Feat: Fügt IsarService und Repositories hinzu

lib/Repositories/recurring_transacation_repository.dart

@@ -0,0 +1,132 @@
+import 'package:isar/isar.dart';
+
+import '../Entities/recurring_transaction.dart';
+import '../Entities/time_frame_enum.dart';
+import '../Services/isar_service.dart';
+
+/// Funktionen zum interagieren mit der Datenbank für die Transaktionen
+class RecurringTransactionRepository {
+  final IsarService _isarService = IsarService();
+
+  /// Fügt eine neue wiederkehrende Transaktion zur Datenbank hinzu
+  Future<RecurringTransaction?> add(
+    final RecurringTransaction recurringTransaction,
+  ) async {
+    final Isar isar = await _isarService.getDatabase();
+
+    final int id = await isar.writeTxn(
+      () => isar.recurringTransactions.put(recurringTransaction),
+    );
+
+    return find(id);
+  }
+
+  /// Entfernt eine wiederkehrende Transaktion aus der Datenbank
+  Future<bool> remove(final RecurringTransaction recurringTransaction) async {
+    final Isar isar = await _isarService.getDatabase();
+    return isar.writeTxn(
+      () => isar.recurringTransactions.delete(recurringTransaction.id),
+    );
+  }
+
+  /// Sucht eine wiederkehrende Transaktion anhand seiner Id aus der Datenbank
+  Future<RecurringTransaction?> find(final int id) async {
+    final Isar isar = await _isarService.getDatabase();
+
+    return isar.recurringTransactions.get(id);
+  }
+
+  /// Sucht wiederkehrende Transaktionen anhand der gegebenen Parameter
+  /// aus der Datenbank
+  /// Sucht wiederkehrende Transaktionen anhand der gegebenen Parameter
+  Future<List<RecurringTransaction>> findBy({
+    final int? id,
+    final String? name,
+
+    final DateTime? startDate,
+    final DateTime? startDateBefore,
+    final DateTime? startDateAfter,
+    final DateTime? startDateFrom,
+    final DateTime? startDateTo,
+
+    final TimeFrameEnum? timeFrame,
+
+    final double? amount,
+    final double? amountMin,
+    final double? amountMax,
+
+    final String? orderBy,
+  }) async {
+    final Isar isar = await _isarService.getDatabase();
+
+    final QueryBuilder<
+      RecurringTransaction,
+      RecurringTransaction,
+      QAfterFilterCondition
+    >
+    baseQuery = isar.recurringTransactions
+        .filter()
+        .optional(id != null, (final q) => q.idEqualTo(id!))
+        .optional(
+          name != null && name.isNotEmpty,
+          (final q) => q.nameMatches('*$name*', caseSensitive: false),
+        )
+        // --- StartDate Filter ---
+        .optional(startDate != null, (final q) => q.startDateEqualTo(startDate))
+        .optional(
+          startDateAfter != null,
+          (final q) => q.startDateGreaterThan(startDateAfter),
+        )
+        .optional(
+          startDateBefore != null,
+          (final q) => q.startDateLessThan(startDateBefore),
+        )
+        .optional(
+          startDateFrom != null && startDateTo != null,
+          (final q) => q.startDateBetween(startDateFrom, startDateTo),
+        )
+        // --- TimeFrame ---
+        .optional(
+          timeFrame != null,
+          (final q) => q.timeFrameEqualTo(timeFrame!),
+        )
+        // --- Amount Filter ---
+        .optional(amount != null, (final q) => q.amountEqualTo(amount!))
+        .optional(
+          amountMin != null && amountMax == null,
+          (final q) => q.amountGreaterThan(amountMin!),
+        )
+        .optional(
+          amountMin == null && amountMax != null,
+          (final q) => q.amountLessThan(amountMax!),
+        )
+        .optional(
+          amountMin != null && amountMax != null,
+          (final q) => q.amountBetween(amountMin!, amountMax!),
+        );
+
+    // --- Sortierung ---
+    switch (orderBy) {
+      case 'nameAsc':
+        return baseQuery.sortByName().findAll();
+
+      case 'nameDesc':
+        return baseQuery.sortByNameDesc().findAll();
+
+      case 'amountAsc':
+        return baseQuery.sortByAmount().findAll();
+
+      case 'amountDesc':
+        return baseQuery.sortByAmountDesc().findAll();
+
+      case 'startDateAsc':
+        return baseQuery.sortByStartDate().findAll();
+
+      case 'startDateDesc':
+        return baseQuery.sortByStartDateDesc().findAll();
+
+      default:
+        return baseQuery.findAll();
+    }
+  }
+}