opt.: split webdav & other settings (#569)

lib/core/sync.dart

@@ -0,0 +1,40 @@
+import 'dart:io';
+
+import 'package:fl_lib/fl_lib.dart';
+import 'package:server_box/data/model/app/backup.dart';
+import 'package:server_box/data/store/no_backup.dart';
+
+const sync = Sync._();
+
+final class Sync extends SyncCfg {
+  const Sync._() : super();
+
+  @override
+  Future<void> saveToFile() => Backup.backup();
+
+  @override
+  Future<Mergeable> fromFile(String path) async {
+    final content = await File(path).readAsString();
+    return Backup.fromJsonString(content);
+  }
+
+  @override
+  Future<RemoteStorage?> get remoteStorage async {
+    if (isMacOS || isIOS) await icloud.init('iCloud.tech.lolli.serverbox');
+    final settings = NoBackupStore.instance;
+    await webdav.init(WebdavInitArgs(
+      url: settings.webdavUrl.fetch(),
+      user: settings.webdavUser.fetch(),
+      pwd: settings.webdavPwd.fetch(),
+      prefix: 'serverbox/',
+    ));
+
+    final icloudEnabled = settings.icloudSync.fetch();
+    if (icloudEnabled) return icloud;
+
+    final webdavEnabled = settings.webdavSync.fetch();
+    if (webdavEnabled) return webdav;
+
+    return null;
+  }
+}