import 'package:shared_preferences/shared_preferences.dart';

const _legacyActiveCollectionPrefKey = 'active_collection_id';

String activeCollectionPrefKeyForUser(String userId) {
  return 'active_collection_id_$userId';
}

Future<String?> readActiveCollectionId(
  SharedPreferences prefs, {
  required String userId,
}) async {
  final scopedKey = activeCollectionPrefKeyForUser(userId);
  final scopedValue = prefs.getString(scopedKey);
  if (scopedValue != null && scopedValue.isNotEmpty) {
    return scopedValue;
  }

  final legacyValue = prefs.getString(_legacyActiveCollectionPrefKey);
  if (legacyValue == null || legacyValue.isEmpty) {
    return null;
  }

  await prefs.setString(scopedKey, legacyValue);
  await prefs.remove(_legacyActiveCollectionPrefKey);
  return legacyValue;
}

Future<void> writeActiveCollectionId(
  SharedPreferences prefs, {
  required String userId,
  required String collectionId,
}) {
  return prefs.setString(activeCollectionPrefKeyForUser(userId), collectionId);
}

Future<void> clearActiveCollectionId(
  SharedPreferences prefs, {
  required String userId,
}) async {
  await prefs.remove(activeCollectionPrefKeyForUser(userId));
  await prefs.remove(_legacyActiveCollectionPrefKey);
}