Fix: Resolve critical linting issues and bugs (concurrency, syntax, dead code)

apps/mobile/packages/features/client/billing/lib/src/presentation/blocs/billing_bloc.dart

@@ -1,4 +1,5 @@
 import 'package:flutter_bloc/flutter_bloc.dart';
+import 'package:krow_core/core.dart';
 import 'package:krow_domain/krow_domain.dart';
 import '../../domain/usecases/get_current_bill_amount.dart';
 import '../../domain/usecases/get_invoice_history.dart';
@@ -11,7 +12,8 @@ import 'billing_event.dart';
 import 'billing_state.dart';
 
 /// BLoC for managing billing state and data loading.
-class BillingBloc extends Bloc<BillingEvent, BillingState> {
+class BillingBloc extends Bloc<BillingEvent, BillingState>
+    with BlocErrorHandler<BillingState> {
   /// Creates a [BillingBloc] with the given use cases.
   BillingBloc({
     required GetCurrentBillAmountUseCase getCurrentBillAmount,
@@ -40,82 +42,82 @@ class BillingBloc extends Bloc<BillingEvent, BillingState> {
     Emitter<BillingState> emit,
   ) async {
     emit(state.copyWith(status: BillingStatus.loading));
-    try {
-      final List<dynamic> results = await Future.wait<dynamic>(<Future<dynamic>>[
-        _getCurrentBillAmount.call(),
-        _getSavingsAmount.call(),
-        _getPendingInvoices.call(),
-        _getInvoiceHistory.call(),
-        _getSpendingBreakdown.call(state.period),
-      ]);
+    await handleError(
+      emit: emit,
+      action: () async {
+        final List<dynamic> results =
+            await Future.wait<dynamic>(<Future<dynamic>>[
+          _getCurrentBillAmount.call(),
+          _getSavingsAmount.call(),
+          _getPendingInvoices.call(),
+          _getInvoiceHistory.call(),
+          _getSpendingBreakdown.call(state.period),
+        ]);
 
-      final double currentBill = results[0] as double;
-      final double savings = results[1] as double;
-      final List<Invoice> pendingInvoices = results[2] as List<Invoice>;
-      final List<Invoice> invoiceHistory = results[3] as List<Invoice>;
-      final List<InvoiceItem> spendingItems = results[4] as List<InvoiceItem>;
+        final double currentBill = results[0] as double;
+        final double savings = results[1] as double;
+        final List<Invoice> pendingInvoices = results[2] as List<Invoice>;
+        final List<Invoice> invoiceHistory = results[3] as List<Invoice>;
+        final List<InvoiceItem> spendingItems = results[4] as List<InvoiceItem>;
 
-      // Map Domain Entities to Presentation Models
-      final List<BillingInvoice> uiPendingInvoices = pendingInvoices
-          .map(_mapInvoiceToUiModel)
-          .toList();
-      final List<BillingInvoice> uiInvoiceHistory = invoiceHistory
-          .map(_mapInvoiceToUiModel)
-          .toList();
-      final List<SpendingBreakdownItem> uiSpendingBreakdown = _mapSpendingItemsToUiModel(spendingItems);
-      final double periodTotal = uiSpendingBreakdown.fold(
-        0.0,
-        (double sum, SpendingBreakdownItem item) => sum + item.amount,
-      );
+        // Map Domain Entities to Presentation Models
+        final List<BillingInvoice> uiPendingInvoices =
+            pendingInvoices.map(_mapInvoiceToUiModel).toList();
+        final List<BillingInvoice> uiInvoiceHistory =
+            invoiceHistory.map(_mapInvoiceToUiModel).toList();
+        final List<SpendingBreakdownItem> uiSpendingBreakdown =
+            _mapSpendingItemsToUiModel(spendingItems);
+        final double periodTotal = uiSpendingBreakdown.fold(
+          0.0,
+          (double sum, SpendingBreakdownItem item) => sum + item.amount,
+        );
 
-      emit(
-        state.copyWith(
-          status: BillingStatus.success,
-          currentBill: periodTotal,
-          savings: savings,
-          pendingInvoices: uiPendingInvoices,
-          invoiceHistory: uiInvoiceHistory,
-          spendingBreakdown: uiSpendingBreakdown,
-        ),
-      );
-    } catch (e) {
-      emit(
-        state.copyWith(
-          status: BillingStatus.failure,
-          errorMessage: e.toString(),
-        ),
-      );
-    }
+        emit(
+          state.copyWith(
+            status: BillingStatus.success,
+            currentBill: periodTotal,
+            savings: savings,
+            pendingInvoices: uiPendingInvoices,
+            invoiceHistory: uiInvoiceHistory,
+            spendingBreakdown: uiSpendingBreakdown,
+          ),
+        );
+      },
+      onError: (String errorKey) => state.copyWith(
+        status: BillingStatus.failure,
+        errorMessage: errorKey,
+      ),
+    );
   }
 
   Future<void> _onPeriodChanged(
     BillingPeriodChanged event,
     Emitter<BillingState> emit,
   ) async {
-    try {
-      final List<InvoiceItem> spendingItems =
-          await _getSpendingBreakdown.call(event.period);
-      final List<SpendingBreakdownItem> uiSpendingBreakdown =
-          _mapSpendingItemsToUiModel(spendingItems);
-      final double periodTotal = uiSpendingBreakdown.fold(
-        0.0,
-        (double sum, SpendingBreakdownItem item) => sum + item.amount,
-      );
-      emit(
-        state.copyWith(
-          period: event.period,
-          spendingBreakdown: uiSpendingBreakdown,
-          currentBill: periodTotal,
-        ),
-      );
-    } catch (e) {
-      emit(
-        state.copyWith(
-          status: BillingStatus.failure,
-          errorMessage: e.toString(),
-        ),
-      );
-    }
+    await handleError(
+      emit: emit,
+      action: () async {
+        final List<InvoiceItem> spendingItems =
+            await _getSpendingBreakdown.call(event.period);
+        final List<SpendingBreakdownItem> uiSpendingBreakdown =
+            _mapSpendingItemsToUiModel(spendingItems);
+        final double periodTotal = uiSpendingBreakdown.fold(
+          0.0,
+          (double sum, SpendingBreakdownItem item) => sum + item.amount,
+        );
+        emit(
+          state.copyWith(
+            period: event.period,
+            spendingBreakdown: uiSpendingBreakdown,
+            currentBill: periodTotal,
+          ),
+        );
+      },
+      onError: (String errorKey) => state.copyWith(
+        status: BillingStatus.failure,
+        errorMessage: errorKey,
+      ),
+    );
   }
 
   BillingInvoice _mapInvoiceToUiModel(Invoice invoice) {