restructured preferences

src/lib/preferences/db-state.ts

@@ -0,0 +1,35 @@
+import type { UserPreferences } from '$lib/types';
+import clamp from 'just-clamp';
+import { writable } from 'svelte/store';
+import { load_preferences, save_preferences } from './db-local-storage';
+
+const _default_user_preferences = {
+	playback_rate: 1,
+	volume: 1,
+} satisfies UserPreferences;
+
+const _user_preferences = writable<UserPreferences>(_default_user_preferences);
+
+function clamp_preferences(prefs: UserPreferences) {
+	return {
+		playback_rate: clamp(prefs.playback_rate, 0.5, 5),
+		volume: clamp(prefs.volume, 0, 1),
+	};
+}
+
+function edit(prefs: Partial<UserPreferences>) {
+	_user_preferences.update((prev) => clamp_preferences({ ...prev, ...prefs }));
+	save_preferences();
+}
+
+const clear = () => {
+	_user_preferences.set(_default_user_preferences);
+	save_preferences();
+};
+
+export const user_preferences = {
+	subscribe: _user_preferences.subscribe,
+	edit,
+	clear,
+	load: load_preferences,
+};