update

lib/shared/services/storage_service.dart

@@ -1,10 +1,15 @@
 import 'dart:convert';
 import 'package:shared_preferences/shared_preferences.dart';
+import 'package:uuid/uuid.dart';
 import '../models/transaction.dart';
 
+const _uuid = Uuid();
+
 class StorageService {
   static const _transactionsKey = 'transactions';
   static const _budgetKey = 'monthly_budget';
+  static const _currencyKey = 'currency_symbol';
+  static const _themeKey = 'is_dark_mode';
 
   final SharedPreferences _prefs;
 
@@ -55,4 +60,86 @@ class StorageService {
       await _prefs.setDouble(_budgetKey, budget);
     }
   }
+
+  String loadCurrency() {
+    return _prefs.getString(_currencyKey) ?? '\$';
+  }
+
+  Future<void> saveCurrency(String symbol) async {
+    await _prefs.setString(_currencyKey, symbol);
+  }
+
+  bool loadThemeMode() {
+    return _prefs.getBool(_themeKey) ?? true; // default dark
+  }
+
+  Future<void> saveThemeMode(bool isDark) async {
+    await _prefs.setBool(_themeKey, isDark);
+  }
+
+  // Process recurring transactions
+  Future<void> processRecurringTransactions() async {
+    final transactions = loadTransactions();
+    final now = DateTime.now();
+    final today = DateTime(now.year, now.month, now.day);
+    bool hasChanges = false;
+
+    for (final tx in transactions) {
+      if (tx.recurrence == RecurrenceType.none) continue;
+
+      final lastOccurrence = tx.lastOccurrence ?? tx.date;
+      final lastDate = DateTime(
+        lastOccurrence.year,
+        lastOccurrence.month,
+        lastOccurrence.day,
+      );
+
+      bool shouldCreate = false;
+
+      switch (tx.recurrence) {
+        case RecurrenceType.daily:
+          shouldCreate = today.isAfter(lastDate);
+          break;
+        case RecurrenceType.weekly:
+          final daysDiff = today.difference(lastDate).inDays;
+          shouldCreate = daysDiff >= 7;
+          break;
+        case RecurrenceType.monthly:
+          shouldCreate = (today.year > lastDate.year ||
+                  (today.year == lastDate.year &&
+                      today.month > lastDate.month)) &&
+              today.day >= lastDate.day;
+          break;
+        case RecurrenceType.none:
+          break;
+      }
+
+      if (shouldCreate) {
+        // Create new occurrence
+        final newTx = Transaction(
+          id: _uuid.v4(),
+          amount: tx.amount,
+          category: tx.category,
+          type: tx.type,
+          date: today,
+          note: tx.note,
+          recurrence: tx.recurrence,
+          lastOccurrence: today,
+        );
+        transactions.add(newTx);
+
+        // Update original transaction's lastOccurrence
+        final index = transactions.indexWhere((t) => t.id == tx.id);
+        if (index != -1) {
+          transactions[index] = tx.copyWith(lastOccurrence: today);
+        }
+
+        hasChanges = true;
+      }
+    }
+
+    if (hasChanges) {
+      await saveTransactions(transactions);
+    }
+  }
 }