api and storage restructure

lib/api/holidays/getHolidaysCache.dart

@@ -1,26 +1,18 @@
-import 'dart:convert';
-
 import '../requestCache.dart';
 import 'getHolidays.dart';
 import 'getHolidaysResponse.dart';
 
-class GetHolidaysCache extends RequestCache<GetHolidaysResponse> {
-  GetHolidaysCache({void Function(GetHolidaysResponse)? onUpdate, bool? renew}) : super(RequestCache.cacheDay, onUpdate, renew: renew) {
+class GetHolidaysCache extends SimpleCache<GetHolidaysResponse> {
+  GetHolidaysCache({super.onUpdate, super.renew})
+      : super(
+          cacheTime: RequestCache.cacheDay,
+          loader: () => GetHolidays().query(),
+          fromJson: (json) => GetHolidaysResponse(
+            (json['data'] as List)
+                .map((i) => GetHolidaysResponseObject.fromJson(i as Map<String, dynamic>))
+                .toList(),
+          ),
+        ) {
     start('state-holidays');
   }
-
-  @override
-  GetHolidaysResponse onLocalData(String json) {
-    List<dynamic> parsedListJson = jsonDecode(json)['data'];
-    return GetHolidaysResponse(
-      List<GetHolidaysResponseObject>.from(
-        parsedListJson.map<GetHolidaysResponseObject>(
-          (i) => GetHolidaysResponseObject.fromJson(i as Map<String, dynamic>)
-        )
-      )
-    );
-  }
-
-  @override
-  Future<GetHolidaysResponse> onLoad() => GetHolidays().query();
 }