From 5066ce695df30ff8b9cb674a1c34bbaa1b9cfdf1 Mon Sep 17 00:00:00 2001
From: Jakob Moser <moser@cl.uni-heidelberg.de>
Date: Thu, 13 Nov 2025 00:18:54 +0100
Subject: [PATCH] Add rather dull favorite handling code

---
 karaokatalog/ui/static/model/favorites.js | 32 +++++++++++++++++++++++
 1 file changed, 32 insertions(+)
 create mode 100644 karaokatalog/ui/static/model/favorites.js

diff --git a/karaokatalog/ui/static/model/favorites.js b/karaokatalog/ui/static/model/favorites.js
new file mode 100644
index 0000000..3f6cdb5
--- /dev/null
+++ b/karaokatalog/ui/static/model/favorites.js
@@ -0,0 +1,32 @@
+const FAVORITES_STORAGE_KEY = "songAppFavorites"
+
+let favoriteIds = null
+
+export function getFavoriteIds() {
+    if (favoriteIds === null) {
+        favoriteIds = new Set(
+            JSON.parse(localStorage.getItem(FAVORITES_STORAGE_KEY)) || [],
+        )
+    }
+
+    return favoriteIds
+}
+
+function setFavoriteIds(favs) {
+    localStorage.setItem(
+        FAVORITES_STORAGE_KEY,
+        JSON.stringify(Array.from(favs)),
+    )
+}
+
+export function addFavorite(id) {
+    const favs = getFavoriteIds()
+    favs.add(id)
+    setFavoriteIds(favs)
+}
+
+export function removeFavorite(id) {
+    const favs = getFavoriteIds()
+    favs.delete(id)
+    setFavoriteIds(favs)
+}