#157 new: icloud sync

lib/data/model/app/error.dart

@@ -52,3 +52,19 @@ class DockerErr extends Err<DockerErrType> {
     return 'DockerErr<$type>: $message';
   }
 }
+
+enum ICloudErrType {
+  generic,
+  notFound,
+  multipleFiles,
+}
+
+class ICloudErr extends Err<ICloudErrType> {
+  ICloudErr({required ICloudErrType type, String? message})
+      : super(from: ErrFrom.docker, type: type, message: message);
+
+  @override
+  String toString() {
+    return 'ICloudErr<$type>: $message';
+  }
+}

lib/data/model/app/json.dart

@@ -0,0 +1,7 @@
+abstract class JsonSerializable<T> {
+  /// Convert [this] to json
+  Map<String, dynamic> toJson();
+
+  /// Create [this] from json
+  T fromJson(Map<String, dynamic> json);
+}

lib/data/model/app/syncable.dart

@@ -0,0 +1,9 @@
+abstract class SyncAble<T> {
+  /// If [other] is newer than [this] then return true,
+  /// else return false
+  bool needSync(T other);
+
+  /// Merge [other] into [this],
+  /// return [this] after merge
+  T merge(T other);
+}