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)';
  }
}