobble.mammoth.internal.documents;
+
+import com.google.common.collect.Maps;
+import com.google.common.collect.Multimaps;
+
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+
+import static org.zwobble.mammoth.internal.util.MammothLists.list;
+
+public class Notes {
+    public final static Notes EMPTY = new Notes(list());
+
+    private final Map<NoteType, Map<String, Note>> notes;
+
+    public Notes(List<Note> notes) {
+        this.notes = Maps.transformValues(
+            Multimaps.index(notes, Note::getNoteType).asMap(),
+            notesOfType -> Maps.uniqueIndex(notesOfType, Note::getId));
+    }
+
+    public Optional<Note> findNote(NoteType noteType, String noteId) {
+        return Optional.ofNullable(notes.get(noteType))
+            .flatMap(notesOfType -> Optional.ofNullable(notesOfType.get(noteId)));
+    }
+}