update

lib/features/dashboard/provider.dart

@@ -0,0 +1,62 @@
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+import '../../shared/models/transaction.dart';
+import '../../shared/services/storage_service.dart';
+
+final sharedPreferencesProvider = Provider<SharedPreferences>((ref) {
+  throw UnimplementedError('Override in main');
+});
+
+final storageServiceProvider = Provider<StorageService>((ref) {
+  return StorageService(ref.watch(sharedPreferencesProvider));
+});
+
+final transactionsProvider =
+    StateNotifierProvider<TransactionsNotifier, List<Transaction>>((ref) {
+  final storage = ref.watch(storageServiceProvider);
+  return TransactionsNotifier(storage);
+});
+
+class TransactionsNotifier extends StateNotifier<List<Transaction>> {
+  final StorageService _storage;
+
+  TransactionsNotifier(this._storage) : super(_storage.loadTransactions());
+
+  Future<void> add(Transaction transaction) async {
+    await _storage.addTransaction(transaction);
+    state = _storage.loadTransactions();
+  }
+
+  Future<void> delete(String id) async {
+    await _storage.deleteTransaction(id);
+    state = _storage.loadTransactions();
+  }
+}
+
+// Derived providers
+final totalBalanceProvider = Provider<double>((ref) {
+  final txs = ref.watch(transactionsProvider);
+  return txs.fold(0.0, (sum, t) {
+    return t.type == TransactionType.income ? sum + t.amount : sum - t.amount;
+  });
+});
+
+final totalIncomeProvider = Provider<double>((ref) {
+  return ref
+      .watch(transactionsProvider)
+      .where((t) => t.type == TransactionType.income)
+      .fold(0.0, (sum, t) => sum + t.amount);
+});
+
+final totalExpenseProvider = Provider<double>((ref) {
+  return ref
+      .watch(transactionsProvider)
+      .where((t) => t.type == TransactionType.expense)
+      .fold(0.0, (sum, t) => sum + t.amount);
+});
+
+final recentTransactionsProvider = Provider<List<Transaction>>((ref) {
+  final txs = List<Transaction>.from(ref.watch(transactionsProvider));
+  txs.sort((a, b) => b.date.compareTo(a.date));
+  return txs.take(20).toList();
+});