runable

lib/features/home/presentation/providers/cart_total_provider.dart

@@ -0,0 +1,83 @@
+import 'package:riverpod_annotation/riverpod_annotation.dart';
+import 'cart_provider.dart';
+import '../../../settings/presentation/providers/settings_provider.dart';
+
+part 'cart_total_provider.g.dart';
+
+/// Cart totals calculation provider
+@riverpod
+class CartTotal extends _$CartTotal {
+  @override
+  CartTotalData build() {
+    final itemsAsync = ref.watch(cartProvider);
+    final settingsAsync = ref.watch(settingsProvider);
+
+    final items = itemsAsync.when(
+      data: (data) => data,
+      loading: () => <dynamic>[],
+      error: (_, __) => <dynamic>[],
+    );
+
+    final settings = settingsAsync.when(
+      data: (data) => data,
+      loading: () => null,
+      error: (_, __) => null,
+    );
+
+    // Calculate subtotal
+    final subtotal = items.fold<double>(
+      0.0,
+      (sum, item) => sum + item.lineTotal,
+    );
+
+    // Calculate tax
+    final taxRate = settings?.taxRate ?? 0.0;
+    final tax = subtotal * taxRate;
+
+    // Calculate total
+    final total = subtotal + tax;
+
+    return CartTotalData(
+      subtotal: subtotal,
+      tax: tax,
+      taxRate: taxRate,
+      total: total,
+      itemCount: items.length,
+    );
+  }
+
+  /// Apply discount amount to total
+  double applyDiscount(double discountAmount) {
+    final currentTotal = state.total;
+    return (currentTotal - discountAmount).clamp(0.0, double.infinity);
+  }
+
+  /// Apply discount percentage to total
+  double applyDiscountPercentage(double discountPercent) {
+    final currentTotal = state.total;
+    final discountAmount = currentTotal * (discountPercent / 100);
+    return (currentTotal - discountAmount).clamp(0.0, double.infinity);
+  }
+}
+
+/// Cart total data model
+class CartTotalData {
+  final double subtotal;
+  final double tax;
+  final double taxRate;
+  final double total;
+  final int itemCount;
+
+  const CartTotalData({
+    required this.subtotal,
+    required this.tax,
+    required this.taxRate,
+    required this.total,
+    required this.itemCount,
+  });
+
+  @override
+  String toString() {
+    return 'CartTotalData(subtotal: $subtotal, tax: $tax, total: $total, items: $itemCount)';
+  }
+}