Feat: Fügt einen Task zur Generierung der Transaktionen anhand der wiederkehrenden Transaktionen hinzu

lib/Repositories/transaction_repository.dart

@@ -50,6 +50,7 @@ class TransactionRepository {
     final double? amountMin,
     final double? amountMax,
     final Account? account,
+    final RecurringTransaction? recurringTransaction,
     final int? limit,
     final int? offset,
     final String? orderBy,
@@ -93,6 +94,12 @@ class TransactionRepository {
       query.where((final t) => t.accountId.equals(account.id));
     }
 
+    if (recurringTransaction != null) {
+      query.where(
+        (final t) => t.recurringTransactionId.equals(recurringTransaction.id),
+      );
+    }
+
     if (limit != null) {
       query.limit(limit, offset: offset);
     }

lib/Tasks/generate_transactions_task.dart

@@ -0,0 +1,61 @@
+import 'package:drift/drift.dart';
+
+import '../Entities/drift_database.dart';
+import '../Entities/time_frame_enum.dart';
+import '../Repositories/recurring_transacation_repository.dart';
+import '../Repositories/transaction_repository.dart';
+import 'task.dart';
+
+/// Generiert neue Transaktionen
+/// anhand der erstellten wiederkehrenden Transaktionen
+class GenerateTransactionsTask extends Task {
+  final TransactionRepository _transactionRepository = TransactionRepository();
+  final RecurringTransactionRepository _recurringTransactionRepository =
+      RecurringTransactionRepository();
+
+  @override
+  Future<bool> execute() async {
+    final List<RecurringTransaction> recurringTransactions =
+        await _recurringTransactionRepository.findBy();
+
+    for (final recurringTransaction in recurringTransactions) {
+      final List<Transaction> transactions = await _transactionRepository
+          .findBy(
+            recurringTransaction: recurringTransaction,
+            orderBy: 'dateDesc',
+          );
+      final Transaction? transaction = transactions.firstOrNull;
+
+      final DateTime date = (transaction != null)
+          ? transaction.date!
+          : recurringTransaction.startDate!;
+      final DateTime nextTransactionDate;
+
+      switch (recurringTransaction.timeFrame) {
+        case TimeFrameEnum.daily:
+          nextTransactionDate = date.add(const Duration(days: 1));
+        case TimeFrameEnum.weekly:
+          nextTransactionDate = date.add(const Duration(days: 7));
+        case TimeFrameEnum.monthly:
+          nextTransactionDate = DateTime(date.year, date.month + 1, date.day);
+        case TimeFrameEnum.yearly:
+          nextTransactionDate = DateTime(date.year + 1, date.month, date.day);
+      }
+
+      if (DateTime.now().compareTo(nextTransactionDate) <= 0) {
+        final TransactionsCompanion transaction = TransactionsCompanion(
+          name: Value(recurringTransaction.name),
+          date: Value(nextTransactionDate),
+          amount: Value(recurringTransaction.amount),
+          checked: const Value(false),
+          accountId: Value(recurringTransaction.accountId),
+          recurringTransactionId: Value(recurringTransaction.id),
+        );
+
+        await _transactionRepository.add(transaction);
+      }
+    }
+
+    return true;
+  }
+}

lib/Tasks/task.dart

@@ -0,0 +1,5 @@
+/// Ein Command, welcher ausgeführt werden kann
+abstract class Task {
+  /// Führt den Command aus
+  Future<bool> execute();
+}